refactor: use ajv instead of cafy (#8324)

* wip

* wip

* Update abuse-user-reports.ts

* Update files.ts

* Update list-remote.ts

* Update list.ts

* Update show-users.ts

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* Update update.ts

* Update search.ts

* Update reactions.ts

* Update search.ts

* wip

* wip

* wip

* wip

* Update update.ts

* Update relation.ts

* Update available.ts

* wip

* wip

* wip

* Update packages/backend/src/server/api/define.ts

Co-authored-by: Johann150 <johann.galle@protonmail.com>

* Update define.ts

* Update define.ts

* typo

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* wip

* Update update.ts

* wip

* Update signup.ts

* Update call.ts

* minimum for limit

* type

* remove needless annotation

* wip

* Update signup.ts

* wip

* wip

* fix

* Update create.ts

Co-authored-by: Johann150 <johann.galle@protonmail.com>

34 files changed, 378 insertions, 525 deletions

diff --git a/packages/backend/src/server/api/endpoints/users/clips.ts b/packages/backend/src/server/api/endpoints/users/clips.ts
index d4152fbf50..e224bdf603 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';
 
 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),
-		},
+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..5607b4cc73 100644
--- a/packages/backend/src/server/api/endpoints/users/followers.ts
+++ b/packages/backend/src/server/api/endpoints/users/followers.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../define';
 import { ApiError } from '../../error';
 import { Users, Followings, UserProfiles } from '@/models/index';
@@ -11,33 +9,6 @@ export const meta = {
 
 	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;
 
+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..36943232d1 100644
--- a/packages/backend/src/server/api/endpoints/users/following.ts
+++ b/packages/backend/src/server/api/endpoints/users/following.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../define';
 import { ApiError } from '../../error';
 import { Users, Followings, UserProfiles } from '@/models/index';
@@ -11,33 +9,6 @@ export const meta = {
 
 	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;
 
+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..e874a54c77 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';
 
 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),
-		},
+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..a08587cd16 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
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../define';
 import { maximum } from '@/prelude/array';
 import { ApiError } from '../../error';
@@ -12,17 +10,6 @@ export const meta = {
 
 	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;
 
+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..e7bc95791f 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/create.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/create.ts
@@ -1,4 +1,3 @@
-import $ from 'cafy';
 import define from '../../../define';
 import { UserGroups, UserGroupJoinings } from '@/models/index';
 import { genId } from '@/misc/gen-id';
@@ -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;
 
+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..cb30b4d813 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/delete.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/delete.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserGroups } from '@/models/index';
@@ -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;
 
+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..7a6a620cb3 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
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../../define';
 import { ApiError } from '../../../../error';
 import { UserGroupJoinings, UserGroupInvitations } from '@/models/index';
@@ -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;
 
+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..b5c7f0908a 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
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../../define';
 import { ApiError } from '../../../../error';
 import { UserGroupInvitations } from '@/models/index';
@@ -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;
 
+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..ba78a28a38 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/invite.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/invite.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { getUser } from '../../../common/getters';
@@ -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;
 
+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..192a52a66b 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/joined.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/joined.ts
@@ -20,8 +20,14 @@ export const meta = {
 	},
 } as const;
 
+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..b7c7b328fd 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/leave.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/leave.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserGroups, UserGroupJoinings } from '@/models/index';
@@ -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;
 
+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..4592fc437f 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/owned.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/owned.ts
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+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..d50f61b159 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/pull.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/pull.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { getUser } from '../../../common/getters';
@@ -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;
 
+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..230254060d 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/show.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserGroups, UserGroupJoinings } from '@/models/index';
@@ -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;
 
+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..4b5206fa18 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { getUser } from '../../../common/getters';
@@ -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;
 
+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..0714fb4bd4 100644
--- a/packages/backend/src/server/api/endpoints/users/groups/update.ts
+++ b/packages/backend/src/server/api/endpoints/users/groups/update.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserGroups } from '@/models/index';
@@ -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;
 
+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..0a74424e0e 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/create.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/create.ts
@@ -1,4 +1,3 @@
-import $ from 'cafy';
 import define from '../../../define';
 import { UserLists } from '@/models/index';
 import { genId } from '@/misc/gen-id';
@@ -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;
 
+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..6795a227dc 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/delete.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/delete.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserLists } from '@/models/index';
@@ -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;
 
+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..d439723403 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/list.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/list.ts
@@ -19,8 +19,14 @@ export const meta = {
 	},
 } as const;
 
+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..5eca5a999d 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/pull.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/pull.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import { publishUserListStream } from '@/services/stream';
 import define from '../../../define';
 import { ApiError } from '../../../error';
@@ -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;
 
+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..68a1f00774 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/push.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/push.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { getUser } from '../../../common/getters';
@@ -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;
 
+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..3e9aa836ba 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/show.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserLists } from '@/models/index';
@@ -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;
 
+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..ee1489fc6a 100644
--- a/packages/backend/src/server/api/endpoints/users/lists/update.ts
+++ b/packages/backend/src/server/api/endpoints/users/lists/update.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../../define';
 import { ApiError } from '../../../error';
 import { UserLists } from '@/models/index';
@@ -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;
 
+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..956d90b7ad 100644
--- a/packages/backend/src/server/api/endpoints/users/notes.ts
+++ b/packages/backend/src/server/api/endpoints/users/notes.ts
@@ -1,5 +1,3 @@
-import $ from 'cafy';
-import { ID } from '@/misc/cafy-id';
 import define from '../../define';
 import { ApiError } from '../../error';
 import { getUser } from '../../common/getters';
@@ -14,57 +12,6 @@ import { generateMutedInstanceQuery } from '../../common/generate-muted-instance
 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;
 
+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);
@@ -141,7 +108,7 @@ 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..873b5e80fa 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';
 
 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),
-		},
+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..8d968210bc 100644
--- a/packages/backend/src/server/api/endpoints/users/reactions.ts
+++ b/packages/backend/src/server/api/endpoints/users/reactions.ts
@@ -1,5 +1,3 @@
-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';
@@ -11,33 +9,6 @@ export const meta = {
 
 	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;
 
+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..4a2d8d7e4a 100644
--- a/packages/backend/src/server/api/endpoints/users/recommendation.ts
+++ b/packages/backend/src/server/api/endpoints/users/recommendation.ts
@@ -1,5 +1,4 @@
 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';
@@ -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;
 
+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..fac1a4b92d 100644
--- a/packages/backend/src/server/api/endpoints/users/relation.ts
+++ b/packages/backend/src/server/api/endpoints/users/relation.ts
@@ -1,6 +1,4 @@
-import $ from 'cafy';
 import define from '../../define';
-import { ID } from '@/misc/cafy-id';
 import { Users } from '@/models/index';
 
 export const meta = {
@@ -8,12 +6,6 @@ export const meta = {
 
 	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;
 
+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..1df5e1573f 100644
--- a/packages/backend/src/server/api/endpoints/users/report-abuse.ts
+++ b/packages/backend/src/server/api/endpoints/users/report-abuse.ts
@@ -1,6 +1,4 @@
-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';
@@ -15,16 +13,6 @@ export const meta = {
 
 	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;
 
+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 72e79c8824..433779ae2d 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
@@ -1,4 +1,3 @@
-import $ from 'cafy';
 import define from '../../define';
 import { Followings, Users } from '@/models/index';
 import { Brackets } from 'typeorm';
@@ -10,26 +9,6 @@ export const meta = {
 
 	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 +20,19 @@ export const meta = {
 	},
 } as const;
 
+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;
+
 // 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 +47,7 @@ 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 +72,10 @@ 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 +87,7 @@ 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);
@@ -108,7 +98,7 @@ 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();
 		}
 
diff --git a/packages/backend/src/server/api/endpoints/users/search.ts b/packages/backend/src/server/api/endpoints/users/search.ts
index 26f818afcc..8c28e7c3a6 100644
--- a/packages/backend/src/server/api/endpoints/users/search.ts
+++ b/packages/backend/src/server/api/endpoints/users/search.ts
@@ -1,4 +1,3 @@
-import $ from 'cafy';
 import define from '../../define';
 import { UserProfiles, Users } from '@/models/index';
 import { User } from '@/models/entities/user';
@@ -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;
 
+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..29c90963ad 100644
--- a/packages/backend/src/server/api/endpoints/users/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/show.ts
@@ -1,9 +1,7 @@
-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 { In } from 'typeorm';
 import { User } from '@/models/entities/user';
@@ -13,24 +11,6 @@ export const meta = {
 
 	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;
 
+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..29dd8fdf93 100644
--- a/packages/backend/src/server/api/endpoints/users/stats.ts
+++ b/packages/backend/src/server/api/endpoints/users/stats.ts
@@ -1,7 +1,5 @@
-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';
 
 export const meta = {
@@ -9,12 +7,6 @@ export const meta = {
 
 	requireCredential: false,
 
-	params: {
-		userId: {
-			validator: $.type(ID),
-		},
-	},
-
 	errors: {
 		noSuchUser: {
 			message: 'No such user.',
@@ -24,8 +16,16 @@ export const meta = {
 	},
 } as const;
 
+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);