Merge branch 'develop' into pizzax-indexeddb

305 files changed, 4742 insertions, 6359 deletions

diff --git a/packages/backend/src/server/api/endpoints/admin/abuse-user-reports.ts b/packages/backend/src/server/api/endpoints/admin/abuse-user-reports.ts
index ed7b146d03..333746f423 100644
--- a/packages/backend/src/server/api/endpoints/admin/abuse-user-reports.ts
+++ b/packages/backend/src/server/api/endpoints/admin/abuse-user-reports.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { AbuseUserReports } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { AbuseUserReports } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,49 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		state: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		reporterOrigin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'combined',
-		},
-
-		targetUserOrigin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'combined',
-		},
-
-		forwarded: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -115,8 +70,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		state: { type: 'string', nullable: true, default: null },
+		reporterOrigin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "combined" },
+		targetUserOrigin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "combined" },
+		forwarded: { type: 'boolean', default: false },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const query = makePaginationQuery(AbuseUserReports.createQueryBuilder('report'), ps.sinceId, ps.untilId);
 
 	switch (ps.state) {
@@ -134,7 +103,7 @@ export default define(meta, async (ps) => {
 		case 'remote': query.andWhere('report.targetUserHost IS NOT NULL'); break;
 	}
 
-	const reports = await query.take(ps.limit!).getMany();
+	const reports = await query.take(ps.limit).getMany();
 
 	return await AbuseUserReports.packMany(reports);
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/accounts/create.ts b/packages/backend/src/server/api/endpoints/admin/accounts/create.ts
index 20f1232959..2820c7993d 100644
--- a/packages/backend/src/server/api/endpoints/admin/accounts/create.ts
+++ b/packages/backend/src/server/api/endpoints/admin/accounts/create.ts
@@ -1,20 +1,10 @@
-import define from '../../../define';
-import { Users } from '@/models/index';
-import { signup } from '../../../common/signup';
+import define from '../../../define.js';
+import { Users } from '@/models/index.js';
+import { signup } from '../../../common/signup.js';
 
 export const meta = {
 	tags: ['admin'],
 
-	params: {
-		username: {
-			validator: Users.validateLocalUsername,
-		},
-
-		password: {
-			validator: Users.validatePassword,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -28,8 +18,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		username: Users.localUsernameSchema,
+		password: Users.passwordSchema,
+	},
+	required: ['username', 'password'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, _me) => {
+export default define(meta, paramDef, async (ps, _me) => {
 	const me = _me ? await Users.findOneOrFail(_me.id) : null;
 	const noUsers = (await Users.count({
 		host: null,
diff --git a/packages/backend/src/server/api/endpoints/admin/accounts/delete.ts b/packages/backend/src/server/api/endpoints/admin/accounts/delete.ts
index 1701c1e3a7..01754ec8f3 100644
--- a/packages/backend/src/server/api/endpoints/admin/accounts/delete.ts
+++ b/packages/backend/src/server/api/endpoints/admin/accounts/delete.ts
@@ -1,26 +1,26 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Users } from '@/models/index';
-import { doPostSuspend } from '@/services/suspend-user';
-import { publishUserEvent } from '@/services/stream';
-import { createDeleteAccountJob } from '@/queue';
-import { ID } from '@/misc/cafy-id';
+import define from '../../../define.js';
+import { Users } from '@/models/index.js';
+import { doPostSuspend } from '@/services/suspend-user.js';
+import { publishUserEvent } from '@/services/stream.js';
+import { createDeleteAccountJob } from '@/queue/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/ad/create.ts b/packages/backend/src/server/api/endpoints/admin/ad/create.ts
index 00ad2012fe..ab2c50b50f 100644
--- a/packages/backend/src/server/api/endpoints/admin/ad/create.ts
+++ b/packages/backend/src/server/api/endpoints/admin/ad/create.ts
@@ -1,41 +1,30 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Ads } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { Ads } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		url: {
-			validator: $.str.min(1),
-		},
-		memo: {
-			validator: $.str,
-		},
-		place: {
-			validator: $.str,
-		},
-		priority: {
-			validator: $.str,
-		},
-		ratio: {
-			validator: $.num.int().min(0),
-		},
-		expiresAt: {
-			validator: $.num.int(),
-		},
-		imageUrl: {
-			validator: $.str.min(1),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		url: { type: 'string', minLength: 1 },
+		memo: { type: 'string' },
+		place: { type: 'string' },
+		priority: { type: 'string' },
+		ratio: { type: 'integer' },
+		expiresAt: { type: 'integer' },
+		imageUrl: { type: 'string', minLength: 1 },
 	},
+	required: ['url', 'memo', 'place', 'priority', 'ratio', 'expiresAt', 'imageUrl'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	await Ads.insert({
 		id: genId(),
 		createdAt: new Date(),
diff --git a/packages/backend/src/server/api/endpoints/admin/ad/delete.ts b/packages/backend/src/server/api/endpoints/admin/ad/delete.ts
index c0124e2484..3663d974c5 100644
--- a/packages/backend/src/server/api/endpoints/admin/ad/delete.ts
+++ b/packages/backend/src/server/api/endpoints/admin/ad/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Ads } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { Ads } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,12 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchAd: {
 			message: 'No such ad.',
@@ -25,8 +17,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['id'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const ad = await Ads.findOne(ps.id);
 
 	if (ad == null) throw new ApiError(meta.errors.noSuchAd);
diff --git a/packages/backend/src/server/api/endpoints/admin/ad/list.ts b/packages/backend/src/server/api/endpoints/admin/ad/list.ts
index 7a83637f3b..74f154f272 100644
--- a/packages/backend/src/server/api/endpoints/admin/ad/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/ad/list.ts
@@ -1,37 +1,30 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { Ads } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
+import define from '../../../define.js';
+import { Ads } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const query = makePaginationQuery(Ads.createQueryBuilder('ad'), ps.sinceId, ps.untilId)
 		.andWhere('ad.expiresAt > :now', { now: new Date() });
 
-	const ads = await query.take(ps.limit!).getMany();
+	const ads = await query.take(ps.limit).getMany();
 
 	return ads;
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/ad/update.ts b/packages/backend/src/server/api/endpoints/admin/ad/update.ts
index c2b09ab9cf..89c421db66 100644
--- a/packages/backend/src/server/api/endpoints/admin/ad/update.ts
+++ b/packages/backend/src/server/api/endpoints/admin/ad/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Ads } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { Ads } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,33 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-		memo: {
-			validator: $.str,
-		},
-		url: {
-			validator: $.str.min(1),
-		},
-		imageUrl: {
-			validator: $.str.min(1),
-		},
-		place: {
-			validator: $.str,
-		},
-		priority: {
-			validator: $.str,
-		},
-		ratio: {
-			validator: $.num.int().min(0),
-		},
-		expiresAt: {
-			validator: $.num.int(),
-		},
-	},
-
 	errors: {
 		noSuchAd: {
 			message: 'No such ad.',
@@ -46,8 +17,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+		memo: { type: 'string' },
+		url: { type: 'string', minLength: 1 },
+		imageUrl: { type: 'string', minLength: 1 },
+		place: { type: 'string' },
+		priority: { type: 'string' },
+		ratio: { type: 'integer' },
+		expiresAt: { type: 'integer' },
+	},
+	required: ['id', 'memo', 'url', 'imageUrl', 'place', 'priority', 'ratio', 'expiresAt'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const ad = await Ads.findOne(ps.id);
 
 	if (ad == null) throw new ApiError(meta.errors.noSuchAd);
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/create.ts b/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
index 24c4caa37d..41570078d4 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
@@ -1,7 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Announcements } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { Announcements } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -9,18 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		title: {
-			validator: $.str.min(1),
-		},
-		text: {
-			validator: $.str.min(1),
-		},
-		imageUrl: {
-			validator: $.nullable.str.min(1),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -57,8 +44,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		title: { type: 'string', minLength: 1 },
+		text: { type: 'string', minLength: 1 },
+		imageUrl: { type: 'string', nullable: true, minLength: 1 },
+	},
+	required: ['title', 'text', 'imageUrl'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const announcement = await Announcements.insert({
 		id: genId(),
 		createdAt: new Date(),
@@ -68,5 +65,5 @@ export default define(meta, async (ps) => {
 		imageUrl: ps.imageUrl,
 	}).then(x => Announcements.findOneOrFail(x.identifiers[0]));
 
-	return announcement;
+	return Object.assign({}, announcement, { createdAt: announcement.createdAt.toISOString(), updatedAt: null });
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/delete.ts b/packages/backend/src/server/api/endpoints/admin/announcements/delete.ts
index 5548f99006..4871dc4e12 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/delete.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Announcements } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { Announcements } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,12 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchAnnouncement: {
 			message: 'No such announcement.',
@@ -25,8 +17,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['id'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const announcement = await Announcements.findOne(ps.id);
 
 	if (announcement == null) throw new ApiError(meta.errors.noSuchAnnouncement);
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/list.ts b/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
index e5cc53ccdd..0ba0a8ee08 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { Announcements, AnnouncementReads } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
+import define from '../../../define.js';
+import { Announcements, AnnouncementReads } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,21 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -69,11 +52,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const query = makePaginationQuery(Announcements.createQueryBuilder('announcement'), ps.sinceId, ps.untilId);
 
-	const announcements = await query.take(ps.limit!).getMany();
+	const announcements = await query.take(ps.limit).getMany();
 
 	for (const announcement of announcements) {
 		(announcement as any).reads = await AnnouncementReads.count({
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/update.ts b/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
index f66293bb18..138337ef5b 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Announcements } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { Announcements } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,21 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-		title: {
-			validator: $.str.min(1),
-		},
-		text: {
-			validator: $.str.min(1),
-		},
-		imageUrl: {
-			validator: $.nullable.str.min(1),
-		},
-	},
-
 	errors: {
 		noSuchAnnouncement: {
 			message: 'No such announcement.',
@@ -34,8 +17,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+		title: { type: 'string', minLength: 1 },
+		text: { type: 'string', minLength: 1 },
+		imageUrl: { type: 'string', nullable: true, minLength: 1 },
+	},
+	required: ['id', 'title', 'text', 'imageUrl'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const announcement = await Announcements.findOne(ps.id);
 
 	if (announcement == null) throw new ApiError(meta.errors.noSuchAnnouncement);
diff --git a/packages/backend/src/server/api/endpoints/admin/delete-all-files-of-a-user.ts b/packages/backend/src/server/api/endpoints/admin/delete-all-files-of-a-user.ts
index 249e63a0f8..90e65ec4cd 100644
--- a/packages/backend/src/server/api/endpoints/admin/delete-all-files-of-a-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/delete-all-files-of-a-user.ts
@@ -1,24 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { deleteFile } from '@/services/drive/delete-file';
-import { DriveFiles } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
+import define from '../../define.js';
+import { deleteFile } from '@/services/drive/delete-file.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const files = await DriveFiles.find({
 		userId: ps.userId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/drive/clean-remote-files.ts b/packages/backend/src/server/api/endpoints/admin/drive/clean-remote-files.ts
index acabbfef5c..bab149532e 100644
--- a/packages/backend/src/server/api/endpoints/admin/drive/clean-remote-files.ts
+++ b/packages/backend/src/server/api/endpoints/admin/drive/clean-remote-files.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { createCleanRemoteFilesJob } from '@/queue/index';
+import define from '../../../define.js';
+import { createCleanRemoteFilesJob } from '@/queue/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -8,7 +8,13 @@ export const meta = {
 	requireModerator: true,
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	createCleanRemoteFilesJob();
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/drive/cleanup.ts b/packages/backend/src/server/api/endpoints/admin/drive/cleanup.ts
index 452e7069a8..3e7d43fb0b 100644
--- a/packages/backend/src/server/api/endpoints/admin/drive/cleanup.ts
+++ b/packages/backend/src/server/api/endpoints/admin/drive/cleanup.ts
@@ -1,7 +1,7 @@
 import { IsNull } from 'typeorm';
-import define from '../../../define';
-import { deleteFile } from '@/services/drive/delete-file';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { deleteFile } from '@/services/drive/delete-file.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,8 +10,14 @@ export const meta = {
 	requireModerator: true,
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const files = await DriveFiles.find({
 		userId: IsNull(),
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/drive/files.ts b/packages/backend/src/server/api/endpoints/admin/drive/files.ts
index 264f549867..646d85a1e0 100644
--- a/packages/backend/src/server/api/endpoints/admin/drive/files.ts
+++ b/packages/backend/src/server/api/endpoints/admin/drive/files.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { DriveFiles } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
-import { ID } from '@/misc/cafy-id';
+import define from '../../../define.js';
+import { DriveFiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,39 +8,6 @@ export const meta = {
 	requireCredential: false,
 	requireModerator: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		type: {
-			validator: $.optional.nullable.str.match(/^[a-zA-Z0-9\/\-*]+$/),
-		},
-
-		origin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'local',
-		},
-
-		hostname: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -54,8 +19,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		type: { type: 'string', nullable: true, pattern: /^[a-zA-Z0-9\/\-*]+$/.toString().slice(1, -1) },
+		origin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "local" },
+		hostname: { type: 'string', nullable: true, default: null },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(DriveFiles.createQueryBuilder('file'), ps.sinceId, ps.untilId);
 
 	if (ps.origin === 'local') {
@@ -76,7 +54,7 @@ export default define(meta, async (ps, me) => {
 		}
 	}
 
-	const files = await query.take(ps.limit!).getMany();
+	const files = await query.take(ps.limit).getMany();
 
 	return await DriveFiles.packMany(files, { detail: true, withUser: true, self: true });
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/drive/show-file.ts b/packages/backend/src/server/api/endpoints/admin/drive/show-file.ts
index 5d9a1f2703..e821160095 100644
--- a/packages/backend/src/server/api/endpoints/admin/drive/show-file.ts
+++ b/packages/backend/src/server/api/endpoints/admin/drive/show-file.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,16 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		fileId: {
-			validator: $.optional.type(ID),
-		},
-
-		url: {
-			validator: $.optional.str,
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -161,8 +149,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+		url: { type: 'string' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const file = ps.fileId ? await DriveFiles.findOne(ps.fileId) : await DriveFiles.findOne({
 		where: [{
 			url: ps.url,
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/add-aliases-bulk.ts b/packages/backend/src/server/api/endpoints/admin/emoji/add-aliases-bulk.ts
index f0fd73c276..77a4adea61 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/add-aliases-bulk.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/add-aliases-bulk.ts
@@ -1,29 +1,30 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection, In } from 'typeorm';
-import { ApiError } from '../../../error';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		ids: {
-			validator: $.arr($.type(ID)),
-		},
-
-		aliases: {
-			validator: $.arr($.str),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		ids: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		aliases: { type: 'array', items: {
+			type: 'string',
+		} },
 	},
+	required: ['ids', 'aliases'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const emojis = await Emojis.find({
 		id: In(ps.ids),
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/add.ts b/packages/backend/src/server/api/endpoints/admin/emoji/add.ts
index 1dfeae262f..c5787d59dc 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/add.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/add.ts
@@ -1,13 +1,11 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Emojis, DriveFiles } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { Emojis, DriveFiles } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 import { getConnection } from 'typeorm';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { ApiError } from '../../../error';
-import { ID } from '@/misc/cafy-id';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { ApiError } from '../../../error.js';
 import rndstr from 'rndstr';
-import { publishBroadcastStream } from '@/services/stream';
+import { publishBroadcastStream } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -15,12 +13,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -30,8 +22,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) throw new ApiError(meta.errors.noSuchFile);
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/copy.ts b/packages/backend/src/server/api/endpoints/admin/emoji/copy.ts
index 17cbf208aa..a0eaa61258 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/copy.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/copy.ts
@@ -1,13 +1,11 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Emojis } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 import { getConnection } from 'typeorm';
-import { ApiError } from '../../../error';
-import { DriveFile } from '@/models/entities/drive-file';
-import { ID } from '@/misc/cafy-id';
-import { uploadFromUrl } from '@/services/drive/upload-from-url';
-import { publishBroadcastStream } from '@/services/stream';
+import { ApiError } from '../../../error.js';
+import { DriveFile } from '@/models/entities/drive-file.js';
+import { uploadFromUrl } from '@/services/drive/upload-from-url.js';
+import { publishBroadcastStream } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -15,12 +13,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		emojiId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchEmoji: {
 			message: 'No such emoji.',
@@ -42,8 +34,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		emojiId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['emojiId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const emoji = await Emojis.findOne(ps.emojiId);
 
 	if (emoji == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/delete-bulk.ts b/packages/backend/src/server/api/endpoints/admin/emoji/delete-bulk.ts
index 797a5de672..38a2d65cf6 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/delete-bulk.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/delete-bulk.ts
@@ -1,26 +1,28 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection, In } from 'typeorm';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { ApiError } from '../../../error';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		ids: {
-			validator: $.arr($.type(ID)),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		ids: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
 	},
+	required: ['ids'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const emojis = await Emojis.find({
 		id: In(ps.ids),
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/delete.ts b/packages/backend/src/server/api/endpoints/admin/emoji/delete.ts
index 1580439024..a0cffb47f8 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/delete.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/delete.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection } from 'typeorm';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { ApiError } from '../../../error';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -12,12 +10,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchEmoji: {
 			message: 'No such emoji.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['id'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const emoji = await Emojis.findOne(ps.id);
 
 	if (emoji == null) throw new ApiError(meta.errors.noSuchEmoji);
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/import-zip.ts b/packages/backend/src/server/api/endpoints/admin/emoji/import-zip.ts
index 8856a38f24..3f03dc2da4 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/import-zip.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/import-zip.ts
@@ -1,21 +1,22 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { createImportCustomEmojisJob } from '@/queue/index';
+import define from '../../../define.js';
+import { createImportCustomEmojisJob } from '@/queue/index.js';
 import ms from 'ms';
-import { ID } from '@/misc/cafy-id';
 
 export const meta = {
 	secure: true,
 	requireCredential: true,
 	requireModerator: true,
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['fileId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createImportCustomEmojisJob(user, ps.fileId);
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts b/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
index 6e502547f5..f19c3ddbd8 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Emojis } from '@/models/index';
-import { toPuny } from '@/misc/convert-host';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
-import { ID } from '@/misc/cafy-id';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
+import { toPuny } from '@/misc/convert-host.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -11,31 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		query: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -77,8 +50,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		query: { type: 'string', nullable: true, default: null },
+		host: { type: 'string', nullable: true, default: null },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const q = makePaginationQuery(Emojis.createQueryBuilder('emoji'), ps.sinceId, ps.untilId);
 
 	if (ps.host == null) {
@@ -93,7 +78,7 @@ export default define(meta, async (ps) => {
 
 	const emojis = await q
 		.orderBy('emoji.id', 'DESC')
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return Emojis.packMany(emojis);
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/list.ts b/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
index 76ef190f94..f488a71a00 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Emojis } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
-import { ID } from '@/misc/cafy-id';
-import { Emoji } from '@/models/entities/emoji';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
+import { Emoji } from '@/models/entities/emoji.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -11,26 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		query: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -72,8 +50,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		query: { type: 'string', nullable: true, default: null },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const q = makePaginationQuery(Emojis.createQueryBuilder('emoji'), ps.sinceId, ps.untilId)
 		.andWhere(`emoji.host IS NULL`);
 
@@ -81,7 +70,7 @@ export default define(meta, async (ps) => {
 
 	if (ps.query) {
 		//q.andWhere('emoji.name ILIKE :q', { q: `%${ps.query}%` });
-		//const emojis = await q.take(ps.limit!).getMany();
+		//const emojis = await q.take(ps.limit).getMany();
 
 		emojis = await q.getMany();
 
@@ -90,9 +79,9 @@ export default define(meta, async (ps) => {
 			emoji.aliases.some(a => a.includes(ps.query!)) ||
 			emoji.category?.includes(ps.query!));
 
-		emojis.splice(ps.limit! + 1);
+		emojis.splice(ps.limit + 1);
 	} else {
-		emojis = await q.take(ps.limit!).getMany();
+		emojis = await q.take(ps.limit).getMany();
 	}
 
 	return Emojis.packMany(emojis);
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/remove-aliases-bulk.ts b/packages/backend/src/server/api/endpoints/admin/emoji/remove-aliases-bulk.ts
index c49f84b7fb..dbad93d336 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/remove-aliases-bulk.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/remove-aliases-bulk.ts
@@ -1,29 +1,30 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection, In } from 'typeorm';
-import { ApiError } from '../../../error';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		ids: {
-			validator: $.arr($.type(ID)),
-		},
-
-		aliases: {
-			validator: $.arr($.str),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		ids: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		aliases: { type: 'array', items: {
+			type: 'string',
+		} },
 	},
+	required: ['ids', 'aliases'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const emojis = await Emojis.find({
 		id: In(ps.ids),
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/set-aliases-bulk.ts b/packages/backend/src/server/api/endpoints/admin/emoji/set-aliases-bulk.ts
index 06197820f0..470b9bef08 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/set-aliases-bulk.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/set-aliases-bulk.ts
@@ -1,29 +1,30 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection, In } from 'typeorm';
-import { ApiError } from '../../../error';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		ids: {
-			validator: $.arr($.type(ID)),
-		},
-
-		aliases: {
-			validator: $.arr($.str),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		ids: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		aliases: { type: 'array', items: {
+			type: 'string',
+		} },
 	},
+	required: ['ids', 'aliases'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	await Emojis.update({
 		id: In(ps.ids),
 	}, {
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/set-category-bulk.ts b/packages/backend/src/server/api/endpoints/admin/emoji/set-category-bulk.ts
index f0645f111b..40e4c0199e 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/set-category-bulk.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/set-category-bulk.ts
@@ -1,29 +1,28 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection, In } from 'typeorm';
-import { ApiError } from '../../../error';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		ids: {
-			validator: $.arr($.type(ID)),
-		},
-
-		category: {
-			validator: $.optional.nullable.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		ids: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		category: { type: 'string', nullable: true },
 	},
+	required: ['ids'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	await Emojis.update({
 		id: In(ps.ids),
 	}, {
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/update.ts b/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
index 54a2cf9517..c6d07e16fa 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { Emojis } from '@/models/index';
+import define from '../../../define.js';
+import { Emojis } from '@/models/index.js';
 import { getConnection } from 'typeorm';
-import { ApiError } from '../../../error';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -11,24 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		id: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.str,
-		},
-
-		category: {
-			validator: $.optional.nullable.str,
-		},
-
-		aliases: {
-			validator: $.arr($.str),
-		},
-	},
-
 	errors: {
 		noSuchEmoji: {
 			message: 'No such emoji.',
@@ -38,8 +18,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		id: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string' },
+		category: { type: 'string', nullable: true },
+		aliases: { type: 'array', items: {
+			type: 'string',
+		} },
+	},
+	required: ['id', 'name', 'aliases'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const emoji = await Emojis.findOne(ps.id);
 
 	if (emoji == null) throw new ApiError(meta.errors.noSuchEmoji);
diff --git a/packages/backend/src/server/api/endpoints/admin/federation/delete-all-files.ts b/packages/backend/src/server/api/endpoints/admin/federation/delete-all-files.ts
index db023c6f0b..d4251f2feb 100644
--- a/packages/backend/src/server/api/endpoints/admin/federation/delete-all-files.ts
+++ b/packages/backend/src/server/api/endpoints/admin/federation/delete-all-files.ts
@@ -1,23 +1,24 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { deleteFile } from '@/services/drive/delete-file';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { deleteFile } from '@/services/drive/delete-file.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		host: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
 	},
+	required: ['host'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const files = await DriveFiles.find({
 		userHost: ps.host,
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/federation/refresh-remote-instance-metadata.ts b/packages/backend/src/server/api/endpoints/admin/federation/refresh-remote-instance-metadata.ts
index b68252ef2e..86978cc309 100644
--- a/packages/backend/src/server/api/endpoints/admin/federation/refresh-remote-instance-metadata.ts
+++ b/packages/backend/src/server/api/endpoints/admin/federation/refresh-remote-instance-metadata.ts
@@ -1,24 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Instances } from '@/models/index';
-import { toPuny } from '@/misc/convert-host';
-import { fetchInstanceMetadata } from '@/services/fetch-instance-metadata';
+import define from '../../../define.js';
+import { Instances } from '@/models/index.js';
+import { toPuny } from '@/misc/convert-host.js';
+import { fetchInstanceMetadata } from '@/services/fetch-instance-metadata.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		host: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
 	},
+	required: ['host'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const instance = await Instances.findOne({ host: toPuny(ps.host) });
 
 	if (instance == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/federation/remove-all-following.ts b/packages/backend/src/server/api/endpoints/admin/federation/remove-all-following.ts
index 4de8ad1336..ccd07489cb 100644
--- a/packages/backend/src/server/api/endpoints/admin/federation/remove-all-following.ts
+++ b/packages/backend/src/server/api/endpoints/admin/federation/remove-all-following.ts
@@ -1,23 +1,24 @@
-import $ from 'cafy';
-import define from '../../../define';
-import deleteFollowing from '@/services/following/delete';
-import { Followings, Users } from '@/models/index';
+import define from '../../../define.js';
+import deleteFollowing from '@/services/following/delete.js';
+import { Followings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		host: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
 	},
+	required: ['host'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const followings = await Followings.find({
 		followerHost: ps.host,
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/federation/update-instance.ts b/packages/backend/src/server/api/endpoints/admin/federation/update-instance.ts
index 6ac2f1f467..1981082428 100644
--- a/packages/backend/src/server/api/endpoints/admin/federation/update-instance.ts
+++ b/packages/backend/src/server/api/endpoints/admin/federation/update-instance.ts
@@ -1,27 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Instances } from '@/models/index';
-import { toPuny } from '@/misc/convert-host';
+import define from '../../../define.js';
+import { Instances } from '@/models/index.js';
+import { toPuny } from '@/misc/convert-host.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		host: {
-			validator: $.str,
-		},
-
-		isSuspended: {
-			validator: $.bool,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
+		isSuspended: { type: 'boolean' },
 	},
+	required: ['host', 'isSuspended'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const instance = await Instances.findOne({ host: toPuny(ps.host) });
 
 	if (instance == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/get-index-stats.ts b/packages/backend/src/server/api/endpoints/admin/get-index-stats.ts
index 9a2bccec77..37878c4143 100644
--- a/packages/backend/src/server/api/endpoints/admin/get-index-stats.ts
+++ b/packages/backend/src/server/api/endpoints/admin/get-index-stats.ts
@@ -1,4 +1,4 @@
-import define from '../../define';
+import define from '../../define.js';
 import { getConnection } from 'typeorm';
 
 export const meta = {
@@ -6,13 +6,16 @@ export const meta = {
 	requireModerator: true,
 
 	tags: ['admin'],
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const stats = await
 		getConnection().query(`SELECT * FROM pg_indexes;`)
 		.then(recs => {
diff --git a/packages/backend/src/server/api/endpoints/admin/get-table-stats.ts b/packages/backend/src/server/api/endpoints/admin/get-table-stats.ts
index 1c5f250676..7cf2d5ffd4 100644
--- a/packages/backend/src/server/api/endpoints/admin/get-table-stats.ts
+++ b/packages/backend/src/server/api/endpoints/admin/get-table-stats.ts
@@ -1,4 +1,4 @@
-import define from '../../define';
+import define from '../../define.js';
 import { getConnection } from 'typeorm';
 
 export const meta = {
@@ -7,9 +7,6 @@ export const meta = {
 
 	tags: ['admin'],
 
-	params: {
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -22,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const sizes = await
 		getConnection().query(`
 			SELECT relname AS "table", reltuples as "count", pg_total_relation_size(C.oid) AS "size"
diff --git a/packages/backend/src/server/api/endpoints/admin/invite.ts b/packages/backend/src/server/api/endpoints/admin/invite.ts
index 3428709c04..7e950cf87b 100644
--- a/packages/backend/src/server/api/endpoints/admin/invite.ts
+++ b/packages/backend/src/server/api/endpoints/admin/invite.ts
@@ -1,7 +1,7 @@
 import rndstr from 'rndstr';
-import define from '../../define';
-import { RegistrationTickets } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../define.js';
+import { RegistrationTickets } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -9,8 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -26,8 +24,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const code = rndstr({
 		length: 8,
 		chars: '2-9A-HJ-NP-Z', // [0-9A-Z] w/o [01IO] (32 patterns)
diff --git a/packages/backend/src/server/api/endpoints/admin/moderators/add.ts b/packages/backend/src/server/api/endpoints/admin/moderators/add.ts
index 0308cf2761..4206e3a3c2 100644
--- a/packages/backend/src/server/api/endpoints/admin/moderators/add.ts
+++ b/packages/backend/src/server/api/endpoints/admin/moderators/add.ts
@@ -1,23 +1,23 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { Users } from '@/models/index';
+import define from '../../../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireAdmin: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/moderators/remove.ts b/packages/backend/src/server/api/endpoints/admin/moderators/remove.ts
index bdb976e9ec..143119bfe4 100644
--- a/packages/backend/src/server/api/endpoints/admin/moderators/remove.ts
+++ b/packages/backend/src/server/api/endpoints/admin/moderators/remove.ts
@@ -1,23 +1,23 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { Users } from '@/models/index';
+import define from '../../../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireAdmin: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/promo/create.ts b/packages/backend/src/server/api/endpoints/admin/promo/create.ts
index f2735ac9f8..2eec5bf0db 100644
--- a/packages/backend/src/server/api/endpoints/admin/promo/create.ts
+++ b/packages/backend/src/server/api/endpoints/admin/promo/create.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getNote } from '../../../common/getters';
-import { PromoNotes } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getNote } from '../../../common/getters.js';
+import { PromoNotes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -11,16 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		expiresAt: {
-			validator: $.num.int(),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -36,8 +24,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		expiresAt: { type: 'integer' },
+	},
+	required: ['noteId', 'expiresAt'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
@@ -51,7 +48,6 @@ export default define(meta, async (ps, user) => {
 
 	await PromoNotes.insert({
 		noteId: note.id,
-		createdAt: new Date(),
 		expiresAt: new Date(ps.expiresAt),
 		userId: note.userId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/admin/queue/clear.ts b/packages/backend/src/server/api/endpoints/admin/queue/clear.ts
index 3c8e7a27a2..8f015c280a 100644
--- a/packages/backend/src/server/api/endpoints/admin/queue/clear.ts
+++ b/packages/backend/src/server/api/endpoints/admin/queue/clear.ts
@@ -1,18 +1,22 @@
-import define from '../../../define';
-import { destroy } from '@/queue/index';
-import { insertModerationLog } from '@/services/insert-moderation-log';
+import define from '../../../define.js';
+import { destroy } from '@/queue/index.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	destroy();
 
 	insertModerationLog(me, 'clearQueue');
diff --git a/packages/backend/src/server/api/endpoints/admin/queue/deliver-delayed.ts b/packages/backend/src/server/api/endpoints/admin/queue/deliver-delayed.ts
index 4760e2c310..70f7d77de4 100644
--- a/packages/backend/src/server/api/endpoints/admin/queue/deliver-delayed.ts
+++ b/packages/backend/src/server/api/endpoints/admin/queue/deliver-delayed.ts
@@ -1,6 +1,6 @@
-import { deliverQueue } from '@/queue/queues';
-import { URL } from 'url';
-import define from '../../../define';
+import { deliverQueue } from '@/queue/queues.js';
+import { URL } from 'node:url';
+import define from '../../../define.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -8,9 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -35,8 +32,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const jobs = await deliverQueue.getJobs(['delayed']);
 
 	const res = [] as [string, number][];
diff --git a/packages/backend/src/server/api/endpoints/admin/queue/inbox-delayed.ts b/packages/backend/src/server/api/endpoints/admin/queue/inbox-delayed.ts
index a95aabc506..2235ce8f97 100644
--- a/packages/backend/src/server/api/endpoints/admin/queue/inbox-delayed.ts
+++ b/packages/backend/src/server/api/endpoints/admin/queue/inbox-delayed.ts
@@ -1,6 +1,6 @@
-import { URL } from 'url';
-import define from '../../../define';
-import { inboxQueue } from '@/queue/queues';
+import { URL } from 'node:url';
+import define from '../../../define.js';
+import { inboxQueue } from '@/queue/queues.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -8,9 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -35,8 +32,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const jobs = await inboxQueue.getJobs(['delayed']);
 
 	const res = [] as [string, number][];
diff --git a/packages/backend/src/server/api/endpoints/admin/queue/jobs.ts b/packages/backend/src/server/api/endpoints/admin/queue/jobs.ts
deleted file mode 100644
index df0b4a8f13..0000000000
--- a/packages/backend/src/server/api/endpoints/admin/queue/jobs.ts
+++ /dev/null
@@ -1,82 +0,0 @@
-import { deliverQueue, inboxQueue, dbQueue, objectStorageQueue } from '@/queue/queues';
-import $ from 'cafy';
-import define from '../../../define';
-
-export const meta = {
-	tags: ['admin'],
-
-	requireCredential: true,
-	requireModerator: true,
-
-	params: {
-		domain: {
-			validator: $.str.or(['deliver', 'inbox', 'db', 'objectStorage']),
-		},
-
-		state: {
-			validator: $.str.or(['active', 'waiting', 'delayed']),
-		},
-
-		limit: {
-			validator: $.optional.num,
-			default: 50,
-		},
-	},
-
-	res: {
-		type: 'array',
-		optional: false, nullable: false,
-		items: {
-			type: 'object',
-			optional: false, nullable: false,
-			properties: {
-				id: {
-					type: 'string',
-					optional: false, nullable: false,
-					format: 'id',
-				},
-				data: {
-					type: 'object',
-					optional: false, nullable: false,
-				},
-				attempts: {
-					type: 'number',
-					optional: false, nullable: false,
-				},
-				maxAttempts: {
-					type: 'number',
-					optional: false, nullable: false,
-				},
-				timestamp: {
-					type: 'number',
-					optional: false, nullable: false,
-				},
-			},
-		},
-	},
-} as const;
-
-// eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	const queue =
-		ps.domain === 'deliver' ? deliverQueue :
-		ps.domain === 'inbox' ? inboxQueue :
-		ps.domain === 'db' ? dbQueue :
-		ps.domain === 'objectStorage' ? objectStorageQueue :
-		null as never;
-
-	const jobs = await queue.getJobs([ps.state], 0, ps.limit!);
-
-	return jobs.map(job => {
-		const data = job.data;
-		delete data.content;
-		delete data.user;
-		return {
-			id: job.id,
-			data,
-			attempts: job.attemptsMade,
-			maxAttempts: job.opts ? job.opts.attempts : 0,
-			timestamp: job.timestamp,
-		};
-	});
-});
diff --git a/packages/backend/src/server/api/endpoints/admin/queue/stats.ts b/packages/backend/src/server/api/endpoints/admin/queue/stats.ts
index dab0be5dbc..988b5a5e35 100644
--- a/packages/backend/src/server/api/endpoints/admin/queue/stats.ts
+++ b/packages/backend/src/server/api/endpoints/admin/queue/stats.ts
@@ -1,5 +1,5 @@
-import { deliverQueue, inboxQueue, dbQueue, objectStorageQueue } from '@/queue/queues';
-import define from '../../../define';
+import { deliverQueue, inboxQueue, dbQueue, objectStorageQueue } from '@/queue/queues.js';
+import define from '../../../define.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -7,8 +7,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -33,8 +31,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const deliverJobCounts = await deliverQueue.getJobCounts();
 	const inboxJobCounts = await inboxQueue.getJobCounts();
 	const dbJobCounts = await dbQueue.getJobCounts();
diff --git a/packages/backend/src/server/api/endpoints/admin/relays/add.ts b/packages/backend/src/server/api/endpoints/admin/relays/add.ts
index 65890a00f7..348e9baca1 100644
--- a/packages/backend/src/server/api/endpoints/admin/relays/add.ts
+++ b/packages/backend/src/server/api/endpoints/admin/relays/add.ts
@@ -1,8 +1,7 @@
-import { URL } from 'url';
-import $ from 'cafy';
-import define from '../../../define';
-import { addRelay } from '@/services/relay';
-import { ApiError } from '../../../error';
+import { URL } from 'node:url';
+import define from '../../../define.js';
+import { addRelay } from '@/services/relay.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,12 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		inbox: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 		invalidUrl: {
 			message: 'Invalid URL',
@@ -52,8 +45,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		inbox: { type: 'string' },
+	},
+	required: ['inbox'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	try {
 		if (new URL(ps.inbox).protocol !== 'https:') throw 'https only';
 	} catch {
diff --git a/packages/backend/src/server/api/endpoints/admin/relays/list.ts b/packages/backend/src/server/api/endpoints/admin/relays/list.ts
index bdddf13374..89ec651e61 100644
--- a/packages/backend/src/server/api/endpoints/admin/relays/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/relays/list.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { listRelay } from '@/services/relay';
+import define from '../../../define.js';
+import { listRelay } from '@/services/relay.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -7,9 +7,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -42,7 +39,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	return await listRelay();
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/relays/remove.ts b/packages/backend/src/server/api/endpoints/admin/relays/remove.ts
index 4b04e620c1..b59cf72c58 100644
--- a/packages/backend/src/server/api/endpoints/admin/relays/remove.ts
+++ b/packages/backend/src/server/api/endpoints/admin/relays/remove.ts
@@ -1,21 +1,22 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { removeRelay } from '@/services/relay';
+import define from '../../../define.js';
+import { removeRelay } from '@/services/relay.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		inbox: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		inbox: { type: 'string' },
 	},
+	required: ['inbox'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	return await removeRelay(ps.inbox);
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/reset-password.ts b/packages/backend/src/server/api/endpoints/admin/reset-password.ts
index b6cf1ee2d0..1fd5c8d5a5 100644
--- a/packages/backend/src/server/api/endpoints/admin/reset-password.ts
+++ b/packages/backend/src/server/api/endpoints/admin/reset-password.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import * as bcrypt from 'bcryptjs';
+import define from '../../define.js';
+import bcrypt from 'bcryptjs';
 import rndstr from 'rndstr';
-import { Users, UserProfiles } from '@/models/index';
+import { Users, UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -11,12 +9,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -31,8 +23,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/resolve-abuse-user-report.ts b/packages/backend/src/server/api/endpoints/admin/resolve-abuse-user-report.ts
index b00457f092..a9e5658413 100644
--- a/packages/backend/src/server/api/endpoints/admin/resolve-abuse-user-report.ts
+++ b/packages/backend/src/server/api/endpoints/admin/resolve-abuse-user-report.ts
@@ -1,33 +1,28 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { AbuseUserReports, Users } from '@/models/index';
-import { getInstanceActor } from '@/services/instance-actor';
-import { deliver } from '@/queue/index';
-import { renderActivity } from '@/remote/activitypub/renderer/index';
-import { renderFlag } from '@/remote/activitypub/renderer/flag';
+import define from '../../define.js';
+import { AbuseUserReports, Users } from '@/models/index.js';
+import { getInstanceActor } from '@/services/instance-actor.js';
+import { deliver } from '@/queue/index.js';
+import { renderActivity } from '@/remote/activitypub/renderer/index.js';
+import { renderFlag } from '@/remote/activitypub/renderer/flag.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		reportId: {
-			validator: $.type(ID),
-		},
-
-		forward: {
-			validator: $.optional.boolean,
-			required: false,
-			default: false,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		reportId: { type: 'string', format: 'misskey:id' },
+		forward: { type: 'boolean', default: false },
 	},
+	required: ['reportId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const report = await AbuseUserReports.findOne(ps.reportId);
 
 	if (report == null) {
@@ -36,9 +31,9 @@ export default define(meta, async (ps, me) => {
 
 	if (ps.forward && report.targetUserHost != null) {
 		const actor = await getInstanceActor();
-		const targetUser = await Users.findOne(report.targetUserId);
+		const targetUser = await Users.findOneOrFail(report.targetUserId);
 
-		deliver(actor, renderActivity(renderFlag(actor, [targetUser.uri], report.comment)), targetUser.inbox);
+		deliver(actor, renderActivity(renderFlag(actor, [targetUser.uri!], report.comment)), targetUser.inbox);
 	}
 
 	await AbuseUserReports.update(report.id, {
diff --git a/packages/backend/src/server/api/endpoints/admin/resync-chart.ts b/packages/backend/src/server/api/endpoints/admin/resync-chart.ts
deleted file mode 100644
index d80d2b0426..0000000000
--- a/packages/backend/src/server/api/endpoints/admin/resync-chart.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-import define from '../../define';
-import { driveChart, notesChart, usersChart } from '@/services/chart/index';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-
-export const meta = {
-	tags: ['admin'],
-
-	requireCredential: true,
-	requireModerator: true,
-} as const;
-
-// eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
-	insertModerationLog(me, 'chartResync');
-
-	driveChart.resync();
-	notesChart.resync();
-	usersChart.resync();
-
-	// TODO: ユーザーごとのチャートもキューに入れて更新する
-	// TODO: インスタンスごとのチャートもキューに入れて更新する
-});
diff --git a/packages/backend/src/server/api/endpoints/admin/send-email.ts b/packages/backend/src/server/api/endpoints/admin/send-email.ts
index c2972c35fa..bbdd66e4c9 100644
--- a/packages/backend/src/server/api/endpoints/admin/send-email.ts
+++ b/packages/backend/src/server/api/endpoints/admin/send-email.ts
@@ -1,27 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { sendEmail } from '@/services/send-email';
+import define from '../../define.js';
+import { sendEmail } from '@/services/send-email.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		to: {
-			validator: $.str,
-		},
-		subject: {
-			validator: $.str,
-		},
-		text: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		to: { type: 'string' },
+		subject: { type: 'string' },
+		text: { type: 'string' },
 	},
+	required: ['to', 'subject', 'text'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	await sendEmail(ps.to, ps.subject, ps.text, ps.text);
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/server-info.ts b/packages/backend/src/server/api/endpoints/admin/server-info.ts
index cd282e364c..8bf1c4341c 100644
--- a/packages/backend/src/server/api/endpoints/admin/server-info.ts
+++ b/packages/backend/src/server/api/endpoints/admin/server-info.ts
@@ -1,8 +1,8 @@
-import * as os from 'os';
-import * as si from 'systeminformation';
+import * as os from 'node:os';
+import si from 'systeminformation';
 import { getConnection } from 'typeorm';
-import define from '../../define';
-import { redisClient } from '../../../../db/redis';
+import define from '../../define.js';
+import { redisClient } from '../../../../db/redis.js';
 
 export const meta = {
 	requireCredential: true,
@@ -10,9 +10,6 @@ export const meta = {
 
 	tags: ['admin', 'meta'],
 
-	params: {
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -90,8 +87,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const memStats = await si.mem();
 	const fsStats = await si.fsSize();
 	const netInterface = await si.networkInterfaceDefault();
diff --git a/packages/backend/src/server/api/endpoints/admin/show-moderation-logs.ts b/packages/backend/src/server/api/endpoints/admin/show-moderation-logs.ts
index 84e2b84bb5..3545536aa2 100644
--- a/packages/backend/src/server/api/endpoints/admin/show-moderation-logs.ts
+++ b/packages/backend/src/server/api/endpoints/admin/show-moderation-logs.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ModerationLogs } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { ModerationLogs } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -10,21 +8,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -65,11 +48,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const query = makePaginationQuery(ModerationLogs.createQueryBuilder('report'), ps.sinceId, ps.untilId);
 
-	const reports = await query.take(ps.limit!).getMany();
+	const reports = await query.take(ps.limit).getMany();
 
 	return await ModerationLogs.packMany(reports);
 });
diff --git a/packages/backend/src/server/api/endpoints/admin/show-user.ts b/packages/backend/src/server/api/endpoints/admin/show-user.ts
index c2a6a294b5..a435dcc288 100644
--- a/packages/backend/src/server/api/endpoints/admin/show-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/show-user.ts
@@ -1,7 +1,5 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Users } from '@/models/index';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -9,158 +7,22 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		nullable: false, optional: false,
-		properties: {
-			id: {
-				type: 'string',
-				nullable: false, optional: false,
-				format: 'id',
-			},
-			createdAt: {
-				type: 'string',
-				nullable: false, optional: false,
-				format: 'date-time',
-			},
-			updatedAt: {
-				type: 'string',
-				nullable: true, optional: false,
-				format: 'date-time',
-			},
-			lastFetchedAt: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			username: {
-				type: 'string',
-				nullable: false, optional: false,
-			},
-			name: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			folowersCount: {
-				type: 'number',
-				nullable: false, optional: true,
-			},
-			followingCount: {
-				type: 'number',
-				nullable: false, optional: false,
-			},
-			notesCount: {
-				type: 'number',
-				nullable: false, optional: false,
-			},
-			avatarId: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			bannerId: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			tags: {
-				type: 'array',
-				nullable: false, optional: false,
-				items: {
-					type: 'string',
-					nullable: false, optional: false,
-				},
-			},
-			avatarUrl: {
-				type: 'string',
-				nullable: true, optional: false,
-				format: 'url',
-			},
-			bannerUrl: {
-				type: 'string',
-				nullable: true, optional: false,
-				format: 'url',
-			},
-			avatarBlurhash: {
-				type: 'any',
-				nullable: true, optional: false,
-				default: null,
-			},
-			bannerBlurhash: {
-				type: 'any',
-				nullable: true, optional: false,
-				default: null,
-			},
-			isSuspended: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isSilenced: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isLocked: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isBot: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isCat: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isAdmin: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			isModerator: {
-				type: 'boolean',
-				nullable: false, optional: false,
-			},
-			emojis: {
-				type: 'array',
-				nullable: false, optional: false,
-				items: {
-					type: 'string',
-					nullable: false, optional: false,
-				},
-			},
-			host: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			inbox: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			sharedInbox: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			featured: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			uri: {
-				type: 'string',
-				nullable: true, optional: false,
-			},
-			token: {
-				type: 'string',
-				nullable: true, optional: false,
-				default: '<MASKED>',
-			},
-		},
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/show-users.ts b/packages/backend/src/server/api/endpoints/admin/show-users.ts
index d3dde99b72..1ec86fef2e 100644
--- a/packages/backend/src/server/api/endpoints/admin/show-users.ts
+++ b/packages/backend/src/server/api/endpoints/admin/show-users.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Users } from '@/models/index';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -8,61 +7,6 @@ export const meta = {
 	requireCredential: true,
 	requireModerator: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-
-		sort: {
-			validator: $.optional.str.or([
-				'+follower',
-				'-follower',
-				'+createdAt',
-				'-createdAt',
-				'+updatedAt',
-				'-updatedAt',
-			]),
-		},
-
-		state: {
-			validator: $.optional.str.or([
-				'all',
-				'available',
-				'admin',
-				'moderator',
-				'adminOrModerator',
-				'silenced',
-				'suspended',
-			]),
-			default: 'all',
-		},
-
-		origin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'local',
-		},
-
-		username: {
-			validator: $.optional.str,
-			default: null,
-		},
-
-		hostname: {
-			validator: $.optional.str,
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		nullable: false, optional: false,
@@ -74,8 +18,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+		sort: { type: 'string', enum: ['+follower', '-follower', '+createdAt', '-createdAt', '+updatedAt', '-updatedAt'] },
+		state: { type: 'string', enum: ['all', 'available', 'admin', 'moderator', 'adminOrModerator', 'silenced', 'suspended'], default: "all" },
+		origin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "local" },
+		username: { type: 'string', default: null },
+		hostname: { type: 'string', default: null },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Users.createQueryBuilder('user');
 
 	switch (ps.state) {
@@ -111,7 +69,7 @@ export default define(meta, async (ps, me) => {
 		default: query.orderBy('user.id', 'ASC'); break;
 	}
 
-	query.take(ps.limit!);
+	query.take(ps.limit);
 	query.skip(ps.offset);
 
 	const users = await query.getMany();
diff --git a/packages/backend/src/server/api/endpoints/admin/silence-user.ts b/packages/backend/src/server/api/endpoints/admin/silence-user.ts
index 872bd2a6ac..4a74c3fb00 100644
--- a/packages/backend/src/server/api/endpoints/admin/silence-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/silence-user.ts
@@ -1,24 +1,24 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Users } from '@/models/index';
-import { insertModerationLog } from '@/services/insert-moderation-log';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/suspend-user.ts b/packages/backend/src/server/api/endpoints/admin/suspend-user.ts
index 2bb1875fc0..adaa7b86ce 100644
--- a/packages/backend/src/server/api/endpoints/admin/suspend-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/suspend-user.ts
@@ -1,28 +1,28 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import deleteFollowing from '@/services/following/delete';
-import { Users, Followings, Notifications } from '@/models/index';
-import { User } from '@/models/entities/user';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { doPostSuspend } from '@/services/suspend-user';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import deleteFollowing from '@/services/following/delete.js';
+import { Users, Followings, Notifications } from '@/models/index.js';
+import { User } from '@/models/entities/user.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { doPostSuspend } from '@/services/suspend-user.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/unsilence-user.ts b/packages/backend/src/server/api/endpoints/admin/unsilence-user.ts
index a4c6ff2ade..4e6366aa18 100644
--- a/packages/backend/src/server/api/endpoints/admin/unsilence-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/unsilence-user.ts
@@ -1,24 +1,24 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Users } from '@/models/index';
-import { insertModerationLog } from '@/services/insert-moderation-log';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/unsuspend-user.ts b/packages/backend/src/server/api/endpoints/admin/unsuspend-user.ts
index 5ab56d51c7..3b9e0a94e0 100644
--- a/packages/backend/src/server/api/endpoints/admin/unsuspend-user.ts
+++ b/packages/backend/src/server/api/endpoints/admin/unsuspend-user.ts
@@ -1,25 +1,25 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Users } from '@/models/index';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { doPostUnsuspend } from '@/services/unsuspend-user';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { doPostUnsuspend } from '@/services/unsuspend-user.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId as string);
 
 	if (user == null) {
diff --git a/packages/backend/src/server/api/endpoints/admin/update-meta.ts b/packages/backend/src/server/api/endpoints/admin/update-meta.ts
index aa2d1222f7..66b634c877 100644
--- a/packages/backend/src/server/api/endpoints/admin/update-meta.ts
+++ b/packages/backend/src/server/api/endpoints/admin/update-meta.ts
@@ -1,306 +1,107 @@
-import $ from 'cafy';
-import define from '../../define';
+import define from '../../define.js';
 import { getConnection } from 'typeorm';
-import { Meta } from '@/models/entities/meta';
-import { insertModerationLog } from '@/services/insert-moderation-log';
-import { DB_MAX_NOTE_TEXT_LENGTH } from '@/misc/hard-limits';
-import { ID } from '@/misc/cafy-id';
+import { Meta } from '@/models/entities/meta.js';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '@/misc/hard-limits.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireAdmin: true,
+} as const;
 
-	params: {
-		disableRegistration: {
-			validator: $.optional.nullable.bool,
-		},
-
-		disableLocalTimeline: {
-			validator: $.optional.nullable.bool,
-		},
-
-		disableGlobalTimeline: {
-			validator: $.optional.nullable.bool,
-		},
-
-		useStarForReactionFallback: {
-			validator: $.optional.nullable.bool,
-		},
-
-		pinnedUsers: {
-			validator: $.optional.nullable.arr($.str),
-		},
-
-		hiddenTags: {
-			validator: $.optional.nullable.arr($.str),
-		},
-
-		blockedHosts: {
-			validator: $.optional.nullable.arr($.str),
-		},
-
-		mascotImageUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		bannerUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		errorImageUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		iconUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		backgroundImageUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		logoImageUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		name: {
-			validator: $.optional.nullable.str,
-		},
-
-		description: {
-			validator: $.optional.nullable.str,
-		},
-
-		maxNoteTextLength: {
-			validator: $.optional.num.min(0).max(DB_MAX_NOTE_TEXT_LENGTH),
-		},
-
-		localDriveCapacityMb: {
-			validator: $.optional.num.min(0),
-		},
-
-		remoteDriveCapacityMb: {
-			validator: $.optional.num.min(0),
-		},
-
-		cacheRemoteFiles: {
-			validator: $.optional.bool,
-		},
-
-		proxyRemoteFiles: {
-			validator: $.optional.bool,
-		},
-
-		emailRequiredForSignup: {
-			validator: $.optional.bool,
-		},
-
-		enableHcaptcha: {
-			validator: $.optional.bool,
-		},
-
-		hcaptchaSiteKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		hcaptchaSecretKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		enableRecaptcha: {
-			validator: $.optional.bool,
-		},
-
-		recaptchaSiteKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		recaptchaSecretKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		proxyAccountId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		maintainerName: {
-			validator: $.optional.nullable.str,
-		},
-
-		maintainerEmail: {
-			validator: $.optional.nullable.str,
-		},
-
-		pinnedPages: {
-			validator: $.optional.arr($.str),
-		},
-
-		pinnedClipId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		langs: {
-			validator: $.optional.arr($.str),
-		},
-
-		summalyProxy: {
-			validator: $.optional.nullable.str,
-		},
-
-		deeplAuthKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		deeplIsPro: {
-			validator: $.optional.bool,
-		},
-
-		enableTwitterIntegration: {
-			validator: $.optional.bool,
-		},
-
-		twitterConsumerKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		twitterConsumerSecret: {
-			validator: $.optional.nullable.str,
-		},
-
-		enableGithubIntegration: {
-			validator: $.optional.bool,
-		},
-
-		githubClientId: {
-			validator: $.optional.nullable.str,
-		},
-
-		githubClientSecret: {
-			validator: $.optional.nullable.str,
-		},
-
-		enableDiscordIntegration: {
-			validator: $.optional.bool,
-		},
-
-		discordClientId: {
-			validator: $.optional.nullable.str,
-		},
-
-		discordClientSecret: {
-			validator: $.optional.nullable.str,
-		},
-
-		enableEmail: {
-			validator: $.optional.bool,
-		},
-
-		email: {
-			validator: $.optional.nullable.str,
-		},
-
-		smtpSecure: {
-			validator: $.optional.bool,
-		},
-
-		smtpHost: {
-			validator: $.optional.nullable.str,
-		},
-
-		smtpPort: {
-			validator: $.optional.nullable.num,
-		},
-
-		smtpUser: {
-			validator: $.optional.nullable.str,
-		},
-
-		smtpPass: {
-			validator: $.optional.nullable.str,
-		},
-
-		enableServiceWorker: {
-			validator: $.optional.bool,
-		},
-
-		swPublicKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		swPrivateKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		tosUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		repositoryUrl: {
-			validator: $.optional.str,
-		},
-
-		feedbackUrl: {
-			validator: $.optional.str,
-		},
-
-		useObjectStorage: {
-			validator: $.optional.bool,
-		},
-
-		objectStorageBaseUrl: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStorageBucket: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStoragePrefix: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStorageEndpoint: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStorageRegion: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStoragePort: {
-			validator: $.optional.nullable.num,
-		},
-
-		objectStorageAccessKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStorageSecretKey: {
-			validator: $.optional.nullable.str,
-		},
-
-		objectStorageUseSSL: {
-			validator: $.optional.bool,
-		},
-
-		objectStorageUseProxy: {
-			validator: $.optional.bool,
-		},
-
-		objectStorageSetPublicRead: {
-			validator: $.optional.bool,
-		},
-
-		objectStorageS3ForcePathStyle: {
-			validator: $.optional.bool,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		disableRegistration: { type: 'boolean', nullable: true },
+		disableLocalTimeline: { type: 'boolean', nullable: true },
+		disableGlobalTimeline: { type: 'boolean', nullable: true },
+		useStarForReactionFallback: { type: 'boolean', nullable: true },
+		pinnedUsers: { type: 'array', nullable: true, items: {
+			type: 'string',
+		} },
+		hiddenTags: { type: 'array', nullable: true, items: {
+			type: 'string',
+		} },
+		blockedHosts: { type: 'array', nullable: true, items: {
+			type: 'string',
+		} },
+		themeColor: { type: 'string', nullable: true },
+		mascotImageUrl: { type: 'string', nullable: true },
+		bannerUrl: { type: 'string', nullable: true },
+		errorImageUrl: { type: 'string', nullable: true },
+		iconUrl: { type: 'string', nullable: true },
+		backgroundImageUrl: { type: 'string', nullable: true },
+		logoImageUrl: { type: 'string', nullable: true },
+		name: { type: 'string', nullable: true },
+		description: { type: 'string', nullable: true },
+		defaultLightTheme: { type: 'string', nullable: true },
+		defaultDarkTheme: { type: 'string', nullable: true },
+		localDriveCapacityMb: { type: 'integer' },
+		remoteDriveCapacityMb: { type: 'integer' },
+		cacheRemoteFiles: { type: 'boolean' },
+		emailRequiredForSignup: { type: 'boolean' },
+		enableHcaptcha: { type: 'boolean' },
+		hcaptchaSiteKey: { type: 'string', nullable: true },
+		hcaptchaSecretKey: { type: 'string', nullable: true },
+		enableRecaptcha: { type: 'boolean' },
+		recaptchaSiteKey: { type: 'string', nullable: true },
+		recaptchaSecretKey: { type: 'string', nullable: true },
+		proxyAccountId: { type: 'string', format: 'misskey:id', nullable: true },
+		maintainerName: { type: 'string', nullable: true },
+		maintainerEmail: { type: 'string', nullable: true },
+		pinnedPages: { type: 'array', items: {
+			type: 'string',
+		} },
+		pinnedClipId: { type: 'string', format: 'misskey:id', nullable: true },
+		langs: { type: 'array', items: {
+			type: 'string',
+		} },
+		summalyProxy: { type: 'string', nullable: true },
+		deeplAuthKey: { type: 'string', nullable: true },
+		deeplIsPro: { type: 'boolean' },
+		enableTwitterIntegration: { type: 'boolean' },
+		twitterConsumerKey: { type: 'string', nullable: true },
+		twitterConsumerSecret: { type: 'string', nullable: true },
+		enableGithubIntegration: { type: 'boolean' },
+		githubClientId: { type: 'string', nullable: true },
+		githubClientSecret: { type: 'string', nullable: true },
+		enableDiscordIntegration: { type: 'boolean' },
+		discordClientId: { type: 'string', nullable: true },
+		discordClientSecret: { type: 'string', nullable: true },
+		enableEmail: { type: 'boolean' },
+		email: { type: 'string', nullable: true },
+		smtpSecure: { type: 'boolean' },
+		smtpHost: { type: 'string', nullable: true },
+		smtpPort: { type: 'integer', nullable: true },
+		smtpUser: { type: 'string', nullable: true },
+		smtpPass: { type: 'string', nullable: true },
+		enableServiceWorker: { type: 'boolean' },
+		swPublicKey: { type: 'string', nullable: true },
+		swPrivateKey: { type: 'string', nullable: true },
+		tosUrl: { type: 'string', nullable: true },
+		repositoryUrl: { type: 'string' },
+		feedbackUrl: { type: 'string' },
+		useObjectStorage: { type: 'boolean' },
+		objectStorageBaseUrl: { type: 'string', nullable: true },
+		objectStorageBucket: { type: 'string', nullable: true },
+		objectStoragePrefix: { type: 'string', nullable: true },
+		objectStorageEndpoint: { type: 'string', nullable: true },
+		objectStorageRegion: { type: 'string', nullable: true },
+		objectStoragePort: { type: 'integer', nullable: true },
+		objectStorageAccessKey: { type: 'string', nullable: true },
+		objectStorageSecretKey: { type: 'string', nullable: true },
+		objectStorageUseSSL: { type: 'boolean' },
+		objectStorageUseProxy: { type: 'boolean' },
+		objectStorageSetPublicRead: { type: 'boolean' },
+		objectStorageS3ForcePathStyle: { type: 'boolean' },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const set = {} as Partial<Meta>;
 
 	if (typeof ps.disableRegistration === 'boolean') {
@@ -331,6 +132,10 @@ export default define(meta, async (ps, me) => {
 		set.blockedHosts = ps.blockedHosts.filter(Boolean);
 	}
 
+	if (ps.themeColor !== undefined) {
+		set.themeColor = ps.themeColor;
+	}
+
 	if (ps.mascotImageUrl !== undefined) {
 		set.mascotImageUrl = ps.mascotImageUrl;
 	}
@@ -359,8 +164,12 @@ export default define(meta, async (ps, me) => {
 		set.description = ps.description;
 	}
 
-	if (ps.maxNoteTextLength) {
-		set.maxNoteTextLength = ps.maxNoteTextLength;
+	if (ps.defaultLightTheme !== undefined) {
+		set.defaultLightTheme = ps.defaultLightTheme;
+	}
+
+	if (ps.defaultDarkTheme !== undefined) {
+		set.defaultDarkTheme = ps.defaultDarkTheme;
 	}
 
 	if (ps.localDriveCapacityMb !== undefined) {
@@ -375,10 +184,6 @@ export default define(meta, async (ps, me) => {
 		set.cacheRemoteFiles = ps.cacheRemoteFiles;
 	}
 
-	if (ps.proxyRemoteFiles !== undefined) {
-		set.proxyRemoteFiles = ps.proxyRemoteFiles;
-	}
-
 	if (ps.emailRequiredForSignup !== undefined) {
 		set.emailRequiredForSignup = ps.emailRequiredForSignup;
 	}
diff --git a/packages/backend/src/server/api/endpoints/admin/vacuum.ts b/packages/backend/src/server/api/endpoints/admin/vacuum.ts
index 4229ef0d29..4c04e019da 100644
--- a/packages/backend/src/server/api/endpoints/admin/vacuum.ts
+++ b/packages/backend/src/server/api/endpoints/admin/vacuum.ts
@@ -1,26 +1,25 @@
-import $ from 'cafy';
-import define from '../../define';
+import define from '../../define.js';
 import { getConnection } from 'typeorm';
-import { insertModerationLog } from '@/services/insert-moderation-log';
+import { insertModerationLog } from '@/services/insert-moderation-log.js';
 
 export const meta = {
 	tags: ['admin'],
 
 	requireCredential: true,
 	requireModerator: true,
+} as const;
 
-	params: {
-		full: {
-			validator: $.bool,
-		},
-		analyze: {
-			validator: $.bool,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		full: { type: 'boolean' },
+		analyze: { type: 'boolean' },
 	},
+	required: ['full', 'analyze'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const params: string[] = [];
 
 	if (ps.full) {
diff --git a/packages/backend/src/server/api/endpoints/announcements.ts b/packages/backend/src/server/api/endpoints/announcements.ts
index 0bd29607d6..bba66e98cf 100644
--- a/packages/backend/src/server/api/endpoints/announcements.ts
+++ b/packages/backend/src/server/api/endpoints/announcements.ts
@@ -1,34 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../define';
-import { Announcements, AnnouncementReads } from '@/models/index';
-import { makePaginationQuery } from '../common/make-pagination-query';
+import define from '../define.js';
+import { Announcements, AnnouncementReads } from '@/models/index.js';
+import { makePaginationQuery } from '../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['meta'],
 
 	requireCredential: false,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		withUnreads: {
-			validator: $.optional.boolean,
-			default: false,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -73,11 +51,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		withUnreads: { type: 'boolean', default: false },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Announcements.createQueryBuilder('announcement'), ps.sinceId, ps.untilId);
 
-	const announcements = await query.take(ps.limit!).getMany();
+	const announcements = await query.take(ps.limit).getMany();
 
 	if (user) {
 		const reads = (await AnnouncementReads.find({
@@ -89,5 +78,9 @@ export default define(meta, async (ps, user) => {
 		}
 	}
 
-	return ps.withUnreads ? announcements.filter((a: any) => !a.isRead) : announcements;
+	return (ps.withUnreads ? announcements.filter((a: any) => !a.isRead) : announcements).map((a) => ({
+		...a,
+		createdAt: a.createdAt.toISOString(),
+		updatedAt: a.updatedAt?.toISOString() ?? null,
+	}));
 });
diff --git a/packages/backend/src/server/api/endpoints/antennas/create.ts b/packages/backend/src/server/api/endpoints/antennas/create.ts
index 2092d177ba..92cbba817e 100644
--- a/packages/backend/src/server/api/endpoints/antennas/create.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/create.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import define from '../../define';
-import { genId } from '@/misc/gen-id';
-import { Antennas, UserLists, UserGroupJoinings } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
-import { ApiError } from '../../error';
-import { publishInternalEvent } from '@/services/stream';
+import define from '../../define.js';
+import { genId } from '@/misc/gen-id.js';
+import { Antennas, UserLists, UserGroupJoinings } from '@/models/index.js';
+import { ApiError } from '../../error.js';
+import { publishInternalEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['antennas'],
@@ -13,52 +11,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		name: {
-			validator: $.str.range(1, 100),
-		},
-
-		src: {
-			validator: $.str.or(['home', 'all', 'users', 'list', 'group']),
-		},
-
-		userListId: {
-			validator: $.nullable.optional.type(ID),
-		},
-
-		userGroupId: {
-			validator: $.nullable.optional.type(ID),
-		},
-
-		keywords: {
-			validator: $.arr($.arr($.str)),
-		},
-
-		excludeKeywords: {
-			validator: $.arr($.arr($.str)),
-		},
-
-		users: {
-			validator: $.arr($.str),
-		},
-
-		caseSensitive: {
-			validator: $.bool,
-		},
-
-		withReplies: {
-			validator: $.bool,
-		},
-
-		withFile: {
-			validator: $.bool,
-		},
-
-		notify: {
-			validator: $.bool,
-		},
-	},
-
 	errors: {
 		noSuchUserList: {
 			message: 'No such user list.',
@@ -80,8 +32,36 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+		src: { type: 'string', enum: ['home', 'all', 'users', 'list', 'group'] },
+		userListId: { type: 'string', format: 'misskey:id', nullable: true },
+		userGroupId: { type: 'string', format: 'misskey:id', nullable: true },
+		keywords: { type: 'array', items: {
+			type: 'array', items: {
+				type: 'string',
+			},
+		} },
+		excludeKeywords: { type: 'array', items: {
+			type: 'array', items: {
+				type: 'string',
+			},
+		} },
+		users: { type: 'array', items: {
+			type: 'string',
+		} },
+		caseSensitive: { type: 'boolean' },
+		withReplies: { type: 'boolean' },
+		withFile: { type: 'boolean' },
+		notify: { type: 'boolean' },
+	},
+	required: ['name', 'src', 'keywords', 'excludeKeywords', 'users', 'caseSensitive', 'withReplies', 'withFile', 'notify'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let userList;
 	let userGroupJoining;
 
diff --git a/packages/backend/src/server/api/endpoints/antennas/delete.ts b/packages/backend/src/server/api/endpoints/antennas/delete.ts
index b2793fc70d..4e6b8b3d2e 100644
--- a/packages/backend/src/server/api/endpoints/antennas/delete.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/delete.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Antennas } from '@/models/index';
-import { publishInternalEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Antennas } from '@/models/index.js';
+import { publishInternalEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['antennas'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		antennaId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchAntenna: {
 			message: 'No such antenna.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		antennaId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['antennaId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const antenna = await Antennas.findOne({
 		id: ps.antennaId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/antennas/list.ts b/packages/backend/src/server/api/endpoints/antennas/list.ts
index bb58912612..accca5de76 100644
--- a/packages/backend/src/server/api/endpoints/antennas/list.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/list.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { Antennas } from '@/models/index';
+import define from '../../define.js';
+import { Antennas } from '@/models/index.js';
 
 export const meta = {
 	tags: ['antennas', 'account'],
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const antennas = await Antennas.find({
 		userId: me.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/antennas/notes.ts b/packages/backend/src/server/api/endpoints/antennas/notes.ts
index eb7de901c5..f0cb2ba3c0 100644
--- a/packages/backend/src/server/api/endpoints/antennas/notes.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/notes.ts
@@ -1,13 +1,11 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import readNote from '@/services/note/read';
-import { Antennas, Notes, AntennaNotes } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { ApiError } from '../../error';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import readNote from '@/services/note/read.js';
+import { Antennas, Notes, AntennaNotes } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { ApiError } from '../../error.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['antennas', 'account', 'notes'],
@@ -16,33 +14,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		antennaId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-	},
-
 	errors: {
 		noSuchAntenna: {
 			message: 'No such antenna.',
@@ -62,8 +33,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		antennaId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+	},
+	required: ['antennaId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const antenna = await Antennas.findOne({
 		id: ps.antennaId,
 		userId: user.id,
@@ -81,10 +65,16 @@ export default define(meta, async (ps, user) => {
 			ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
 		.andWhere(`note.id IN (${ antennaQuery.getQuery() })`)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.setParameters(antennaQuery.getParameters());
 
 	generateVisibilityQuery(query, user);
@@ -92,7 +82,7 @@ export default define(meta, async (ps, user) => {
 	generateBlockedUserQuery(query, user);
 
 	const notes = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	if (notes.length > 0) {
diff --git a/packages/backend/src/server/api/endpoints/antennas/show.ts b/packages/backend/src/server/api/endpoints/antennas/show.ts
index a37d37d31c..36c4da81b7 100644
--- a/packages/backend/src/server/api/endpoints/antennas/show.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/show.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Antennas } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Antennas } from '@/models/index.js';
 
 export const meta = {
 	tags: ['antennas', 'account'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		antennaId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchAntenna: {
 			message: 'No such antenna.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		antennaId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['antennaId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the antenna
 	const antenna = await Antennas.findOne({
 		id: ps.antennaId,
diff --git a/packages/backend/src/server/api/endpoints/antennas/update.ts b/packages/backend/src/server/api/endpoints/antennas/update.ts
index 900f725505..a99964555b 100644
--- a/packages/backend/src/server/api/endpoints/antennas/update.ts
+++ b/packages/backend/src/server/api/endpoints/antennas/update.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Antennas, UserLists, UserGroupJoinings } from '@/models/index';
-import { publishInternalEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Antennas, UserLists, UserGroupJoinings } from '@/models/index.js';
+import { publishInternalEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['antennas'],
@@ -12,56 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		antennaId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.str.range(1, 100),
-		},
-
-		src: {
-			validator: $.str.or(['home', 'all', 'users', 'list', 'group']),
-		},
-
-		userListId: {
-			validator: $.nullable.optional.type(ID),
-		},
-
-		userGroupId: {
-			validator: $.nullable.optional.type(ID),
-		},
-
-		keywords: {
-			validator: $.arr($.arr($.str)),
-		},
-
-		excludeKeywords: {
-			validator: $.arr($.arr($.str)),
-		},
-
-		users: {
-			validator: $.arr($.str),
-		},
-
-		caseSensitive: {
-			validator: $.bool,
-		},
-
-		withReplies: {
-			validator: $.bool,
-		},
-
-		withFile: {
-			validator: $.bool,
-		},
-
-		notify: {
-			validator: $.bool,
-		},
-	},
-
 	errors: {
 		noSuchAntenna: {
 			message: 'No such antenna.',
@@ -89,8 +37,37 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		antennaId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+		src: { type: 'string', enum: ['home', 'all', 'users', 'list', 'group'] },
+		userListId: { type: 'string', format: 'misskey:id', nullable: true },
+		userGroupId: { type: 'string', format: 'misskey:id', nullable: true },
+		keywords: { type: 'array', items: {
+			type: 'array', items: {
+				type: 'string',
+			},
+		} },
+		excludeKeywords: { type: 'array', items: {
+			type: 'array', items: {
+				type: 'string',
+			},
+		} },
+		users: { type: 'array', items: {
+			type: 'string',
+		} },
+		caseSensitive: { type: 'boolean' },
+		withReplies: { type: 'boolean' },
+		withFile: { type: 'boolean' },
+		notify: { type: 'boolean' },
+	},
+	required: ['antennaId', 'name', 'src', 'keywords', 'excludeKeywords', 'users', 'caseSensitive', 'withReplies', 'withFile', 'notify'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch the antenna
 	const antenna = await Antennas.findOne({
 		id: ps.antennaId,
diff --git a/packages/backend/src/server/api/endpoints/ap/get.ts b/packages/backend/src/server/api/endpoints/ap/get.ts
index ff8c677b91..0cbe7ebc67 100644
--- a/packages/backend/src/server/api/endpoints/ap/get.ts
+++ b/packages/backend/src/server/api/endpoints/ap/get.ts
@@ -1,7 +1,6 @@
-import $ from 'cafy';
-import define from '../../define';
-import Resolver from '@/remote/activitypub/resolver';
-import { ApiError } from '../../error';
+import define from '../../define.js';
+import Resolver from '@/remote/activitypub/resolver.js';
+import { ApiError } from '../../error.js';
 import ms from 'ms';
 
 export const meta = {
@@ -14,12 +13,6 @@ export const meta = {
 		max: 30,
 	},
 
-	params: {
-		uri: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 	},
 
@@ -29,8 +22,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		uri: { type: 'string' },
+	},
+	required: ['uri'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const resolver = new Resolver();
 	const object = await resolver.resolve(ps.uri);
 	return object;
diff --git a/packages/backend/src/server/api/endpoints/ap/show.ts b/packages/backend/src/server/api/endpoints/ap/show.ts
index 7d17d8edce..7595c38e8a 100644
--- a/packages/backend/src/server/api/endpoints/ap/show.ts
+++ b/packages/backend/src/server/api/endpoints/ap/show.ts
@@ -1,18 +1,17 @@
-import $ from 'cafy';
-import define from '../../define';
-import config from '@/config/index';
-import { createPerson } from '@/remote/activitypub/models/person';
-import { createNote } from '@/remote/activitypub/models/note';
-import Resolver from '@/remote/activitypub/resolver';
-import { ApiError } from '../../error';
-import { extractDbHost } from '@/misc/convert-host';
-import { Users, Notes } from '@/models/index';
-import { Note } from '@/models/entities/note';
-import { User } from '@/models/entities/user';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { isActor, isPost, getApId } from '@/remote/activitypub/type';
+import define from '../../define.js';
+import config from '@/config/index.js';
+import { createPerson } from '@/remote/activitypub/models/person.js';
+import { createNote } from '@/remote/activitypub/models/note.js';
+import Resolver from '@/remote/activitypub/resolver.js';
+import { ApiError } from '../../error.js';
+import { extractDbHost } from '@/misc/convert-host.js';
+import { Users, Notes } from '@/models/index.js';
+import { Note } from '@/models/entities/note.js';
+import { User } from '@/models/entities/user.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { isActor, isPost, getApId } from '@/remote/activitypub/type.js';
 import ms from 'ms';
-import { SchemaType } from '@/misc/schema';
+import { SchemaType } from '@/misc/schema.js';
 
 export const meta = {
 	tags: ['federation'],
@@ -24,12 +23,6 @@ export const meta = {
 		max: 30,
 	},
 
-	params: {
-		uri: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 		noSuchObject: {
 			message: 'No such object.',
@@ -75,8 +68,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		uri: { type: 'string' },
+	},
+	required: ['uri'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const object = await fetchAny(ps.uri);
 	if (object) {
 		return object;
diff --git a/packages/backend/src/server/api/endpoints/app/create.ts b/packages/backend/src/server/api/endpoints/app/create.ts
index fbe6690f1d..e0cf8632fb 100644
--- a/packages/backend/src/server/api/endpoints/app/create.ts
+++ b/packages/backend/src/server/api/endpoints/app/create.ts
@@ -1,35 +1,14 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Apps } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { unique } from '@/prelude/array';
-import { secureRndstr } from '@/misc/secure-rndstr';
+import define from '../../define.js';
+import { Apps } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { unique } from '@/prelude/array.js';
+import { secureRndstr } from '@/misc/secure-rndstr.js';
 
 export const meta = {
 	tags: ['app'],
 
 	requireCredential: false,
 
-	params: {
-		name: {
-			validator: $.str,
-		},
-
-		description: {
-			validator: $.str,
-		},
-
-		permission: {
-			validator: $.arr($.str).unique(),
-		},
-
-		// TODO: Check it is valid url
-		callbackUrl: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -37,8 +16,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string' },
+		description: { type: 'string' },
+		permission: { type: 'array', uniqueItems: true, items: {
+			type: 'string',
+		} },
+		callbackUrl: { type: 'string', nullable: true },
+	},
+	required: ['name', 'description', 'permission'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Generate secret
 	const secret = secureRndstr(32, true);
 
diff --git a/packages/backend/src/server/api/endpoints/app/show.ts b/packages/backend/src/server/api/endpoints/app/show.ts
index 9f4777b383..54e714e193 100644
--- a/packages/backend/src/server/api/endpoints/app/show.ts
+++ b/packages/backend/src/server/api/endpoints/app/show.ts
@@ -1,18 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Apps } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Apps } from '@/models/index.js';
 
 export const meta = {
 	tags: ['app'],
 
-	params: {
-		appId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchApp: {
 			message: 'No such app.',
@@ -28,8 +20,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		appId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['appId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user, token) => {
+export default define(meta, paramDef, async (ps, user, token) => {
 	const isSecure = user != null && token == null;
 
 	// Lookup app
diff --git a/packages/backend/src/server/api/endpoints/auth/accept.ts b/packages/backend/src/server/api/endpoints/auth/accept.ts
index f028135ca5..0760eef52b 100644
--- a/packages/backend/src/server/api/endpoints/auth/accept.ts
+++ b/packages/backend/src/server/api/endpoints/auth/accept.ts
@@ -1,10 +1,9 @@
-import * as crypto from 'crypto';
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { AuthSessions, AccessTokens, Apps } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { secureRndstr } from '@/misc/secure-rndstr';
+import * as crypto from 'node:crypto';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { AuthSessions, AccessTokens, Apps } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { secureRndstr } from '@/misc/secure-rndstr.js';
 
 export const meta = {
 	tags: ['auth'],
@@ -13,12 +12,6 @@ export const meta = {
 
 	secure: true,
 
-	params: {
-		token: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 		noSuchSession: {
 			message: 'No such session.',
@@ -28,8 +21,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		token: { type: 'string' },
+	},
+	required: ['token'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch token
 	const session = await AuthSessions
 		.findOne({ token: ps.token });
diff --git a/packages/backend/src/server/api/endpoints/auth/session/generate.ts b/packages/backend/src/server/api/endpoints/auth/session/generate.ts
index 98987eba5b..bd571327d2 100644
--- a/packages/backend/src/server/api/endpoints/auth/session/generate.ts
+++ b/packages/backend/src/server/api/endpoints/auth/session/generate.ts
@@ -1,22 +1,15 @@
 import { v4 as uuid } from 'uuid';
-import $ from 'cafy';
-import config from '@/config/index';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { Apps, AuthSessions } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import config from '@/config/index.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { Apps, AuthSessions } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['auth'],
 
 	requireCredential: false,
 
-	params: {
-		appSecret: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -42,8 +35,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		appSecret: { type: 'string' },
+	},
+	required: ['appSecret'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	// Lookup app
 	const app = await Apps.findOne({
 		secret: ps.appSecret,
diff --git a/packages/backend/src/server/api/endpoints/auth/session/show.ts b/packages/backend/src/server/api/endpoints/auth/session/show.ts
index ae0d016cea..d40c9363c6 100644
--- a/packages/backend/src/server/api/endpoints/auth/session/show.ts
+++ b/packages/backend/src/server/api/endpoints/auth/session/show.ts
@@ -1,19 +1,12 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { AuthSessions } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { AuthSessions } from '@/models/index.js';
 
 export const meta = {
 	tags: ['auth'],
 
 	requireCredential: false,
 
-	params: {
-		token: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 		noSuchSession: {
 			message: 'No such session.',
@@ -44,8 +37,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		token: { type: 'string' },
+	},
+	required: ['token'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Lookup session
 	const session = await AuthSessions.findOne({
 		token: ps.token,
diff --git a/packages/backend/src/server/api/endpoints/auth/session/userkey.ts b/packages/backend/src/server/api/endpoints/auth/session/userkey.ts
index fe0211ebe3..b699c6fa25 100644
--- a/packages/backend/src/server/api/endpoints/auth/session/userkey.ts
+++ b/packages/backend/src/server/api/endpoints/auth/session/userkey.ts
@@ -1,23 +1,12 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { Apps, AuthSessions, AccessTokens, Users } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { Apps, AuthSessions, AccessTokens, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['auth'],
 
 	requireCredential: false,
 
-	params: {
-		appSecret: {
-			validator: $.str,
-		},
-
-		token: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -56,8 +45,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		appSecret: { type: 'string' },
+		token: { type: 'string' },
+	},
+	required: ['appSecret', 'token'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	// Lookup app
 	const app = await Apps.findOne({
 		secret: ps.appSecret,
diff --git a/packages/backend/src/server/api/endpoints/blocking/create.ts b/packages/backend/src/server/api/endpoints/blocking/create.ts
index 6d555ff569..c5e73c0131 100644
--- a/packages/backend/src/server/api/endpoints/blocking/create.ts
+++ b/packages/backend/src/server/api/endpoints/blocking/create.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import ms from 'ms';
-import create from '@/services/blocking/create';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Blockings, NoteWatchings, Users } from '@/models/index';
+import create from '@/services/blocking/create.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Blockings, NoteWatchings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
@@ -19,12 +17,6 @@ export const meta = {
 
 	kind: 'write:blocks',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -52,8 +44,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const blocker = await Users.findOneOrFail(user.id);
 
 	// 自分自身
diff --git a/packages/backend/src/server/api/endpoints/blocking/delete.ts b/packages/backend/src/server/api/endpoints/blocking/delete.ts
index 942cddaedf..a45547290c 100644
--- a/packages/backend/src/server/api/endpoints/blocking/delete.ts
+++ b/packages/backend/src/server/api/endpoints/blocking/delete.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import ms from 'ms';
-import deleteBlocking from '@/services/blocking/delete';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Blockings, Users } from '@/models/index';
+import deleteBlocking from '@/services/blocking/delete.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Blockings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
@@ -19,12 +17,6 @@ export const meta = {
 
 	kind: 'write:blocks',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -52,8 +44,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const blocker = await Users.findOneOrFail(user.id);
 
 	// Check if the blockee is yourself
diff --git a/packages/backend/src/server/api/endpoints/blocking/list.ts b/packages/backend/src/server/api/endpoints/blocking/list.ts
index 9a4f662140..29095ebe21 100644
--- a/packages/backend/src/server/api/endpoints/blocking/list.ts
+++ b/packages/backend/src/server/api/endpoints/blocking/list.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Blockings } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Blockings } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:blocks',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 30,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 30 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Blockings.createQueryBuilder('blocking'), ps.sinceId, ps.untilId)
 		.andWhere(`blocking.blockerId = :meId`, { meId: me.id });
 
 	const blockings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Blockings.packMany(blockings, me);
diff --git a/packages/backend/src/server/api/endpoints/channels/create.ts b/packages/backend/src/server/api/endpoints/channels/create.ts
index 68cdf1143e..16456b9c01 100644
--- a/packages/backend/src/server/api/endpoints/channels/create.ts
+++ b/packages/backend/src/server/api/endpoints/channels/create.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Channels, DriveFiles } from '@/models/index';
-import { Channel } from '@/models/entities/channel';
-import { genId } from '@/misc/gen-id';
-import { ID } from '@/misc/cafy-id';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Channels, DriveFiles } from '@/models/index.js';
+import { Channel } from '@/models/entities/channel.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['channels'],
@@ -13,20 +11,6 @@ export const meta = {
 
 	kind: 'write:channels',
 
-	params: {
-		name: {
-			validator: $.str.range(1, 128),
-		},
-
-		description: {
-			validator: $.nullable.optional.str.range(1, 2048),
-		},
-
-		bannerId: {
-			validator: $.nullable.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -42,8 +26,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', minLength: 1, maxLength: 128 },
+		description: { type: 'string', nullable: true, minLength: 1, maxLength: 2048 },
+		bannerId: { type: 'string', format: 'misskey:id', nullable: true },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let banner = null;
 	if (ps.bannerId != null) {
 		banner = await DriveFiles.findOne({
diff --git a/packages/backend/src/server/api/endpoints/channels/featured.ts b/packages/backend/src/server/api/endpoints/channels/featured.ts
index ceadde907c..73980c0fad 100644
--- a/packages/backend/src/server/api/endpoints/channels/featured.ts
+++ b/packages/backend/src/server/api/endpoints/channels/featured.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { Channels } from '@/models/index';
+import define from '../../define.js';
+import { Channels } from '@/models/index.js';
 
 export const meta = {
 	tags: ['channels'],
@@ -17,8 +17,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Channels.createQueryBuilder('channel')
 		.where('channel.lastNotedAt IS NOT NULL')
 		.orderBy('channel.lastNotedAt', 'DESC');
diff --git a/packages/backend/src/server/api/endpoints/channels/follow.ts b/packages/backend/src/server/api/endpoints/channels/follow.ts
index bf580eea60..4372c283cb 100644
--- a/packages/backend/src/server/api/endpoints/channels/follow.ts
+++ b/packages/backend/src/server/api/endpoints/channels/follow.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Channels, ChannelFollowings } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Channels, ChannelFollowings } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['channels'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:channels',
 
-	params: {
-		channelId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchChannel: {
 			message: 'No such channel.',
@@ -28,8 +20,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		channelId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['channelId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const channel = await Channels.findOne({
 		id: ps.channelId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/channels/followed.ts b/packages/backend/src/server/api/endpoints/channels/followed.ts
index 9e4c942af2..e4aa4d1614 100644
--- a/packages/backend/src/server/api/endpoints/channels/followed.ts
+++ b/packages/backend/src/server/api/endpoints/channels/followed.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Channels, ChannelFollowings } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Channels, ChannelFollowings } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['channels', 'account'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:channels',
 
-	params: {
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 5,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 5 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(ChannelFollowings.createQueryBuilder(), ps.sinceId, ps.untilId)
 		.andWhere({ followerId: me.id });
 
 	const followings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Promise.all(followings.map(x => Channels.pack(x.followeeId, me)));
diff --git a/packages/backend/src/server/api/endpoints/channels/owned.ts b/packages/backend/src/server/api/endpoints/channels/owned.ts
index 5473636a85..ed7e41cac2 100644
--- a/packages/backend/src/server/api/endpoints/channels/owned.ts
+++ b/packages/backend/src/server/api/endpoints/channels/owned.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Channels } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Channels } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['channels', 'account'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:channels',
 
-	params: {
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 5,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 5 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Channels.createQueryBuilder(), ps.sinceId, ps.untilId)
 		.andWhere({ userId: me.id });
 
 	const channels = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Promise.all(channels.map(x => Channels.pack(x, me)));
diff --git a/packages/backend/src/server/api/endpoints/channels/show.ts b/packages/backend/src/server/api/endpoints/channels/show.ts
index 598a87ec4e..ea4e013073 100644
--- a/packages/backend/src/server/api/endpoints/channels/show.ts
+++ b/packages/backend/src/server/api/endpoints/channels/show.ts
@@ -1,20 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Channels } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Channels } from '@/models/index.js';
 
 export const meta = {
 	tags: ['channels'],
 
 	requireCredential: false,
 
-	params: {
-		channelId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -30,8 +22,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		channelId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['channelId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const channel = await Channels.findOne({
 		id: ps.channelId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/channels/timeline.ts b/packages/backend/src/server/api/endpoints/channels/timeline.ts
index 927ce7c741..57a9fa44b8 100644
--- a/packages/backend/src/server/api/endpoints/channels/timeline.ts
+++ b/packages/backend/src/server/api/endpoints/channels/timeline.ts
@@ -1,43 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Notes, Channels } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { activeUsersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Notes, Channels } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['notes', 'channels'],
 
 	requireCredential: false,
 
-	params: {
-		channelId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -57,8 +28,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		channelId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+	},
+	required: ['channelId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const channel = await Channels.findOne({
 		id: ps.channelId,
 	});
@@ -71,16 +55,22 @@ export default define(meta, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
 		.andWhere('note.channelId = :channelId', { channelId: channel.id })
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.leftJoinAndSelect('note.channel', 'channel');
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
-	if (user) activeUsersChart.update(user);
+	if (user) activeUsersChart.read(user);
 
 	return await Notes.packMany(timeline, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/channels/unfollow.ts b/packages/backend/src/server/api/endpoints/channels/unfollow.ts
index ada0cb29fd..32beb24d6f 100644
--- a/packages/backend/src/server/api/endpoints/channels/unfollow.ts
+++ b/packages/backend/src/server/api/endpoints/channels/unfollow.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Channels, ChannelFollowings } from '@/models/index';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Channels, ChannelFollowings } from '@/models/index.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['channels'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:channels',
 
-	params: {
-		channelId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchChannel: {
 			message: 'No such channel.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		channelId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['channelId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const channel = await Channels.findOne({
 		id: ps.channelId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/channels/update.ts b/packages/backend/src/server/api/endpoints/channels/update.ts
index 1f7108a1cb..2f2b4aeeb2 100644
--- a/packages/backend/src/server/api/endpoints/channels/update.ts
+++ b/packages/backend/src/server/api/endpoints/channels/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Channels, DriveFiles } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Channels, DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['channels'],
@@ -11,24 +9,6 @@ export const meta = {
 
 	kind: 'write:channels',
 
-	params: {
-		channelId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.optional.str.range(1, 128),
-		},
-
-		description: {
-			validator: $.nullable.optional.str.range(1, 2048),
-		},
-
-		bannerId: {
-			validator: $.nullable.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -56,8 +36,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		channelId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', minLength: 1, maxLength: 128 },
+		description: { type: 'string', nullable: true, minLength: 1, maxLength: 2048 },
+		bannerId: { type: 'string', format: 'misskey:id', nullable: true },
+	},
+	required: ['channelId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const channel = await Channels.findOne({
 		id: ps.channelId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/charts/active-users.ts b/packages/backend/src/server/api/endpoints/charts/active-users.ts
index f7eadc7089..97f7885dbe 100644
--- a/packages/backend/src/server/api/endpoints/charts/active-users.ts
+++ b/packages/backend/src/server/api/endpoints/charts/active-users.ts
@@ -1,31 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { activeUsersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { activeUsersChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'users'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
+	res: getJsonSchema(activeUsersChart.schema),
+} as const;
 
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
 	},
-
-	res: convertLog(activeUsersChart.schema),
+	required: ['span'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await activeUsersChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
+export default define(meta, paramDef, async (ps) => {
+	return await activeUsersChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/ap-request.ts b/packages/backend/src/server/api/endpoints/charts/ap-request.ts
new file mode 100644
index 0000000000..4477bfc987
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/charts/ap-request.ts
@@ -0,0 +1,24 @@
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { apRequestChart } from '@/services/chart/index.js';
+
+export const meta = {
+	tags: ['charts'],
+
+	res: getJsonSchema(apRequestChart.schema),
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+	},
+	required: ['span'],
+} as const;
+
+// eslint-disable-next-line import/no-default-export
+export default define(meta, paramDef, async (ps) => {
+	return await apRequestChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
+});
diff --git a/packages/backend/src/server/api/endpoints/charts/drive.ts b/packages/backend/src/server/api/endpoints/charts/drive.ts
index 364279da95..fd6033392f 100644
--- a/packages/backend/src/server/api/endpoints/charts/drive.ts
+++ b/packages/backend/src/server/api/endpoints/charts/drive.ts
@@ -1,31 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { driveChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { driveChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'drive'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
+	res: getJsonSchema(driveChart.schema),
+} as const;
 
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
 	},
-
-	res: convertLog(driveChart.schema),
+	required: ['span'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await driveChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
+export default define(meta, paramDef, async (ps) => {
+	return await driveChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/federation.ts b/packages/backend/src/server/api/endpoints/charts/federation.ts
index 6feb82b6d9..f842f574ec 100644
--- a/packages/backend/src/server/api/endpoints/charts/federation.ts
+++ b/packages/backend/src/server/api/endpoints/charts/federation.ts
@@ -1,31 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { federationChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { federationChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
+	res: getJsonSchema(federationChart.schema),
+} as const;
 
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
 	},
-
-	res: convertLog(federationChart.schema),
+	required: ['span'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await federationChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
+export default define(meta, paramDef, async (ps) => {
+	return await federationChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/hashtag.ts b/packages/backend/src/server/api/endpoints/charts/hashtag.ts
index 99dc77998e..01407defdd 100644
--- a/packages/backend/src/server/api/endpoints/charts/hashtag.ts
+++ b/packages/backend/src/server/api/endpoints/charts/hashtag.ts
@@ -1,35 +1,25 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { hashtagChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { hashtagChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'hashtags'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(hashtagChart.schema),
+} as const;
 
-		tag: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		tag: { type: 'string' },
 	},
-
-	res: convertLog(hashtagChart.schema),
+	required: ['span', 'tag'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await hashtagChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.tag);
+export default define(meta, paramDef, async (ps) => {
+	return await hashtagChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.tag);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/instance.ts b/packages/backend/src/server/api/endpoints/charts/instance.ts
index 23e6fbf2b0..2d12951c6c 100644
--- a/packages/backend/src/server/api/endpoints/charts/instance.ts
+++ b/packages/backend/src/server/api/endpoints/charts/instance.ts
@@ -1,35 +1,25 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { instanceChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { instanceChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(instanceChart.schema),
+} as const;
 
-		host: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		host: { type: 'string' },
 	},
-
-	res: convertLog(instanceChart.schema),
+	required: ['span', 'host'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await instanceChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.host);
+export default define(meta, paramDef, async (ps) => {
+	return await instanceChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.host);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/network.ts b/packages/backend/src/server/api/endpoints/charts/network.ts
deleted file mode 100644
index c5a39bbd76..0000000000
--- a/packages/backend/src/server/api/endpoints/charts/network.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { networkChart } from '@/services/chart/index';
-
-export const meta = {
-	tags: ['charts'],
-
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
-	},
-
-	res: convertLog(networkChart.schema),
-} as const;
-
-// eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await networkChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
-});
diff --git a/packages/backend/src/server/api/endpoints/charts/notes.ts b/packages/backend/src/server/api/endpoints/charts/notes.ts
index dcbd80c3e9..b6089f67ef 100644
--- a/packages/backend/src/server/api/endpoints/charts/notes.ts
+++ b/packages/backend/src/server/api/endpoints/charts/notes.ts
@@ -1,31 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { notesChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { notesChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'notes'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
+	res: getJsonSchema(notesChart.schema),
+} as const;
 
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
 	},
-
-	res: convertLog(notesChart.schema),
+	required: ['span'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await notesChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
+export default define(meta, paramDef, async (ps) => {
+	return await notesChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/user/drive.ts b/packages/backend/src/server/api/endpoints/charts/user/drive.ts
index 94787b4a57..e5db7131a8 100644
--- a/packages/backend/src/server/api/endpoints/charts/user/drive.ts
+++ b/packages/backend/src/server/api/endpoints/charts/user/drive.ts
@@ -1,36 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { convertLog } from '@/services/chart/core';
-import { perUserDriveChart } from '@/services/chart/index';
+import define from '../../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { perUserDriveChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'drive', 'users'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(perUserDriveChart.schema),
+} as const;
 
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		userId: { type: 'string', format: 'misskey:id' },
 	},
-
-	res: convertLog(perUserDriveChart.schema),
+	required: ['span', 'userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await perUserDriveChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.userId);
+export default define(meta, paramDef, async (ps) => {
+	return await perUserDriveChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.userId);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/user/following.ts b/packages/backend/src/server/api/endpoints/charts/user/following.ts
index effe0c54b9..9b72de745d 100644
--- a/packages/backend/src/server/api/endpoints/charts/user/following.ts
+++ b/packages/backend/src/server/api/endpoints/charts/user/following.ts
@@ -1,36 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { convertLog } from '@/services/chart/core';
-import { perUserFollowingChart } from '@/services/chart/index';
+import define from '../../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { perUserFollowingChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'users', 'following'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(perUserFollowingChart.schema),
+} as const;
 
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		userId: { type: 'string', format: 'misskey:id' },
 	},
-
-	res: convertLog(perUserFollowingChart.schema),
+	required: ['span', 'userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await perUserFollowingChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.userId);
+export default define(meta, paramDef, async (ps) => {
+	return await perUserFollowingChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.userId);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/user/notes.ts b/packages/backend/src/server/api/endpoints/charts/user/notes.ts
index df68a5fe52..7cc6cbf316 100644
--- a/packages/backend/src/server/api/endpoints/charts/user/notes.ts
+++ b/packages/backend/src/server/api/endpoints/charts/user/notes.ts
@@ -1,36 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { convertLog } from '@/services/chart/core';
-import { perUserNotesChart } from '@/services/chart/index';
+import define from '../../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { perUserNotesChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'users', 'notes'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(perUserNotesChart.schema),
+} as const;
 
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		userId: { type: 'string', format: 'misskey:id' },
 	},
-
-	res: convertLog(perUserNotesChart.schema),
+	required: ['span', 'userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await perUserNotesChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.userId);
+export default define(meta, paramDef, async (ps) => {
+	return await perUserNotesChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.userId);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/user/reactions.ts b/packages/backend/src/server/api/endpoints/charts/user/reactions.ts
index dcd067305f..5c58a7f152 100644
--- a/packages/backend/src/server/api/endpoints/charts/user/reactions.ts
+++ b/packages/backend/src/server/api/endpoints/charts/user/reactions.ts
@@ -1,36 +1,25 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ID } from '@/misc/cafy-id';
-import { convertLog } from '@/services/chart/core';
-import { perUserReactionsChart } from '@/services/chart/index';
+import define from '../../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { perUserReactionsChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'users', 'reactions'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+	res: getJsonSchema(perUserReactionsChart.schema),
+} as const;
 
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
+		userId: { type: 'string', format: 'misskey:id' },
 	},
-
-	res: convertLog(perUserReactionsChart.schema),
+	required: ['span', 'userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await perUserReactionsChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null, ps.userId);
+export default define(meta, paramDef, async (ps) => {
+	return await perUserReactionsChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null, ps.userId);
 });
diff --git a/packages/backend/src/server/api/endpoints/charts/users.ts b/packages/backend/src/server/api/endpoints/charts/users.ts
index d32e14ad61..49c762b2e4 100644
--- a/packages/backend/src/server/api/endpoints/charts/users.ts
+++ b/packages/backend/src/server/api/endpoints/charts/users.ts
@@ -1,31 +1,24 @@
-import $ from 'cafy';
-import define from '../../define';
-import { convertLog } from '@/services/chart/core';
-import { usersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { getJsonSchema } from '@/services/chart/core.js';
+import { usersChart } from '@/services/chart/index.js';
 
 export const meta = {
 	tags: ['charts', 'users'],
 
-	params: {
-		span: {
-			validator: $.str.or(['day', 'hour']),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 500),
-			default: 30,
-		},
+	res: getJsonSchema(usersChart.schema),
+} as const;
 
-		offset: {
-			validator: $.optional.nullable.num,
-			default: null,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		span: { type: 'string', enum: ['day', 'hour'] },
+		limit: { type: 'integer', minimum: 1, maximum: 500, default: 30 },
+		offset: { type: 'integer', nullable: true, default: null },
 	},
-
-	res: convertLog(usersChart.schema),
+	required: ['span'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
-	return await usersChart.getChart(ps.span as any, ps.limit!, ps.offset ? new Date(ps.offset) : null);
+export default define(meta, paramDef, async (ps) => {
+	return await usersChart.getChart(ps.span, ps.limit, ps.offset ? new Date(ps.offset) : null);
 });
diff --git a/packages/backend/src/server/api/endpoints/clips/add-note.ts b/packages/backend/src/server/api/endpoints/clips/add-note.ts
index 4a740b6cfe..c630302b98 100644
--- a/packages/backend/src/server/api/endpoints/clips/add-note.ts
+++ b/packages/backend/src/server/api/endpoints/clips/add-note.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ClipNotes, Clips } from '@/models/index';
-import { ApiError } from '../../error';
-import { genId } from '@/misc/gen-id';
-import { getNote } from '../../common/getters';
+import define from '../../define.js';
+import { ClipNotes, Clips } from '@/models/index.js';
+import { ApiError } from '../../error.js';
+import { genId } from '@/misc/gen-id.js';
+import { getNote } from '../../common/getters.js';
 
 export const meta = {
 	tags: ['account', 'notes', 'clips'],
@@ -13,16 +11,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		clipId: {
-			validator: $.type(ID),
-		},
-
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchClip: {
 			message: 'No such clip.',
@@ -44,8 +32,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clipId: { type: 'string', format: 'misskey:id' },
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['clipId', 'noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const clip = await Clips.findOne({
 		id: ps.clipId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/clips/create.ts b/packages/backend/src/server/api/endpoints/clips/create.ts
index 852e66c9e4..531847d15c 100644
--- a/packages/backend/src/server/api/endpoints/clips/create.ts
+++ b/packages/backend/src/server/api/endpoints/clips/create.ts
@@ -1,7 +1,6 @@
-import $ from 'cafy';
-import define from '../../define';
-import { genId } from '@/misc/gen-id';
-import { Clips } from '@/models/index';
+import define from '../../define.js';
+import { genId } from '@/misc/gen-id.js';
+import { Clips } from '@/models/index.js';
 
 export const meta = {
 	tags: ['clips'],
@@ -10,20 +9,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		name: {
-			validator: $.str.range(1, 100),
-		},
-
-		isPublic: {
-			validator: $.optional.bool,
-		},
-
-		description: {
-			validator: $.optional.nullable.str.range(1, 2048),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -31,8 +16,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+		isPublic: { type: 'boolean' },
+		description: { type: 'string', nullable: true, minLength: 1, maxLength: 2048 },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const clip = await Clips.insert({
 		id: genId(),
 		createdAt: new Date(),
diff --git a/packages/backend/src/server/api/endpoints/clips/delete.ts b/packages/backend/src/server/api/endpoints/clips/delete.ts
index 85c64a115d..675db1d57f 100644
--- a/packages/backend/src/server/api/endpoints/clips/delete.ts
+++ b/packages/backend/src/server/api/endpoints/clips/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Clips } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Clips } from '@/models/index.js';
 
 export const meta = {
 	tags: ['clips'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		clipId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchClip: {
 			message: 'No such clip.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clipId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['clipId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const clip = await Clips.findOne({
 		id: ps.clipId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/clips/list.ts b/packages/backend/src/server/api/endpoints/clips/list.ts
index d88897d164..1c955d64fc 100644
--- a/packages/backend/src/server/api/endpoints/clips/list.ts
+++ b/packages/backend/src/server/api/endpoints/clips/list.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { Clips } from '@/models/index';
+import define from '../../define.js';
+import { Clips } from '@/models/index.js';
 
 export const meta = {
 	tags: ['clips', 'account'],
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const clips = await Clips.find({
 		userId: me.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/clips/notes.ts b/packages/backend/src/server/api/endpoints/clips/notes.ts
index eeb20631c1..2627884ee1 100644
--- a/packages/backend/src/server/api/endpoints/clips/notes.ts
+++ b/packages/backend/src/server/api/endpoints/clips/notes.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ClipNotes, Clips, Notes } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { ApiError } from '../../error';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { ClipNotes, Clips, Notes } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { ApiError } from '../../error.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['account', 'notes', 'clips'],
@@ -15,25 +13,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		clipId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchClip: {
 			message: 'No such clip.',
@@ -53,8 +32,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clipId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['clipId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const clip = await Clips.findOne({
 		id: ps.clipId,
 	});
@@ -74,10 +64,16 @@ export default define(meta, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere(`note.id IN (${ clipQuery.getQuery() })`)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.setParameters(clipQuery.getParameters());
 
 	if (user) {
@@ -87,7 +83,7 @@ export default define(meta, async (ps, user) => {
 	}
 
 	const notes = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Notes.packMany(notes, user);
diff --git a/packages/backend/src/server/api/endpoints/clips/show.ts b/packages/backend/src/server/api/endpoints/clips/show.ts
index 0a45672019..0a3b25c94e 100644
--- a/packages/backend/src/server/api/endpoints/clips/show.ts
+++ b/packages/backend/src/server/api/endpoints/clips/show.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Clips } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Clips } from '@/models/index.js';
 
 export const meta = {
 	tags: ['clips', 'account'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		clipId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchClip: {
 			message: 'No such clip.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clipId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['clipId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the clip
 	const clip = await Clips.findOne({
 		id: ps.clipId,
diff --git a/packages/backend/src/server/api/endpoints/clips/update.ts b/packages/backend/src/server/api/endpoints/clips/update.ts
index 795483d5b2..0ac5ccd047 100644
--- a/packages/backend/src/server/api/endpoints/clips/update.ts
+++ b/packages/backend/src/server/api/endpoints/clips/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Clips } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Clips } from '@/models/index.js';
 
 export const meta = {
 	tags: ['clips'],
@@ -11,24 +9,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		clipId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.str.range(1, 100),
-		},
-
-		isPublic: {
-			validator: $.optional.bool,
-		},
-
-		description: {
-			validator: $.optional.nullable.str.range(1, 2048),
-		},
-	},
-
 	errors: {
 		noSuchClip: {
 			message: 'No such clip.',
@@ -44,8 +24,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clipId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+		isPublic: { type: 'boolean' },
+		description: { type: 'string', nullable: true, minLength: 1, maxLength: 2048 },
+	},
+	required: ['clipId', 'name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch the clip
 	const clip = await Clips.findOne({
 		id: ps.clipId,
diff --git a/packages/backend/src/server/api/endpoints/drive.ts b/packages/backend/src/server/api/endpoints/drive.ts
index d9ab9883ca..c599d96ca4 100644
--- a/packages/backend/src/server/api/endpoints/drive.ts
+++ b/packages/backend/src/server/api/endpoints/drive.ts
@@ -1,6 +1,6 @@
-import define from '../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { DriveFiles } from '@/models/index';
+import define from '../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive', 'account'],
@@ -25,8 +25,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const instance = await fetchMeta(true);
 
 	// Calculate drive usage
diff --git a/packages/backend/src/server/api/endpoints/drive/files.ts b/packages/backend/src/server/api/endpoints/drive/files.ts
index a5c0a626a1..40e6c16c9c 100644
--- a/packages/backend/src/server/api/endpoints/drive/files.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { DriveFiles } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { DriveFiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -11,30 +9,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-
-		type: {
-			validator: $.optional.nullable.str.match(/^[a-zA-Z\/\-*]+$/),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -46,8 +20,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+		type: { type: 'string', nullable: true, pattern: /^[a-zA-Z\/\-*]+$/.toString().slice(1, -1) },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(DriveFiles.createQueryBuilder('file'), ps.sinceId, ps.untilId)
 		.andWhere('file.userId = :userId', { userId: user.id });
 
@@ -65,7 +51,7 @@ export default define(meta, async (ps, user) => {
 		}
 	}
 
-	const files = await query.take(ps.limit!).getMany();
+	const files = await query.take(ps.limit).getMany();
 
 	return await DriveFiles.packMany(files, { detail: false, self: true });
 });
diff --git a/packages/backend/src/server/api/endpoints/drive/files/attached-notes.ts b/packages/backend/src/server/api/endpoints/drive/files/attached-notes.ts
index 835dde8058..3c68beee17 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/attached-notes.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/attached-notes.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFiles, Notes } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFiles, Notes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive', 'notes'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -36,8 +28,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch file
 	const file = await DriveFiles.findOne({
 		id: ps.fileId,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/check-existence.ts b/packages/backend/src/server/api/endpoints/drive/files/check-existence.ts
index a45d357ee8..7e5cb2498e 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/check-existence.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/check-existence.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -9,20 +8,22 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		md5: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'boolean',
 		optional: false, nullable: false,
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		md5: { type: 'string' },
+	},
+	required: ['md5'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne({
 		md5: ps.md5,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/create.ts b/packages/backend/src/server/api/endpoints/drive/files/create.ts
index dd65ab0611..b6a2cf7200 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/create.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/create.ts
@@ -1,12 +1,10 @@
 import ms from 'ms';
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { addFile } from '@/services/drive/add-file';
-import define from '../../../define';
-import { apiLogger } from '../../../logger';
-import { ApiError } from '../../../error';
-import { DriveFiles } from '@/models/index';
-import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits';
+import { addFile } from '@/services/drive/add-file.js';
+import define from '../../../define.js';
+import { apiLogger } from '../../../logger.js';
+import { ApiError } from '../../../error.js';
+import { DriveFiles } from '@/models/index.js';
+import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -22,35 +20,6 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-
-		name: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		comment: {
-			validator: $.optional.nullable.str.max(DB_MAX_IMAGE_COMMENT_LENGTH),
-			default: null,
-		},
-
-		isSensitive: {
-			validator: $.optional.either($.bool, $.str),
-			default: false,
-			transform: (v: any): boolean => v === true || v === 'true',
-		},
-
-		force: {
-			validator: $.optional.either($.bool, $.str),
-			default: false,
-			transform: (v: any): boolean => v === true || v === 'true',
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -66,8 +35,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+		name: { type: 'string', nullable: true, default: null },
+		comment: { type: 'string', nullable: true, maxLength: DB_MAX_IMAGE_COMMENT_LENGTH, default: null },
+		isSensitive: { type: 'boolean', default: false },
+		force: { type: 'boolean', default: false },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user, _, file, cleanup) => {
+// @ts-ignore
+export default define(meta, paramDef, async (ps, user, _, file, cleanup) => {
 	// Get 'name' parameter
 	let name = ps.name || file.originalname;
 	if (name !== undefined && name !== null) {
@@ -88,7 +70,9 @@ export default define(meta, async (ps, user, _, file, cleanup) => {
 		const driveFile = await addFile({ user, path: file.path, name, comment: ps.comment, folderId: ps.folderId, force: ps.force, sensitive: ps.isSensitive });
 		return await DriveFiles.pack(driveFile, { self: true });
 	} catch (e) {
-		apiLogger.error(e);
+		if (e instanceof Error || typeof e === 'string') {
+			apiLogger.error(e);
+		}
 		throw new ApiError();
 	} finally {
 		cleanup!();
diff --git a/packages/backend/src/server/api/endpoints/drive/files/delete.ts b/packages/backend/src/server/api/endpoints/drive/files/delete.ts
index 308beb58a4..5f565a63fb 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/delete.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/delete.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { deleteFile } from '@/services/drive/delete-file';
-import { publishDriveStream } from '@/services/stream';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFiles } from '@/models/index';
+import { deleteFile } from '@/services/drive/delete-file.js';
+import { publishDriveStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -34,8 +26,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) {
diff --git a/packages/backend/src/server/api/endpoints/drive/files/find-by-hash.ts b/packages/backend/src/server/api/endpoints/drive/files/find-by-hash.ts
index dc74dcb7e6..e45ec633d3 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/find-by-hash.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/find-by-hash.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -9,12 +8,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		md5: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -26,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		md5: { type: 'string' },
+	},
+	required: ['md5'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const files = await DriveFiles.find({
 		md5: ps.md5,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/find.ts b/packages/backend/src/server/api/endpoints/drive/files/find.ts
index 2244df13cd..974fc9fbad 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/find.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/find.ts
@@ -1,7 +1,5 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
@@ -10,17 +8,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		name: {
-			validator: $.str,
-		},
-
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -32,8 +19,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string' },
+		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const files = await DriveFiles.find({
 		name: ps.name,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/show.ts b/packages/backend/src/server/api/endpoints/drive/files/show.ts
index 18b17c4653..181365c7e6 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/show.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/show.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFile } from '@/models/entities/drive-file';
-import { DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFile } from '@/models/entities/drive-file.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -12,16 +10,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		fileId: {
-			validator: $.optional.type(ID),
-		},
-
-		url: {
-			validator: $.optional.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -49,8 +37,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+		url: { type: 'string' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let file: DriveFile | undefined;
 
 	if (ps.fileId) {
diff --git a/packages/backend/src/server/api/endpoints/drive/files/update.ts b/packages/backend/src/server/api/endpoints/drive/files/update.ts
index b7ca80e83c..ab8e4aeeb2 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/update.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/update.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishDriveStream } from '@/services/stream';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFiles, DriveFolders } from '@/models/index';
-import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits';
+import { publishDriveStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFiles, DriveFolders } from '@/models/index.js';
+import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -13,33 +11,13 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: undefined as any,
-		},
-
-		name: {
-			validator: $.optional.str.pipe(DriveFiles.validateFileName),
-			default: undefined as any,
-		},
-
-		isSensitive: {
-			validator: $.optional.bool,
-			default: undefined as any,
-		},
-
-		comment: {
-			validator: $.optional.nullable.str.max(DB_MAX_IMAGE_COMMENT_LENGTH),
-			default: undefined as any,
+	errors: {
+		invalidFileName: {
+			message: 'Invalid file name.',
+			code: 'INVALID_FILE_NAME',
+			id: '395e7156-f9f0-475e-af89-53c3c23080c2',
 		},
-	},
 
-	errors: {
 		noSuchFile: {
 			message: 'No such file.',
 			code: 'NO_SUCH_FILE',
@@ -66,8 +44,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+		folderId: { type: 'string', format: 'misskey:id', nullable: true },
+		name: { type: 'string' },
+		isSensitive: { type: 'boolean' },
+		comment: { type: 'string', nullable: true, maxLength: 512 },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) {
@@ -79,6 +69,9 @@ export default define(meta, async (ps, user) => {
 	}
 
 	if (ps.name) file.name = ps.name;
+	if (!DriveFiles.validateFileName(file.name)) {
+		throw new ApiError(meta.errors.invalidFileName);
+	}
 
 	if (ps.comment !== undefined) file.comment = ps.comment;
 
diff --git a/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts b/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
index 40da1a4fb4..3bfecac802 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import ms from 'ms';
-import { uploadFromUrl } from '@/services/drive/upload-from-url';
-import define from '../../../define';
-import { DriveFiles } from '@/models/index';
-import { publishMainStream } from '@/services/stream';
-import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits';
+import { uploadFromUrl } from '@/services/drive/upload-from-url.js';
+import define from '../../../define.js';
+import { DriveFiles } from '@/models/index.js';
+import { publishMainStream } from '@/services/stream.js';
+import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/misc/hard-limits.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -18,42 +16,23 @@ export const meta = {
 	requireCredential: true,
 
 	kind: 'write:drive',
+} as const;
 
-	params: {
-		url: {
-			// TODO: Validate this url
-			validator: $.str,
-		},
-
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-
-		isSensitive: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		comment: {
-			validator: $.optional.nullable.str.max(DB_MAX_IMAGE_COMMENT_LENGTH),
-			default: null,
-		},
-
-		marker: {
-			validator: $.optional.nullable.str,
-			default: null,
-		},
-
-		force: {
-			validator: $.optional.bool,
-			default: false,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		url: { type: 'string' },
+		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+		isSensitive: { type: 'boolean', default: false },
+		comment: { type: 'string', nullable: true, maxLength: 512, default: null },
+		marker: { type: 'string', nullable: true, default: null },
+		force: { type: 'boolean', default: false },
 	},
+	required: ['url'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	uploadFromUrl({ url: ps.url, user, folderId: ps.folderId, sensitive: ps.isSensitive, force: ps.force, comment: ps.comment }).then(file => {
 		DriveFiles.pack(file, { self: true }).then(packedFile => {
 			publishMainStream(user.id, 'urlUploadFinished', {
diff --git a/packages/backend/src/server/api/endpoints/drive/folders.ts b/packages/backend/src/server/api/endpoints/drive/folders.ts
index 8f8d1d2c0a..d4d530ba9e 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { DriveFolders } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { DriveFolders } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -11,26 +9,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		folderId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -42,8 +20,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(DriveFolders.createQueryBuilder('folder'), ps.sinceId, ps.untilId)
 		.andWhere('folder.userId = :userId', { userId: user.id });
 
@@ -53,7 +42,7 @@ export default define(meta, async (ps, user) => {
 		query.andWhere('folder.parentId IS NULL');
 	}
 
-	const folders = await query.take(ps.limit!).getMany();
+	const folders = await query.take(ps.limit).getMany();
 
 	return await Promise.all(folders.map(folder => DriveFolders.pack(folder)));
 });
diff --git a/packages/backend/src/server/api/endpoints/drive/folders/create.ts b/packages/backend/src/server/api/endpoints/drive/folders/create.ts
index 38ed17e0e5..4ae10f0621 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders/create.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders/create.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishDriveStream } from '@/services/stream';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFolders } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import { publishDriveStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFolders } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -13,17 +11,6 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		name: {
-			validator: $.optional.str.pipe(DriveFolders.validateFolderName),
-			default: 'Untitled',
-		},
-
-		parentId: {
-			validator: $.optional.nullable.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFolder: {
 			message: 'No such folder.',
@@ -39,8 +26,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', default: "Untitled", maxLength: 200 },
+		parentId: { type: 'string', format: 'misskey:id', nullable: true },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// If the parent folder is specified
 	let parent = null;
 	if (ps.parentId) {
diff --git a/packages/backend/src/server/api/endpoints/drive/folders/delete.ts b/packages/backend/src/server/api/endpoints/drive/folders/delete.ts
index 13716fccea..4994615cc6 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders/delete.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders/delete.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { publishDriveStream } from '@/services/stream';
-import { ApiError } from '../../../error';
-import { DriveFolders, DriveFiles } from '@/models/index';
+import define from '../../../define.js';
+import { publishDriveStream } from '@/services/stream.js';
+import { ApiError } from '../../../error.js';
+import { DriveFolders, DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		folderId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFolder: {
 			message: 'No such folder.',
@@ -33,8 +25,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		folderId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['folderId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Get folder
 	const folder = await DriveFolders.findOne({
 		id: ps.folderId,
diff --git a/packages/backend/src/server/api/endpoints/drive/folders/find.ts b/packages/backend/src/server/api/endpoints/drive/folders/find.ts
index 911f51d78b..9bf0e3d61b 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders/find.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders/find.ts
@@ -1,7 +1,5 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { DriveFolders } from '@/models/index';
+import define from '../../../define.js';
+import { DriveFolders } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -10,17 +8,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		name: {
-			validator: $.str,
-		},
-
-		parentId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -32,8 +19,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string' },
+		parentId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const folders = await DriveFolders.find({
 		name: ps.name,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/drive/folders/show.ts b/packages/backend/src/server/api/endpoints/drive/folders/show.ts
index 58a6dd3c06..f09816d57a 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders/show.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders/show.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFolders } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFolders } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		folderId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		folderId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['folderId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Get folder
 	const folder = await DriveFolders.findOne({
 		id: ps.folderId,
diff --git a/packages/backend/src/server/api/endpoints/drive/folders/update.ts b/packages/backend/src/server/api/endpoints/drive/folders/update.ts
index 5b0cccd1c6..c020b243ef 100644
--- a/packages/backend/src/server/api/endpoints/drive/folders/update.ts
+++ b/packages/backend/src/server/api/endpoints/drive/folders/update.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishDriveStream } from '@/services/stream';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { DriveFolders } from '@/models/index';
+import { publishDriveStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { DriveFolders } from '@/models/index.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -12,20 +10,6 @@ export const meta = {
 
 	kind: 'write:drive',
 
-	params: {
-		folderId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.optional.str.pipe(DriveFolders.validateFolderName),
-		},
-
-		parentId: {
-			validator: $.optional.nullable.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFolder: {
 			message: 'No such folder.',
@@ -53,8 +37,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		folderId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', maxLength: 200 },
+		parentId: { type: 'string', format: 'misskey:id', nullable: true },
+	},
+	required: ['folderId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch folder
 	const folder = await DriveFolders.findOne({
 		id: ps.folderId,
diff --git a/packages/backend/src/server/api/endpoints/drive/stream.ts b/packages/backend/src/server/api/endpoints/drive/stream.ts
index 9ba7804946..99e8d024fb 100644
--- a/packages/backend/src/server/api/endpoints/drive/stream.ts
+++ b/packages/backend/src/server/api/endpoints/drive/stream.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { DriveFiles } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { DriveFiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['drive'],
@@ -11,25 +9,6 @@ export const meta = {
 
 	kind: 'read:drive',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		type: {
-			validator: $.optional.str.match(/^[a-zA-Z\/\-*]+$/),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -41,8 +20,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		type: { type: 'string', pattern: /^[a-zA-Z\/\-*]+$/.toString().slice(1, -1) },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(DriveFiles.createQueryBuilder('file'), ps.sinceId, ps.untilId)
 		.andWhere('file.userId = :userId', { userId: user.id });
 
@@ -54,7 +44,7 @@ export default define(meta, async (ps, user) => {
 		}
 	}
 
-	const files = await query.take(ps.limit!).getMany();
+	const files = await query.take(ps.limit).getMany();
 
 	return await DriveFiles.packMany(files, { detail: false, self: true });
 });
diff --git a/packages/backend/src/server/api/endpoints/email-address/available.ts b/packages/backend/src/server/api/endpoints/email-address/available.ts
index 19f9b7ccdc..07064ce9fa 100644
--- a/packages/backend/src/server/api/endpoints/email-address/available.ts
+++ b/packages/backend/src/server/api/endpoints/email-address/available.ts
@@ -1,18 +1,11 @@
-import $ from 'cafy';
-import define from '../../define';
-import { validateEmailForAccount } from '@/services/validate-email-for-account';
+import define from '../../define.js';
+import { validateEmailForAccount } from '@/services/validate-email-for-account.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		emailAddress: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -29,7 +22,15 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		emailAddress: { type: 'string' },
+	},
+	required: ['emailAddress'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	return await validateEmailForAccount(ps.emailAddress);
 });
diff --git a/packages/backend/src/server/api/endpoints/endpoint.ts b/packages/backend/src/server/api/endpoints/endpoint.ts
index 42fd468838..9db140183c 100644
--- a/packages/backend/src/server/api/endpoints/endpoint.ts
+++ b/packages/backend/src/server/api/endpoints/endpoint.ts
@@ -1,21 +1,22 @@
-import $ from 'cafy';
-import define from '../define';
-import endpoints from '../endpoints';
+import define from '../define.js';
+import endpoints from '../endpoints.js';
 
 export const meta = {
 	requireCredential: false,
 
 	tags: ['meta'],
+} as const;
 
-	params: {
-		endpoint: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		endpoint: { type: 'string' },
 	},
+	required: ['endpoint'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const ep = endpoints.find(x => x.name === ps.endpoint);
 	if (ep == null) return null;
 	return {
diff --git a/packages/backend/src/server/api/endpoints/endpoints.ts b/packages/backend/src/server/api/endpoints/endpoints.ts
index ebb78de337..b20da96eb3 100644
--- a/packages/backend/src/server/api/endpoints/endpoints.ts
+++ b/packages/backend/src/server/api/endpoints/endpoints.ts
@@ -1,14 +1,11 @@
-import define from '../define';
-import endpoints from '../endpoints';
+import define from '../define.js';
+import endpoints from '../endpoints.js';
 
 export const meta = {
 	requireCredential: false,
 
 	tags: ['meta'],
 
-	params: {
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -25,7 +22,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	return endpoints.map(x => x.name);
 });
diff --git a/packages/backend/src/server/api/endpoints/export-custom-emojis.ts b/packages/backend/src/server/api/endpoints/export-custom-emojis.ts
index 24c9f56aa6..bc8d2e2ac0 100644
--- a/packages/backend/src/server/api/endpoints/export-custom-emojis.ts
+++ b/packages/backend/src/server/api/endpoints/export-custom-emojis.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../define';
-import { createExportCustomEmojisJob } from '@/queue/index';
+import define from '../define.js';
+import { createExportCustomEmojisJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -12,7 +11,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportCustomEmojisJob(user);
 });
diff --git a/packages/backend/src/server/api/endpoints/federation/followers.ts b/packages/backend/src/server/api/endpoints/federation/followers.ts
index c0a85f166c..7b1197d1e5 100644
--- a/packages/backend/src/server/api/endpoints/federation/followers.ts
+++ b/packages/backend/src/server/api/endpoints/federation/followers.ts
@@ -1,33 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Followings } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Followings } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
-	params: {
-		host: {
-			validator: $.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -39,13 +18,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: ['host'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Followings.createQueryBuilder('following'), ps.sinceId, ps.untilId)
 		.andWhere(`following.followeeHost = :host`, { host: ps.host });
 
 	const followings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Followings.packMany(followings, me, { populateFollowee: true });
diff --git a/packages/backend/src/server/api/endpoints/federation/following.ts b/packages/backend/src/server/api/endpoints/federation/following.ts
index 147f0aedb2..ed1f142d88 100644
--- a/packages/backend/src/server/api/endpoints/federation/following.ts
+++ b/packages/backend/src/server/api/endpoints/federation/following.ts
@@ -1,33 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Followings } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Followings } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
-	params: {
-		host: {
-			validator: $.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -39,13 +18,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: ['host'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Followings.createQueryBuilder('following'), ps.sinceId, ps.untilId)
 		.andWhere(`following.followerHost = :host`, { host: ps.host });
 
 	const followings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Followings.packMany(followings, me, { populateFollowee: true });
diff --git a/packages/backend/src/server/api/endpoints/federation/instances.ts b/packages/backend/src/server/api/endpoints/federation/instances.ts
index 11df7ed6b6..70fef051ba 100644
--- a/packages/backend/src/server/api/endpoints/federation/instances.ts
+++ b/packages/backend/src/server/api/endpoints/federation/instances.ts
@@ -1,58 +1,13 @@
-import $ from 'cafy';
-import config from '@/config/index';
-import define from '../../define';
-import { Instances } from '@/models/index';
-import { fetchMeta } from '@/misc/fetch-meta';
+import config from '@/config/index.js';
+import define from '../../define.js';
+import { Instances } from '@/models/index.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
-	params: {
-		host: {
-			validator: $.optional.nullable.str,
-		},
-
-		blocked: {
-			validator: $.optional.nullable.bool,
-		},
-
-		notResponding: {
-			validator: $.optional.nullable.bool,
-		},
-
-		suspended: {
-			validator: $.optional.nullable.bool,
-		},
-
-		federating: {
-			validator: $.optional.nullable.bool,
-		},
-
-		subscribing: {
-			validator: $.optional.nullable.bool,
-		},
-
-		publishing: {
-			validator: $.optional.nullable.bool,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 30,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-
-		sort: {
-			validator: $.optional.str,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -64,8 +19,25 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string', nullable: true },
+		blocked: { type: 'boolean', nullable: true },
+		notResponding: { type: 'boolean', nullable: true },
+		suspended: { type: 'boolean', nullable: true },
+		federating: { type: 'boolean', nullable: true },
+		subscribing: { type: 'boolean', nullable: true },
+		publishing: { type: 'boolean', nullable: true },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 30 },
+		offset: { type: 'integer', default: 0 },
+		sort: { type: 'string' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Instances.createQueryBuilder('instance');
 
 	switch (ps.sort) {
@@ -144,7 +116,7 @@ export default define(meta, async (ps, me) => {
 		query.andWhere('instance.host like :host', { host: '%' + ps.host.toLowerCase() + '%' });
 	}
 
-	const instances = await query.take(ps.limit!).skip(ps.offset).getMany();
+	const instances = await query.take(ps.limit).skip(ps.offset).getMany();
 
-	return instances;
+	return await Instances.packMany(instances);
 });
diff --git a/packages/backend/src/server/api/endpoints/federation/show-instance.ts b/packages/backend/src/server/api/endpoints/federation/show-instance.ts
index 6f13b28cae..5bfe43fc9c 100644
--- a/packages/backend/src/server/api/endpoints/federation/show-instance.ts
+++ b/packages/backend/src/server/api/endpoints/federation/show-instance.ts
@@ -1,30 +1,34 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Instances } from '@/models/index';
-import { toPuny } from '@/misc/convert-host';
+import define from '../../define.js';
+import { Instances } from '@/models/index.js';
+import { toPuny } from '@/misc/convert-host.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
-	params: {
-		host: {
-			validator: $.str,
-		},
+	res: {
+		oneOf: [{
+			type: 'object',
+			ref: 'FederationInstance',
+		}, {
+			type: 'null',
+		}],
 	},
+} as const;
 
-	res: {
-		type: 'object',
-		optional: true, nullable: false,
-		ref: 'FederationInstance',
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
 	},
+	required: ['host'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const instance = await Instances
 		.findOne({ host: toPuny(ps.host) });
 
-	return instance;
+	return instance ? await Instances.pack(instance) : null;
 });
diff --git a/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts b/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
index 092f805bc2..409cc7695e 100644
--- a/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
+++ b/packages/backend/src/server/api/endpoints/federation/update-remote-user.ts
@@ -1,23 +1,23 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { getRemoteUser } from '../../common/getters';
-import { updatePerson } from '@/remote/activitypub/models/person';
+import define from '../../define.js';
+import { getRemoteUser } from '../../common/getters.js';
+import { updatePerson } from '@/remote/activitypub/models/person.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: true,
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const user = await getRemoteUser(ps.userId);
 	await updatePerson(user.uri!);
 });
diff --git a/packages/backend/src/server/api/endpoints/federation/users.ts b/packages/backend/src/server/api/endpoints/federation/users.ts
index 9a8f749936..65ad9f88d3 100644
--- a/packages/backend/src/server/api/endpoints/federation/users.ts
+++ b/packages/backend/src/server/api/endpoints/federation/users.ts
@@ -1,33 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Users } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['federation'],
 
 	requireCredential: false,
 
-	params: {
-		host: {
-			validator: $.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -39,13 +18,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		host: { type: 'string' },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: ['host'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Users.createQueryBuilder('user'), ps.sinceId, ps.untilId)
 		.andWhere(`user.host = :host`, { host: ps.host });
 
 	const users = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Users.packMany(users, me, { detail: true });
diff --git a/packages/backend/src/server/api/endpoints/following/create.ts b/packages/backend/src/server/api/endpoints/following/create.ts
index 96aede4550..8758a64a39 100644
--- a/packages/backend/src/server/api/endpoints/following/create.ts
+++ b/packages/backend/src/server/api/endpoints/following/create.ts
@@ -1,11 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import ms from 'ms';
-import create from '@/services/following/create';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Followings, Users } from '@/models/index';
+import create from '@/services/following/create.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Followings, Users } from '@/models/index.js';
+import { IdentifiableError } from '@/misc/identifiable-error.js';
 
 export const meta = {
 	tags: ['following', 'users'],
@@ -19,12 +18,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -64,8 +57,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const follower = user;
 
 	// 自分自身
@@ -92,8 +93,10 @@ export default define(meta, async (ps, user) => {
 	try {
 		await create(follower, followee);
 	} catch (e) {
-		if (e.id === '710e8fb0-b8c3-4922-be49-d5d93d8e6a6e') throw new ApiError(meta.errors.blocking);
-		if (e.id === '3338392a-f764-498d-8855-db939dcf8c48') throw new ApiError(meta.errors.blocked);
+		if (e instanceof IdentifiableError) {
+			if (e.id === '710e8fb0-b8c3-4922-be49-d5d93d8e6a6e') throw new ApiError(meta.errors.blocking);
+			if (e.id === '3338392a-f764-498d-8855-db939dcf8c48') throw new ApiError(meta.errors.blocked);
+		}
 		throw e;
 	}
 
diff --git a/packages/backend/src/server/api/endpoints/following/delete.ts b/packages/backend/src/server/api/endpoints/following/delete.ts
index 4cd0c49452..47efc59b81 100644
--- a/packages/backend/src/server/api/endpoints/following/delete.ts
+++ b/packages/backend/src/server/api/endpoints/following/delete.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import ms from 'ms';
-import deleteFollowing from '@/services/following/delete';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Followings, Users } from '@/models/index';
+import deleteFollowing from '@/services/following/delete.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Followings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['following', 'users'],
@@ -19,12 +17,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -52,8 +44,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const follower = user;
 
 	// Check if the followee is yourself
diff --git a/packages/backend/src/server/api/endpoints/following/invalidate.ts b/packages/backend/src/server/api/endpoints/following/invalidate.ts
index 92e887e00b..24d8256ca6 100644
--- a/packages/backend/src/server/api/endpoints/following/invalidate.ts
+++ b/packages/backend/src/server/api/endpoints/following/invalidate.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import * as ms from 'ms';
-import deleteFollowing from '@/services/following/delete';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Followings, Users } from '@/models/index';
+import ms from 'ms';
+import deleteFollowing from '@/services/following/delete.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Followings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['following', 'users'],
@@ -19,12 +17,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -52,8 +44,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const followee = user;
 
 	// Check if the follower is yourself
diff --git a/packages/backend/src/server/api/endpoints/following/requests/accept.ts b/packages/backend/src/server/api/endpoints/following/requests/accept.ts
index 7e7c056f55..e5df55375e 100644
--- a/packages/backend/src/server/api/endpoints/following/requests/accept.ts
+++ b/packages/backend/src/server/api/endpoints/following/requests/accept.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import acceptFollowRequest from '@/services/following/requests/accept';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
+import acceptFollowRequest from '@/services/following/requests/accept.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
 
 export const meta = {
 	tags: ['following', 'account'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch follower
 	const follower = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
diff --git a/packages/backend/src/server/api/endpoints/following/requests/cancel.ts b/packages/backend/src/server/api/endpoints/following/requests/cancel.ts
index 19ed02c152..80d37fb075 100644
--- a/packages/backend/src/server/api/endpoints/following/requests/cancel.ts
+++ b/packages/backend/src/server/api/endpoints/following/requests/cancel.ts
@@ -1,10 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import cancelFollowRequest from '@/services/following/requests/cancel';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { Users } from '@/models/index';
+import cancelFollowRequest from '@/services/following/requests/cancel.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { Users } from '@/models/index.js';
+import { IdentifiableError } from '@/misc/identifiable-error.js';
 
 export const meta = {
 	tags: ['following', 'account'],
@@ -13,12 +12,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -40,8 +33,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch followee
 	const followee = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
@@ -51,7 +52,9 @@ export default define(meta, async (ps, user) => {
 	try {
 		await cancelFollowRequest(followee, user);
 	} catch (e) {
-		if (e.id === '17447091-ce07-46dd-b331-c1fd4f15b1e7') throw new ApiError(meta.errors.followRequestNotFound);
+		if (e instanceof IdentifiableError) {
+			if (e.id === '17447091-ce07-46dd-b331-c1fd4f15b1e7') throw new ApiError(meta.errors.followRequestNotFound);
+		}
 		throw e;
 	}
 
diff --git a/packages/backend/src/server/api/endpoints/following/requests/list.ts b/packages/backend/src/server/api/endpoints/following/requests/list.ts
index ec0c76502c..3b60b89b3c 100644
--- a/packages/backend/src/server/api/endpoints/following/requests/list.ts
+++ b/packages/backend/src/server/api/endpoints/following/requests/list.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { FollowRequests } from '@/models/index';
+import define from '../../../define.js';
+import { FollowRequests } from '@/models/index.js';
 
 export const meta = {
 	tags: ['following', 'account'],
@@ -35,8 +35,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const reqs = await FollowRequests.find({
 		followeeId: user.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/following/requests/reject.ts b/packages/backend/src/server/api/endpoints/following/requests/reject.ts
index a5ce1e7c77..cebe604284 100644
--- a/packages/backend/src/server/api/endpoints/following/requests/reject.ts
+++ b/packages/backend/src/server/api/endpoints/following/requests/reject.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { rejectFollowRequest } from '@/services/following/reject';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
+import { rejectFollowRequest } from '@/services/following/reject.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
 
 export const meta = {
 	tags: ['following', 'account'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:following',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch follower
 	const follower = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
diff --git a/packages/backend/src/server/api/endpoints/gallery/featured.ts b/packages/backend/src/server/api/endpoints/gallery/featured.ts
index ff7c16889f..e6acd36911 100644
--- a/packages/backend/src/server/api/endpoints/gallery/featured.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/featured.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { GalleryPosts } from '@/models/index';
+import define from '../../define.js';
+import { GalleryPosts } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -17,8 +17,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = GalleryPosts.createQueryBuilder('post')
 		.andWhere('post.createdAt > :date', { date: new Date(Date.now() - (1000 * 60 * 60 * 24 * 3)) })
 		.andWhere('post.likedCount > 0')
diff --git a/packages/backend/src/server/api/endpoints/gallery/popular.ts b/packages/backend/src/server/api/endpoints/gallery/popular.ts
index 2c3368a19d..c4c8982fcc 100644
--- a/packages/backend/src/server/api/endpoints/gallery/popular.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/popular.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { GalleryPosts } from '@/models/index';
+import define from '../../define.js';
+import { GalleryPosts } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -17,8 +17,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = GalleryPosts.createQueryBuilder('post')
 		.andWhere('post.likedCount > 0')
 		.orderBy('post.likedCount', 'DESC');
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts.ts b/packages/backend/src/server/api/endpoints/gallery/posts.ts
index 9d2601c7e9..428ba9cc71 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts.ts
@@ -1,27 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { GalleryPosts } from '@/models/index';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { GalleryPosts } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -33,12 +16,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(GalleryPosts.createQueryBuilder('post'), ps.sinceId, ps.untilId)
 		.innerJoinAndSelect('post.user', 'user');
 
-	const posts = await query.take(ps.limit!).getMany();
+	const posts = await query.take(ps.limit).getMany();
 
 	return await GalleryPosts.packMany(posts, me);
 });
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/create.ts b/packages/backend/src/server/api/endpoints/gallery/posts/create.ts
index e9d5df1ab6..eb6c0f3eb1 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/create.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/create.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
 import ms from 'ms';
-import define from '../../../define';
-import { ID } from '../../../../../misc/cafy-id';
-import { DriveFiles, GalleryPosts } from '@/models/index';
-import { genId } from '../../../../../misc/gen-id';
-import { GalleryPost } from '@/models/entities/gallery-post';
-import { ApiError } from '../../../error';
-import { DriveFile } from '@/models/entities/drive-file';
+import define from '../../../define.js';
+import { DriveFiles, GalleryPosts } from '@/models/index.js';
+import { genId } from '../../../../../misc/gen-id.js';
+import { GalleryPost } from '@/models/entities/gallery-post.js';
+import { ApiError } from '../../../error.js';
+import { DriveFile } from '@/models/entities/drive-file.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -20,25 +18,6 @@ export const meta = {
 		max: 300,
 	},
 
-	params: {
-		title: {
-			validator: $.str.min(1),
-		},
-
-		description: {
-			validator: $.optional.nullable.str,
-		},
-
-		fileIds: {
-			validator: $.arr($.type(ID)).unique().range(1, 32),
-		},
-
-		isSensitive: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -50,8 +29,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		title: { type: 'string', minLength: 1 },
+		description: { type: 'string', nullable: true },
+		fileIds: { type: 'array', uniqueItems: true, minItems: 1, maxItems: 32, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		isSensitive: { type: 'boolean', default: false },
+	},
+	required: ['title', 'fileIds'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const files = (await Promise.all(ps.fileIds.map(fileId =>
 		DriveFiles.findOne({
 			id: fileId,
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/delete.ts b/packages/backend/src/server/api/endpoints/gallery/posts/delete.ts
index 2a13b9ed58..f8bf785ee6 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/delete.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { GalleryPosts } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { GalleryPosts } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:gallery',
 
-	params: {
-		postId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPost: {
 			message: 'No such post.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		postId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['postId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const post = await GalleryPosts.findOne({
 		id: ps.postId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/like.ts b/packages/backend/src/server/api/endpoints/gallery/posts/like.ts
index 0fb408fa5f..d154bfc3c6 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/like.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/like.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { GalleryPosts, GalleryLikes } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { GalleryPosts, GalleryLikes } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:gallery-likes',
 
-	params: {
-		postId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPost: {
 			message: 'No such post.',
@@ -39,8 +31,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		postId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['postId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const post = await GalleryPosts.findOne(ps.postId);
 	if (post == null) {
 		throw new ApiError(meta.errors.noSuchPost);
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/show.ts b/packages/backend/src/server/api/endpoints/gallery/posts/show.ts
index 4325d2ad37..5b4594070c 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/show.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/show.ts
@@ -1,20 +1,12 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { GalleryPosts } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { GalleryPosts } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
 
 	requireCredential: false,
 
-	params: {
-		postId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPost: {
 			message: 'No such post.',
@@ -30,8 +22,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		postId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['postId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const post = await GalleryPosts.findOne({
 		id: ps.postId,
 	});
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/unlike.ts b/packages/backend/src/server/api/endpoints/gallery/posts/unlike.ts
index 9cca09bddc..b00008a864 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/unlike.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/unlike.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { GalleryPosts, GalleryLikes } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { GalleryPosts, GalleryLikes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:gallery-likes',
 
-	params: {
-		postId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPost: {
 			message: 'No such post.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		postId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['postId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const post = await GalleryPosts.findOne(ps.postId);
 	if (post == null) {
 		throw new ApiError(meta.errors.noSuchPost);
diff --git a/packages/backend/src/server/api/endpoints/gallery/posts/update.ts b/packages/backend/src/server/api/endpoints/gallery/posts/update.ts
index c35e1bbf58..123794d08c 100644
--- a/packages/backend/src/server/api/endpoints/gallery/posts/update.ts
+++ b/packages/backend/src/server/api/endpoints/gallery/posts/update.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
 import ms from 'ms';
-import define from '../../../define';
-import { ID } from '../../../../../misc/cafy-id';
-import { DriveFiles, GalleryPosts } from '@/models/index';
-import { GalleryPost } from '@/models/entities/gallery-post';
-import { ApiError } from '../../../error';
-import { DriveFile } from '@/models/entities/drive-file';
+import define from '../../../define.js';
+import { DriveFiles, GalleryPosts } from '@/models/index.js';
+import { GalleryPost } from '@/models/entities/gallery-post.js';
+import { ApiError } from '../../../error.js';
+import { DriveFile } from '@/models/entities/drive-file.js';
 
 export const meta = {
 	tags: ['gallery'],
@@ -19,29 +17,6 @@ export const meta = {
 		max: 300,
 	},
 
-	params: {
-		postId: {
-			validator: $.type(ID),
-		},
-
-		title: {
-			validator: $.str.min(1),
-		},
-
-		description: {
-			validator: $.optional.nullable.str,
-		},
-
-		fileIds: {
-			validator: $.arr($.type(ID)).unique().range(1, 32),
-		},
-
-		isSensitive: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -53,8 +28,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		postId: { type: 'string', format: 'misskey:id' },
+		title: { type: 'string', minLength: 1 },
+		description: { type: 'string', nullable: true },
+		fileIds: { type: 'array', uniqueItems: true, minItems: 1, maxItems: 32, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		isSensitive: { type: 'boolean', default: false },
+	},
+	required: ['postId', 'title', 'fileIds'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const files = (await Promise.all(ps.fileIds.map(fileId =>
 		DriveFiles.findOne({
 			id: fileId,
diff --git a/packages/backend/src/server/api/endpoints/get-online-users-count.ts b/packages/backend/src/server/api/endpoints/get-online-users-count.ts
index 5b13d5a3b8..80a2334cfa 100644
--- a/packages/backend/src/server/api/endpoints/get-online-users-count.ts
+++ b/packages/backend/src/server/api/endpoints/get-online-users-count.ts
@@ -1,19 +1,22 @@
-import { USER_ONLINE_THRESHOLD } from '@/const';
-import { Users } from '@/models/index';
+import { USER_ONLINE_THRESHOLD } from '@/const.js';
+import { Users } from '@/models/index.js';
 import { MoreThan } from 'typeorm';
-import define from '../define';
+import define from '../define.js';
 
 export const meta = {
 	tags: ['meta'],
 
 	requireCredential: false,
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const count = await Users.count({
 		lastActiveDate: MoreThan(new Date(Date.now() - USER_ONLINE_THRESHOLD)),
 	});
diff --git a/packages/backend/src/server/api/endpoints/hashtags/list.ts b/packages/backend/src/server/api/endpoints/hashtags/list.ts
index 9fa9b3edc6..50e36386cf 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/list.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/list.ts
@@ -1,51 +1,11 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Hashtags } from '@/models/index';
+import define from '../../define.js';
+import { Hashtags } from '@/models/index.js';
 
 export const meta = {
 	tags: ['hashtags'],
 
 	requireCredential: false,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		attachedToUserOnly: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		attachedToLocalUserOnly: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		attachedToRemoteUserOnly: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		sort: {
-			validator: $.str.or([
-				'+mentionedUsers',
-				'-mentionedUsers',
-				'+mentionedLocalUsers',
-				'-mentionedLocalUsers',
-				'+mentionedRemoteUsers',
-				'-mentionedRemoteUsers',
-				'+attachedUsers',
-				'-attachedUsers',
-				'+attachedLocalUsers',
-				'-attachedLocalUsers',
-				'+attachedRemoteUsers',
-				'-attachedRemoteUsers',
-			]),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -57,8 +17,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		attachedToUserOnly: { type: 'boolean', default: false },
+		attachedToLocalUserOnly: { type: 'boolean', default: false },
+		attachedToRemoteUserOnly: { type: 'boolean', default: false },
+		sort: { type: 'string', enum: ['+mentionedUsers', '-mentionedUsers', '+mentionedLocalUsers', '-mentionedLocalUsers', '+mentionedRemoteUsers', '-mentionedRemoteUsers', '+attachedUsers', '-attachedUsers', '+attachedLocalUsers', '-attachedLocalUsers', '+attachedRemoteUsers', '-attachedRemoteUsers'] },
+	},
+	required: ['sort'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Hashtags.createQueryBuilder('tag');
 
 	if (ps.attachedToUserOnly) query.andWhere('tag.attachedUsersCount != 0');
@@ -90,7 +62,7 @@ export default define(meta, async (ps, me) => {
 		'tag.attachedRemoteUsersCount',
 	]);
 
-	const tags = await query.take(ps.limit!).getMany();
+	const tags = await query.take(ps.limit).getMany();
 
 	return Hashtags.packMany(tags);
 });
diff --git a/packages/backend/src/server/api/endpoints/hashtags/search.ts b/packages/backend/src/server/api/endpoints/hashtags/search.ts
index 0d646c64f5..c289844775 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/search.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/search.ts
@@ -1,28 +1,11 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Hashtags } from '@/models/index';
+import define from '../../define.js';
+import { Hashtags } from '@/models/index.js';
 
 export const meta = {
 	tags: ['hashtags'],
 
 	requireCredential: false,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		query: {
-			validator: $.str,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -33,13 +16,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		query: { type: 'string' },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: ['query'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const hashtags = await Hashtags.createQueryBuilder('tag')
 		.where('tag.name like :q', { q: ps.query.toLowerCase() + '%' })
 		.orderBy('tag.count', 'DESC')
 		.groupBy('tag.id')
-		.take(ps.limit!)
+		.take(ps.limit)
 		.skip(ps.offset)
 		.getMany();
 
diff --git a/packages/backend/src/server/api/endpoints/hashtags/show.ts b/packages/backend/src/server/api/endpoints/hashtags/show.ts
index 242cef99d4..6e6afa4f13 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/show.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/show.ts
@@ -1,20 +1,13 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Hashtags } from '@/models/index';
-import { normalizeForSearch } from '@/misc/normalize-for-search';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Hashtags } from '@/models/index.js';
+import { normalizeForSearch } from '@/misc/normalize-for-search.js';
 
 export const meta = {
 	tags: ['hashtags'],
 
 	requireCredential: false,
 
-	params: {
-		tag: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -30,8 +23,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		tag: { type: 'string' },
+	},
+	required: ['tag'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const hashtag = await Hashtags.findOne({ name: normalizeForSearch(ps.tag) });
 	if (hashtag == null) {
 		throw new ApiError(meta.errors.noSuchHashtag);
diff --git a/packages/backend/src/server/api/endpoints/hashtags/trend.ts b/packages/backend/src/server/api/endpoints/hashtags/trend.ts
index be964ad639..9cdbc8941c 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/trend.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/trend.ts
@@ -1,10 +1,10 @@
 import { Brackets } from 'typeorm';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { Notes } from '@/models/index';
-import { Note } from '@/models/entities/note';
-import { safeForSql } from '@/misc/safe-for-sql';
-import { normalizeForSearch } from '@/misc/normalize-for-search';
+import define from '../../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { Notes } from '@/models/index.js';
+import { Note } from '@/models/entities/note.js';
+import { safeForSql } from '@/misc/safe-for-sql.js';
+import { normalizeForSearch } from '@/misc/normalize-for-search.js';
 
 /*
 トレンドに載るためには「『直近a分間のユニーク投稿数が今からa分前～今からb分前の間のユニーク投稿数のn倍以上』のハッシュタグの上位5位以内に入る」ことが必要
@@ -53,8 +53,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const instance = await fetchMeta(true);
 	const hiddenTags = instance.hiddenTags.map(t => normalizeForSearch(t));
 
diff --git a/packages/backend/src/server/api/endpoints/hashtags/users.ts b/packages/backend/src/server/api/endpoints/hashtags/users.ts
index 2158dc4349..a5df21a7e3 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/users.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/users.ts
@@ -1,52 +1,12 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Users } from '@/models/index';
-import { normalizeForSearch } from '@/misc/normalize-for-search';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
+import { normalizeForSearch } from '@/misc/normalize-for-search.js';
 
 export const meta = {
 	requireCredential: false,
 
 	tags: ['hashtags', 'users'],
 
-	params: {
-		tag: {
-			validator: $.str,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sort: {
-			validator: $.str.or([
-				'+follower',
-				'-follower',
-				'+createdAt',
-				'-createdAt',
-				'+updatedAt',
-				'-updatedAt',
-			]),
-		},
-
-		state: {
-			validator: $.optional.str.or([
-				'all',
-				'alive',
-			]),
-			default: 'all',
-		},
-
-		origin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'local',
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -58,8 +18,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		tag: { type: 'string' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sort: { type: 'string', enum: ['+follower', '-follower', '+createdAt', '-createdAt', '+updatedAt', '-updatedAt'] },
+		state: { type: 'string', enum: ['all', 'alive'], default: "all" },
+		origin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "local" },
+	},
+	required: ['tag', 'sort'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Users.createQueryBuilder('user')
 		.where(':tag = ANY(user.tags)', { tag: normalizeForSearch(ps.tag) });
 
@@ -84,7 +56,7 @@ export default define(meta, async (ps, me) => {
 		case '-updatedAt': query.orderBy('user.updatedAt', 'ASC'); break;
 	}
 
-	const users = await query.take(ps.limit!).getMany();
+	const users = await query.take(ps.limit).getMany();
 
 	return await Users.packMany(users, me, { detail: true });
 });
diff --git a/packages/backend/src/server/api/endpoints/i.ts b/packages/backend/src/server/api/endpoints/i.ts
index d69c118cfc..5b1ad2b098 100644
--- a/packages/backend/src/server/api/endpoints/i.ts
+++ b/packages/backend/src/server/api/endpoints/i.ts
@@ -1,13 +1,11 @@
-import define from '../define';
-import { Users } from '@/models/index';
+import define from '../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
 
 	requireCredential: true,
 
-	params: {},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -15,8 +13,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user, token) => {
+export default define(meta, paramDef, async (ps, user, token) => {
 	const isSecure = token == null;
 
 	// ここで渡ってきている user はキャッシュされていて古い可能性もあるので id だけ渡す
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/done.ts b/packages/backend/src/server/api/endpoints/i/2fa/done.ts
index 4853908693..70478430db 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/done.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/done.ts
@@ -1,22 +1,23 @@
-import $ from 'cafy';
 import * as speakeasy from 'speakeasy';
-import define from '../../../define';
-import { UserProfiles } from '@/models/index';
+import define from '../../../define.js';
+import { UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		token: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		token: { type: 'string' },
 	},
+	required: ['token'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const token = ps.token.replace(/\s/g, '');
 
 	const profile = await UserProfiles.findOneOrFail(user.id);
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/key-done.ts b/packages/backend/src/server/api/endpoints/i/2fa/key-done.ts
index 26e9a60886..f33237c8bf 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/key-done.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/key-done.ts
@@ -1,48 +1,40 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import { promisify } from 'util';
+import bcrypt from 'bcryptjs';
+import { promisify } from 'node:util';
 import * as cbor from 'cbor';
-import define from '../../../define';
+import define from '../../../define.js';
 import {
 	UserProfiles,
 	UserSecurityKeys,
 	AttestationChallenges,
 	Users,
-} from '@/models/index';
-import config from '@/config/index';
-import { procedures, hash } from '../../../2fa';
-import { publishMainStream } from '@/services/stream';
+} from '@/models/index.js';
+import config from '@/config/index.js';
+import { procedures, hash } from '../../../2fa.js';
+import { publishMainStream } from '@/services/stream.js';
 
 const cborDecodeFirst = promisify(cbor.decodeFirst) as any;
+const rpIdHashReal = hash(Buffer.from(config.hostname, 'utf-8'));
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		clientDataJSON: {
-			validator: $.str,
-		},
-		attestationObject: {
-			validator: $.str,
-		},
-		password: {
-			validator: $.str,
-		},
-		challengeId: {
-			validator: $.str,
-		},
-		name: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		clientDataJSON: { type: 'string' },
+		attestationObject: { type: 'string' },
+		password: { type: 'string' },
+		challengeId: { type: 'string' },
+		name: { type: 'string' },
 	},
+	required: ['clientDataJSON', 'attestationObject', 'password', 'challengeId', 'name'],
 } as const;
 
-const rpIdHashReal = hash(Buffer.from(config.hostname, 'utf-8'));
-
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/password-less.ts b/packages/backend/src/server/api/endpoints/i/2fa/password-less.ts
index 854848a434..4bfa24f97f 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/password-less.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/password-less.ts
@@ -1,21 +1,22 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { UserProfiles } from '@/models/index';
+import define from '../../../define.js';
+import { UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		value: {
-			validator: $.boolean,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		value: { type: 'boolean' },
 	},
+	required: ['value'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	await UserProfiles.update(user.id, {
 		usePasswordLessLogin: ps.value,
 	});
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/register-key.ts b/packages/backend/src/server/api/endpoints/i/2fa/register-key.ts
index 057e54c69b..0c4c99271e 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/register-key.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/register-key.ts
@@ -1,11 +1,10 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import define from '../../../define';
-import { UserProfiles, AttestationChallenges } from '@/models/index';
-import { promisify } from 'util';
-import * as crypto from 'crypto';
-import { genId } from '@/misc/gen-id';
-import { hash } from '../../../2fa';
+import bcrypt from 'bcryptjs';
+import define from '../../../define.js';
+import { UserProfiles, AttestationChallenges } from '@/models/index.js';
+import { promisify } from 'node:util';
+import * as crypto from 'node:crypto';
+import { genId } from '@/misc/gen-id.js';
+import { hash } from '../../../2fa.js';
 
 const randomBytes = promisify(crypto.randomBytes);
 
@@ -13,16 +12,18 @@ export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
 	},
+	required: ['password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/register.ts b/packages/backend/src/server/api/endpoints/i/2fa/register.ts
index c5cfb9dfad..7951e393b8 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/register.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/register.ts
@@ -1,25 +1,26 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
+import bcrypt from 'bcryptjs';
 import * as speakeasy from 'speakeasy';
 import * as QRCode from 'qrcode';
-import config from '@/config/index';
-import define from '../../../define';
-import { UserProfiles } from '@/models/index';
+import config from '@/config/index.js';
+import define from '../../../define.js';
+import { UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
 	},
+	required: ['password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/remove-key.ts b/packages/backend/src/server/api/endpoints/i/2fa/remove-key.ts
index 03e1d0434d..2b69b1f8c3 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/remove-key.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/remove-key.ts
@@ -1,26 +1,25 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import define from '../../../define';
-import { UserProfiles, UserSecurityKeys, Users } from '@/models/index';
-import { publishMainStream } from '@/services/stream';
+import bcrypt from 'bcryptjs';
+import define from '../../../define.js';
+import { UserProfiles, UserSecurityKeys, Users } from '@/models/index.js';
+import { publishMainStream } from '@/services/stream.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
-		credentialId: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
+		credentialId: { type: 'string' },
 	},
+	required: ['password', 'credentialId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/2fa/unregister.ts b/packages/backend/src/server/api/endpoints/i/2fa/unregister.ts
index a19ad6810d..c5633f68b1 100644
--- a/packages/backend/src/server/api/endpoints/i/2fa/unregister.ts
+++ b/packages/backend/src/server/api/endpoints/i/2fa/unregister.ts
@@ -1,22 +1,23 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import define from '../../../define';
-import { UserProfiles } from '@/models/index';
+import bcrypt from 'bcryptjs';
+import define from '../../../define.js';
+import { UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
 	},
+	required: ['password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/apps.ts b/packages/backend/src/server/api/endpoints/i/apps.ts
index 63999b0981..eca9558847 100644
--- a/packages/backend/src/server/api/endpoints/i/apps.ts
+++ b/packages/backend/src/server/api/endpoints/i/apps.ts
@@ -1,26 +1,22 @@
-import $ from 'cafy';
-import define from '../../define';
-import { AccessTokens } from '@/models/index';
+import define from '../../define.js';
+import { AccessTokens } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		sort: {
-			validator: $.optional.str.or([
-				'+createdAt',
-				'-createdAt',
-				'+lastUsedAt',
-				'-lastUsedAt',
-			]),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		sort: { type: 'string', enum: ['+createdAt', '-createdAt', '+lastUsedAt', '-lastUsedAt'] },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = AccessTokens.createQueryBuilder('token')
 		.where('token.userId = :userId', { userId: user.id });
 
diff --git a/packages/backend/src/server/api/endpoints/i/authorized-apps.ts b/packages/backend/src/server/api/endpoints/i/authorized-apps.ts
index 52122b851b..3301808e75 100644
--- a/packages/backend/src/server/api/endpoints/i/authorized-apps.ts
+++ b/packages/backend/src/server/api/endpoints/i/authorized-apps.ts
@@ -1,38 +1,30 @@
-import $ from 'cafy';
-import define from '../../define';
-import { AccessTokens, Apps } from '@/models/index';
+import define from '../../define.js';
+import { AccessTokens, Apps } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-
-		sort: {
-			validator: $.optional.str.or('desc|asc'),
-			default: 'desc',
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+		sort: { type: 'string', enum: ['desc', 'asc'], default: "desc" },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Get tokens
 	const tokens = await AccessTokens.find({
 		where: {
 			userId: user.id,
 		},
-		take: ps.limit!,
+		take: ps.limit,
 		skip: ps.offset,
 		order: {
 			id: ps.sort == 'asc' ? 1 : -1,
diff --git a/packages/backend/src/server/api/endpoints/i/change-password.ts b/packages/backend/src/server/api/endpoints/i/change-password.ts
index 7b6c137737..16509d2dcf 100644
--- a/packages/backend/src/server/api/endpoints/i/change-password.ts
+++ b/packages/backend/src/server/api/endpoints/i/change-password.ts
@@ -1,26 +1,24 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import define from '../../define';
-import { UserProfiles } from '@/models/index';
+import bcrypt from 'bcryptjs';
+import define from '../../define.js';
+import { UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		currentPassword: {
-			validator: $.str,
-		},
-
-		newPassword: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		currentPassword: { type: 'string' },
+		newPassword: { type: 'string', minLength: 1 },
 	},
+	required: ['currentPassword', 'newPassword'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/delete-account.ts b/packages/backend/src/server/api/endpoints/i/delete-account.ts
index e1eee949fc..8cb6b6a631 100644
--- a/packages/backend/src/server/api/endpoints/i/delete-account.ts
+++ b/packages/backend/src/server/api/endpoints/i/delete-account.ts
@@ -1,25 +1,26 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import define from '../../define';
-import { UserProfiles, Users } from '@/models/index';
-import { doPostSuspend } from '@/services/suspend-user';
-import { publishUserEvent } from '@/services/stream';
-import { createDeleteAccountJob } from '@/queue';
+import bcrypt from 'bcryptjs';
+import define from '../../define.js';
+import { UserProfiles, Users } from '@/models/index.js';
+import { doPostSuspend } from '@/services/suspend-user.js';
+import { publishUserEvent } from '@/services/stream.js';
+import { createDeleteAccountJob } from '@/queue/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
 	},
+	required: ['password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 	const userDetailed = await Users.findOneOrFail(user.id);
 	if (userDetailed.isDeleted) {
diff --git a/packages/backend/src/server/api/endpoints/i/export-blocking.ts b/packages/backend/src/server/api/endpoints/i/export-blocking.ts
index 44d8a1cb38..aed4c2e0a3 100644
--- a/packages/backend/src/server/api/endpoints/i/export-blocking.ts
+++ b/packages/backend/src/server/api/endpoints/i/export-blocking.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { createExportBlockingJob } from '@/queue/index';
+import define from '../../define.js';
+import { createExportBlockingJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -11,7 +11,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportBlockingJob(user);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/export-following.ts b/packages/backend/src/server/api/endpoints/i/export-following.ts
index 5d1617d57b..058d77b3c2 100644
--- a/packages/backend/src/server/api/endpoints/i/export-following.ts
+++ b/packages/backend/src/server/api/endpoints/i/export-following.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../define';
-import { createExportFollowingJob } from '@/queue/index';
+import define from '../../define.js';
+import { createExportFollowingJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -10,19 +9,18 @@ export const meta = {
 		duration: ms('1hour'),
 		max: 1,
 	},
-	params: {
-		excludeMuting: {
-			validator: $.optional.bool,
-			default: false,
-		},
-		excludeInactive: {
-			validator: $.optional.bool,
-			default: false,
-		},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		excludeMuting: { type: 'boolean', default: false },
+		excludeInactive: { type: 'boolean', default: false },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportFollowingJob(user, ps.excludeMuting, ps.excludeInactive);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/export-mute.ts b/packages/backend/src/server/api/endpoints/i/export-mute.ts
index 27ce8f0b29..c0216fac0c 100644
--- a/packages/backend/src/server/api/endpoints/i/export-mute.ts
+++ b/packages/backend/src/server/api/endpoints/i/export-mute.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { createExportMuteJob } from '@/queue/index';
+import define from '../../define.js';
+import { createExportMuteJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -11,7 +11,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportMuteJob(user);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/export-notes.ts b/packages/backend/src/server/api/endpoints/i/export-notes.ts
index 25b1849e80..4b85a45554 100644
--- a/packages/backend/src/server/api/endpoints/i/export-notes.ts
+++ b/packages/backend/src/server/api/endpoints/i/export-notes.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { createExportNotesJob } from '@/queue/index';
+import define from '../../define.js';
+import { createExportNotesJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -11,7 +11,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportNotesJob(user);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/export-user-lists.ts b/packages/backend/src/server/api/endpoints/i/export-user-lists.ts
index d28b699c5a..fa5c1f5e5a 100644
--- a/packages/backend/src/server/api/endpoints/i/export-user-lists.ts
+++ b/packages/backend/src/server/api/endpoints/i/export-user-lists.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { createExportUserListsJob } from '@/queue/index';
+import define from '../../define.js';
+import { createExportUserListsJob } from '@/queue/index.js';
 import ms from 'ms';
 
 export const meta = {
@@ -11,7 +11,13 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	createExportUserListsJob(user);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/favorites.ts b/packages/backend/src/server/api/endpoints/i/favorites.ts
index 92c767876b..3c420e4d0f 100644
--- a/packages/backend/src/server/api/endpoints/i/favorites.ts
+++ b/packages/backend/src/server/api/endpoints/i/favorites.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { NoteFavorites } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { NoteFavorites } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'notes', 'favorites'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:favorites',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,14 +20,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(NoteFavorites.createQueryBuilder('favorite'), ps.sinceId, ps.untilId)
 		.andWhere(`favorite.userId = :meId`, { meId: user.id })
 		.leftJoinAndSelect('favorite.note', 'note');
 
 	const favorites = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await NoteFavorites.packMany(favorites, user);
diff --git a/packages/backend/src/server/api/endpoints/i/gallery/likes.ts b/packages/backend/src/server/api/endpoints/i/gallery/likes.ts
index f1c5763593..a38383f30e 100644
--- a/packages/backend/src/server/api/endpoints/i/gallery/likes.ts
+++ b/packages/backend/src/server/api/endpoints/i/gallery/likes.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { GalleryLikes } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
+import define from '../../../define.js';
+import { GalleryLikes } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'gallery'],
@@ -11,47 +9,46 @@ export const meta = {
 
 	kind: 'read:gallery-likes',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
-		type: 'object',
+		type: 'array',
 		optional: false, nullable: false,
-		properties: {
-			id: {
-				type: 'string',
-				optional: false, nullable: false,
-				format: 'id',
+		items: {
+			type: 'object',
+			optional: false, nullable: false,
+			properties: {
+				id: {
+					type: 'string',
+					optional: false, nullable: false,
+					format: 'id',
+				},
+				post: {
+					type: 'object',
+					optional: false, nullable: false,
+					ref: 'GalleryPost',
+				},
 			},
-			page: {
-				type: 'object',
-				optional: false, nullable: false,
-				ref: 'GalleryPost',
-			},
-		},
+		}
+	},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(GalleryLikes.createQueryBuilder('like'), ps.sinceId, ps.untilId)
 		.andWhere(`like.userId = :meId`, { meId: user.id })
 		.leftJoinAndSelect('like.post', 'post');
 
 	const likes = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await GalleryLikes.packMany(likes, user);
diff --git a/packages/backend/src/server/api/endpoints/i/gallery/posts.ts b/packages/backend/src/server/api/endpoints/i/gallery/posts.ts
index d46d42f633..b4edb5f73d 100644
--- a/packages/backend/src/server/api/endpoints/i/gallery/posts.ts
+++ b/packages/backend/src/server/api/endpoints/i/gallery/posts.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { GalleryPosts } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
+import define from '../../../define.js';
+import { GalleryPosts } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'gallery'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:gallery',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(GalleryPosts.createQueryBuilder('post'), ps.sinceId, ps.untilId)
 		.andWhere(`post.userId = :meId`, { meId: user.id });
 
 	const posts = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await GalleryPosts.packMany(posts, user);
diff --git a/packages/backend/src/server/api/endpoints/i/get-word-muted-notes-count.ts b/packages/backend/src/server/api/endpoints/i/get-word-muted-notes-count.ts
index 4e1a4d3db9..bc3e0aff47 100644
--- a/packages/backend/src/server/api/endpoints/i/get-word-muted-notes-count.ts
+++ b/packages/backend/src/server/api/endpoints/i/get-word-muted-notes-count.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { MutedNotes } from '@/models/index';
+import define from '../../define.js';
+import { MutedNotes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
@@ -8,9 +8,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -23,8 +20,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	return {
 		count: await MutedNotes.count({
 			userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/i/import-blocking.ts b/packages/backend/src/server/api/endpoints/i/import-blocking.ts
index acc5797420..c70704f9a8 100644
--- a/packages/backend/src/server/api/endpoints/i/import-blocking.ts
+++ b/packages/backend/src/server/api/endpoints/i/import-blocking.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { createImportBlockingJob } from '@/queue/index';
+import define from '../../define.js';
+import { createImportBlockingJob } from '@/queue/index.js';
 import ms from 'ms';
-import { ApiError } from '../../error';
-import { DriveFiles } from '@/models/index';
+import { ApiError } from '../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	secure: true,
@@ -15,12 +13,6 @@ export const meta = {
 		max: 1,
 	},
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -48,8 +40,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) throw new ApiError(meta.errors.noSuchFile);
diff --git a/packages/backend/src/server/api/endpoints/i/import-following.ts b/packages/backend/src/server/api/endpoints/i/import-following.ts
index 35006746fb..7e9175cbf8 100644
--- a/packages/backend/src/server/api/endpoints/i/import-following.ts
+++ b/packages/backend/src/server/api/endpoints/i/import-following.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { createImportFollowingJob } from '@/queue/index';
+import define from '../../define.js';
+import { createImportFollowingJob } from '@/queue/index.js';
 import ms from 'ms';
-import { ApiError } from '../../error';
-import { DriveFiles } from '@/models/index';
+import { ApiError } from '../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	secure: true,
@@ -14,12 +12,6 @@ export const meta = {
 		max: 1,
 	},
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -47,8 +39,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) throw new ApiError(meta.errors.noSuchFile);
diff --git a/packages/backend/src/server/api/endpoints/i/import-muting.ts b/packages/backend/src/server/api/endpoints/i/import-muting.ts
index 7bbb2e008e..abbf07212e 100644
--- a/packages/backend/src/server/api/endpoints/i/import-muting.ts
+++ b/packages/backend/src/server/api/endpoints/i/import-muting.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { createImportMutingJob } from '@/queue/index';
+import define from '../../define.js';
+import { createImportMutingJob } from '@/queue/index.js';
 import ms from 'ms';
-import { ApiError } from '../../error';
-import { DriveFiles } from '@/models/index';
+import { ApiError } from '../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	secure: true,
@@ -15,12 +13,6 @@ export const meta = {
 		max: 1,
 	},
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -48,8 +40,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) throw new ApiError(meta.errors.noSuchFile);
diff --git a/packages/backend/src/server/api/endpoints/i/import-user-lists.ts b/packages/backend/src/server/api/endpoints/i/import-user-lists.ts
index 759d41b6cd..be162817f1 100644
--- a/packages/backend/src/server/api/endpoints/i/import-user-lists.ts
+++ b/packages/backend/src/server/api/endpoints/i/import-user-lists.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { createImportUserListsJob } from '@/queue/index';
+import define from '../../define.js';
+import { createImportUserListsJob } from '@/queue/index.js';
 import ms from 'ms';
-import { ApiError } from '../../error';
-import { DriveFiles } from '@/models/index';
+import { ApiError } from '../../error.js';
+import { DriveFiles } from '@/models/index.js';
 
 export const meta = {
 	secure: true,
@@ -14,12 +12,6 @@ export const meta = {
 		max: 1,
 	},
 
-	params: {
-		fileId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchFile: {
 			message: 'No such file.',
@@ -47,8 +39,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['fileId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const file = await DriveFiles.findOne(ps.fileId);
 
 	if (file == null) throw new ApiError(meta.errors.noSuchFile);
diff --git a/packages/backend/src/server/api/endpoints/i/notifications.ts b/packages/backend/src/server/api/endpoints/i/notifications.ts
index 59efd32bb2..7d9bd44d1d 100644
--- a/packages/backend/src/server/api/endpoints/i/notifications.ts
+++ b/packages/backend/src/server/api/endpoints/i/notifications.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { readNotification } from '../../common/read-notification';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateMutedInstanceNotificationQuery } from '../../common/generate-muted-instance-query';
-import { Notifications, Followings, Mutings, Users } from '@/models/index';
-import { notificationTypes } from '@/types';
-import read from '@/services/note/read';
+import { readNotification } from '../../common/read-notification.js';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateMutedInstanceNotificationQuery } from '../../common/generate-muted-instance-query.js';
+import { Notifications, Followings, Mutings, Users } from '@/models/index.js';
+import { notificationTypes } from '@/types.js';
+import read from '@/services/note/read.js';
 import { Brackets } from 'typeorm';
 
 export const meta = {
@@ -16,44 +14,6 @@ export const meta = {
 
 	kind: 'read:notifications',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		following: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		unreadOnly: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		markAsRead: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeTypes: {
-			validator: $.optional.arr($.str.or(notificationTypes as unknown as string[])),
-		},
-
-		excludeTypes: {
-			validator: $.optional.arr($.str.or(notificationTypes as unknown as string[])),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -65,8 +25,27 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		following: { type: 'boolean', default: false },
+		unreadOnly: { type: 'boolean', default: false },
+		markAsRead: { type: 'boolean', default: true },
+		includeTypes: { type: 'array', items: {
+			type: 'string', enum: notificationTypes,
+		} },
+		excludeTypes: { type: 'array', items: {
+			type: 'string', enum: notificationTypes,
+		} },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// includeTypes が空の場合はクエリしない
 	if (ps.includeTypes && ps.includeTypes.length === 0) {
 		return [];
@@ -92,10 +71,16 @@ export default define(meta, async (ps, user) => {
 		.leftJoinAndSelect('notification.notifier', 'notifier')
 		.leftJoinAndSelect('notification.note', 'note')
 		.leftJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	query.andWhere(new Brackets(qb => { qb
 		.where(`notification.notifierId NOT IN (${ mutingQuery.getQuery() })`)
@@ -125,7 +110,7 @@ export default define(meta, async (ps, user) => {
 		query.andWhere(`notification.isRead = false`);
 	}
 
-	const notifications = await query.take(ps.limit!).getMany();
+	const notifications = await query.take(ps.limit).getMany();
 
 	// Mark all as read
 	if (notifications.length > 0 && ps.markAsRead) {
diff --git a/packages/backend/src/server/api/endpoints/i/page-likes.ts b/packages/backend/src/server/api/endpoints/i/page-likes.ts
index 59239c7446..71e326e2f0 100644
--- a/packages/backend/src/server/api/endpoints/i/page-likes.ts
+++ b/packages/backend/src/server/api/endpoints/i/page-likes.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { PageLikes } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { PageLikes } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'pages'],
@@ -11,48 +9,46 @@ export const meta = {
 
 	kind: 'read:page-likes',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
-		type: 'object',
+		type: 'array',
 		optional: false, nullable: false,
-		properties: {
-			id: {
-				type: 'string',
-				optional: false, nullable: false,
-				format: 'id',
+		items: {
+			type: 'object',
+			properties: {
+				id: {
+					type: 'string',
+					optional: false, nullable: false,
+					format: 'id',
+				},
+				page: {
+					type: 'object',
+					optional: false, nullable: false,
+					ref: 'Page',
+				},
 			},
-			page: {
-				type: 'object',
-				optional: false, nullable: false,
-				ref: 'Page',
-			},
-		},
+		}
+	},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(PageLikes.createQueryBuilder('like'), ps.sinceId, ps.untilId)
 		.andWhere(`like.userId = :meId`, { meId: user.id })
 		.leftJoinAndSelect('like.page', 'page');
 
 	const likes = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
-	return await PageLikes.packMany(likes, user);
+	return PageLikes.packMany(likes, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/i/pages.ts b/packages/backend/src/server/api/endpoints/i/pages.ts
index bef775d063..f28aed3fd4 100644
--- a/packages/backend/src/server/api/endpoints/i/pages.ts
+++ b/packages/backend/src/server/api/endpoints/i/pages.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Pages } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Pages } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'pages'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:pages',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Pages.createQueryBuilder('page'), ps.sinceId, ps.untilId)
 		.andWhere(`page.userId = :meId`, { meId: user.id });
 
 	const pages = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Pages.packMany(pages);
diff --git a/packages/backend/src/server/api/endpoints/i/pin.ts b/packages/backend/src/server/api/endpoints/i/pin.ts
index a940d1b99b..67b7026be1 100644
--- a/packages/backend/src/server/api/endpoints/i/pin.ts
+++ b/packages/backend/src/server/api/endpoints/i/pin.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { addPinned } from '@/services/i/pin';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Users } from '@/models/index';
+import { addPinned } from '@/services/i/pin.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account', 'notes'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -45,8 +37,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	await addPinned(user, ps.noteId).catch(e => {
 		if (e.id === '70c4e51f-5bea-449c-a030-53bee3cce202') throw new ApiError(meta.errors.noSuchNote);
 		if (e.id === '15a018eb-58e5-4da1-93be-330fcc5e4e1a') throw new ApiError(meta.errors.pinLimitExceeded);
diff --git a/packages/backend/src/server/api/endpoints/i/read-all-messaging-messages.ts b/packages/backend/src/server/api/endpoints/i/read-all-messaging-messages.ts
index 4e4fb3840f..2e291a34a0 100644
--- a/packages/backend/src/server/api/endpoints/i/read-all-messaging-messages.ts
+++ b/packages/backend/src/server/api/endpoints/i/read-all-messaging-messages.ts
@@ -1,6 +1,6 @@
-import { publishMainStream } from '@/services/stream';
-import define from '../../define';
-import { MessagingMessages, UserGroupJoinings } from '@/models/index';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../define.js';
+import { MessagingMessages, UserGroupJoinings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account', 'messaging'],
@@ -8,13 +8,16 @@ export const meta = {
 	requireCredential: true,
 
 	kind: 'write:account',
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Update documents
 	await MessagingMessages.update({
 		recipientId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/i/read-all-unread-notes.ts b/packages/backend/src/server/api/endpoints/i/read-all-unread-notes.ts
index 99f17ddfc9..49f3deb331 100644
--- a/packages/backend/src/server/api/endpoints/i/read-all-unread-notes.ts
+++ b/packages/backend/src/server/api/endpoints/i/read-all-unread-notes.ts
@@ -1,6 +1,6 @@
-import { publishMainStream } from '@/services/stream';
-import define from '../../define';
-import { NoteUnreads } from '@/models/index';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../define.js';
+import { NoteUnreads } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
@@ -8,13 +8,16 @@ export const meta = {
 	requireCredential: true,
 
 	kind: 'write:account',
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Remove documents
 	await NoteUnreads.delete({
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/i/read-announcement.ts b/packages/backend/src/server/api/endpoints/i/read-announcement.ts
index e9bb66264b..647fa77fa4 100644
--- a/packages/backend/src/server/api/endpoints/i/read-announcement.ts
+++ b/packages/backend/src/server/api/endpoints/i/read-announcement.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { genId } from '@/misc/gen-id';
-import { AnnouncementReads, Announcements, Users } from '@/models/index';
-import { publishMainStream } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { genId } from '@/misc/gen-id.js';
+import { AnnouncementReads, Announcements, Users } from '@/models/index.js';
+import { publishMainStream } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['account'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		announcementId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchAnnouncement: {
 			message: 'No such announcement.',
@@ -28,8 +20,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		announcementId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['announcementId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Check if announcement exists
 	const announcement = await Announcements.findOne(ps.announcementId);
 
diff --git a/packages/backend/src/server/api/endpoints/i/regenerate-token.ts b/packages/backend/src/server/api/endpoints/i/regenerate-token.ts
index a20719363b..771c98b212 100644
--- a/packages/backend/src/server/api/endpoints/i/regenerate-token.ts
+++ b/packages/backend/src/server/api/endpoints/i/regenerate-token.ts
@@ -1,24 +1,25 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import { publishMainStream, publishUserEvent } from '@/services/stream';
-import generateUserToken from '../../common/generate-native-user-token';
-import define from '../../define';
-import { Users, UserProfiles } from '@/models/index';
+import bcrypt from 'bcryptjs';
+import { publishMainStream, publishUserEvent } from '@/services/stream.js';
+import generateUserToken from '../../common/generate-native-user-token.js';
+import define from '../../define.js';
+import { Users, UserProfiles } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		password: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
 	},
+	required: ['password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/registry/get-all.ts b/packages/backend/src/server/api/endpoints/i/registry/get-all.ts
index 2941b441e2..d0b16dbc48 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/get-all.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/get-all.ts
@@ -1,22 +1,24 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/registry/get-detail.ts b/packages/backend/src/server/api/endpoints/i/registry/get-detail.ts
index 51371353c9..cc5d5a8c6f 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/get-detail.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/get-detail.ts
@@ -1,24 +1,12 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
 
-	params: {
-		key: {
-			validator: $.str,
-		},
-
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
-	},
-
 	errors: {
 		noSuchKey: {
 			message: 'No such key.',
@@ -28,8 +16,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		key: { type: 'string' },
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
+	},
+	required: ['key'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/registry/get.ts b/packages/backend/src/server/api/endpoints/i/registry/get.ts
index ac617defb0..a79319744c 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/get.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/get.ts
@@ -1,24 +1,12 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
 
-	params: {
-		key: {
-			validator: $.str,
-		},
-
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
-	},
-
 	errors: {
 		noSuchKey: {
 			message: 'No such key.',
@@ -28,8 +16,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		key: { type: 'string' },
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
+	},
+	required: ['key'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/registry/keys-with-type.ts b/packages/backend/src/server/api/endpoints/i/registry/keys-with-type.ts
index 0445922188..ac209c06a6 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/keys-with-type.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/keys-with-type.ts
@@ -1,22 +1,24 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/registry/keys.ts b/packages/backend/src/server/api/endpoints/i/registry/keys.ts
index a3c9d0e5ee..5ea1a9d344 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/keys.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/keys.ts
@@ -1,22 +1,24 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.select('item.key')
 		.where('item.domain IS NULL')
diff --git a/packages/backend/src/server/api/endpoints/i/registry/remove.ts b/packages/backend/src/server/api/endpoints/i/registry/remove.ts
index 08185f224b..92473654c6 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/remove.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/remove.ts
@@ -1,24 +1,12 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
 
-	params: {
-		key: {
-			validator: $.str,
-		},
-
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
-	},
-
 	errors: {
 		noSuchKey: {
 			message: 'No such key.',
@@ -28,8 +16,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		key: { type: 'string' },
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
+	},
+	required: ['key'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/registry/scopes.ts b/packages/backend/src/server/api/endpoints/i/registry/scopes.ts
index 9de68ac6e8..de4b313e25 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/scopes.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/scopes.ts
@@ -1,17 +1,20 @@
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.select('item.scope')
 		.where('item.domain IS NULL')
diff --git a/packages/backend/src/server/api/endpoints/i/registry/set.ts b/packages/backend/src/server/api/endpoints/i/registry/set.ts
index 27884046b4..d380b428a3 100644
--- a/packages/backend/src/server/api/endpoints/i/registry/set.ts
+++ b/packages/backend/src/server/api/endpoints/i/registry/set.ts
@@ -1,32 +1,28 @@
-import $ from 'cafy';
-import { publishMainStream } from '@/services/stream';
-import define from '../../../define';
-import { RegistryItems } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { RegistryItems } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		key: {
-			validator: $.str.min(1),
-		},
-
-		value: {
-			validator: $.nullable.any,
-		},
-
-		scope: {
-			validator: $.optional.arr($.str.match(/^[a-zA-Z0-9_]+$/)),
-			default: [],
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		key: { type: 'string', minLength: 1 },
+		value: {},
+		scope: { type: 'array', default: [], items: {
+			type: 'string', pattern: /^[a-zA-Z0-9_]+$/.toString().slice(1, -1),
+		} },
 	},
+	required: ['key', 'value'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = RegistryItems.createQueryBuilder('item')
 		.where('item.domain IS NULL')
 		.andWhere('item.userId = :userId', { userId: user.id })
diff --git a/packages/backend/src/server/api/endpoints/i/revoke-token.ts b/packages/backend/src/server/api/endpoints/i/revoke-token.ts
index 51721c5b58..b957fd0796 100644
--- a/packages/backend/src/server/api/endpoints/i/revoke-token.ts
+++ b/packages/backend/src/server/api/endpoints/i/revoke-token.ts
@@ -1,23 +1,23 @@
-import $ from 'cafy';
-import define from '../../define';
-import { AccessTokens } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import { AccessTokens } from '@/models/index.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		tokenId: {
-			validator: $.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		tokenId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['tokenId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const token = await AccessTokens.findOne(ps.tokenId);
 
 	if (token) {
diff --git a/packages/backend/src/server/api/endpoints/i/signin-history.ts b/packages/backend/src/server/api/endpoints/i/signin-history.ts
index 796e2ec309..ca37411662 100644
--- a/packages/backend/src/server/api/endpoints/i/signin-history.ts
+++ b/packages/backend/src/server/api/endpoints/i/signin-history.ts
@@ -1,36 +1,29 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Signins } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Signins } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	requireCredential: true,
 
 	secure: true,
+} as const;
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Signins.createQueryBuilder('signin'), ps.sinceId, ps.untilId)
 		.andWhere(`signin.userId = :meId`, { meId: user.id });
 
-	const history = await query.take(ps.limit!).getMany();
+	const history = await query.take(ps.limit).getMany();
 
 	return await Promise.all(history.map(record => Signins.pack(record)));
 });
diff --git a/packages/backend/src/server/api/endpoints/i/unpin.ts b/packages/backend/src/server/api/endpoints/i/unpin.ts
index 9c82b74960..9912689da5 100644
--- a/packages/backend/src/server/api/endpoints/i/unpin.ts
+++ b/packages/backend/src/server/api/endpoints/i/unpin.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { removePinned } from '@/services/i/pin';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Users } from '@/models/index';
+import { removePinned } from '@/services/i/pin.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account', 'notes'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -33,8 +25,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	await removePinned(user, ps.noteId).catch(e => {
 		if (e.id === 'b302d4cf-c050-400a-bbb3-be208681f40c') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/i/update-email.ts b/packages/backend/src/server/api/endpoints/i/update-email.ts
index b4479aa50d..389ff1b81d 100644
--- a/packages/backend/src/server/api/endpoints/i/update-email.ts
+++ b/packages/backend/src/server/api/endpoints/i/update-email.ts
@@ -1,14 +1,13 @@
-import $ from 'cafy';
-import { publishMainStream } from '@/services/stream';
-import define from '../../define';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../define.js';
 import rndstr from 'rndstr';
-import config from '@/config/index';
+import config from '@/config/index.js';
 import ms from 'ms';
-import * as bcrypt from 'bcryptjs';
-import { Users, UserProfiles } from '@/models/index';
-import { sendEmail } from '@/services/send-email';
-import { ApiError } from '../../error';
-import { validateEmailForAccount } from '@/services/validate-email-for-account';
+import bcrypt from 'bcryptjs';
+import { Users, UserProfiles } from '@/models/index.js';
+import { sendEmail } from '@/services/send-email.js';
+import { ApiError } from '../../error.js';
+import { validateEmailForAccount } from '@/services/validate-email-for-account.js';
 
 export const meta = {
 	requireCredential: true,
@@ -20,16 +19,6 @@ export const meta = {
 		max: 3,
 	},
 
-	params: {
-		password: {
-			validator: $.str,
-		},
-
-		email: {
-			validator: $.optional.nullable.str,
-		},
-	},
-
 	errors: {
 		incorrectPassword: {
 			message: 'Incorrect password.',
@@ -45,8 +34,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		password: { type: 'string' },
+		email: { type: 'string', nullable: true },
+	},
+	required: ['password'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const profile = await UserProfiles.findOneOrFail(user.id);
 
 	// Compare password
diff --git a/packages/backend/src/server/api/endpoints/i/update.ts b/packages/backend/src/server/api/endpoints/i/update.ts
index 6b7e53aa1f..85d0a62548 100644
--- a/packages/backend/src/server/api/endpoints/i/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/update.ts
@@ -1,20 +1,19 @@
-import $ from 'cafy';
+import RE2 from 're2';
 import * as mfm from 'mfm-js';
-import { ID } from '@/misc/cafy-id';
-import { publishMainStream, publishUserEvent } from '@/services/stream';
-import acceptAllFollowRequests from '@/services/following/requests/accept-all';
-import { publishToFollowers } from '@/services/i/update';
-import define from '../../define';
-import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm';
-import { extractHashtags } from '@/misc/extract-hashtags';
-import * as langmap from 'langmap';
-import { updateUsertags } from '@/services/update-hashtag';
-import { ApiError } from '../../error';
-import { Users, DriveFiles, UserProfiles, Pages } from '@/models/index';
-import { User } from '@/models/entities/user';
-import { UserProfile } from '@/models/entities/user-profile';
-import { notificationTypes } from '@/types';
-import { normalizeForSearch } from '@/misc/normalize-for-search';
+import { publishMainStream, publishUserEvent } from '@/services/stream.js';
+import acceptAllFollowRequests from '@/services/following/requests/accept-all.js';
+import { publishToFollowers } from '@/services/i/update.js';
+import define from '../../define.js';
+import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm.js';
+import { extractHashtags } from '@/misc/extract-hashtags.js';
+import { updateUsertags } from '@/services/update-hashtag.js';
+import { ApiError } from '../../error.js';
+import { Users, DriveFiles, UserProfiles, Pages } from '@/models/index.js';
+import { User } from '@/models/entities/user.js';
+import { UserProfile } from '@/models/entities/user-profile.js';
+import { notificationTypes } from '@/types.js';
+import { normalizeForSearch } from '@/misc/normalize-for-search.js';
+import { langmap } from '@/misc/langmap.js';
 
 export const meta = {
 	tags: ['account'],
@@ -23,112 +22,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		name: {
-			validator: $.optional.nullable.use(Users.validateName),
-		},
-
-		description: {
-			validator: $.optional.nullable.use(Users.validateDescription),
-		},
-
-		lang: {
-			validator: $.optional.nullable.str.or(Object.keys(langmap)),
-		},
-
-		location: {
-			validator: $.optional.nullable.use(Users.validateLocation),
-		},
-
-		birthday: {
-			validator: $.optional.nullable.use(Users.validateBirthday),
-		},
-
-		avatarId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		bannerId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		fields: {
-			validator: $.optional.arr($.object()).range(1, 4),
-		},
-
-		isLocked: {
-			validator: $.optional.bool,
-		},
-
-		isExplorable: {
-			validator: $.optional.bool,
-		},
-
-		hideOnlineStatus: {
-			validator: $.optional.bool,
-		},
-
-		publicReactions: {
-			validator: $.optional.bool,
-		},
-
-		ffVisibility: {
-			validator: $.optional.str,
-		},
-
-		carefulBot: {
-			validator: $.optional.bool,
-		},
-
-		autoAcceptFollowed: {
-			validator: $.optional.bool,
-		},
-
-		noCrawle: {
-			validator: $.optional.bool,
-		},
-
-		isBot: {
-			validator: $.optional.bool,
-		},
-
-		isCat: {
-			validator: $.optional.bool,
-		},
-
-		injectFeaturedNote: {
-			validator: $.optional.bool,
-		},
-
-		receiveAnnouncementEmail: {
-			validator: $.optional.bool,
-		},
-
-		alwaysMarkNsfw: {
-			validator: $.optional.bool,
-		},
-
-		pinnedPageId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		mutedWords: {
-			validator: $.optional.arr($.arr($.str)),
-		},
-
-		mutedInstances: {
-			validator: $.optional.arr($.str),
-		},
-
-		mutingNotificationTypes: {
-			validator: $.optional.arr($.str.or(notificationTypes as unknown as string[])),
-		},
-
-		emailNotificationTypes: {
-			validator: $.optional.arr($.str),
-		},
-	},
-
 	errors: {
 		noSuchAvatar: {
 			message: 'No such avatar file.',
@@ -159,6 +52,12 @@ export const meta = {
 			code: 'NO_SUCH_PAGE',
 			id: '8e01b590-7eb9-431b-a239-860e086c408e',
 		},
+
+		invalidRegexp: {
+			message: 'Invalid Regular Expression.',
+			code: 'INVALID_REGEXP',
+			id: '0d786918-10df-41cd-8f33-8dec7d9a89a5',
+		}
 	},
 
 	res: {
@@ -168,8 +67,60 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { ...Users.nameSchema, nullable: true },
+		description: { ...Users.descriptionSchema, nullable: true },
+		location: { ...Users.locationSchema, nullable: true },
+		birthday: { ...Users.birthdaySchema, nullable: true },
+		lang: { type: 'string', enum: [null, ...Object.keys(langmap)], nullable: true },
+		avatarId: { type: 'string', format: 'misskey:id', nullable: true },
+		bannerId: { type: 'string', format: 'misskey:id', nullable: true },
+		fields: { type: 'array',
+			minItems: 0,
+			maxItems: 16,
+			items: {
+				type: 'object',
+				properties: {
+					name: { type: 'string' },
+					value: { type: 'string' },
+				},
+				required: ['name', 'value'],
+			},
+		},
+		isLocked: { type: 'boolean' },
+		isExplorable: { type: 'boolean' },
+		hideOnlineStatus: { type: 'boolean' },
+		publicReactions: { type: 'boolean' },
+		carefulBot: { type: 'boolean' },
+		autoAcceptFollowed: { type: 'boolean' },
+		noCrawle: { type: 'boolean' },
+		isBot: { type: 'boolean' },
+		isCat: { type: 'boolean' },
+		showTimelineReplies: { type: 'boolean' },
+		injectFeaturedNote: { type: 'boolean' },
+		receiveAnnouncementEmail: { type: 'boolean' },
+		alwaysMarkNsfw: { type: 'boolean' },
+		ffVisibility: { type: 'string', enum: ['public', 'followers', 'private'] },
+		pinnedPageId: { type: 'array', items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		mutedWords: { type: 'array' },
+		mutedInstances: { type: 'array', items: {
+			type: 'string',
+		} },
+		mutingNotificationTypes: { type: 'array', items: {
+			type: 'string', enum: notificationTypes,
+		} },
+		emailNotificationTypes: { type: 'array', items: {
+			type: 'string',
+		} },
+	},
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, _user, token) => {
+export default define(meta, paramDef, async (ps, _user, token) => {
 	const user = await Users.findOneOrFail(_user.id);
 	const isSecure = token == null;
 
@@ -187,6 +138,18 @@ export default define(meta, async (ps, _user, token) => {
 	if (ps.avatarId !== undefined) updates.avatarId = ps.avatarId;
 	if (ps.bannerId !== undefined) updates.bannerId = ps.bannerId;
 	if (ps.mutedWords !== undefined) {
+		// validate regular expression syntax
+		ps.mutedWords.filter(x => !Array.isArray(x)).forEach(x => {
+			const regexp = x.match(/^\/(.+)\/(.*)$/);
+			if (!regexp) throw new ApiError(meta.errors.invalidRegexp);
+
+			try {
+				new RE2(regexp[1], regexp[2]);
+			} catch (err) {
+				throw new ApiError(meta.errors.invalidRegexp);
+			}
+		});
+
 		profileUpdates.mutedWords = ps.mutedWords;
 		profileUpdates.enableWordMute = ps.mutedWords.length > 0;
 	}
@@ -197,6 +160,7 @@ export default define(meta, async (ps, _user, token) => {
 	if (typeof ps.hideOnlineStatus === 'boolean') updates.hideOnlineStatus = ps.hideOnlineStatus;
 	if (typeof ps.publicReactions === 'boolean') profileUpdates.publicReactions = ps.publicReactions;
 	if (typeof ps.isBot === 'boolean') updates.isBot = ps.isBot;
+	if (typeof ps.showTimelineReplies === 'boolean') updates.showTimelineReplies = ps.showTimelineReplies;
 	if (typeof ps.carefulBot === 'boolean') profileUpdates.carefulBot = ps.carefulBot;
 	if (typeof ps.autoAcceptFollowed === 'boolean') profileUpdates.autoAcceptFollowed = ps.autoAcceptFollowed;
 	if (typeof ps.noCrawle === 'boolean') profileUpdates.noCrawle = ps.noCrawle;
@@ -211,12 +175,6 @@ export default define(meta, async (ps, _user, token) => {
 
 		if (avatar == null || avatar.userId !== user.id) throw new ApiError(meta.errors.noSuchAvatar);
 		if (!avatar.type.startsWith('image/')) throw new ApiError(meta.errors.avatarNotAnImage);
-
-		updates.avatarUrl = DriveFiles.getPublicUrl(avatar, true);
-
-		if (avatar.blurhash) {
-			updates.avatarBlurhash = avatar.blurhash;
-		}
 	}
 
 	if (ps.bannerId) {
@@ -224,12 +182,6 @@ export default define(meta, async (ps, _user, token) => {
 
 		if (banner == null || banner.userId !== user.id) throw new ApiError(meta.errors.noSuchBanner);
 		if (!banner.type.startsWith('image/')) throw new ApiError(meta.errors.bannerNotAnImage);
-
-		updates.bannerUrl = DriveFiles.getPublicUrl(banner, false);
-
-		if (banner.blurhash) {
-			updates.bannerBlurhash = banner.blurhash;
-		}
 	}
 
 	if (ps.pinnedPageId) {
diff --git a/packages/backend/src/server/api/endpoints/i/user-group-invites.ts b/packages/backend/src/server/api/endpoints/i/user-group-invites.ts
index 76a3131e6d..1d7e4a16b3 100644
--- a/packages/backend/src/server/api/endpoints/i/user-group-invites.ts
+++ b/packages/backend/src/server/api/endpoints/i/user-group-invites.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { UserGroupInvitations } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { UserGroupInvitations } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['account', 'groups'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:user-groups',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -48,14 +31,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(UserGroupInvitations.createQueryBuilder('invitation'), ps.sinceId, ps.untilId)
 		.andWhere(`invitation.userId = :meId`, { meId: user.id })
 		.leftJoinAndSelect('invitation.userGroup', 'user_group');
 
 	const invitations = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await UserGroupInvitations.packMany(invitations);
diff --git a/packages/backend/src/server/api/endpoints/messaging/history.ts b/packages/backend/src/server/api/endpoints/messaging/history.ts
index 5ac49cf96b..14de4e1028 100644
--- a/packages/backend/src/server/api/endpoints/messaging/history.ts
+++ b/packages/backend/src/server/api/endpoints/messaging/history.ts
@@ -1,7 +1,6 @@
-import $ from 'cafy';
-import define from '../../define';
-import { MessagingMessage } from '@/models/entities/messaging-message';
-import { MessagingMessages, Mutings, UserGroupJoinings } from '@/models/index';
+import define from '../../define.js';
+import { MessagingMessage } from '@/models/entities/messaging-message.js';
+import { MessagingMessages, Mutings, UserGroupJoinings } from '@/models/index.js';
 import { Brackets } from 'typeorm';
 
 export const meta = {
@@ -11,18 +10,6 @@ export const meta = {
 
 	kind: 'read:messaging',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		group: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -34,8 +21,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		group: { type: 'boolean', default: false },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const mute = await Mutings.find({
 		muterId: user.id,
 	});
@@ -50,7 +46,7 @@ export default define(meta, async (ps, user) => {
 
 	const history: MessagingMessage[] = [];
 
-	for (let i = 0; i < ps.limit!; i++) {
+	for (let i = 0; i < ps.limit; i++) {
 		const found = ps.group
 			? history.map(m => m.groupId!)
 			: history.map(m => (m.userId === user.id) ? m.recipientId! : m.userId!);
diff --git a/packages/backend/src/server/api/endpoints/messaging/messages.ts b/packages/backend/src/server/api/endpoints/messaging/messages.ts
index 7dbddd80e2..49ace21600 100644
--- a/packages/backend/src/server/api/endpoints/messaging/messages.ts
+++ b/packages/backend/src/server/api/endpoints/messaging/messages.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { MessagingMessages, UserGroups, UserGroupJoinings, Users } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { MessagingMessages, UserGroups, UserGroupJoinings, Users } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 import { Brackets } from 'typeorm';
-import { readUserMessagingMessage, readGroupMessagingMessage, deliverReadActivity } from '../../common/read-messaging-message';
+import { readUserMessagingMessage, readGroupMessagingMessage, deliverReadActivity } from '../../common/read-messaging-message.js';
 
 export const meta = {
 	tags: ['messaging'],
@@ -15,34 +13,6 @@ export const meta = {
 
 	kind: 'read:messaging',
 
-	params: {
-		userId: {
-			validator: $.optional.type(ID),
-		},
-
-		groupId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		markAsRead: {
-			validator: $.optional.bool,
-			default: true,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -74,8 +44,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		groupId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		markAsRead: { type: 'boolean', default: true },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	if (ps.userId != null) {
 		// Fetch recipient (user)
 		const recipient = await getUser(ps.userId).catch(e => {
@@ -97,7 +80,7 @@ export default define(meta, async (ps, user) => {
 			.setParameter('meId', user.id)
 			.setParameter('recipientId', recipient.id);
 
-		const messages = await query.take(ps.limit!).getMany();
+		const messages = await query.take(ps.limit).getMany();
 
 		// Mark all as read
 		if (ps.markAsRead) {
@@ -133,7 +116,7 @@ export default define(meta, async (ps, user) => {
 		const query = makePaginationQuery(MessagingMessages.createQueryBuilder('message'), ps.sinceId, ps.untilId)
 			.andWhere(`message.groupId = :groupId`, { groupId: recipientGroup.id });
 
-		const messages = await query.take(ps.limit!).getMany();
+		const messages = await query.take(ps.limit).getMany();
 
 		// Mark all as read
 		if (ps.markAsRead) {
diff --git a/packages/backend/src/server/api/endpoints/messaging/messages/create.ts b/packages/backend/src/server/api/endpoints/messaging/messages/create.ts
index 5ec16f5e5a..a9b926c4fb 100644
--- a/packages/backend/src/server/api/endpoints/messaging/messages/create.ts
+++ b/packages/backend/src/server/api/endpoints/messaging/messages/create.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { MessagingMessages, DriveFiles, UserGroups, UserGroupJoinings, Blockings } from '@/models/index';
-import { User } from '@/models/entities/user';
-import { UserGroup } from '@/models/entities/user-group';
-import { createMessage } from '@/services/messages/create';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { MessagingMessages, DriveFiles, UserGroups, UserGroupJoinings, Blockings } from '@/models/index.js';
+import { User } from '@/models/entities/user.js';
+import { UserGroup } from '@/models/entities/user-group.js';
+import { createMessage } from '@/services/messages/create.js';
 
 export const meta = {
 	tags: ['messaging'],
@@ -15,24 +13,6 @@ export const meta = {
 
 	kind: 'write:messaging',
 
-	params: {
-		userId: {
-			validator: $.optional.type(ID),
-		},
-
-		groupId: {
-			validator: $.optional.type(ID),
-		},
-
-		text: {
-			validator: $.optional.str.pipe(MessagingMessages.validateText),
-		},
-
-		fileId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -84,8 +64,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		groupId: { type: 'string', format: 'misskey:id' },
+		text: { type: 'string', nullable: true, maxLength: 3000 },
+		fileId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let recipientUser: User | undefined;
 	let recipientGroup: UserGroup | undefined;
 
diff --git a/packages/backend/src/server/api/endpoints/messaging/messages/delete.ts b/packages/backend/src/server/api/endpoints/messaging/messages/delete.ts
index 2975419cef..a0945af510 100644
--- a/packages/backend/src/server/api/endpoints/messaging/messages/delete.ts
+++ b/packages/backend/src/server/api/endpoints/messaging/messages/delete.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
+import define from '../../../define.js';
 import ms from 'ms';
-import { ApiError } from '../../../error';
-import { MessagingMessages } from '@/models/index';
-import { deleteMessage } from '@/services/messages/delete';
+import { ApiError } from '../../../error.js';
+import { MessagingMessages } from '@/models/index.js';
+import { deleteMessage } from '@/services/messages/delete.js';
 
 export const meta = {
 	tags: ['messaging'],
@@ -19,12 +17,6 @@ export const meta = {
 		minInterval: ms('1sec'),
 	},
 
-	params: {
-		messageId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchMessage: {
 			message: 'No such message.',
@@ -34,8 +26,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		messageId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['messageId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const message = await MessagingMessages.findOne({
 		id: ps.messageId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/messaging/messages/read.ts b/packages/backend/src/server/api/endpoints/messaging/messages/read.ts
index 42c3f49f6f..8d38e509ac 100644
--- a/packages/backend/src/server/api/endpoints/messaging/messages/read.ts
+++ b/packages/backend/src/server/api/endpoints/messaging/messages/read.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { MessagingMessages } from '@/models/index';
-import { readUserMessagingMessage, readGroupMessagingMessage } from '../../../common/read-messaging-message';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { MessagingMessages } from '@/models/index.js';
+import { readUserMessagingMessage, readGroupMessagingMessage } from '../../../common/read-messaging-message.js';
 
 export const meta = {
 	tags: ['messaging'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:messaging',
 
-	params: {
-		messageId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchMessage: {
 			message: 'No such message.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		messageId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['messageId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const message = await MessagingMessages.findOne(ps.messageId);
 
 	if (message == null) {
diff --git a/packages/backend/src/server/api/endpoints/meta.ts b/packages/backend/src/server/api/endpoints/meta.ts
index 693a7a04ec..6231c35ab9 100644
--- a/packages/backend/src/server/api/endpoints/meta.ts
+++ b/packages/backend/src/server/api/endpoints/meta.ts
@@ -1,23 +1,16 @@
-import $ from 'cafy';
-import config from '@/config/index';
-import define from '../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { Ads, Emojis, Users } from '@/models/index';
-import { DB_MAX_NOTE_TEXT_LENGTH } from '@/misc/hard-limits';
+import config from '@/config/index.js';
+import define from '../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { Ads, Emojis, Users } from '@/models/index.js';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '@/misc/hard-limits.js';
 import { MoreThan } from 'typeorm';
+import { MAX_NOTE_TEXT_LENGTH } from '@/const.js';
 
 export const meta = {
 	tags: ['meta'],
 
 	requireCredential: false,
 
-	params: {
-		detail: {
-			validator: $.optional.bool,
-			default: true,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -76,6 +69,14 @@ export const meta = {
 				optional: false, nullable: false,
 				default: false,
 			},
+			defaultDarkTheme: {
+				type: 'string',
+				optional: false, nullable: true,
+			},
+			defaultLightTheme: {
+				type: 'string',
+				optional: false, nullable: true,
+			},
 			disableRegistration: {
 				type: 'boolean',
 				optional: false, nullable: false,
@@ -100,10 +101,6 @@ export const meta = {
 				type: 'boolean',
 				optional: false, nullable: false,
 			},
-			proxyRemoteFiles: {
-				type: 'boolean',
-				optional: false, nullable: false,
-			},
 			emailRequiredForSignup: {
 				type: 'boolean',
 				optional: false, nullable: false,
@@ -149,7 +146,6 @@ export const meta = {
 			maxNoteTextLength: {
 				type: 'number',
 				optional: false, nullable: false,
-				default: 500,
 			},
 			emojis: {
 				type: 'array',
@@ -448,8 +444,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		detail: { type: 'boolean', default: true },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const instance = await fetchMeta(true);
 
 	const emojis = await Emojis.find({
@@ -499,14 +503,17 @@ export default define(meta, async (ps, me) => {
 		enableRecaptcha: instance.enableRecaptcha,
 		recaptchaSiteKey: instance.recaptchaSiteKey,
 		swPublickey: instance.swPublicKey,
+		themeColor: instance.themeColor,
 		mascotImageUrl: instance.mascotImageUrl,
 		bannerUrl: instance.bannerUrl,
 		errorImageUrl: instance.errorImageUrl,
 		iconUrl: instance.iconUrl,
 		backgroundImageUrl: instance.backgroundImageUrl,
 		logoImageUrl: instance.logoImageUrl,
-		maxNoteTextLength: Math.min(instance.maxNoteTextLength, DB_MAX_NOTE_TEXT_LENGTH),
+		maxNoteTextLength: MAX_NOTE_TEXT_LENGTH, // 後方互換性のため
 		emojis: await Emojis.packMany(emojis),
+		defaultLightTheme: instance.defaultLightTheme,
+		defaultDarkTheme: instance.defaultDarkTheme,
 		ads: ads.map(ad => ({
 			id: ad.id,
 			url: ad.url,
@@ -528,7 +535,6 @@ export default define(meta, async (ps, me) => {
 			pinnedPages: instance.pinnedPages,
 			pinnedClipId: instance.pinnedClipId,
 			cacheRemoteFiles: instance.cacheRemoteFiles,
-			proxyRemoteFiles: instance.proxyRemoteFiles,
 			requireSetup: (await Users.count({
 				host: null,
 			})) === 0,
diff --git a/packages/backend/src/server/api/endpoints/miauth/gen-token.ts b/packages/backend/src/server/api/endpoints/miauth/gen-token.ts
index 158c8877e9..73ecdaeb03 100644
--- a/packages/backend/src/server/api/endpoints/miauth/gen-token.ts
+++ b/packages/backend/src/server/api/endpoints/miauth/gen-token.ts
@@ -1,8 +1,7 @@
-import $ from 'cafy';
-import define from '../../define';
-import { AccessTokens } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { secureRndstr } from '@/misc/secure-rndstr';
+import define from '../../define.js';
+import { AccessTokens } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { secureRndstr } from '@/misc/secure-rndstr.js';
 
 export const meta = {
 	tags: ['auth'],
@@ -11,28 +10,6 @@ export const meta = {
 
 	secure: true,
 
-	params: {
-		session: {
-			validator: $.nullable.str,
-		},
-
-		name: {
-			validator: $.nullable.optional.str,
-		},
-
-		description: {
-			validator: $.nullable.optional.str,
-		},
-
-		iconUrl: {
-			validator: $.nullable.optional.str,
-		},
-
-		permission: {
-			validator: $.arr($.str).unique(),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -45,8 +22,22 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		session: { type: 'string', nullable: true },
+		name: { type: 'string', nullable: true },
+		description: { type: 'string', nullable: true },
+		iconUrl: { type: 'string', nullable: true },
+		permission: { type: 'array', uniqueItems: true, items: {
+			type: 'string',
+		} },
+	},
+	required: ['session', 'permission'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Generate access token
 	const accessToken = secureRndstr(32, true);
 
diff --git a/packages/backend/src/server/api/endpoints/mute/create.ts b/packages/backend/src/server/api/endpoints/mute/create.ts
index 6ba5a453c3..0178aab143 100644
--- a/packages/backend/src/server/api/endpoints/mute/create.ts
+++ b/packages/backend/src/server/api/endpoints/mute/create.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { genId } from '@/misc/gen-id';
-import { Mutings, NoteWatchings } from '@/models/index';
-import { Muting } from '@/models/entities/muting';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { genId } from '@/misc/gen-id.js';
+import { Mutings, NoteWatchings } from '@/models/index.js';
+import { Muting } from '@/models/entities/muting.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['account'],
@@ -15,12 +13,6 @@ export const meta = {
 
 	kind: 'write:mutes',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -42,8 +34,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const muter = user;
 
 	// 自分自身
diff --git a/packages/backend/src/server/api/endpoints/mute/delete.ts b/packages/backend/src/server/api/endpoints/mute/delete.ts
index 21948dc3d1..a8cf2a6667 100644
--- a/packages/backend/src/server/api/endpoints/mute/delete.ts
+++ b/packages/backend/src/server/api/endpoints/mute/delete.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { Mutings } from '@/models/index';
-import { publishUserEvent } from '@/services/stream';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { Mutings } from '@/models/index.js';
+import { publishUserEvent } from '@/services/stream.js';
 
 export const meta = {
 	tags: ['account'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:mutes',
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -40,8 +32,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const muter = user;
 
 	// Check if the mutee is yourself
diff --git a/packages/backend/src/server/api/endpoints/mute/list.ts b/packages/backend/src/server/api/endpoints/mute/list.ts
index 4c6a81b63c..31283cf4c1 100644
--- a/packages/backend/src/server/api/endpoints/mute/list.ts
+++ b/packages/backend/src/server/api/endpoints/mute/list.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Mutings } from '@/models/index';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Mutings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
@@ -11,21 +9,6 @@ export const meta = {
 
 	kind: 'read:mutes',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 30,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -37,13 +20,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 30 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Mutings.createQueryBuilder('muting'), ps.sinceId, ps.untilId)
 		.andWhere(`muting.muterId = :meId`, { meId: me.id });
 
 	const mutings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Mutings.packMany(mutings, me);
diff --git a/packages/backend/src/server/api/endpoints/my/apps.ts b/packages/backend/src/server/api/endpoints/my/apps.ts
index 42bd5c5f75..85b75c15df 100644
--- a/packages/backend/src/server/api/endpoints/my/apps.ts
+++ b/packages/backend/src/server/api/endpoints/my/apps.ts
@@ -1,83 +1,40 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Apps } from '@/models/index';
+import define from '../../define.js';
+import { Apps } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account', 'app'],
 
 	requireCredential: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
 		items: {
 			type: 'object',
 			optional: false, nullable: false,
-			properties: {
-				id: {
-					type: 'string',
-					optional: false, nullable: false,
-				},
-				name: {
-					type: 'string',
-					optional: false, nullable: false,
-				},
-				callbackUrl: {
-					type: 'string',
-					optional: false, nullable: false,
-				},
-				permission: {
-					type: 'array',
-					optional: false, nullable: false,
-					items: {
-						type: 'string',
-						optional: false, nullable: false,
-					},
-				},
-				secret: {
-					type: 'string',
-					optional: true, nullable: false,
-				},
-				isAuthorized: {
-					type: 'object',
-					optional: true, nullable: false,
-					properties: {
-						appId: {
-							type: 'string',
-							optional: false, nullable: false,
-						},
-						userId: {
-							type: 'string',
-							optional: false, nullable: false,
-						},
-					},
-				},
-			},
+			ref: 'App',
 		},
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = {
 		userId: user.id,
 	};
 
 	const apps = await Apps.find({
 		where: query,
-		take: ps.limit!,
+		take: ps.limit,
 		skip: ps.offset,
 	});
 
diff --git a/packages/backend/src/server/api/endpoints/notes.ts b/packages/backend/src/server/api/endpoints/notes.ts
index 9edc6cb11c..96657f8d3f 100644
--- a/packages/backend/src/server/api/endpoints/notes.ts
+++ b/packages/backend/src/server/api/endpoints/notes.ts
@@ -1,47 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../define';
-import { makePaginationQuery } from '../common/make-pagination-query';
-import { Notes } from '@/models/index';
+import define from '../define.js';
+import { makePaginationQuery } from '../common/make-pagination-query.js';
+import { Notes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
 
-	params: {
-		local: {
-			validator: $.optional.bool,
-		},
-
-		reply: {
-			validator: $.optional.bool,
-		},
-
-		renote: {
-			validator: $.optional.bool,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-		},
-
-		poll: {
-			validator: $.optional.bool,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -53,16 +16,37 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		local: { type: 'boolean' },
+		reply: { type: 'boolean' },
+		renote: { type: 'boolean' },
+		withFiles: { type: 'boolean' },
+		poll: { type: 'boolean' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere(`note.visibility = 'public'`)
 		.andWhere(`note.localOnly = FALSE`)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	if (ps.local) {
 		query.andWhere('note.userHost IS NULL');
@@ -89,7 +73,7 @@ export default define(meta, async (ps) => {
 	//	query.isBot = bot;
 	//}
 
-	const notes = await query.take(ps.limit!).getMany();
+	const notes = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(notes);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/children.ts b/packages/backend/src/server/api/endpoints/notes/children.ts
index 088ef65e96..86dde30d64 100644
--- a/packages/backend/src/server/api/endpoints/notes/children.ts
+++ b/packages/backend/src/server/api/endpoints/notes/children.ts
@@ -1,38 +1,17 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
 import { Brackets } from 'typeorm';
-import { Notes } from '@/models/index';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
-import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query';
+import { Notes } from '@/models/index.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
+import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -44,8 +23,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere(new Brackets(qb => { qb
 			.where(`note.replyId = :noteId`, { noteId: ps.noteId })
@@ -59,17 +49,23 @@ export default define(meta, async (ps, user) => {
 			}));
 		}))
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, user);
 	if (user) generateMutedUserQuery(query, user);
 	if (user) generateBlockedUserQuery(query, user);
 	if (user) generateMutedInstanceQuery(query, user);
 
-	const notes = await query.take(ps.limit!).getMany();
+	const notes = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(notes, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/clips.ts b/packages/backend/src/server/api/endpoints/notes/clips.ts
index b89c6db4a8..9a863b7148 100644
--- a/packages/backend/src/server/api/endpoints/notes/clips.ts
+++ b/packages/backend/src/server/api/endpoints/notes/clips.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ClipNotes, Clips } from '@/models/index';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
+import define from '../../define.js';
+import { ClipNotes, Clips } from '@/models/index.js';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
 import { In } from 'typeorm';
 
 export const meta = {
@@ -11,12 +9,6 @@ export const meta = {
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -36,8 +28,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/conversation.ts b/packages/backend/src/server/api/endpoints/notes/conversation.ts
index 4bd89c32e7..2552c0f99d 100644
--- a/packages/backend/src/server/api/endpoints/notes/conversation.ts
+++ b/packages/backend/src/server/api/endpoints/notes/conversation.ts
@@ -1,32 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getNote } from '../../common/getters';
-import { Note } from '@/models/entities/note';
-import { Notes } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getNote } from '../../common/getters.js';
+import { Note } from '@/models/entities/note.js';
+import { Notes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -46,8 +28,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
@@ -65,7 +57,7 @@ export default define(meta, async (ps, user) => {
 			conversation.push(p);
 		}
 
-		if (conversation.length == ps.limit!) {
+		if (conversation.length == ps.limit) {
 			return;
 		}
 
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index 4efa76b248..e4a9b28891 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -1,26 +1,14 @@
-import $ from 'cafy';
 import ms from 'ms';
-import { length } from 'stringz';
-import create from '@/services/note/create';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { ApiError } from '../../error';
-import { ID } from '@/misc/cafy-id';
-import { User } from '@/models/entities/user';
-import { Users, DriveFiles, Notes, Channels, Blockings } from '@/models/index';
-import { DriveFile } from '@/models/entities/drive-file';
-import { Note } from '@/models/entities/note';
-import { DB_MAX_NOTE_TEXT_LENGTH } from '@/misc/hard-limits';
-import { noteVisibilities } from '../../../../types';
-import { Channel } from '@/models/entities/channel';
-
-let maxNoteTextLength = 500;
-
-setInterval(() => {
-	fetchMeta().then(m => {
-		maxNoteTextLength = m.maxNoteTextLength;
-	});
-}, 3000);
+import create from '@/services/note/create.js';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { User } from '@/models/entities/user.js';
+import { Users, DriveFiles, Notes, Channels, Blockings } from '@/models/index.js';
+import { DriveFile } from '@/models/entities/drive-file.js';
+import { Note } from '@/models/entities/note.js';
+import { noteVisibilities } from '../../../../types.js';
+import { Channel } from '@/models/entities/channel.js';
+import { MAX_NOTE_TEXT_LENGTH } from '@/const.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -34,84 +22,6 @@ export const meta = {
 
 	kind: 'write:notes',
 
-	params: {
-		visibility: {
-			validator: $.optional.str.or(noteVisibilities as unknown as string[]),
-			default: 'public',
-		},
-
-		visibleUserIds: {
-			validator: $.optional.arr($.type(ID)).unique().min(0),
-		},
-
-		text: {
-			validator: $.optional.nullable.str.pipe(text =>
-				text.trim() != ''
-					&& length(text.trim()) <= maxNoteTextLength
-					&& Array.from(text.trim()).length <= DB_MAX_NOTE_TEXT_LENGTH,	// DB limit
-			),
-			default: null,
-		},
-
-		cw: {
-			validator: $.optional.nullable.str.pipe(Notes.validateCw),
-		},
-
-		localOnly: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		noExtractMentions: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		noExtractHashtags: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		noExtractEmojis: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		fileIds: {
-			validator: $.optional.arr($.type(ID)).unique().range(1, 16),
-		},
-
-		mediaIds: {
-			validator: $.optional.arr($.type(ID)).unique().range(1, 16),
-			deprecated: true,
-		},
-
-		replyId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		renoteId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		channelId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		poll: {
-			validator: $.optional.nullable.obj({
-				choices: $.arr($.str)
-					.unique()
-					.range(2, 10)
-					.each(c => c.length > 0 && c.length < 50),
-				multiple: $.optional.bool,
-				expiresAt: $.optional.nullable.num.int(),
-				expiredAfter: $.optional.nullable.num.int().min(1),
-			}).strict(),
-			ref: 'poll',
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -175,8 +85,49 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		visibility: { type: 'string', enum: ['public', 'home', 'followers', 'specified'], default: "public" },
+		visibleUserIds: { type: 'array', uniqueItems: true, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		text: { type: 'string', nullable: true, maxLength: MAX_NOTE_TEXT_LENGTH, default: null },
+		cw: { type: 'string', nullable: true, maxLength: 100 },
+		localOnly: { type: 'boolean', default: false },
+		noExtractMentions: { type: 'boolean', default: false },
+		noExtractHashtags: { type: 'boolean', default: false },
+		noExtractEmojis: { type: 'boolean', default: false },
+		fileIds: { type: 'array', uniqueItems: true, minItems: 1, maxItems: 16, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		mediaIds: { type: 'array', uniqueItems: true, minItems: 1, maxItems: 16, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		replyId: { type: 'string', format: 'misskey:id', nullable: true },
+		renoteId: { type: 'string', format: 'misskey:id', nullable: true },
+		channelId: { type: 'string', format: 'misskey:id', nullable: true },
+		poll: {
+			type: 'object', nullable: true,
+			properties: {
+				choices: {
+					type: 'array', uniqueItems: true, minItems: 2, maxItems: 10, 
+					items: {
+						type: 'string', minLength: 1, maxLength: 50,
+					},
+				},
+				multiple: { type: 'boolean', default: false },
+				expiresAt: { type: 'integer', nullable: true },
+				expiredAfter: { type: 'integer', nullable: true, minimum: 1 },
+			},
+			required: ['choices'],
+		},
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let visibleUsers: User[] = [];
 	if (ps.visibleUserIds) {
 		visibleUsers = (await Promise.all(ps.visibleUserIds.map(id => Users.findOne(id))))
diff --git a/packages/backend/src/server/api/endpoints/notes/delete.ts b/packages/backend/src/server/api/endpoints/notes/delete.ts
index 9e080d9e99..22ff2275ca 100644
--- a/packages/backend/src/server/api/endpoints/notes/delete.ts
+++ b/packages/backend/src/server/api/endpoints/notes/delete.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import deleteNote from '@/services/note/delete';
-import define from '../../define';
+import deleteNote from '@/services/note/delete.js';
+import define from '../../define.js';
 import ms from 'ms';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
-import { Users } from '@/models/index';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -20,12 +18,6 @@ export const meta = {
 		minInterval: ms('1sec'),
 	},
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -41,8 +33,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/favorites/create.ts b/packages/backend/src/server/api/endpoints/notes/favorites/create.ts
index 78da6a3b00..bcc2c44c02 100644
--- a/packages/backend/src/server/api/endpoints/notes/favorites/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/favorites/create.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getNote } from '../../../common/getters';
-import { NoteFavorites } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getNote } from '../../../common/getters.js';
+import { NoteFavorites } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['notes', 'favorites'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:favorites',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -34,8 +26,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Get favoritee
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
diff --git a/packages/backend/src/server/api/endpoints/notes/favorites/delete.ts b/packages/backend/src/server/api/endpoints/notes/favorites/delete.ts
index 3f3d50f0d5..d41fab22d3 100644
--- a/packages/backend/src/server/api/endpoints/notes/favorites/delete.ts
+++ b/packages/backend/src/server/api/endpoints/notes/favorites/delete.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getNote } from '../../../common/getters';
-import { NoteFavorites } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getNote } from '../../../common/getters.js';
+import { NoteFavorites } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes', 'favorites'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:favorites',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -33,8 +25,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Get favoritee
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
diff --git a/packages/backend/src/server/api/endpoints/notes/featured.ts b/packages/backend/src/server/api/endpoints/notes/featured.ts
index 5a47fb9e08..6308d23696 100644
--- a/packages/backend/src/server/api/endpoints/notes/featured.ts
+++ b/packages/backend/src/server/api/endpoints/notes/featured.ts
@@ -1,26 +1,13 @@
-import $ from 'cafy';
-import define from '../../define';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { Notes } from '@/models/index';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { Notes } from '@/models/index.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -32,8 +19,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const max = 30;
 	const day = 1000 * 60 * 60 * 24 * 3; // 3日前まで
 
@@ -44,10 +40,16 @@ export default define(meta, async (ps, user) => {
 		.andWhere(`note.createdAt > :date`, { date: new Date(Date.now() - day) })
 		.andWhere(`note.visibility = 'public'`)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	if (user) generateMutedUserQuery(query, user);
 	if (user) generateBlockedUserQuery(query, user);
diff --git a/packages/backend/src/server/api/endpoints/notes/global-timeline.ts b/packages/backend/src/server/api/endpoints/notes/global-timeline.ts
index cac8b7d8a9..26aaa0919c 100644
--- a/packages/backend/src/server/api/endpoints/notes/global-timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/global-timeline.ts
@@ -1,47 +1,18 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { ApiError } from '../../error';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Notes } from '@/models/index';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query';
-import { activeUsersChart } from '@/services/chart/index';
-import { generateRepliesQuery } from '../../common/generate-replies-query';
-import { generateMutedNoteQuery } from '../../common/generate-muted-note-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { ApiError } from '../../error.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Notes } from '@/models/index.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
+import { generateRepliesQuery } from '../../common/generate-replies-query.js';
+import { generateMutedNoteQuery } from '../../common/generate-muted-note-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
-	params: {
-		withFiles: {
-			validator: $.optional.bool,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -61,8 +32,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		withFiles: { type: 'boolean' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const m = await fetchMeta();
 	if (m.disableGlobalTimeline) {
 		if (user == null || (!user.isAdmin && !user.isModerator)) {
@@ -76,10 +60,16 @@ export default define(meta, async (ps, user) => {
 		.andWhere('note.visibility = \'public\'')
 		.andWhere('note.channelId IS NULL')
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateRepliesQuery(query, user);
 	if (user) generateMutedUserQuery(query, user);
@@ -92,11 +82,11 @@ export default define(meta, async (ps, user) => {
 	}
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	process.nextTick(() => {
 		if (user) {
-			activeUsersChart.update(user);
+			activeUsersChart.read(user);
 		}
 	});
 
diff --git a/packages/backend/src/server/api/endpoints/notes/hybrid-timeline.ts b/packages/backend/src/server/api/endpoints/notes/hybrid-timeline.ts
index 9683df4611..9bcb64b656 100644
--- a/packages/backend/src/server/api/endpoints/notes/hybrid-timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/hybrid-timeline.ts
@@ -1,67 +1,23 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { ApiError } from '../../error';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Followings, Notes } from '@/models/index';
+import define from '../../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { ApiError } from '../../error.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Followings, Notes } from '@/models/index.js';
 import { Brackets } from 'typeorm';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query';
-import { activeUsersChart } from '@/services/chart/index';
-import { generateRepliesQuery } from '../../common/generate-replies-query';
-import { generateMutedNoteQuery } from '../../common/generate-muted-note-query';
-import { generateChannelQuery } from '../../common/generate-channel-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
+import { generateRepliesQuery } from '../../common/generate-replies-query.js';
+import { generateMutedNoteQuery } from '../../common/generate-muted-note-query.js';
+import { generateChannelQuery } from '../../common/generate-channel-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-
-		includeMyRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeRenotedMyNotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeLocalRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -81,8 +37,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+		includeMyRenotes: { type: 'boolean', default: true },
+		includeRenotedMyNotes: { type: 'boolean', default: true },
+		includeLocalRenotes: { type: 'boolean', default: true },
+		withFiles: { type: 'boolean' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const m = await fetchMeta();
 	if (m.disableLocalTimeline && !user.isAdmin && !user.isModerator) {
 		throw new ApiError(meta.errors.stlDisabled);
@@ -100,10 +72,16 @@ export default define(meta, async (ps, user) => {
 				.orWhere('(note.visibility = \'public\') AND (note.userHost IS NULL)');
 		}))
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.setParameters(followingQuery.getParameters());
 
 	generateChannelQuery(query, user);
@@ -149,11 +127,11 @@ export default define(meta, async (ps, user) => {
 	}
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	process.nextTick(() => {
 		if (user) {
-			activeUsersChart.update(user);
+			activeUsersChart.read(user);
 		}
 	});
 
diff --git a/packages/backend/src/server/api/endpoints/notes/local-timeline.ts b/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
index 7776644124..12fc88b1fd 100644
--- a/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
@@ -1,58 +1,20 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { ApiError } from '../../error';
-import { Notes } from '@/models/index';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { activeUsersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { ApiError } from '../../error.js';
+import { Notes } from '@/models/index.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
 import { Brackets } from 'typeorm';
-import { generateRepliesQuery } from '../../common/generate-replies-query';
-import { generateMutedNoteQuery } from '../../common/generate-muted-note-query';
-import { generateChannelQuery } from '../../common/generate-channel-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import { generateRepliesQuery } from '../../common/generate-replies-query.js';
+import { generateMutedNoteQuery } from '../../common/generate-muted-note-query.js';
+import { generateChannelQuery } from '../../common/generate-channel-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
-	params: {
-		withFiles: {
-			validator: $.optional.bool,
-		},
-
-		fileType: {
-			validator: $.optional.arr($.str),
-		},
-
-		excludeNsfw: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -72,8 +34,25 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		withFiles: { type: 'boolean' },
+		fileType: { type: 'array', items: {
+			type: 'string',
+		} },
+		excludeNsfw: { type: 'boolean', default: false },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const m = await fetchMeta();
 	if (m.disableLocalTimeline) {
 		if (user == null || (!user.isAdmin && !user.isModerator)) {
@@ -86,10 +65,16 @@ export default define(meta, async (ps, user) => {
 			ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
 		.andWhere('(note.visibility = \'public\') AND (note.userHost IS NULL)')
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateChannelQuery(query, user);
 	generateRepliesQuery(query, user);
@@ -118,11 +103,11 @@ export default define(meta, async (ps, user) => {
 	}
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	process.nextTick(() => {
 		if (user) {
-			activeUsersChart.update(user);
+			activeUsersChart.read(user);
 		}
 	});
 
diff --git a/packages/backend/src/server/api/endpoints/notes/mentions.ts b/packages/backend/src/server/api/endpoints/notes/mentions.ts
index 81b3844365..eafbba322d 100644
--- a/packages/backend/src/server/api/endpoints/notes/mentions.ts
+++ b/packages/backend/src/server/api/endpoints/notes/mentions.ts
@@ -1,44 +1,18 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import read from '@/services/note/read';
-import { Notes, Followings } from '@/models/index';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import read from '@/services/note/read.js';
+import { Notes, Followings } from '@/models/index.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 import { Brackets } from 'typeorm';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
-import { generateMutedNoteThreadQuery } from '../../common/generate-muted-note-thread-query';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
+import { generateMutedNoteThreadQuery } from '../../common/generate-muted-note-thread-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: true,
 
-	params: {
-		following: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		visibility: {
-			validator: $.optional.str,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -50,8 +24,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		following: { type: 'boolean', default: false },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		visibility: { type: 'string' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const followingQuery = Followings.createQueryBuilder('following')
 		.select('following.followeeId')
 		.where('following.followerId = :followerId', { followerId: user.id });
@@ -62,10 +48,16 @@ export default define(meta, async (ps, user) => {
 			.orWhere(`'{"${user.id}"}' <@ note.visibleUserIds`);
 		}))
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, user);
 	generateMutedUserQuery(query, user);
@@ -81,7 +73,7 @@ export default define(meta, async (ps, user) => {
 		query.setParameters(followingQuery.getParameters());
 	}
 
-	const mentions = await query.take(ps.limit!).getMany();
+	const mentions = await query.take(ps.limit).getMany();
 
 	read(user.id, mentions);
 
diff --git a/packages/backend/src/server/api/endpoints/notes/polls/recommendation.ts b/packages/backend/src/server/api/endpoints/notes/polls/recommendation.ts
index 79b558e65e..bdd1aeecd4 100644
--- a/packages/backend/src/server/api/endpoints/notes/polls/recommendation.ts
+++ b/packages/backend/src/server/api/endpoints/notes/polls/recommendation.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { Polls, Mutings, Notes, PollVotes } from '@/models/index';
+import define from '../../../define.js';
+import { Polls, Mutings, Notes, PollVotes } from '@/models/index.js';
 import { Brackets, In } from 'typeorm';
 
 export const meta = {
@@ -8,18 +7,6 @@ export const meta = {
 
 	requireCredential: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -31,8 +18,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = Polls.createQueryBuilder('poll')
 		.where('poll.userHost IS NULL')
 		.andWhere(`poll.userId != :meId`, { meId: user.id })
@@ -64,7 +60,7 @@ export default define(meta, async (ps, user) => {
 	query.setParameters(mutingQuery.getParameters());
 	//#endregion
 
-	const polls = await query.take(ps.limit!).skip(ps.offset).getMany();
+	const polls = await query.take(ps.limit).skip(ps.offset).getMany();
 
 	if (polls.length === 0) return [];
 
diff --git a/packages/backend/src/server/api/endpoints/notes/polls/vote.ts b/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
index 77387cacb2..ef52d03664 100644
--- a/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
+++ b/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
@@ -1,18 +1,16 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishNoteStream } from '@/services/stream';
-import { createNotification } from '@/services/create-notification';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getNote } from '../../../common/getters';
-import { deliver } from '@/queue/index';
-import { renderActivity } from '@/remote/activitypub/renderer/index';
-import renderVote from '@/remote/activitypub/renderer/vote';
-import { deliverQuestionUpdate } from '@/services/note/polls/update';
-import { PollVotes, NoteWatchings, Users, Polls, Blockings } from '@/models/index';
+import { publishNoteStream } from '@/services/stream.js';
+import { createNotification } from '@/services/create-notification.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getNote } from '../../../common/getters.js';
+import { deliver } from '@/queue/index.js';
+import { renderActivity } from '@/remote/activitypub/renderer/index.js';
+import renderVote from '@/remote/activitypub/renderer/vote.js';
+import { deliverQuestionUpdate } from '@/services/note/polls/update.js';
+import { PollVotes, NoteWatchings, Users, Polls, Blockings } from '@/models/index.js';
 import { Not } from 'typeorm';
-import { IRemoteUser } from '@/models/entities/user';
-import { genId } from '@/misc/gen-id';
+import { IRemoteUser } from '@/models/entities/user.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -21,16 +19,6 @@ export const meta = {
 
 	kind: 'write:votes',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		choice: {
-			validator: $.num,
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -70,8 +58,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		choice: { type: 'integer' },
+	},
+	required: ['noteId', 'choice'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const createdAt = new Date();
 
 	// Get votee
diff --git a/packages/backend/src/server/api/endpoints/notes/reactions.ts b/packages/backend/src/server/api/endpoints/notes/reactions.ts
index 5205a78171..43e5d1ef6f 100644
--- a/packages/backend/src/server/api/endpoints/notes/reactions.ts
+++ b/packages/backend/src/server/api/endpoints/notes/reactions.ts
@@ -1,45 +1,15 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
-import { NoteReactions } from '@/models/index';
+import define from '../../define.js';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
+import { NoteReactions } from '@/models/index.js';
 import { DeepPartial } from 'typeorm';
-import { NoteReaction } from '@/models/entities/note-reaction';
+import { NoteReaction } from '@/models/entities/note-reaction.js';
 
 export const meta = {
 	tags: ['notes', 'reactions'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		type: {
-			validator: $.optional.nullable.str,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num,
-			default: 0,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -59,8 +29,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		type: { type: 'string', nullable: true },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
@@ -80,11 +63,12 @@ export default define(meta, async (ps, user) => {
 
 	const reactions = await NoteReactions.find({
 		where: query,
-		take: ps.limit!,
+		take: ps.limit,
 		skip: ps.offset,
 		order: {
 			id: -1,
 		},
+		relations: ['user', 'user.avatar', 'user.banner', 'note'],
 	});
 
 	return await Promise.all(reactions.map(reaction => NoteReactions.pack(reaction, user)));
diff --git a/packages/backend/src/server/api/endpoints/notes/reactions/create.ts b/packages/backend/src/server/api/endpoints/notes/reactions/create.ts
index 1b42781ceb..07e52a9266 100644
--- a/packages/backend/src/server/api/endpoints/notes/reactions/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/reactions/create.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import createReaction from '@/services/note/reaction/create';
-import define from '../../../define';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
+import createReaction from '@/services/note/reaction/create.js';
+import define from '../../../define.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['reactions', 'notes'],
@@ -12,16 +10,6 @@ export const meta = {
 
 	kind: 'write:reactions',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		reaction: {
-			validator: $.str,
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -43,8 +31,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		reaction: { type: 'string' },
+	},
+	required: ['noteId', 'reaction'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/reactions/delete.ts b/packages/backend/src/server/api/endpoints/notes/reactions/delete.ts
index 1d686b5971..639ecae264 100644
--- a/packages/backend/src/server/api/endpoints/notes/reactions/delete.ts
+++ b/packages/backend/src/server/api/endpoints/notes/reactions/delete.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
+import define from '../../../define.js';
 import ms from 'ms';
-import deleteReaction from '@/services/note/reaction/delete';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
+import deleteReaction from '@/services/note/reaction/delete.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['reactions', 'notes'],
@@ -19,12 +17,6 @@ export const meta = {
 		minInterval: ms('3sec'),
 	},
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -40,8 +32,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/renotes.ts b/packages/backend/src/server/api/endpoints/notes/renotes.ts
index f71d23146a..87c855a5e8 100644
--- a/packages/backend/src/server/api/endpoints/notes/renotes.ts
+++ b/packages/backend/src/server/api/endpoints/notes/renotes.ts
@@ -1,38 +1,17 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Notes } from '@/models/index';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Notes } from '@/models/index.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -52,8 +31,19 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
@@ -62,16 +52,22 @@ export default define(meta, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere(`note.renoteId = :renoteId`, { renoteId: note.id })
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, user);
 	if (user) generateMutedUserQuery(query, user);
 	if (user) generateBlockedUserQuery(query, user);
 
-	const renotes = await query.take(ps.limit!).getMany();
+	const renotes = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(renotes, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/replies.ts b/packages/backend/src/server/api/endpoints/notes/replies.ts
index 62c56534e1..3053eabe33 100644
--- a/packages/backend/src/server/api/endpoints/notes/replies.ts
+++ b/packages/backend/src/server/api/endpoints/notes/replies.ts
@@ -1,36 +1,15 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Notes } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { Notes } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -42,21 +21,38 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere('note.replyId = :replyId', { replyId: ps.noteId })
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, user);
 	if (user) generateMutedUserQuery(query, user);
 	if (user) generateBlockedUserQuery(query, user);
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(timeline, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/search-by-tag.ts b/packages/backend/src/server/api/endpoints/notes/search-by-tag.ts
index 87eaffe2f1..c6503eb057 100644
--- a/packages/backend/src/server/api/endpoints/notes/search-by-tag.ts
+++ b/packages/backend/src/server/api/endpoints/notes/search-by-tag.ts
@@ -1,60 +1,16 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Notes } from '@/models/index';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Notes } from '@/models/index.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
 import { Brackets } from 'typeorm';
-import { safeForSql } from '@/misc/safe-for-sql';
-import { normalizeForSearch } from '@/misc/normalize-for-search';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import { safeForSql } from '@/misc/safe-for-sql.js';
+import { normalizeForSearch } from '@/misc/normalize-for-search.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes', 'hashtags'],
 
-	params: {
-		tag: {
-			validator: $.optional.str,
-		},
-
-		query: {
-			validator: $.optional.arr($.arr($.str)),
-		},
-
-		reply: {
-			validator: $.optional.nullable.bool,
-			default: null,
-		},
-
-		renote: {
-			validator: $.optional.nullable.bool,
-			default: null,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-		},
-
-		poll: {
-			validator: $.optional.nullable.bool,
-			default: null,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -66,14 +22,40 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		tag: { type: 'string' },
+		query: { type: 'array', items: {
+			type: 'array', items: {
+				type: 'string',
+			},
+		} },
+		reply: { type: 'boolean', nullable: true, default: null },
+		renote: { type: 'boolean', nullable: true, default: null },
+		withFiles: { type: 'boolean' },
+		poll: { type: 'boolean', nullable: true, default: null },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, me);
 	if (me) generateMutedUserQuery(query, me);
@@ -129,7 +111,7 @@ export default define(meta, async (ps, me) => {
 	}
 
 	// Search notes
-	const notes = await query.take(ps.limit!).getMany();
+	const notes = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(notes, me);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/search.ts b/packages/backend/src/server/api/endpoints/notes/search.ts
index e75212b14b..e77892b150 100644
--- a/packages/backend/src/server/api/endpoints/notes/search.ts
+++ b/packages/backend/src/server/api/endpoints/notes/search.ts
@@ -1,54 +1,18 @@
-import $ from 'cafy';
-import es from '../../../../db/elasticsearch';
-import define from '../../define';
-import { Notes } from '@/models/index';
+import es from '../../../../db/elasticsearch.js';
+import define from '../../define.js';
+import { Notes } from '@/models/index.js';
 import { In } from 'typeorm';
-import { ID } from '@/misc/cafy-id';
-import config from '@/config/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import config from '@/config/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		query: {
-			validator: $.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-			default: undefined,
-		},
-
-		userId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-
-		channelId: {
-			validator: $.optional.nullable.type(ID),
-			default: null,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -63,8 +27,23 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		query: { type: 'string' },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+		host: { type: 'string', nullable: true },
+		userId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+		channelId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
+	},
+	required: ['query'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	if (es == null) {
 		const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId);
 
@@ -77,16 +56,22 @@ export default define(meta, async (ps, me) => {
 		query
 			.andWhere('note.text ILIKE :q', { q: `%${ps.query}%` })
 			.innerJoinAndSelect('note.user', 'user')
+			.leftJoinAndSelect('user.avatar', 'avatar')
+			.leftJoinAndSelect('user.banner', 'banner')
 			.leftJoinAndSelect('note.reply', 'reply')
 			.leftJoinAndSelect('note.renote', 'renote')
 			.leftJoinAndSelect('reply.user', 'replyUser')
-			.leftJoinAndSelect('renote.user', 'renoteUser');
+			.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+			.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+			.leftJoinAndSelect('renote.user', 'renoteUser')
+			.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+			.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 		generateVisibilityQuery(query, me);
 		if (me) generateMutedUserQuery(query, me);
 		if (me) generateBlockedUserQuery(query, me);
 
-		const notes = await query.take(ps.limit!).getMany();
+		const notes = await query.take(ps.limit).getMany();
 
 		return await Notes.packMany(notes, me);
 	} else {
@@ -115,7 +100,7 @@ export default define(meta, async (ps, me) => {
 		const result = await es.search({
 			index: config.elasticsearch.index || 'misskey_note',
 			body: {
-				size: ps.limit!,
+				size: ps.limit,
 				from: ps.offset,
 				query: {
 					bool: {
diff --git a/packages/backend/src/server/api/endpoints/notes/show.ts b/packages/backend/src/server/api/endpoints/notes/show.ts
index feb94be1a1..d6692923c3 100644
--- a/packages/backend/src/server/api/endpoints/notes/show.ts
+++ b/packages/backend/src/server/api/endpoints/notes/show.ts
@@ -1,21 +1,13 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
-import { Notes } from '@/models/index';
+import define from '../../define.js';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
+import { Notes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -31,8 +23,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/state.ts b/packages/backend/src/server/api/endpoints/notes/state.ts
index c3e9090bbf..6fdb8e88fb 100644
--- a/packages/backend/src/server/api/endpoints/notes/state.ts
+++ b/packages/backend/src/server/api/endpoints/notes/state.ts
@@ -1,19 +1,11 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { NoteFavorites, Notes, NoteThreadMutings, NoteWatchings } from '@/models/index';
+import define from '../../define.js';
+import { NoteFavorites, Notes, NoteThreadMutings, NoteWatchings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: true,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -34,8 +26,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await Notes.findOneOrFail(ps.noteId);
 
 	const [favorite, watching, threadMuting] = await Promise.all([
diff --git a/packages/backend/src/server/api/endpoints/notes/thread-muting/create.ts b/packages/backend/src/server/api/endpoints/notes/thread-muting/create.ts
index a8b50d90f6..e48a2cf576 100644
--- a/packages/backend/src/server/api/endpoints/notes/thread-muting/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/thread-muting/create.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
-import { Notes, NoteThreadMutings } from '@/models';
-import { genId } from '@/misc/gen-id';
-import readNote from '@/services/note/read';
+import define from '../../../define.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
+import { Notes, NoteThreadMutings } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import readNote from '@/services/note/read.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -14,12 +12,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -29,8 +21,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/thread-muting/delete.ts b/packages/backend/src/server/api/endpoints/notes/thread-muting/delete.ts
index f76b526ce1..4fb3137a5e 100644
--- a/packages/backend/src/server/api/endpoints/notes/thread-muting/delete.ts
+++ b/packages/backend/src/server/api/endpoints/notes/thread-muting/delete.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
-import { NoteThreadMutings } from '@/models';
+import define from '../../../define.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
+import { NoteThreadMutings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/timeline.ts b/packages/backend/src/server/api/endpoints/notes/timeline.ts
index 8be2861aec..fde66b241b 100644
--- a/packages/backend/src/server/api/endpoints/notes/timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/timeline.ts
@@ -1,65 +1,21 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { Notes, Followings } from '@/models/index';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
-import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query';
-import { activeUsersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { Notes, Followings } from '@/models/index.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
+import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
 import { Brackets } from 'typeorm';
-import { generateRepliesQuery } from '../../common/generate-replies-query';
-import { generateMutedNoteQuery } from '../../common/generate-muted-note-query';
-import { generateChannelQuery } from '../../common/generate-channel-query';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
+import { generateRepliesQuery } from '../../common/generate-replies-query.js';
+import { generateMutedNoteQuery } from '../../common/generate-muted-note-query.js';
+import { generateChannelQuery } from '../../common/generate-channel-query.js';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: true,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-
-		includeMyRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeRenotedMyNotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeLocalRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -71,8 +27,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+		includeMyRenotes: { type: 'boolean', default: true },
+		includeRenotedMyNotes: { type: 'boolean', default: true },
+		includeLocalRenotes: { type: 'boolean', default: true },
+		withFiles: { type: 'boolean' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const hasFollowing = (await Followings.count({
 		where: {
 			followerId: user.id,
@@ -92,10 +64,16 @@ export default define(meta, async (ps, user) => {
 			if (hasFollowing) qb.orWhere(`note.userId IN (${ followingQuery.getQuery() })`);
 		}))
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.setParameters(followingQuery.getParameters());
 
 	generateChannelQuery(query, user);
@@ -141,11 +119,11 @@ export default define(meta, async (ps, user) => {
 	}
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	process.nextTick(() => {
 		if (user) {
-			activeUsersChart.update(user);
+			activeUsersChart.read(user);
 		}
 	});
 
diff --git a/packages/backend/src/server/api/endpoints/notes/translate.ts b/packages/backend/src/server/api/endpoints/notes/translate.ts
index ed069cb75a..068df6940b 100644
--- a/packages/backend/src/server/api/endpoints/notes/translate.ts
+++ b/packages/backend/src/server/api/endpoints/notes/translate.ts
@@ -1,29 +1,18 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
+import define from '../../define.js';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
 import fetch from 'node-fetch';
-import config from '@/config/index';
-import { getAgentByUrl } from '@/misc/fetch';
-import { URLSearchParams } from 'url';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { Notes } from '@/models';
+import config from '@/config/index.js';
+import { getAgentByUrl } from '@/misc/fetch.js';
+import { URLSearchParams } from 'node:url';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { Notes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: false,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-		targetLang: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -38,8 +27,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+		targetLang: { type: 'string' },
+	},
+	required: ['noteId', 'targetLang'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/unrenote.ts b/packages/backend/src/server/api/endpoints/notes/unrenote.ts
index 8db543d328..a9aadba338 100644
--- a/packages/backend/src/server/api/endpoints/notes/unrenote.ts
+++ b/packages/backend/src/server/api/endpoints/notes/unrenote.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import deleteNote from '@/services/note/delete';
-import define from '../../define';
+import deleteNote from '@/services/note/delete.js';
+import define from '../../define.js';
 import ms from 'ms';
-import { getNote } from '../../common/getters';
-import { ApiError } from '../../error';
-import { Notes, Users } from '@/models/index';
+import { getNote } from '../../common/getters.js';
+import { ApiError } from '../../error.js';
+import { Notes, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -20,12 +18,6 @@ export const meta = {
 		minInterval: ms('1sec'),
 	},
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -35,8 +27,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/user-list-timeline.ts b/packages/backend/src/server/api/endpoints/notes/user-list-timeline.ts
index 89de73fb9d..0829d0e4c1 100644
--- a/packages/backend/src/server/api/endpoints/notes/user-list-timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/user-list-timeline.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { UserLists, UserListJoinings, Notes } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { activeUsersChart } from '@/services/chart/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { UserLists, UserListJoinings, Notes } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { activeUsersChart } from '@/services/chart/index.js';
 import { Brackets } from 'typeorm';
 
 export const meta = {
@@ -13,52 +11,6 @@ export const meta = {
 
 	requireCredential: true,
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-
-		includeMyRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeRenotedMyNotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		includeLocalRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -78,8 +30,25 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+		includeMyRenotes: { type: 'boolean', default: true },
+		includeRenotedMyNotes: { type: 'boolean', default: true },
+		includeLocalRenotes: { type: 'boolean', default: true },
+		withFiles: { type: 'boolean' },
+	},
+	required: ['listId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const list = await UserLists.findOne({
 		id: ps.listId,
 		userId: user.id,
@@ -97,10 +66,16 @@ export default define(meta, async (ps, user) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId)
 		.andWhere(`note.userId IN (${ listQuery.getQuery() })`)
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
 		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner')
 		.setParameters(listQuery.getParameters());
 
 	generateVisibilityQuery(query, user);
@@ -140,9 +115,9 @@ export default define(meta, async (ps, user) => {
 	}
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
-	activeUsersChart.update(user);
+	activeUsersChart.read(user);
 
 	return await Notes.packMany(timeline, user);
 });
diff --git a/packages/backend/src/server/api/endpoints/notes/watching/create.ts b/packages/backend/src/server/api/endpoints/notes/watching/create.ts
index 6433c6bc2a..8fdf84624e 100644
--- a/packages/backend/src/server/api/endpoints/notes/watching/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/watching/create.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import watch from '@/services/note/watch';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import watch from '@/services/note/watch.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/watching/delete.ts b/packages/backend/src/server/api/endpoints/notes/watching/delete.ts
index 3e9faa2b23..d58f09797c 100644
--- a/packages/backend/src/server/api/endpoints/notes/watching/delete.ts
+++ b/packages/backend/src/server/api/endpoints/notes/watching/delete.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import unwatch from '@/services/note/unwatch';
-import { getNote } from '../../../common/getters';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import unwatch from '@/services/note/unwatch.js';
+import { getNote } from '../../../common/getters.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['notes'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -27,8 +19,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/notifications/create.ts b/packages/backend/src/server/api/endpoints/notifications/create.ts
index bd8a7ba1b7..b339c8723d 100644
--- a/packages/backend/src/server/api/endpoints/notifications/create.ts
+++ b/packages/backend/src/server/api/endpoints/notifications/create.ts
@@ -1,6 +1,5 @@
-import $ from 'cafy';
-import define from '../../define';
-import { createNotification } from '@/services/create-notification';
+import define from '../../define.js';
+import { createNotification } from '@/services/create-notification.js';
 
 export const meta = {
 	tags: ['notifications'],
@@ -9,26 +8,22 @@ export const meta = {
 
 	kind: 'write:notifications',
 
-	params: {
-		body: {
-			validator: $.str,
-		},
-
-		header: {
-			validator: $.optional.nullable.str,
-		},
-
-		icon: {
-			validator: $.optional.nullable.str,
-		},
+	errors: {
 	},
+} as const;
 
-	errors: {
+export const paramDef = {
+	type: 'object',
+	properties: {
+		body: { type: 'string' },
+		header: { type: 'string', nullable: true },
+		icon: { type: 'string', nullable: true },
 	},
+	required: ['body'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user, token) => {
+export default define(meta, paramDef, async (ps, user, token) => {
 	createNotification(user.id, 'app', {
 		appAccessTokenId: token ? token.id : null,
 		customBody: ps.body,
diff --git a/packages/backend/src/server/api/endpoints/notifications/mark-all-as-read.ts b/packages/backend/src/server/api/endpoints/notifications/mark-all-as-read.ts
index 4cec38a95d..abefe07be6 100644
--- a/packages/backend/src/server/api/endpoints/notifications/mark-all-as-read.ts
+++ b/packages/backend/src/server/api/endpoints/notifications/mark-all-as-read.ts
@@ -1,6 +1,6 @@
-import { publishMainStream } from '@/services/stream';
-import define from '../../define';
-import { Notifications } from '@/models/index';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../define.js';
+import { Notifications } from '@/models/index.js';
 
 export const meta = {
 	tags: ['notifications', 'account'],
@@ -10,8 +10,14 @@ export const meta = {
 	kind: 'write:notifications',
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Update documents
 	await Notifications.update({
 		notifieeId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/notifications/read.ts b/packages/backend/src/server/api/endpoints/notifications/read.ts
index 7e23bc234d..34f4c155fa 100644
--- a/packages/backend/src/server/api/endpoints/notifications/read.ts
+++ b/packages/backend/src/server/api/endpoints/notifications/read.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishMainStream } from '@/services/stream';
-import define from '../../define';
-import { Notifications } from '@/models/index';
-import { readNotification } from '../../common/read-notification';
-import { ApiError } from '../../error';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../../define.js';
+import { Notifications } from '@/models/index.js';
+import { readNotification } from '../../common/read-notification.js';
+import { ApiError } from '../../error.js';
 
 export const meta = {
 	tags: ['notifications', 'account'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:notifications',
 
-	params: {
-		notificationId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNotification: {
 			message: 'No such notification.',
@@ -28,8 +20,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		notificationId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['notificationId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const notification = await Notifications.findOne({
 		notifieeId: user.id,
 		id: ps.notificationId,
diff --git a/packages/backend/src/server/api/endpoints/page-push.ts b/packages/backend/src/server/api/endpoints/page-push.ts
index 61c0160f83..acaa118470 100644
--- a/packages/backend/src/server/api/endpoints/page-push.ts
+++ b/packages/backend/src/server/api/endpoints/page-push.ts
@@ -1,28 +1,12 @@
-import $ from 'cafy';
-import define from '../define';
-import { ID } from '@/misc/cafy-id';
-import { publishMainStream } from '@/services/stream';
-import { Users, Pages } from '@/models/index';
-import { ApiError } from '../error';
+import define from '../define.js';
+import { publishMainStream } from '@/services/stream.js';
+import { Users, Pages } from '@/models/index.js';
+import { ApiError } from '../error.js';
 
 export const meta = {
 	requireCredential: true,
 	secure: true,
 
-	params: {
-		pageId: {
-			validator: $.type(ID),
-		},
-
-		event: {
-			validator: $.str,
-		},
-
-		var: {
-			validator: $.optional.nullable.any,
-		},
-	},
-
 	errors: {
 		noSuchPage: {
 			message: 'No such page.',
@@ -32,8 +16,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+		event: { type: 'string' },
+		var: {},
+	},
+	required: ['pageId', 'event'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const page = await Pages.findOne(ps.pageId);
 	if (page == null) {
 		throw new ApiError(meta.errors.noSuchPage);
diff --git a/packages/backend/src/server/api/endpoints/pages/create.ts b/packages/backend/src/server/api/endpoints/pages/create.ts
index 7ee50fbdfa..7cac530606 100644
--- a/packages/backend/src/server/api/endpoints/pages/create.ts
+++ b/packages/backend/src/server/api/endpoints/pages/create.ts
@@ -1,11 +1,9 @@
-import $ from 'cafy';
 import ms from 'ms';
-import define from '../../define';
-import { ID } from '@/misc/cafy-id';
-import { Pages, DriveFiles } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { Page } from '@/models/entities/page';
-import { ApiError } from '../../error';
+import define from '../../define.js';
+import { Pages, DriveFiles } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { Page } from '@/models/entities/page.js';
+import { ApiError } from '../../error.js';
 
 export const meta = {
 	tags: ['pages'],
@@ -19,51 +17,6 @@ export const meta = {
 		max: 300,
 	},
 
-	params: {
-		title: {
-			validator: $.str,
-		},
-
-		name: {
-			validator: $.str.min(1),
-		},
-
-		summary: {
-			validator: $.optional.nullable.str,
-		},
-
-		content: {
-			validator: $.arr($.obj()),
-		},
-
-		variables: {
-			validator: $.arr($.obj()),
-		},
-
-		script: {
-			validator: $.str,
-		},
-
-		eyeCatchingImageId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		font: {
-			validator: $.optional.str.or(['serif', 'sans-serif']),
-			default: 'sans-serif',
-		},
-
-		alignCenter: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		hideTitleWhenPinned: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -84,8 +37,29 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		title: { type: 'string' },
+		name: { type: 'string', minLength: 1 },
+		summary: { type: 'string', nullable: true },
+		content: { type: 'array', items: {
+			type: 'object', additionalProperties: true,
+		} },
+		variables: { type: 'array', items: {
+			type: 'object', additionalProperties: true,
+		} },
+		script: { type: 'string' },
+		eyeCatchingImageId: { type: 'string', format: 'misskey:id', nullable: true },
+		font: { type: 'string', enum: ['serif', 'sans-serif'], default: "sans-serif" },
+		alignCenter: { type: 'boolean', default: false },
+		hideTitleWhenPinned: { type: 'boolean', default: false },
+	},
+	required: ['title', 'name', 'content', 'variables', 'script'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let eyeCatchingImage = null;
 	if (ps.eyeCatchingImageId != null) {
 		eyeCatchingImage = await DriveFiles.findOne({
diff --git a/packages/backend/src/server/api/endpoints/pages/delete.ts b/packages/backend/src/server/api/endpoints/pages/delete.ts
index aeda823e52..ddf691f53c 100644
--- a/packages/backend/src/server/api/endpoints/pages/delete.ts
+++ b/packages/backend/src/server/api/endpoints/pages/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Pages } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Pages } from '@/models/index.js';
 
 export const meta = {
 	tags: ['pages'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:pages',
 
-	params: {
-		pageId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPage: {
 			message: 'No such page.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['pageId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const page = await Pages.findOne(ps.pageId);
 	if (page == null) {
 		throw new ApiError(meta.errors.noSuchPage);
diff --git a/packages/backend/src/server/api/endpoints/pages/featured.ts b/packages/backend/src/server/api/endpoints/pages/featured.ts
index 7f0d58b350..eeb6d509ca 100644
--- a/packages/backend/src/server/api/endpoints/pages/featured.ts
+++ b/packages/backend/src/server/api/endpoints/pages/featured.ts
@@ -1,5 +1,5 @@
-import define from '../../define';
-import { Pages } from '@/models/index';
+import define from '../../define.js';
+import { Pages } from '@/models/index.js';
 
 export const meta = {
 	tags: ['pages'],
@@ -17,8 +17,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Pages.createQueryBuilder('page')
 		.where('page.visibility = \'public\'')
 		.andWhere('page.likedCount > 0')
diff --git a/packages/backend/src/server/api/endpoints/pages/like.ts b/packages/backend/src/server/api/endpoints/pages/like.ts
index c479f637a9..cab78e576c 100644
--- a/packages/backend/src/server/api/endpoints/pages/like.ts
+++ b/packages/backend/src/server/api/endpoints/pages/like.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Pages, PageLikes } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Pages, PageLikes } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['pages'],
@@ -12,12 +10,6 @@ export const meta = {
 
 	kind: 'write:page-likes',
 
-	params: {
-		pageId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPage: {
 			message: 'No such page.',
@@ -39,8 +31,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['pageId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const page = await Pages.findOne(ps.pageId);
 	if (page == null) {
 		throw new ApiError(meta.errors.noSuchPage);
diff --git a/packages/backend/src/server/api/endpoints/pages/show.ts b/packages/backend/src/server/api/endpoints/pages/show.ts
index 5cda5386d5..4e3facae5b 100644
--- a/packages/backend/src/server/api/endpoints/pages/show.ts
+++ b/packages/backend/src/server/api/endpoints/pages/show.ts
@@ -1,29 +1,13 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Pages, Users } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
-import { Page } from '@/models/entities/page';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Pages, Users } from '@/models/index.js';
+import { Page } from '@/models/entities/page.js';
 
 export const meta = {
 	tags: ['pages'],
 
 	requireCredential: false,
 
-	params: {
-		pageId: {
-			validator: $.optional.type(ID),
-		},
-
-		name: {
-			validator: $.optional.str,
-		},
-
-		username: {
-			validator: $.optional.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -39,8 +23,18 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string' },
+		username: { type: 'string' },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	let page: Page | undefined;
 
 	if (ps.pageId) {
diff --git a/packages/backend/src/server/api/endpoints/pages/unlike.ts b/packages/backend/src/server/api/endpoints/pages/unlike.ts
index cca5e5b5a9..31cd1a3359 100644
--- a/packages/backend/src/server/api/endpoints/pages/unlike.ts
+++ b/packages/backend/src/server/api/endpoints/pages/unlike.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Pages, PageLikes } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Pages, PageLikes } from '@/models/index.js';
 
 export const meta = {
 	tags: ['pages'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:page-likes',
 
-	params: {
-		pageId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchPage: {
 			message: 'No such page.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['pageId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const page = await Pages.findOne(ps.pageId);
 	if (page == null) {
 		throw new ApiError(meta.errors.noSuchPage);
diff --git a/packages/backend/src/server/api/endpoints/pages/update.ts b/packages/backend/src/server/api/endpoints/pages/update.ts
index 991085ee09..24c8f467e6 100644
--- a/packages/backend/src/server/api/endpoints/pages/update.ts
+++ b/packages/backend/src/server/api/endpoints/pages/update.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
 import ms from 'ms';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Pages, DriveFiles } from '@/models/index';
-import { ID } from '@/misc/cafy-id';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Pages, DriveFiles } from '@/models/index.js';
 import { Not } from 'typeorm';
 
 export const meta = {
@@ -18,52 +16,6 @@ export const meta = {
 		max: 300,
 	},
 
-	params: {
-		pageId: {
-			validator: $.type(ID),
-		},
-
-		title: {
-			validator: $.str,
-		},
-
-		name: {
-			validator: $.str.min(1),
-		},
-
-		summary: {
-			validator: $.optional.nullable.str,
-		},
-
-		content: {
-			validator: $.arr($.obj()),
-		},
-
-		variables: {
-			validator: $.arr($.obj()),
-		},
-
-		script: {
-			validator: $.str,
-		},
-
-		eyeCatchingImageId: {
-			validator: $.optional.nullable.type(ID),
-		},
-
-		font: {
-			validator: $.optional.str.or(['serif', 'sans-serif']),
-		},
-
-		alignCenter: {
-			validator: $.optional.bool,
-		},
-
-		hideTitleWhenPinned: {
-			validator: $.optional.bool,
-		},
-	},
-
 	errors: {
 		noSuchPage: {
 			message: 'No such page.',
@@ -90,8 +42,30 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		pageId: { type: 'string', format: 'misskey:id' },
+		title: { type: 'string' },
+		name: { type: 'string', minLength: 1 },
+		summary: { type: 'string', nullable: true },
+		content: { type: 'array', items: {
+			type: 'object', additionalProperties: true,
+		} },
+		variables: { type: 'array', items: {
+			type: 'object', additionalProperties: true,
+		} },
+		script: { type: 'string' },
+		eyeCatchingImageId: { type: 'string', format: 'misskey:id', nullable: true },
+		font: { type: 'string', enum: ['serif', 'sans-serif'] },
+		alignCenter: { type: 'boolean' },
+		hideTitleWhenPinned: { type: 'boolean' },
+	},
+	required: ['pageId', 'title', 'name', 'content', 'variables', 'script'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const page = await Pages.findOne(ps.pageId);
 	if (page == null) {
 		throw new ApiError(meta.errors.noSuchPage);
diff --git a/packages/backend/src/server/api/endpoints/ping.ts b/packages/backend/src/server/api/endpoints/ping.ts
index 3eab70ae2e..2891a0860a 100644
--- a/packages/backend/src/server/api/endpoints/ping.ts
+++ b/packages/backend/src/server/api/endpoints/ping.ts
@@ -1,13 +1,10 @@
-import define from '../define';
+import define from '../define.js';
 
 export const meta = {
 	requireCredential: false,
 
 	tags: ['meta'],
 
-	params: {
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -20,8 +17,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	return {
 		pong: Date.now(),
 	};
diff --git a/packages/backend/src/server/api/endpoints/pinned-users.ts b/packages/backend/src/server/api/endpoints/pinned-users.ts
index ff0e22555f..1d26ab266e 100644
--- a/packages/backend/src/server/api/endpoints/pinned-users.ts
+++ b/packages/backend/src/server/api/endpoints/pinned-users.ts
@@ -1,17 +1,14 @@
-import define from '../define';
-import { Users } from '@/models/index';
-import { fetchMeta } from '@/misc/fetch-meta';
-import * as Acct from 'misskey-js/built/acct';
-import { User } from '@/models/entities/user';
+import define from '../define.js';
+import { Users } from '@/models/index.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import * as Acct from '@/misc/acct.js';
+import { User } from '@/models/entities/user.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -23,8 +20,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const meta = await fetchMeta();
 
 	const users = await Promise.all(meta.pinnedUsers.map(acct => Users.findOne(Acct.parse(acct))));
diff --git a/packages/backend/src/server/api/endpoints/promo/read.ts b/packages/backend/src/server/api/endpoints/promo/read.ts
index 8d8c60d755..ea34ca3aad 100644
--- a/packages/backend/src/server/api/endpoints/promo/read.ts
+++ b/packages/backend/src/server/api/endpoints/promo/read.ts
@@ -1,22 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getNote } from '../../common/getters';
-import { PromoReads } from '@/models/index';
-import { genId } from '@/misc/gen-id';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getNote } from '../../common/getters.js';
+import { PromoReads } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['notes'],
 
 	requireCredential: true,
 
-	params: {
-		noteId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchNote: {
 			message: 'No such note.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		noteId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['noteId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const note = await getNote(ps.noteId).catch(e => {
 		if (e.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
 		throw e;
diff --git a/packages/backend/src/server/api/endpoints/request-reset-password.ts b/packages/backend/src/server/api/endpoints/request-reset-password.ts
index af1aeb4311..18cd98b164 100644
--- a/packages/backend/src/server/api/endpoints/request-reset-password.ts
+++ b/packages/backend/src/server/api/endpoints/request-reset-password.ts
@@ -1,13 +1,12 @@
-import $ from 'cafy';
-import { publishMainStream } from '@/services/stream';
-import define from '../define';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../define.js';
 import rndstr from 'rndstr';
-import config from '@/config/index';
+import config from '@/config/index.js';
 import ms from 'ms';
-import { Users, UserProfiles, PasswordResetRequests } from '@/models/index';
-import { sendEmail } from '@/services/send-email';
-import { ApiError } from '../error';
-import { genId } from '@/misc/gen-id';
+import { Users, UserProfiles, PasswordResetRequests } from '@/models/index.js';
+import { sendEmail } from '@/services/send-email.js';
+import { ApiError } from '../error.js';
+import { genId } from '@/misc/gen-id.js';
 import { IsNull } from 'typeorm';
 
 export const meta = {
@@ -18,23 +17,22 @@ export const meta = {
 		max: 3,
 	},
 
-	params: {
-		username: {
-			validator: $.str,
-		},
+	errors: {
 
-		email: {
-			validator: $.str,
-		},
 	},
+} as const;
 
-	errors: {
-
+export const paramDef = {
+	type: 'object',
+	properties: {
+		username: { type: 'string' },
+		email: { type: 'string' },
 	},
+	required: ['username', 'email'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	const user = await Users.findOne({
 		usernameLower: ps.username.toLowerCase(),
 		host: IsNull(),
diff --git a/packages/backend/src/server/api/endpoints/reset-db.ts b/packages/backend/src/server/api/endpoints/reset-db.ts
index e99dc9db15..dbe64e9a13 100644
--- a/packages/backend/src/server/api/endpoints/reset-db.ts
+++ b/packages/backend/src/server/api/endpoints/reset-db.ts
@@ -1,21 +1,23 @@
-import $ from 'cafy';
-import define from '../define';
-import { ApiError } from '../error';
-import { resetDb } from '@/db/postgre';
+import define from '../define.js';
+import { ApiError } from '../error.js';
+import { resetDb } from '@/db/postgre.js';
 
 export const meta = {
 	requireCredential: false,
 
-	params: {
-	},
-
 	errors: {
 
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	if (process.env.NODE_ENV !== 'test') throw 'NODE_ENV is not a test';
 
 	await resetDb();
diff --git a/packages/backend/src/server/api/endpoints/reset-password.ts b/packages/backend/src/server/api/endpoints/reset-password.ts
index a7366584b1..3abf232af0 100644
--- a/packages/backend/src/server/api/endpoints/reset-password.ts
+++ b/packages/backend/src/server/api/endpoints/reset-password.ts
@@ -1,30 +1,28 @@
-import $ from 'cafy';
-import * as bcrypt from 'bcryptjs';
-import { publishMainStream } from '@/services/stream';
-import define from '../define';
-import { Users, UserProfiles, PasswordResetRequests } from '@/models/index';
-import { ApiError } from '../error';
+import bcrypt from 'bcryptjs';
+import { publishMainStream } from '@/services/stream.js';
+import define from '../define.js';
+import { Users, UserProfiles, PasswordResetRequests } from '@/models/index.js';
+import { ApiError } from '../error.js';
 
 export const meta = {
 	requireCredential: false,
 
-	params: {
-		token: {
-			validator: $.str,
-		},
+	errors: {
 
-		password: {
-			validator: $.str,
-		},
 	},
+} as const;
 
-	errors: {
-
+export const paramDef = {
+	type: 'object',
+	properties: {
+		token: { type: 'string' },
+		password: { type: 'string' },
 	},
+	required: ['token', 'password'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const req = await PasswordResetRequests.findOneOrFail({
 		token: ps.token,
 	});
diff --git a/packages/backend/src/server/api/endpoints/server-info.ts b/packages/backend/src/server/api/endpoints/server-info.ts
index 1ad2c54ab5..99f3730e97 100644
--- a/packages/backend/src/server/api/endpoints/server-info.ts
+++ b/packages/backend/src/server/api/endpoints/server-info.ts
@@ -1,21 +1,21 @@
-import * as os from 'os';
-import * as si from 'systeminformation';
-import define from '../define';
+import * as os from 'node:os';
+import si from 'systeminformation';
+import define from '../define.js';
 
 export const meta = {
 	requireCredential: false,
 
-	desc: {
-	},
-
 	tags: ['meta'],
+} as const;
 
-	params: {
-	},
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const memStats = await si.mem();
 	const fsStats = await si.fsSize();
 
diff --git a/packages/backend/src/server/api/endpoints/stats.ts b/packages/backend/src/server/api/endpoints/stats.ts
index 9879ef2adf..92fea4de6a 100644
--- a/packages/backend/src/server/api/endpoints/stats.ts
+++ b/packages/backend/src/server/api/endpoints/stats.ts
@@ -1,15 +1,12 @@
-import define from '../define';
-import { NoteReactions, Notes, Users } from '@/models/index';
-import { federationChart, driveChart } from '@/services/chart/index';
+import define from '../define.js';
+import { Instances, NoteReactions, Notes, Users } from '@/models/index.js';
+import { } from '@/services/chart/index.js';
 
 export const meta = {
 	requireCredential: false,
 
 	tags: ['meta'],
 
-	params: {
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -46,8 +43,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async () => {
+export default define(meta, paramDef, async () => {
 	const [
 		notesCount,
 		originalNotesCount,
@@ -56,8 +59,6 @@ export default define(meta, async () => {
 		reactionsCount,
 		//originalReactionsCount,
 		instances,
-		driveUsageLocal,
-		driveUsageRemote,
 	] = await Promise.all([
 		Notes.count({ cache: 3600000 }), // 1 hour
 		Notes.count({ where: { userHost: null }, cache: 3600000 }),
@@ -65,9 +66,7 @@ export default define(meta, async () => {
 		Users.count({ where: { host: null }, cache: 3600000 }),
 		NoteReactions.count({ cache: 3600000 }), // 1 hour
 		//NoteReactions.count({ where: { userHost: null }, cache: 3600000 }),
-		federationChart.getChart('hour', 1, null).then(chart => chart.instance.total[0]),
-		driveChart.getChart('hour', 1, null).then(chart => chart.local.totalSize[0]),
-		driveChart.getChart('hour', 1, null).then(chart => chart.remote.totalSize[0]),
+		Instances.count({ cache: 3600000 }),
 	]);
 
 	return {
@@ -78,7 +77,7 @@ export default define(meta, async () => {
 		reactionsCount,
 		//originalReactionsCount,
 		instances,
-		driveUsageLocal,
-		driveUsageRemote,
+		driveUsageLocal: 0,
+		driveUsageRemote: 0,
 	};
 });
diff --git a/packages/backend/src/server/api/endpoints/sw/register.ts b/packages/backend/src/server/api/endpoints/sw/register.ts
index ae3e9ce77a..6c7714e19b 100644
--- a/packages/backend/src/server/api/endpoints/sw/register.ts
+++ b/packages/backend/src/server/api/endpoints/sw/register.ts
@@ -1,47 +1,42 @@
-import $ from 'cafy';
-import define from '../../define';
-import { fetchMeta } from '@/misc/fetch-meta';
-import { genId } from '@/misc/gen-id';
-import { SwSubscriptions } from '@/models/index';
+import define from '../../define.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
+import { genId } from '@/misc/gen-id.js';
+import { SwSubscriptions } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
 
 	requireCredential: true,
 
-	params: {
-		endpoint: {
-			validator: $.str,
-		},
-
-		auth: {
-			validator: $.str,
-		},
-
-		publickey: {
-			validator: $.str,
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
 		properties: {
 			state: {
 				type: 'string',
-				optional: false, nullable: false,
+				optional: true, nullable: false,
 				enum: ['already-subscribed', 'subscribed'],
 			},
 			key: {
 				type: 'string',
-				optional: false, nullable: false,
+				optional: false, nullable: true,
 			},
 		},
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		endpoint: { type: 'string' },
+		auth: { type: 'string' },
+		publickey: { type: 'string' },
+	},
+	required: ['endpoint', 'auth', 'publickey'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// if already subscribed
 	const exist = await SwSubscriptions.findOne({
 		userId: user.id,
@@ -54,7 +49,7 @@ export default define(meta, async (ps, user) => {
 
 	if (exist != null) {
 		return {
-			state: 'already-subscribed',
+			state: 'already-subscribed' as const,
 			key: instance.swPublicKey,
 		};
 	}
@@ -69,7 +64,7 @@ export default define(meta, async (ps, user) => {
 	});
 
 	return {
-		state: 'subscribed',
+		state: 'subscribed' as const,
 		key: instance.swPublicKey,
 	};
 });
diff --git a/packages/backend/src/server/api/endpoints/sw/unregister.ts b/packages/backend/src/server/api/endpoints/sw/unregister.ts
index 6f569e9417..9748f2a222 100644
--- a/packages/backend/src/server/api/endpoints/sw/unregister.ts
+++ b/packages/backend/src/server/api/endpoints/sw/unregister.ts
@@ -1,21 +1,22 @@
-import $ from 'cafy';
-import define from '../../define';
-import { SwSubscriptions } from '../../../../models';
+import define from '../../define.js';
+import { SwSubscriptions } from '@/models/index.js';
 
 export const meta = {
 	tags: ['account'],
 
 	requireCredential: true,
+} as const;
 
-	params: {
-		endpoint: {
-			validator: $.str,
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		endpoint: { type: 'string' },
 	},
+	required: ['endpoint'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	await SwSubscriptions.delete({
 		userId: user.id,
 		endpoint: ps.endpoint,
diff --git a/packages/backend/src/server/api/endpoints/test.ts b/packages/backend/src/server/api/endpoints/test.ts
new file mode 100644
index 0000000000..256da1a66f
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/test.ts
@@ -0,0 +1,22 @@
+import define from '../define.js';
+
+export const meta = {
+	requireCredential: false,
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		required: { type: 'boolean' },
+		string: { type: 'string' },
+		default: { type: 'string', default: 'hello' },
+		nullableDefault: { type: 'string', nullable: true, default: 'hello' },
+		id: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['required'],
+} as const;
+
+// eslint-disable-next-line import/no-default-export
+export default define(meta, paramDef, async (ps, me) => {
+	return ps;
+});
diff --git a/packages/backend/src/server/api/endpoints/username/available.ts b/packages/backend/src/server/api/endpoints/username/available.ts
index 74120fc406..5a1c4128ab 100644
--- a/packages/backend/src/server/api/endpoints/username/available.ts
+++ b/packages/backend/src/server/api/endpoints/username/available.ts
@@ -1,18 +1,11 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Users, UsedUsernames } from '@/models/index';
+import define from '../../define.js';
+import { Users, UsedUsernames } from '@/models/index.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		username: {
-			validator: $.use(Users.validateLocalUsername),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -25,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		username: Users.localUsernameSchema,
+	},
+	required: ['username'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps) => {
+export default define(meta, paramDef, async (ps) => {
 	// Get exist
 	const exist = await Users.count({
 		host: null,
diff --git a/packages/backend/src/server/api/endpoints/users.ts b/packages/backend/src/server/api/endpoints/users.ts
index 6b11ec0f01..10527d15cc 100644
--- a/packages/backend/src/server/api/endpoints/users.ts
+++ b/packages/backend/src/server/api/endpoints/users.ts
@@ -1,57 +1,13 @@
-import $ from 'cafy';
-import define from '../define';
-import { Users } from '@/models/index';
-import { generateMutedUserQueryForUsers } from '../common/generate-muted-user-query';
-import { generateBlockQueryForUsers } from '../common/generate-block-query';
+import define from '../define.js';
+import { Users } from '@/models/index.js';
+import { generateMutedUserQueryForUsers } from '../common/generate-muted-user-query.js';
+import { generateBlockQueryForUsers } from '../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-
-		sort: {
-			validator: $.optional.str.or([
-				'+follower',
-				'-follower',
-				'+createdAt',
-				'-createdAt',
-				'+updatedAt',
-				'-updatedAt',
-			]),
-		},
-
-		state: {
-			validator: $.optional.str.or([
-				'all',
-				'admin',
-				'moderator',
-				'adminOrModerator',
-				'alive',
-			]),
-			default: 'all',
-		},
-
-		origin: {
-			validator: $.optional.str.or([
-				'combined',
-				'local',
-				'remote',
-			]),
-			default: 'local',
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -63,8 +19,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+		sort: { type: 'string', enum: ['+follower', '-follower', '+createdAt', '-createdAt', '+updatedAt', '-updatedAt'] },
+		state: { type: 'string', enum: ['all', 'admin', 'moderator', 'adminOrModerator', 'alive'], default: "all" },
+		origin: { type: 'string', enum: ['combined', 'local', 'remote'], default: "local" },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Users.createQueryBuilder('user');
 	query.where('user.isExplorable = TRUE');
 
@@ -93,7 +61,7 @@ export default define(meta, async (ps, me) => {
 	if (me) generateMutedUserQueryForUsers(query, me);
 	if (me) generateBlockQueryForUsers(query, me);
 
-	query.take(ps.limit!);
+	query.take(ps.limit);
 	query.skip(ps.offset);
 
 	const users = await query.getMany();
diff --git a/packages/backend/src/server/api/endpoints/users/clips.ts b/packages/backend/src/server/api/endpoints/users/clips.ts
index d4152fbf50..424c594749 100644
--- a/packages/backend/src/server/api/endpoints/users/clips.ts
+++ b/packages/backend/src/server/api/endpoints/users/clips.ts
@@ -1,40 +1,30 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Clips } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Clips } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['users', 'clips'],
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Clips.createQueryBuilder('clip'), ps.sinceId, ps.untilId)
 		.andWhere(`clip.userId = :userId`, { userId: ps.userId })
 		.andWhere('clip.isPublic = true');
 
 	const clips = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Clips.packMany(clips);
diff --git a/packages/backend/src/server/api/endpoints/users/followers.ts b/packages/backend/src/server/api/endpoints/users/followers.ts
index 6214ab40ba..1e104b6bcc 100644
--- a/packages/backend/src/server/api/endpoints/users/followers.ts
+++ b/packages/backend/src/server/api/endpoints/users/followers.ts
@@ -1,43 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Users, Followings, UserProfiles } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { toPunyNullable } from '@/misc/convert-host';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Users, Followings, UserProfiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { toPunyNullable } from '@/misc/convert-host.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.optional.type(ID),
-		},
-
-		username: {
-			validator: $.optional.str,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -63,8 +34,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		username: { type: 'string' },
+		host: { type: 'string', nullable: true },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId != null
 		? { id: ps.userId }
 		: { usernameLower: ps.username!.toLowerCase(), host: toPunyNullable(ps.host) });
@@ -98,7 +82,7 @@ export default define(meta, async (ps, me) => {
 		.innerJoinAndSelect('following.follower', 'follower');
 
 	const followings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Followings.packMany(followings, me, { populateFollower: true });
diff --git a/packages/backend/src/server/api/endpoints/users/following.ts b/packages/backend/src/server/api/endpoints/users/following.ts
index 76112eab25..b0a1036c76 100644
--- a/packages/backend/src/server/api/endpoints/users/following.ts
+++ b/packages/backend/src/server/api/endpoints/users/following.ts
@@ -1,43 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { Users, Followings, UserProfiles } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { toPunyNullable } from '@/misc/convert-host';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { Users, Followings, UserProfiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { toPunyNullable } from '@/misc/convert-host.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.optional.type(ID),
-		},
-
-		username: {
-			validator: $.optional.str,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -63,8 +34,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		username: { type: 'string' },
+		host: { type: 'string', nullable: true },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId != null
 		? { id: ps.userId }
 		: { usernameLower: ps.username!.toLowerCase(), host: toPunyNullable(ps.host) });
@@ -98,7 +82,7 @@ export default define(meta, async (ps, me) => {
 		.innerJoinAndSelect('following.followee', 'followee');
 
 	const followings = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Followings.packMany(followings, me, { populateFollowee: true });
diff --git a/packages/backend/src/server/api/endpoints/users/gallery/posts.ts b/packages/backend/src/server/api/endpoints/users/gallery/posts.ts
index c5f08b4c94..d7c435256c 100644
--- a/packages/backend/src/server/api/endpoints/users/gallery/posts.ts
+++ b/packages/backend/src/server/api/endpoints/users/gallery/posts.ts
@@ -1,39 +1,29 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { GalleryPosts } from '@/models/index';
-import { makePaginationQuery } from '../../../common/make-pagination-query';
+import define from '../../../define.js';
+import { GalleryPosts } from '@/models/index.js';
+import { makePaginationQuery } from '../../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['users', 'gallery'],
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(GalleryPosts.createQueryBuilder('post'), ps.sinceId, ps.untilId)
 		.andWhere(`post.userId = :userId`, { userId: ps.userId });
 
 	const posts = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await GalleryPosts.packMany(posts, user);
diff --git a/packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts b/packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts
index d886d3355a..73cadc0df7 100644
--- a/packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts
+++ b/packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts
@@ -1,28 +1,15 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { maximum } from '@/prelude/array';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
+import define from '../../define.js';
+import { maximum } from '@/prelude/array.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
 import { Not, In, IsNull } from 'typeorm';
-import { Notes, Users } from '@/models/index';
+import { Notes, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -52,8 +39,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Lookup user
 	const user = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
@@ -104,7 +100,7 @@ export default define(meta, async (ps, me) => {
 	const repliedUsersSorted = Object.keys(repliedUsers).sort((a, b) => repliedUsers[b] - repliedUsers[a]);
 
 	// Extract top replied users
-	const topRepliedUsers = repliedUsersSorted.slice(0, ps.limit!);
+	const topRepliedUsers = repliedUsersSorted.slice(0, ps.limit);
 
 	// Make replies object (includes weights)
 	const repliesObj = await Promise.all(topRepliedUsers.map(async (user) => ({
diff --git a/packages/backend/src/server/api/endpoints/users/groups/create.ts b/packages/backend/src/server/api/endpoints/users/groups/create.ts
index 25e29de01c..9f6d8464d8 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/create.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/create.ts
@@ -1,9 +1,8 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { UserGroup } from '@/models/entities/user-group';
-import { UserGroupJoining } from '@/models/entities/user-group-joining';
+import define from '../../../define.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { UserGroup } from '@/models/entities/user-group.js';
+import { UserGroupJoining } from '@/models/entities/user-group-joining.js';
 
 export const meta = {
 	tags: ['groups'],
@@ -12,12 +11,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		name: {
-			validator: $.str.range(1, 100),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -25,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const userGroup = await UserGroups.insert({
 		id: genId(),
 		createdAt: new Date(),
diff --git a/packages/backend/src/server/api/endpoints/users/groups/delete.ts b/packages/backend/src/server/api/endpoints/users/groups/delete.ts
index f30ab78ca0..f4898a3c7c 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/delete.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserGroups } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserGroups } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchGroup: {
 			message: 'No such group.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/invitations/accept.ts b/packages/backend/src/server/api/endpoints/users/groups/invitations/accept.ts
index 7061db538b..efbdf968f6 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/invitations/accept.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/invitations/accept.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../../define';
-import { ApiError } from '../../../../error';
-import { UserGroupJoinings, UserGroupInvitations } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { UserGroupJoining } from '@/models/entities/user-group-joining';
+import define from '../../../../define.js';
+import { ApiError } from '../../../../error.js';
+import { UserGroupJoinings, UserGroupInvitations } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { UserGroupJoining } from '@/models/entities/user-group-joining.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -13,12 +11,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		invitationId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchInvitation: {
 			message: 'No such invitation.',
@@ -28,8 +20,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		invitationId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['invitationId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch the invitation
 	const invitation = await UserGroupInvitations.findOne({
 		id: ps.invitationId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/invitations/reject.ts b/packages/backend/src/server/api/endpoints/users/groups/invitations/reject.ts
index f5ca3dec8b..fe5d431eab 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/invitations/reject.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/invitations/reject.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../../define';
-import { ApiError } from '../../../../error';
-import { UserGroupInvitations } from '@/models/index';
+import define from '../../../../define.js';
+import { ApiError } from '../../../../error.js';
+import { UserGroupInvitations } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		invitationId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchInvitation: {
 			message: 'No such invitation.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		invitationId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['invitationId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch the invitation
 	const invitation = await UserGroupInvitations.findOne({
 		id: ps.invitationId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/invite.ts b/packages/backend/src/server/api/endpoints/users/groups/invite.ts
index 3b7a4edb81..10bfb7eca1 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/invite.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/invite.ts
@@ -1,12 +1,10 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { UserGroups, UserGroupJoinings, UserGroupInvitations } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { UserGroupInvitation } from '@/models/entities/user-group-invitation';
-import { createNotification } from '@/services/create-notification';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { UserGroups, UserGroupJoinings, UserGroupInvitations } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { UserGroupInvitation } from '@/models/entities/user-group-invitation.js';
+import { createNotification } from '@/services/create-notification.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -15,16 +13,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchGroup: {
 			message: 'No such group.',
@@ -52,8 +40,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId', 'userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/joined.ts b/packages/backend/src/server/api/endpoints/users/groups/joined.ts
index ab48b1910d..e52de78595 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/joined.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/joined.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
+import define from '../../../define.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
 import { Not, In } from 'typeorm';
 
 export const meta = {
@@ -20,8 +20,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const ownedGroups = await UserGroups.find({
 		userId: me.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/leave.ts b/packages/backend/src/server/api/endpoints/users/groups/leave.ts
index d2fcdab301..c1a8c2c024 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/leave.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/leave.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchGroup: {
 			message: 'No such group.',
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/owned.ts b/packages/backend/src/server/api/endpoints/users/groups/owned.ts
index 6193a71019..11aad0f73c 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/owned.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/owned.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { UserGroups } from '@/models/index';
+import define from '../../../define.js';
+import { UserGroups } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'account'],
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const userGroups = await UserGroups.find({
 		userId: me.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/pull.ts b/packages/backend/src/server/api/endpoints/users/groups/pull.ts
index 785bea140d..55ec9f915b 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/pull.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/pull.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -12,16 +10,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchGroup: {
 			message: 'No such group.',
@@ -43,8 +31,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId', 'userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/show.ts b/packages/backend/src/server/api/endpoints/users/groups/show.ts
index eb26eac2a8..28ca1162c8 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/show.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'account'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/transfer.ts b/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
index 4b1c8fbbdb..f48e1ddbf0 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
@@ -1,9 +1,7 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { UserGroups, UserGroupJoinings } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { UserGroups, UserGroupJoinings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups', 'users'],
@@ -12,16 +10,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -49,8 +37,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['groupId', 'userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/groups/update.ts b/packages/backend/src/server/api/endpoints/users/groups/update.ts
index 6caf903555..b3e17dfd9e 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/update.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserGroups } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserGroups } from '@/models/index.js';
 
 export const meta = {
 	tags: ['groups'],
@@ -11,16 +9,6 @@ export const meta = {
 
 	kind: 'write:user-groups',
 
-	params: {
-		groupId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.str.range(1, 100),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -36,8 +24,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		groupId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+	},
+	required: ['groupId', 'name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the group
 	const userGroup = await UserGroups.findOne({
 		id: ps.groupId,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/create.ts b/packages/backend/src/server/api/endpoints/users/lists/create.ts
index 945b511628..1a0599f9e7 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/create.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/create.ts
@@ -1,8 +1,7 @@
-import $ from 'cafy';
-import define from '../../../define';
-import { UserLists } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { UserList } from '@/models/entities/user-list';
+import define from '../../../define.js';
+import { UserLists } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { UserList } from '@/models/entities/user-list.js';
 
 export const meta = {
 	tags: ['lists'],
@@ -11,12 +10,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		name: {
-			validator: $.str.range(1, 100),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -24,8 +17,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+	},
+	required: ['name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const userList = await UserLists.insert({
 		id: genId(),
 		createdAt: new Date(),
diff --git a/packages/backend/src/server/api/endpoints/users/lists/delete.ts b/packages/backend/src/server/api/endpoints/users/lists/delete.ts
index 3183d2a09c..aeefb98c83 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/delete.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/delete.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserLists } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserLists } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchList: {
 			message: 'No such list.',
@@ -26,8 +18,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['listId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const userList = await UserLists.findOne({
 		id: ps.listId,
 		userId: user.id,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/list.ts b/packages/backend/src/server/api/endpoints/users/lists/list.ts
index ae66b0aacc..a8663ada8a 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/list.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/list.ts
@@ -1,5 +1,5 @@
-import define from '../../../define';
-import { UserLists } from '@/models/index';
+import define from '../../../define.js';
+import { UserLists } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists', 'account'],
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const userLists = await UserLists.find({
 		userId: me.id,
 	});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/pull.ts b/packages/backend/src/server/api/endpoints/users/lists/pull.ts
index 4c74aefa8a..2c4c61d51e 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/pull.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/pull.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import { publishUserListStream } from '@/services/stream';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { UserLists, UserListJoinings, Users } from '@/models/index';
+import { publishUserListStream } from '@/services/stream.js';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { UserLists, UserListJoinings, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists', 'users'],
@@ -13,16 +11,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchList: {
 			message: 'No such list.',
@@ -38,8 +26,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['listId', 'userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserLists.findOne({
 		id: ps.listId,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/push.ts b/packages/backend/src/server/api/endpoints/users/lists/push.ts
index 8b50c475b0..034a9d2db6 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/push.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/push.ts
@@ -1,10 +1,8 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { getUser } from '../../../common/getters';
-import { pushUserToUserList } from '@/services/user-list/push';
-import { UserLists, UserListJoinings, Blockings } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { getUser } from '../../../common/getters.js';
+import { pushUserToUserList } from '@/services/user-list/push.js';
+import { UserLists, UserListJoinings, Blockings } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists', 'users'],
@@ -13,16 +11,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchList: {
 			message: 'No such list.',
@@ -50,8 +38,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['listId', 'userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserLists.findOne({
 		id: ps.listId,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/show.ts b/packages/backend/src/server/api/endpoints/users/lists/show.ts
index 06555c1a88..fadb94c90e 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/show.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserLists } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserLists } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists', 'account'],
@@ -11,12 +9,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -32,8 +24,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['listId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserLists.findOne({
 		id: ps.listId,
diff --git a/packages/backend/src/server/api/endpoints/users/lists/update.ts b/packages/backend/src/server/api/endpoints/users/lists/update.ts
index 02b0d5fe18..5ec99031e1 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/update.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/update.ts
@@ -1,8 +1,6 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../../define';
-import { ApiError } from '../../../error';
-import { UserLists } from '@/models/index';
+import define from '../../../define.js';
+import { ApiError } from '../../../error.js';
+import { UserLists } from '@/models/index.js';
 
 export const meta = {
 	tags: ['lists'],
@@ -11,16 +9,6 @@ export const meta = {
 
 	kind: 'write:account',
 
-	params: {
-		listId: {
-			validator: $.type(ID),
-		},
-
-		name: {
-			validator: $.str.range(1, 100),
-		},
-	},
-
 	res: {
 		type: 'object',
 		optional: false, nullable: false,
@@ -36,8 +24,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		listId: { type: 'string', format: 'misskey:id' },
+		name: { type: 'string', minLength: 1, maxLength: 100 },
+	},
+	required: ['listId', 'name'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	// Fetch the list
 	const userList = await UserLists.findOne({
 		id: ps.listId,
diff --git a/packages/backend/src/server/api/endpoints/users/notes.ts b/packages/backend/src/server/api/endpoints/users/notes.ts
index 99158fb0ae..16318d2225 100644
--- a/packages/backend/src/server/api/endpoints/users/notes.ts
+++ b/packages/backend/src/server/api/endpoints/users/notes.ts
@@ -1,70 +1,17 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { Notes } from '@/models/index';
-import { generateMutedUserQuery } from '../../common/generate-muted-user-query';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { Notes } from '@/models/index.js';
+import { generateMutedUserQuery } from '../../common/generate-muted-user-query.js';
 import { Brackets } from 'typeorm';
-import { generateBlockedUserQuery } from '../../common/generate-block-query';
-import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query';
+import { generateBlockedUserQuery } from '../../common/generate-block-query.js';
+import { generateMutedInstanceQuery } from '../../common/generate-muted-instance-query.js';
 
 export const meta = {
 	tags: ['users', 'notes'],
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		includeReplies: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-
-		includeMyRenotes: {
-			validator: $.optional.bool,
-			default: true,
-		},
-
-		withFiles: {
-			validator: $.optional.bool,
-			default: false,
-		},
-
-		fileType: {
-			validator: $.optional.arr($.str),
-		},
-
-		excludeNsfw: {
-			validator: $.optional.bool,
-			default: false,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -84,8 +31,28 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		includeReplies: { type: 'boolean', default: true },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+		includeMyRenotes: { type: 'boolean', default: true },
+		withFiles: { type: 'boolean', default: false },
+		fileType: { type: 'array', items: {
+			type: 'string',
+		} },
+		excludeNsfw: { type: 'boolean', default: false },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Lookup user
 	const user = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
@@ -96,10 +63,16 @@ export default define(meta, async (ps, me) => {
 	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
 		.andWhere('note.userId = :userId', { userId: user.id })
 		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('user.avatar', 'avatar')
+		.leftJoinAndSelect('user.banner', 'banner')
 		.leftJoinAndSelect('note.reply', 'reply')
 		.leftJoinAndSelect('note.renote', 'renote')
 		.leftJoinAndSelect('reply.user', 'replyUser')
-		.leftJoinAndSelect('renote.user', 'renoteUser');
+		.leftJoinAndSelect('replyUser.avatar', 'replyUserAvatar')
+		.leftJoinAndSelect('replyUser.banner', 'replyUserBanner')
+		.leftJoinAndSelect('renote.user', 'renoteUser')
+		.leftJoinAndSelect('renoteUser.avatar', 'renoteUserAvatar')
+		.leftJoinAndSelect('renoteUser.banner', 'renoteUserBanner');
 
 	generateVisibilityQuery(query, me);
 	if (me) generateMutedUserQuery(query, me, user);
@@ -141,7 +114,7 @@ export default define(meta, async (ps, me) => {
 
 	//#endregion
 
-	const timeline = await query.take(ps.limit!).getMany();
+	const timeline = await query.take(ps.limit).getMany();
 
 	return await Notes.packMany(timeline, me);
 });
diff --git a/packages/backend/src/server/api/endpoints/users/pages.ts b/packages/backend/src/server/api/endpoints/users/pages.ts
index 6e003dd1af..b8b3e8192e 100644
--- a/packages/backend/src/server/api/endpoints/users/pages.ts
+++ b/packages/backend/src/server/api/endpoints/users/pages.ts
@@ -1,40 +1,30 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { Pages } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
+import define from '../../define.js';
+import { Pages } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
 
 export const meta = {
 	tags: ['users', 'pages'],
+} as const;
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
 	},
+	required: ['userId'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, user) => {
+export default define(meta, paramDef, async (ps, user) => {
 	const query = makePaginationQuery(Pages.createQueryBuilder('page'), ps.sinceId, ps.untilId)
 		.andWhere(`page.userId = :userId`, { userId: ps.userId })
 		.andWhere('page.visibility = \'public\'');
 
 	const pages = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Pages.packMany(pages);
diff --git a/packages/backend/src/server/api/endpoints/users/reactions.ts b/packages/backend/src/server/api/endpoints/users/reactions.ts
index 312d4dbf23..7b55a16711 100644
--- a/packages/backend/src/server/api/endpoints/users/reactions.ts
+++ b/packages/backend/src/server/api/endpoints/users/reactions.ts
@@ -1,43 +1,14 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { NoteReactions, UserProfiles } from '@/models/index';
-import { makePaginationQuery } from '../../common/make-pagination-query';
-import { generateVisibilityQuery } from '../../common/generate-visibility-query';
-import { ApiError } from '../../error';
+import define from '../../define.js';
+import { NoteReactions, UserProfiles } from '@/models/index.js';
+import { makePaginationQuery } from '../../common/make-pagination-query.js';
+import { generateVisibilityQuery } from '../../common/generate-visibility-query.js';
+import { ApiError } from '../../error.js';
 
 export const meta = {
 	tags: ['users', 'reactions'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		sinceId: {
-			validator: $.optional.type(ID),
-		},
-
-		untilId: {
-			validator: $.optional.type(ID),
-		},
-
-		sinceDate: {
-			validator: $.optional.num,
-		},
-
-		untilDate: {
-			validator: $.optional.num,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -57,8 +28,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		sinceId: { type: 'string', format: 'misskey:id' },
+		untilId: { type: 'string', format: 'misskey:id' },
+		sinceDate: { type: 'integer' },
+		untilDate: { type: 'integer' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const profile = await UserProfiles.findOneOrFail(ps.userId);
 
 	if (me == null || (me.id !== ps.userId && !profile.publicReactions)) {
@@ -73,7 +57,7 @@ export default define(meta, async (ps, me) => {
 	generateVisibilityQuery(query, me);
 
 	const reactions = await query
-		.take(ps.limit!)
+		.take(ps.limit)
 		.getMany();
 
 	return await Promise.all(reactions.map(reaction => NoteReactions.pack(reaction, me, { withNote: true })));
diff --git a/packages/backend/src/server/api/endpoints/users/recommendation.ts b/packages/backend/src/server/api/endpoints/users/recommendation.ts
index 9ea39eb2dd..a8f18de522 100644
--- a/packages/backend/src/server/api/endpoints/users/recommendation.ts
+++ b/packages/backend/src/server/api/endpoints/users/recommendation.ts
@@ -1,9 +1,8 @@
 import ms from 'ms';
-import $ from 'cafy';
-import define from '../../define';
-import { Users, Followings } from '@/models/index';
-import { generateMutedUserQueryForUsers } from '../../common/generate-muted-user-query';
-import { generateBlockedUserQuery, generateBlockQueryForUsers } from '../../common/generate-block-query';
+import define from '../../define.js';
+import { Users, Followings } from '@/models/index.js';
+import { generateMutedUserQueryForUsers } from '../../common/generate-muted-user-query.js';
+import { generateBlockedUserQuery, generateBlockQueryForUsers } from '../../common/generate-block-query.js';
 
 export const meta = {
 	tags: ['users'],
@@ -12,18 +11,6 @@ export const meta = {
 
 	kind: 'read:account',
 
-	params: {
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -35,8 +22,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		offset: { type: 'integer', default: 0 },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const query = Users.createQueryBuilder('user')
 		.where('user.isLocked = FALSE')
 		.andWhere('user.isExplorable = TRUE')
@@ -58,7 +54,7 @@ export default define(meta, async (ps, me) => {
 
 	query.setParameters(followingQuery.getParameters());
 
-	const users = await query.take(ps.limit!).skip(ps.offset).getMany();
+	const users = await query.take(ps.limit).skip(ps.offset).getMany();
 
 	return await Users.packMany(users, me, { detail: true });
 });
diff --git a/packages/backend/src/server/api/endpoints/users/relation.ts b/packages/backend/src/server/api/endpoints/users/relation.ts
index 7e319ca105..c6262122d4 100644
--- a/packages/backend/src/server/api/endpoints/users/relation.ts
+++ b/packages/backend/src/server/api/endpoints/users/relation.ts
@@ -1,19 +1,11 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ID } from '@/misc/cafy-id';
-import { Users } from '@/models/index';
+import define from '../../define.js';
+import { Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: true,
 
-	params: {
-		userId: {
-			validator: $.either($.type(ID), $.arr($.type(ID)).unique()),
-		},
-	},
-
 	res: {
 		optional: false, nullable: false,
 		oneOf: [
@@ -101,8 +93,24 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: {
+			anyOf: [
+				{ type: 'string', format: 'misskey:id' },
+				{
+					type: 'array',
+					items: { type: 'string', format: 'misskey:id' },
+				},
+			],
+		},
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const ids = Array.isArray(ps.userId) ? ps.userId : [ps.userId];
 
 	const relations = await Promise.all(ids.map(id => Users.getRelation(me.id, id)));
diff --git a/packages/backend/src/server/api/endpoints/users/report-abuse.ts b/packages/backend/src/server/api/endpoints/users/report-abuse.ts
index ed2aa7bb26..e091b8e1b1 100644
--- a/packages/backend/src/server/api/endpoints/users/report-abuse.ts
+++ b/packages/backend/src/server/api/endpoints/users/report-abuse.ts
@@ -1,30 +1,18 @@
-import $ from 'cafy';
 import * as sanitizeHtml from 'sanitize-html';
-import { ID } from '@/misc/cafy-id';
-import define from '../../define';
-import { publishAdminStream } from '@/services/stream';
-import { ApiError } from '../../error';
-import { getUser } from '../../common/getters';
-import { AbuseUserReports, Users } from '@/models/index';
-import { genId } from '@/misc/gen-id';
-import { sendEmail } from '@/services/send-email';
-import { fetchMeta } from '@/misc/fetch-meta';
+import define from '../../define.js';
+import { publishAdminStream } from '@/services/stream.js';
+import { ApiError } from '../../error.js';
+import { getUser } from '../../common/getters.js';
+import { AbuseUserReports, Users } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
+import { sendEmail } from '@/services/send-email.js';
+import { fetchMeta } from '@/misc/fetch-meta.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: true,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-
-		comment: {
-			validator: $.str.range(1, 2048),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -46,8 +34,17 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		comment: { type: 'string', minLength: 1, maxLength: 2048 },
+	},
+	required: ['userId', 'comment'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	// Lookup user
 	const user = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
diff --git a/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts b/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
index d67625e624..897b5de3fe 100644
--- a/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
+++ b/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
@@ -1,35 +1,14 @@
-import $ from 'cafy';
-import define from '../../define';
-import { Followings, Users } from '@/models/index';
+import define from '../../define.js';
+import { Followings, Users } from '@/models/index.js';
 import { Brackets } from 'typeorm';
-import { USER_ACTIVE_THRESHOLD } from '@/const';
-import { User } from '@/models/entities/user';
+import { USER_ACTIVE_THRESHOLD } from '@/const.js';
+import { User } from '@/models/entities/user.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		username: {
-			validator: $.optional.nullable.str,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		detail: {
-			validator: $.optional.bool,
-			default: true,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -41,8 +20,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		username: { type: 'string', nullable: true },
+		host: { type: 'string', nullable: true },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		detail: { type: 'boolean', default: true },
+	},
+	required: [],
+} as const;
+
+// TODO: avatar,bannerをJOINしたいけどエラーになる
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const activeThreshold = new Date(Date.now() - (1000 * 60 * 60 * 24 * 30)); // 30日
 
 	if (ps.host) {
@@ -57,7 +49,7 @@ export default define(meta, async (ps, me) => {
 		q.andWhere('user.updatedAt IS NOT NULL');
 		q.orderBy('user.updatedAt', 'DESC');
 
-		const users = await q.take(ps.limit!).getMany();
+		const users = await q.take(ps.limit).getMany();
 
 		return await Users.packMany(users, me, { detail: ps.detail });
 	} else if (ps.username) {
@@ -82,10 +74,10 @@ export default define(meta, async (ps, me) => {
 
 			users = await query
 				.orderBy('user.usernameLower', 'ASC')
-				.take(ps.limit!)
+				.take(ps.limit)
 				.getMany();
 
-			if (users.length < ps.limit!) {
+			if (users.length < ps.limit) {
 				const otherQuery = await Users.createQueryBuilder('user')
 					.where(`user.id NOT IN (${ followingQuery.getQuery() })`)
 					.andWhere(`user.id != :meId`, { meId: me.id })
@@ -97,7 +89,7 @@ export default define(meta, async (ps, me) => {
 
 				const otherUsers = await otherQuery
 					.orderBy('user.updatedAt', 'DESC')
-					.take(ps.limit! - users.length)
+					.take(ps.limit - users.length)
 					.getMany();
 
 				users = users.concat(otherUsers);
@@ -108,10 +100,12 @@ export default define(meta, async (ps, me) => {
 				.andWhere('user.usernameLower LIKE :username', { username: ps.username.toLowerCase() + '%' })
 				.andWhere('user.updatedAt IS NOT NULL')
 				.orderBy('user.updatedAt', 'DESC')
-				.take(ps.limit! - users.length)
+				.take(ps.limit - users.length)
 				.getMany();
 		}
 
 		return await Users.packMany(users, me, { detail: !!ps.detail });
 	}
+
+	return [];
 });
diff --git a/packages/backend/src/server/api/endpoints/users/search.ts b/packages/backend/src/server/api/endpoints/users/search.ts
index 26f818afcc..a72a58a843 100644
--- a/packages/backend/src/server/api/endpoints/users/search.ts
+++ b/packages/backend/src/server/api/endpoints/users/search.ts
@@ -1,7 +1,6 @@
-import $ from 'cafy';
-import define from '../../define';
-import { UserProfiles, Users } from '@/models/index';
-import { User } from '@/models/entities/user';
+import define from '../../define.js';
+import { UserProfiles, Users } from '@/models/index.js';
+import { User } from '@/models/entities/user.js';
 import { Brackets } from 'typeorm';
 
 export const meta = {
@@ -9,32 +8,6 @@ export const meta = {
 
 	requireCredential: false,
 
-	params: {
-		query: {
-			validator: $.str,
-		},
-
-		offset: {
-			validator: $.optional.num.min(0),
-			default: 0,
-		},
-
-		limit: {
-			validator: $.optional.num.range(1, 100),
-			default: 10,
-		},
-
-		origin: {
-			validator: $.optional.str.or(['local', 'remote', 'combined']),
-			default: 'combined',
-		},
-
-		detail: {
-			validator: $.optional.bool,
-			default: true,
-		},
-	},
-
 	res: {
 		type: 'array',
 		optional: false, nullable: false,
@@ -46,8 +19,20 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		query: { type: 'string' },
+		offset: { type: 'integer', default: 0 },
+		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
+		origin: { type: 'string', enum: ['local', 'remote', 'combined'], default: "combined" },
+		detail: { type: 'boolean', default: true },
+	},
+	required: ['query'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const activeThreshold = new Date(Date.now() - (1000 * 60 * 60 * 24 * 30)); // 30日
 
 	const isUsername = ps.query.startsWith('@');
@@ -71,7 +56,7 @@ export default define(meta, async (ps, me) => {
 
 		users = await usernameQuery
 			.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
-			.take(ps.limit!)
+			.take(ps.limit)
 			.skip(ps.offset)
 			.getMany();
 	} else {
@@ -91,11 +76,11 @@ export default define(meta, async (ps, me) => {
 
 		users = await nameQuery
 			.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
-			.take(ps.limit!)
+			.take(ps.limit)
 			.skip(ps.offset)
 			.getMany();
 
-		if (users.length < ps.limit!) {
+		if (users.length < ps.limit) {
 			const profQuery = UserProfiles.createQueryBuilder('prof')
 				.select('prof.userId')
 				.where('prof.description ILIKE :query', { query: '%' + ps.query + '%' });
@@ -117,7 +102,7 @@ export default define(meta, async (ps, me) => {
 
 			users = users.concat(await query
 				.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
-				.take(ps.limit!)
+				.take(ps.limit)
 				.skip(ps.offset)
 				.getMany()
 			);
diff --git a/packages/backend/src/server/api/endpoints/users/show.ts b/packages/backend/src/server/api/endpoints/users/show.ts
index 92910e9ed8..263c102a7a 100644
--- a/packages/backend/src/server/api/endpoints/users/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/show.ts
@@ -1,36 +1,16 @@
-import $ from 'cafy';
-import { resolveUser } from '@/remote/resolve-user';
-import define from '../../define';
-import { apiLogger } from '../../logger';
-import { ApiError } from '../../error';
-import { ID } from '@/misc/cafy-id';
-import { Users } from '@/models/index';
+import { resolveUser } from '@/remote/resolve-user.js';
+import define from '../../define.js';
+import { apiLogger } from '../../logger.js';
+import { ApiError } from '../../error.js';
+import { Users } from '@/models/index.js';
 import { In } from 'typeorm';
-import { User } from '@/models/entities/user';
+import { User } from '@/models/entities/user.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.optional.type(ID),
-		},
-
-		userIds: {
-			validator: $.optional.arr($.type(ID)).unique(),
-		},
-
-		username: {
-			validator: $.optional.str,
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-		},
-	},
-
 	res: {
 		optional: false, nullable: false,
 		oneOf: [
@@ -64,8 +44,21 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+		userIds: { type: 'array', uniqueItems: true, items: {
+			type: 'string', format: 'misskey:id',
+		} },
+		username: { type: 'string' },
+		host: { type: 'string', nullable: true },
+	},
+	required: [],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	let user;
 
 	const isAdminOrModerator = me && (me.isAdmin || me.isModerator);
diff --git a/packages/backend/src/server/api/endpoints/users/stats.ts b/packages/backend/src/server/api/endpoints/users/stats.ts
index 381e433479..180a9386d3 100644
--- a/packages/backend/src/server/api/endpoints/users/stats.ts
+++ b/packages/backend/src/server/api/endpoints/users/stats.ts
@@ -1,20 +1,12 @@
-import $ from 'cafy';
-import define from '../../define';
-import { ApiError } from '../../error';
-import { ID } from '@/misc/cafy-id';
-import { DriveFiles, Followings, NoteFavorites, NoteReactions, Notes, PageLikes, PollVotes, Users } from '@/models/index';
+import define from '../../define.js';
+import { ApiError } from '../../error.js';
+import { DriveFiles, Followings, NoteFavorites, NoteReactions, Notes, PageLikes, PollVotes, Users } from '@/models/index.js';
 
 export const meta = {
 	tags: ['users'],
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -24,8 +16,16 @@ export const meta = {
 	},
 } as const;
 
+export const paramDef = {
+	type: 'object',
+	properties: {
+		userId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['userId'],
+} as const;
+
 // eslint-disable-next-line import/no-default-export
-export default define(meta, async (ps, me) => {
+export default define(meta, paramDef, async (ps, me) => {
 	const user = await Users.findOne(ps.userId);
 	if (user == null) {
 		throw new ApiError(meta.errors.noSuchUser);