refactoring

Resolve #7779

34 files changed, 2432 insertions, 0 deletions

diff --git a/packages/backend/src/server/api/endpoints/users/clips.ts b/packages/backend/src/server/api/endpoints/users/clips.ts
new file mode 100644
index 0000000000..8feca9422a
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/clips.ts
@@ -0,0 +1,40 @@
+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'],
+
+	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 default define(meta, 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!)
+		.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
new file mode 100644
index 0000000000..6d042a2861
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/followers.ts
@@ -0,0 +1,104 @@
+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';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	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' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'Following',
+		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '27fa5435-88ab-43de-9360-387de88727cd'
+		},
+
+		forbidden: {
+			message: 'Forbidden.',
+			code: 'FORBIDDEN',
+			id: '3c6a84db-d619-26af-ca14-06232a21df8a'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	const user = await Users.findOne(ps.userId != null
+		? { id: ps.userId }
+		: { usernameLower: ps.username!.toLowerCase(), host: toPunyNullable(ps.host) });
+
+	if (user == null) {
+		throw new ApiError(meta.errors.noSuchUser);
+	}
+
+	const profile = await UserProfiles.findOneOrFail(user.id);
+
+	if (profile.ffVisibility === 'private') {
+		if (me == null || (me.id !== user.id)) {
+			throw new ApiError(meta.errors.forbidden);
+		}
+	} else if (profile.ffVisibility === 'followers') {
+		if (me == null) {
+			throw new ApiError(meta.errors.forbidden);
+		} else if (me.id !== user.id) {
+			const following = await Followings.findOne({
+				followeeId: user.id,
+				followerId: me.id,
+			});
+			if (following == null) {
+				throw new ApiError(meta.errors.forbidden);
+			}
+		}
+	}
+
+	const query = makePaginationQuery(Followings.createQueryBuilder('following'), ps.sinceId, ps.untilId)
+		.andWhere(`following.followeeId = :userId`, { userId: user.id })
+		.innerJoinAndSelect('following.follower', 'follower');
+
+	const followings = await query
+		.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
new file mode 100644
index 0000000000..1033117ef8
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/following.ts
@@ -0,0 +1,104 @@
+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';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	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' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'Following',
+		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '63e4aba4-4156-4e53-be25-c9559e42d71b'
+		},
+
+		forbidden: {
+			message: 'Forbidden.',
+			code: 'FORBIDDEN',
+			id: 'f6cdb0df-c19f-ec5c-7dbb-0ba84a1f92ba'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	const user = await Users.findOne(ps.userId != null
+		? { id: ps.userId }
+		: { usernameLower: ps.username!.toLowerCase(), host: toPunyNullable(ps.host) });
+
+	if (user == null) {
+		throw new ApiError(meta.errors.noSuchUser);
+	}
+
+	const profile = await UserProfiles.findOneOrFail(user.id);
+
+	if (profile.ffVisibility === 'private') {
+		if (me == null || (me.id !== user.id)) {
+			throw new ApiError(meta.errors.forbidden);
+		}
+	} else if (profile.ffVisibility === 'followers') {
+		if (me == null) {
+			throw new ApiError(meta.errors.forbidden);
+		} else if (me.id !== user.id) {
+			const following = await Followings.findOne({
+				followeeId: user.id,
+				followerId: me.id,
+			});
+			if (following == null) {
+				throw new ApiError(meta.errors.forbidden);
+			}
+		}
+	}
+
+	const query = makePaginationQuery(Followings.createQueryBuilder('following'), ps.sinceId, ps.untilId)
+		.andWhere(`following.followerId = :userId`, { userId: user.id })
+		.innerJoinAndSelect('following.followee', 'followee');
+
+	const followings = await query
+		.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
new file mode 100644
index 0000000000..845de1089c
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/gallery/posts.ts
@@ -0,0 +1,39 @@
+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'],
+
+	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 default define(meta, 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!)
+		.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
new file mode 100644
index 0000000000..32ebfd683a
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/get-frequently-replied-users.ts
@@ -0,0 +1,105 @@
+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 { Not, In, IsNull } from 'typeorm';
+import { Notes, Users } from '@/models/index';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	params: {
+		userId: {
+			validator: $.type(ID),
+		},
+
+		limit: {
+			validator: $.optional.num.range(1, 100),
+			default: 10
+		},
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'User',
+		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'e6965129-7b2a-40a4-bae2-cd84cd434822'
+		}
+	}
+};
+
+export default define(meta, 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);
+		throw e;
+	});
+
+	// Fetch recent notes
+	const recentNotes = await Notes.find({
+		where: {
+			userId: user.id,
+			replyId: Not(IsNull())
+		},
+		order: {
+			id: -1
+		},
+		take: 1000,
+		select: ['replyId']
+	});
+
+	// 投稿が少なかったら中断
+	if (recentNotes.length === 0) {
+		return [];
+	}
+
+	// TODO ミュートを考慮
+	const replyTargetNotes = await Notes.find({
+		where: {
+			id: In(recentNotes.map(p => p.replyId)),
+		},
+		select: ['userId']
+	});
+
+	const repliedUsers: any = {};
+
+	// Extract replies from recent notes
+	for (const userId of replyTargetNotes.map(x => x.userId.toString())) {
+		if (repliedUsers[userId]) {
+			repliedUsers[userId]++;
+		} else {
+			repliedUsers[userId] = 1;
+		}
+	}
+
+	// Calc peak
+	const peak = maximum(Object.values(repliedUsers));
+
+	// Sort replies by frequency
+	const repliedUsersSorted = Object.keys(repliedUsers).sort((a, b) => repliedUsers[b] - repliedUsers[a]);
+
+	// Extract top replied users
+	const topRepliedUsers = repliedUsersSorted.slice(0, ps.limit!);
+
+	// Make replies object (includes weights)
+	const repliesObj = await Promise.all(topRepliedUsers.map(async (user) => ({
+		user: await Users.pack(user, me, { detail: true }),
+		weight: repliedUsers[user] / peak
+	})));
+
+	return repliesObj;
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/create.ts b/packages/backend/src/server/api/endpoints/users/groups/create.ts
new file mode 100644
index 0000000000..dc1ee3879e
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/create.ts
@@ -0,0 +1,45 @@
+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';
+
+export const meta = {
+	tags: ['groups'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		name: {
+			validator: $.str.range(1, 100)
+		}
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserGroup',
+	},
+};
+
+export default define(meta, async (ps, user) => {
+	const userGroup = await UserGroups.insert({
+		id: genId(),
+		createdAt: new Date(),
+		userId: user.id,
+		name: ps.name,
+	} as UserGroup).then(x => UserGroups.findOneOrFail(x.identifiers[0]));
+
+	// Push the owner
+	await UserGroupJoinings.insert({
+		id: genId(),
+		createdAt: new Date(),
+		userId: user.id,
+		userGroupId: userGroup.id
+	} as UserGroupJoining);
+
+	return await UserGroups.pack(userGroup);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/delete.ts b/packages/backend/src/server/api/endpoints/users/groups/delete.ts
new file mode 100644
index 0000000000..7da1b4a273
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/delete.ts
@@ -0,0 +1,40 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserGroups } from '@/models/index';
+
+export const meta = {
+	tags: ['groups'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		}
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '63dbd64c-cd77-413f-8e08-61781e210b38'
+		}
+	}
+};
+
+export default define(meta, async (ps, user) => {
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+		userId: user.id
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	await UserGroups.delete(userGroup.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
new file mode 100644
index 0000000000..09e6ae2647
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/invitations/accept.ts
@@ -0,0 +1,54 @@
+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';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		invitationId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchInvitation: {
+			message: 'No such invitation.',
+			code: 'NO_SUCH_INVITATION',
+			id: '98c11eca-c890-4f42-9806-c8c8303ebb5e'
+		},
+	}
+};
+
+export default define(meta, async (ps, user) => {
+	// Fetch the invitation
+	const invitation = await UserGroupInvitations.findOne({
+		id: ps.invitationId,
+	});
+
+	if (invitation == null) {
+		throw new ApiError(meta.errors.noSuchInvitation);
+	}
+
+	if (invitation.userId !== user.id) {
+		throw new ApiError(meta.errors.noSuchInvitation);
+	}
+
+	// Push the user
+	await UserGroupJoinings.insert({
+		id: genId(),
+		createdAt: new Date(),
+		userId: user.id,
+		userGroupId: invitation.userGroupId
+	} as UserGroupJoining);
+
+	UserGroupInvitations.delete(invitation.id);
+});
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
new file mode 100644
index 0000000000..741fcefb35
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/invitations/reject.ts
@@ -0,0 +1,44 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../../define';
+import { ApiError } from '../../../../error';
+import { UserGroupInvitations } from '@/models/index';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		invitationId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchInvitation: {
+			message: 'No such invitation.',
+			code: 'NO_SUCH_INVITATION',
+			id: 'ad7471d4-2cd9-44b4-ac68-e7136b4ce656'
+		},
+	}
+};
+
+export default define(meta, async (ps, user) => {
+	// Fetch the invitation
+	const invitation = await UserGroupInvitations.findOne({
+		id: ps.invitationId,
+	});
+
+	if (invitation == null) {
+		throw new ApiError(meta.errors.noSuchInvitation);
+	}
+
+	if (invitation.userId !== user.id) {
+		throw new ApiError(meta.errors.noSuchInvitation);
+	}
+
+	await UserGroupInvitations.delete(invitation.id);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/invite.ts b/packages/backend/src/server/api/endpoints/users/groups/invite.ts
new file mode 100644
index 0000000000..f1ee8bf8b7
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/invite.ts
@@ -0,0 +1,102 @@
+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';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '583f8bc0-8eee-4b78-9299-1e14fc91e409'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'da52de61-002c-475b-90e1-ba64f9cf13a8'
+		},
+
+		alreadyAdded: {
+			message: 'That user has already been added to that group.',
+			code: 'ALREADY_ADDED',
+			id: '7e35c6a0-39b2-4488-aea6-6ee20bd5da2c'
+		},
+
+		alreadyInvited: {
+			message: 'That user has already been invited to that group.',
+			code: 'ALREADY_INVITED',
+			id: 'ee0f58b4-b529-4d13-b761-b9a3e69f97e6'
+		}
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+		userId: me.id,
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	// Fetch the user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	const joining = await UserGroupJoinings.findOne({
+		userGroupId: userGroup.id,
+		userId: user.id
+	});
+
+	if (joining) {
+		throw new ApiError(meta.errors.alreadyAdded);
+	}
+
+	const existInvitation = await UserGroupInvitations.findOne({
+		userGroupId: userGroup.id,
+		userId: user.id
+	});
+
+	if (existInvitation) {
+		throw new ApiError(meta.errors.alreadyInvited);
+	}
+
+	const invitation = await UserGroupInvitations.insert({
+		id: genId(),
+		createdAt: new Date(),
+		userId: user.id,
+		userGroupId: userGroup.id
+	} as UserGroupInvitation).then(x => UserGroupInvitations.findOneOrFail(x.identifiers[0]));
+
+	// 通知を作成
+	createNotification(user.id, 'groupInvited', {
+		notifierId: me.id,
+		userGroupInvitationId: invitation.id
+	});
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/joined.ts b/packages/backend/src/server/api/endpoints/users/groups/joined.ts
new file mode 100644
index 0000000000..d5e8fe4032
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/joined.ts
@@ -0,0 +1,36 @@
+import define from '../../../define';
+import { UserGroups, UserGroupJoinings } from '@/models/index';
+import { Not, In } from 'typeorm';
+
+export const meta = {
+	tags: ['groups', 'account'],
+
+	requireCredential: true as const,
+
+	kind: 'read:user-groups',
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'UserGroup',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const ownedGroups = await UserGroups.find({
+		userId: me.id,
+	});
+
+	const joinings = await UserGroupJoinings.find({
+		userId: me.id,
+		...(ownedGroups.length > 0 ? {
+			userGroupId: Not(In(ownedGroups.map(x => x.id)))
+		} : {})
+	});
+
+	return await Promise.all(joinings.map(x => UserGroups.pack(x.userGroupId)));
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/leave.ts b/packages/backend/src/server/api/endpoints/users/groups/leave.ts
new file mode 100644
index 0000000000..0e52f2abdf
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/leave.ts
@@ -0,0 +1,50 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserGroups, UserGroupJoinings } from '@/models/index';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '62780270-1f67-5dc0-daca-3eb510612e31'
+		},
+
+		youAreOwner: {
+			message: 'Your are the owner.',
+			code: 'YOU_ARE_OWNER',
+			id: 'b6d6e0c2-ef8a-9bb8-653d-79f4a3107c69'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	if (me.id === userGroup.userId) {
+		throw new ApiError(meta.errors.youAreOwner);
+	}
+
+	await UserGroupJoinings.delete({ userGroupId: userGroup.id, userId: me.id });
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/owned.ts b/packages/backend/src/server/api/endpoints/users/groups/owned.ts
new file mode 100644
index 0000000000..17de370dbc
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/owned.ts
@@ -0,0 +1,28 @@
+import define from '../../../define';
+import { UserGroups } from '@/models/index';
+
+export const meta = {
+	tags: ['groups', 'account'],
+
+	requireCredential: true as const,
+
+	kind: 'read:user-groups',
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'UserGroup',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const userGroups = await UserGroups.find({
+		userId: me.id,
+	});
+
+	return await Promise.all(userGroups.map(x => UserGroups.pack(x)));
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/pull.ts b/packages/backend/src/server/api/endpoints/users/groups/pull.ts
new file mode 100644
index 0000000000..ce4d2e2881
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/pull.ts
@@ -0,0 +1,69 @@
+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';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '4662487c-05b1-4b78-86e5-fd46998aba74'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '0b5cc374-3681-41da-861e-8bc1146f7a55'
+		},
+
+		isOwner: {
+			message: 'The user is the owner.',
+			code: 'IS_OWNER',
+			id: '1546eed5-4414-4dea-81c1-b0aec4f6d2af'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+		userId: me.id,
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	// Fetch the user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	if (user.id === userGroup.userId) {
+		throw new ApiError(meta.errors.isOwner);
+	}
+
+	// Pull the user
+	await UserGroupJoinings.delete({ userGroupId: userGroup.id, userId: user.id });
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/show.ts b/packages/backend/src/server/api/endpoints/users/groups/show.ts
new file mode 100644
index 0000000000..3c030bf3a5
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/show.ts
@@ -0,0 +1,55 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserGroups, UserGroupJoinings } from '@/models/index';
+
+export const meta = {
+	tags: ['groups', 'account'],
+
+	requireCredential: true as const,
+
+	kind: 'read:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserGroup',
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: 'ea04751e-9b7e-487b-a509-330fb6bd6b9b'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	const joining = await UserGroupJoinings.findOne({
+		userId: me.id,
+		userGroupId: userGroup.id
+	});
+
+	if (joining == null && userGroup.userId !== me.id) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	return await UserGroups.pack(userGroup);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/transfer.ts b/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
new file mode 100644
index 0000000000..17c42e1127
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/transfer.ts
@@ -0,0 +1,83 @@
+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';
+
+export const meta = {
+	tags: ['groups', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserGroup',
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '8e31d36b-2f88-4ccd-a438-e2d78a9162db'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '711f7ebb-bbb9-4dfa-b540-b27809fed5e9'
+		},
+
+		noSuchGroupMember: {
+			message: 'No such group member.',
+			code: 'NO_SUCH_GROUP_MEMBER',
+			id: 'd31bebee-196d-42c2-9a3e-9474d4be6cc4'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+		userId: me.id,
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	// Fetch the user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	const joining = await UserGroupJoinings.findOne({
+		userGroupId: userGroup.id,
+		userId: user.id
+	});
+
+	if (joining == null) {
+		throw new ApiError(meta.errors.noSuchGroupMember);
+	}
+
+	await UserGroups.update(userGroup.id, {
+		userId: ps.userId
+	});
+
+	return await UserGroups.pack(userGroup.id);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/groups/update.ts b/packages/backend/src/server/api/endpoints/users/groups/update.ts
new file mode 100644
index 0000000000..127bbc47a1
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/groups/update.ts
@@ -0,0 +1,55 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserGroups } from '@/models/index';
+
+export const meta = {
+	tags: ['groups'],
+
+	requireCredential: true as const,
+
+	kind: 'write:user-groups',
+
+	params: {
+		groupId: {
+			validator: $.type(ID),
+		},
+
+		name: {
+			validator: $.str.range(1, 100),
+		}
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserGroup',
+	},
+
+	errors: {
+		noSuchGroup: {
+			message: 'No such group.',
+			code: 'NO_SUCH_GROUP',
+			id: '9081cda3-7a9e-4fac-a6ce-908d70f282f6'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the group
+	const userGroup = await UserGroups.findOne({
+		id: ps.groupId,
+		userId: me.id
+	});
+
+	if (userGroup == null) {
+		throw new ApiError(meta.errors.noSuchGroup);
+	}
+
+	await UserGroups.update(userGroup.id, {
+		name: ps.name
+	});
+
+	return await UserGroups.pack(userGroup.id);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/create.ts b/packages/backend/src/server/api/endpoints/users/lists/create.ts
new file mode 100644
index 0000000000..e0bfe611fc
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/create.ts
@@ -0,0 +1,36 @@
+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';
+
+export const meta = {
+	tags: ['lists'],
+
+	requireCredential: true as const,
+
+	kind: 'write:account',
+
+	params: {
+		name: {
+			validator: $.str.range(1, 100)
+		}
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserList',
+	},
+};
+
+export default define(meta, async (ps, user) => {
+	const userList = await UserLists.insert({
+		id: genId(),
+		createdAt: new Date(),
+		userId: user.id,
+		name: ps.name,
+	} as UserList).then(x => UserLists.findOneOrFail(x.identifiers[0]));
+
+	return await UserLists.pack(userList);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/delete.ts b/packages/backend/src/server/api/endpoints/users/lists/delete.ts
new file mode 100644
index 0000000000..5fe3bfb03d
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/delete.ts
@@ -0,0 +1,40 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserLists } from '@/models/index';
+
+export const meta = {
+	tags: ['lists'],
+
+	requireCredential: true as const,
+
+	kind: 'write:account',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+		}
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '78436795-db79-42f5-b1e2-55ea2cf19166'
+		}
+	}
+};
+
+export default define(meta, async (ps, user) => {
+	const userList = await UserLists.findOne({
+		id: ps.listId,
+		userId: user.id
+	});
+
+	if (userList == null) {
+		throw new ApiError(meta.errors.noSuchList);
+	}
+
+	await UserLists.delete(userList.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
new file mode 100644
index 0000000000..cf0c92bb84
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/list.ts
@@ -0,0 +1,28 @@
+import define from '../../../define';
+import { UserLists } from '@/models/index';
+
+export const meta = {
+	tags: ['lists', 'account'],
+
+	requireCredential: true as const,
+
+	kind: 'read:account',
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'UserList',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const userLists = await UserLists.find({
+		userId: me.id,
+	});
+
+	return await Promise.all(userLists.map(x => UserLists.pack(x)));
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/pull.ts b/packages/backend/src/server/api/endpoints/users/lists/pull.ts
new file mode 100644
index 0000000000..d4357fc5e7
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/pull.ts
@@ -0,0 +1,62 @@
+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';
+
+export const meta = {
+	tags: ['lists', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:account',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+		},
+
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '7f44670e-ab16-43b8-b4c1-ccd2ee89cc02'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '588e7f72-c744-4a61-b180-d354e912bda2'
+		}
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the list
+	const userList = await UserLists.findOne({
+		id: ps.listId,
+		userId: me.id,
+	});
+
+	if (userList == null) {
+		throw new ApiError(meta.errors.noSuchList);
+	}
+
+	// Fetch the user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	// Pull the user
+	await UserListJoinings.delete({ userListId: userList.id, userId: user.id });
+
+	publishUserListStream(userList.id, 'userRemoved', await Users.pack(user));
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/push.ts b/packages/backend/src/server/api/endpoints/users/lists/push.ts
new file mode 100644
index 0000000000..8e21059d3d
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/push.ts
@@ -0,0 +1,92 @@
+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';
+
+export const meta = {
+	tags: ['lists', 'users'],
+
+	requireCredential: true as const,
+
+	kind: 'write:account',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+		},
+
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '2214501d-ac96-4049-b717-91e42272a711'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'a89abd3d-f0bc-4cce-beb1-2f446f4f1e6a'
+		},
+
+		alreadyAdded: {
+			message: 'That user has already been added to that list.',
+			code: 'ALREADY_ADDED',
+			id: '1de7c884-1595-49e9-857e-61f12f4d4fc5'
+		},
+
+		youHaveBeenBlocked: {
+			message: 'You cannot push this user because you have been blocked by this user.',
+			code: 'YOU_HAVE_BEEN_BLOCKED',
+			id: '990232c5-3f9d-4d83-9f3f-ef27b6332a4b'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the list
+	const userList = await UserLists.findOne({
+		id: ps.listId,
+		userId: me.id,
+	});
+
+	if (userList == null) {
+		throw new ApiError(meta.errors.noSuchList);
+	}
+
+	// Fetch the user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	// Check blocking
+	if (user.id !== me.id) {
+		const block = await Blockings.findOne({
+			blockerId: user.id,
+			blockeeId: me.id,
+		});
+		if (block) {
+			throw new ApiError(meta.errors.youHaveBeenBlocked);
+		}
+	}
+
+	const exist = await UserListJoinings.findOne({
+		userListId: userList.id,
+		userId: user.id
+	});
+
+	if (exist) {
+		throw new ApiError(meta.errors.alreadyAdded);
+	}
+
+	// Push the user
+	await pushUserToUserList(user, userList);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/show.ts b/packages/backend/src/server/api/endpoints/users/lists/show.ts
new file mode 100644
index 0000000000..f9a35cdab3
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/show.ts
@@ -0,0 +1,47 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserLists } from '@/models/index';
+
+export const meta = {
+	tags: ['lists', 'account'],
+
+	requireCredential: true as const,
+
+	kind: 'read:account',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+		},
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserList',
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '7bc05c21-1d7a-41ae-88f1-66820f4dc686'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Fetch the list
+	const userList = await UserLists.findOne({
+		id: ps.listId,
+		userId: me.id,
+	});
+
+	if (userList == null) {
+		throw new ApiError(meta.errors.noSuchList);
+	}
+
+	return await UserLists.pack(userList);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/lists/update.ts b/packages/backend/src/server/api/endpoints/users/lists/update.ts
new file mode 100644
index 0000000000..1185af5043
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/lists/update.ts
@@ -0,0 +1,55 @@
+import $ from 'cafy';
+import { ID } from '@/misc/cafy-id';
+import define from '../../../define';
+import { ApiError } from '../../../error';
+import { UserLists } from '@/models/index';
+
+export const meta = {
+	tags: ['lists'],
+
+	requireCredential: true as const,
+
+	kind: 'write:account',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+		},
+
+		name: {
+			validator: $.str.range(1, 100),
+		}
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'UserList',
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '796666fe-3dff-4d39-becb-8a5932c1d5b7'
+		},
+	}
+};
+
+export default define(meta, async (ps, user) => {
+	// Fetch the list
+	const userList = await UserLists.findOne({
+		id: ps.listId,
+		userId: user.id
+	});
+
+	if (userList == null) {
+		throw new ApiError(meta.errors.noSuchList);
+	}
+
+	await UserLists.update(userList.id, {
+		name: ps.name
+	});
+
+	return await UserLists.pack(userList.id);
+});
diff --git a/packages/backend/src/server/api/endpoints/users/notes.ts b/packages/backend/src/server/api/endpoints/users/notes.ts
new file mode 100644
index 0000000000..0afbad9d04
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/notes.ts
@@ -0,0 +1,144 @@
+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 { Brackets } from 'typeorm';
+import { generateBlockedUserQuery } from '../../common/generate-block-query';
+
+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: $.optional.bool,
+			default: false,
+		},
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'Note',
+		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '27e494ba-2ac2-48e8-893b-10d4d8c2387b'
+		}
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	// Lookup user
+	const user = await getUser(ps.userId).catch(e => {
+		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
+		throw e;
+	});
+
+	//#region Construct query
+	const query = makePaginationQuery(Notes.createQueryBuilder('note'), ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
+		.andWhere('note.userId = :userId', { userId: user.id })
+		.innerJoinAndSelect('note.user', 'user')
+		.leftJoinAndSelect('note.reply', 'reply')
+		.leftJoinAndSelect('note.renote', 'renote')
+		.leftJoinAndSelect('reply.user', 'replyUser')
+		.leftJoinAndSelect('renote.user', 'renoteUser');
+
+	generateVisibilityQuery(query, me);
+	if (me) generateMutedUserQuery(query, me, user);
+	if (me) generateBlockedUserQuery(query, me);
+
+	if (ps.withFiles) {
+		query.andWhere('note.fileIds != \'{}\'');
+	}
+
+	if (ps.fileType != null) {
+		query.andWhere('note.fileIds != \'{}\'');
+		query.andWhere(new Brackets(qb => {
+			for (const type of ps.fileType!) {
+				const i = ps.fileType!.indexOf(type);
+				qb.orWhere(`:type${i} = ANY(note.attachedFileTypes)`, { [`type${i}`]: type });
+			}
+		}));
+
+		if (ps.excludeNsfw) {
+			query.andWhere('note.cw IS NULL');
+			query.andWhere('0 = (SELECT COUNT(*) FROM drive_file df WHERE df.id = ANY(note."fileIds") AND df."isSensitive" = TRUE)');
+		}
+	}
+
+	if (!ps.includeReplies) {
+		query.andWhere('note.replyId IS NULL');
+	}
+
+	if (ps.includeMyRenotes === false) {
+		query.andWhere(new Brackets(qb => {
+			qb.orWhere('note.userId != :userId', { userId: user.id });
+			qb.orWhere('note.renoteId IS NULL');
+			qb.orWhere('note.text IS NOT NULL');
+			qb.orWhere('note.fileIds != \'{}\'');
+			qb.orWhere('0 < (SELECT COUNT(*) FROM poll WHERE poll."noteId" = note.id)');
+		}));
+	}
+
+	//#endregion
+
+	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
new file mode 100644
index 0000000000..24e9e207fd
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/pages.ts
@@ -0,0 +1,40 @@
+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'],
+
+	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 default define(meta, 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!)
+		.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
new file mode 100644
index 0000000000..fe5e4d84a9
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/reactions.ts
@@ -0,0 +1,79 @@
+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';
+
+export const meta = {
+	tags: ['users', 'reactions'],
+
+	requireCredential: false 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),
+		},
+
+		sinceDate: {
+			validator: $.optional.num,
+		},
+
+		untilDate: {
+			validator: $.optional.num,
+		},
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'NoteReaction',
+		}
+	},
+
+	errors: {
+		reactionsNotPublic: {
+			message: 'Reactions of the user is not public.',
+			code: 'REACTIONS_NOT_PUBLIC',
+			id: '673a7dd2-6924-1093-e0c0-e68456ceae5c'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	const profile = await UserProfiles.findOneOrFail(ps.userId);
+
+	if (me == null || (me.id !== ps.userId && !profile.publicReactions)) {
+		throw new ApiError(meta.errors.reactionsNotPublic);
+	}
+
+	const query = makePaginationQuery(NoteReactions.createQueryBuilder('reaction'),
+			ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate)
+		.andWhere(`reaction.userId = :userId`, { userId: ps.userId })
+		.leftJoinAndSelect('reaction.note', 'note');
+
+	generateVisibilityQuery(query, me);
+
+	const reactions = await query
+		.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
new file mode 100644
index 0000000000..dde6bb1037
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/recommendation.ts
@@ -0,0 +1,63 @@
+import * as 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';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: true as const,
+
+	kind: 'read:account',
+
+	params: {
+		limit: {
+			validator: $.optional.num.range(1, 100),
+			default: 10
+		},
+
+		offset: {
+			validator: $.optional.num.min(0),
+			default: 0
+		}
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'User',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const query = Users.createQueryBuilder('user')
+		.where('user.isLocked = FALSE')
+		.andWhere('user.isExplorable = TRUE')
+		.andWhere('user.host IS NULL')
+		.andWhere('user.updatedAt >= :date', { date: new Date(Date.now() - ms('7days')) })
+		.andWhere('user.id != :meId', { meId: me.id })
+		.orderBy('user.followersCount', 'DESC');
+
+	generateMutedUserQueryForUsers(query, me);
+	generateBlockQueryForUsers(query, me);
+	generateBlockedUserQuery(query, me);
+
+	const followingQuery = Followings.createQueryBuilder('following')
+		.select('following.followeeId')
+		.where('following.followerId = :followerId', { followerId: me.id });
+
+	query
+		.andWhere(`user.id NOT IN (${ followingQuery.getQuery() })`);
+
+	query.setParameters(followingQuery.getParameters());
+
+	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
new file mode 100644
index 0000000000..32d76a5322
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/relation.ts
@@ -0,0 +1,111 @@
+import $ from 'cafy';
+import define from '../../define';
+import { ID } from '@/misc/cafy-id';
+import { Users } from '@/models/index';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: true as const,
+
+	params: {
+		userId: {
+			validator: $.either($.type(ID), $.arr($.type(ID)).unique()),
+		}
+	},
+
+	res: {
+		oneOf: [
+			{
+				type: 'object' as const,
+				optional: false as const, nullable: false as const,
+				properties: {
+					id: {
+						type: 'string' as const,
+						optional: false as const, nullable: false as const,
+						format: 'id'
+					},
+					isFollowing: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					hasPendingFollowRequestFromYou: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					hasPendingFollowRequestToYou: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					isFollowed: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					isBlocking: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					isBlocked: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					},
+					isMuted: {
+						type: 'boolean' as const,
+						optional: false as const, nullable: false as const
+					}
+				}
+			},
+			{
+				type: 'array' as const,
+				optional: false as const, nullable: false as const,
+				items: {
+					type: 'object' as const,
+					optional: false as const, nullable: false as const,
+					properties: {
+						id: {
+							type: 'string' as const,
+							optional: false as const, nullable: false as const,
+							format: 'id'
+						},
+						isFollowing: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						hasPendingFollowRequestFromYou: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						hasPendingFollowRequestToYou: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						isFollowed: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						isBlocking: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						isBlocked: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						},
+						isMuted: {
+							type: 'boolean' as const,
+							optional: false as const, nullable: false as const
+						}
+					}
+				}
+			}
+		]
+	}
+};
+
+export default define(meta, 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)));
+
+	return Array.isArray(ps.userId) ? relations : relations[0];
+});
diff --git a/packages/backend/src/server/api/endpoints/users/report-abuse.ts b/packages/backend/src/server/api/endpoints/users/report-abuse.ts
new file mode 100644
index 0000000000..2c8672cd47
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/report-abuse.ts
@@ -0,0 +1,90 @@
+import $ from 'cafy';
+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';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: true as const,
+
+	params: {
+		userId: {
+			validator: $.type(ID),
+		},
+
+		comment: {
+			validator: $.str.range(1, 2048),
+		},
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '1acefcb5-0959-43fd-9685-b48305736cb5'
+		},
+
+		cannotReportYourself: {
+			message: 'Cannot report yourself.',
+			code: 'CANNOT_REPORT_YOURSELF',
+			id: '1e13149e-b1e8-43cf-902e-c01dbfcb202f'
+		},
+
+		cannotReportAdmin: {
+			message: 'Cannot report the admin.',
+			code: 'CANNOT_REPORT_THE_ADMIN',
+			id: '35e166f5-05fb-4f87-a2d5-adb42676d48f'
+		}
+	}
+};
+
+export default define(meta, 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);
+		throw e;
+	});
+
+	if (user.id === me.id) {
+		throw new ApiError(meta.errors.cannotReportYourself);
+	}
+
+	if (user.isAdmin) {
+		throw new ApiError(meta.errors.cannotReportAdmin);
+	}
+
+	const report = await AbuseUserReports.save({
+		id: genId(),
+		createdAt: new Date(),
+		targetUserId: user.id,
+		targetUserHost: user.host,
+		reporterId: me.id,
+		reporterHost: null,
+		comment: ps.comment,
+	});
+
+	// Publish event to moderators
+	setTimeout(async () => {
+		const moderators = await Users.find({
+			where: [{
+				isAdmin: true
+			}, {
+				isModerator: true
+			}]
+		});
+
+		for (const moderator of moderators) {
+			publishAdminStream(moderator.id, 'newAbuseUserReport', {
+				id: report.id,
+				targetUserId: report.targetUserId,
+				reporterId: report.reporterId,
+				comment: report.comment
+			});
+		}
+	}, 1);
+});
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
new file mode 100644
index 0000000000..1ec5e1a743
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
@@ -0,0 +1,116 @@
+import $ from 'cafy';
+import define from '../../define';
+import { Followings, Users } from '@/models/index';
+import { Brackets } from 'typeorm';
+import { USER_ACTIVE_THRESHOLD } from '@/const';
+import { User } from '@/models/entities/user';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	params: {
+		username: {
+			validator: $.optional.nullable.str,
+		},
+
+		host: {
+			validator: $.optional.nullable.str,
+		},
+
+		limit: {
+			validator: $.optional.num.range(1, 100),
+			default: 10,
+		},
+
+		detail: {
+			validator: $.optional.bool,
+			default: true,
+		},
+	},
+
+	res: {
+		type: 'array' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'User',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const activeThreshold = new Date(Date.now() - (1000 * 60 * 60 * 24 * 30)); // 30日
+
+	if (ps.host) {
+		const q = Users.createQueryBuilder('user')
+			.where('user.isSuspended = FALSE')
+			.andWhere('user.host LIKE :host', { host: ps.host.toLowerCase() + '%' });
+
+		if (ps.username) {
+			q.andWhere('user.usernameLower LIKE :username', { username: ps.username.toLowerCase() + '%' });
+		}
+
+		q.andWhere('user.updatedAt IS NOT NULL');
+		q.orderBy('user.updatedAt', 'DESC');
+
+		const users = await q.take(ps.limit!).getMany();
+
+		return await Users.packMany(users, me, { detail: ps.detail });
+	} else if (ps.username) {
+		let users: User[] = [];
+
+		if (me) {
+			const followingQuery = Followings.createQueryBuilder('following')
+				.select('following.followeeId')
+				.where('following.followerId = :followerId', { followerId: me.id });
+
+			const query = Users.createQueryBuilder('user')
+				.where(`user.id IN (${ followingQuery.getQuery() })`)
+				.andWhere(`user.id != :meId`, { meId: me.id })
+				.andWhere('user.isSuspended = FALSE')
+				.andWhere('user.usernameLower LIKE :username', { username: ps.username.toLowerCase() + '%' })
+				.andWhere(new Brackets(qb => { qb
+					.where('user.updatedAt IS NULL')
+					.orWhere('user.updatedAt > :activeThreshold', { activeThreshold: activeThreshold });
+				}));
+
+			query.setParameters(followingQuery.getParameters());
+
+			users = await query
+				.orderBy('user.usernameLower', 'ASC')
+				.take(ps.limit!)
+				.getMany();
+
+			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 })
+					.andWhere('user.isSuspended = FALSE')
+					.andWhere('user.usernameLower LIKE :username', { username: ps.username.toLowerCase() + '%' })
+					.andWhere('user.updatedAt IS NOT NULL');
+
+				otherQuery.setParameters(followingQuery.getParameters());
+
+				const otherUsers = await otherQuery
+					.orderBy('user.updatedAt', 'DESC')
+					.take(ps.limit! - users.length)
+					.getMany();
+
+				users = users.concat(otherUsers);
+			}
+		} else {
+			users = await Users.createQueryBuilder('user')
+				.where('user.isSuspended = FALSE')
+				.andWhere('user.usernameLower LIKE :username', { username: ps.username.toLowerCase() + '%' })
+				.andWhere('user.updatedAt IS NOT NULL')
+				.orderBy('user.updatedAt', 'DESC')
+				.take(ps.limit! - users.length)
+				.getMany();
+		}
+
+		return await Users.packMany(users, me, { detail: ps.detail });
+	}
+});
diff --git a/packages/backend/src/server/api/endpoints/users/search.ts b/packages/backend/src/server/api/endpoints/users/search.ts
new file mode 100644
index 0000000000..9aa988d9ed
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/search.ts
@@ -0,0 +1,127 @@
+import $ from 'cafy';
+import define from '../../define';
+import { UserProfiles, Users } from '@/models/index';
+import { User } from '@/models/entities/user';
+import { Brackets } from 'typeorm';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	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' as const,
+		optional: false as const, nullable: false as const,
+		items: {
+			type: 'object' as const,
+			optional: false as const, nullable: false as const,
+			ref: 'User',
+		}
+	},
+};
+
+export default define(meta, async (ps, me) => {
+	const activeThreshold = new Date(Date.now() - (1000 * 60 * 60 * 24 * 30)); // 30日
+
+	const isUsername = ps.query.startsWith('@');
+
+	let users: User[] = [];
+
+	if (isUsername) {
+		const usernameQuery = Users.createQueryBuilder('user')
+			.where('user.usernameLower LIKE :username', { username: ps.query.replace('@', '').toLowerCase() + '%' })
+			.andWhere(new Brackets(qb => { qb
+				.where('user.updatedAt IS NULL')
+				.orWhere('user.updatedAt > :activeThreshold', { activeThreshold: activeThreshold });
+			}))
+			.andWhere('user.isSuspended = FALSE');
+
+		if (ps.origin === 'local') {
+			usernameQuery.andWhere('user.host IS NULL');
+		} else if (ps.origin === 'remote') {
+			usernameQuery.andWhere('user.host IS NOT NULL');
+		}
+
+		users = await usernameQuery
+			.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
+			.take(ps.limit!)
+			.skip(ps.offset)
+			.getMany();
+	} else {
+		const nameQuery = Users.createQueryBuilder('user')
+			.where('user.name ILIKE :query', { query: '%' + ps.query + '%' })
+			.andWhere(new Brackets(qb => { qb
+				.where('user.updatedAt IS NULL')
+				.orWhere('user.updatedAt > :activeThreshold', { activeThreshold: activeThreshold });
+			}))
+			.andWhere('user.isSuspended = FALSE');
+
+		if (ps.origin === 'local') {
+			nameQuery.andWhere('user.host IS NULL');
+		} else if (ps.origin === 'remote') {
+			nameQuery.andWhere('user.host IS NOT NULL');
+		}
+
+		users = await nameQuery
+			.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
+			.take(ps.limit!)
+			.skip(ps.offset)
+			.getMany();
+
+		if (users.length < ps.limit!) {
+			const profQuery = UserProfiles.createQueryBuilder('prof')
+				.select('prof.userId')
+				.where('prof.description ILIKE :query', { query: '%' + ps.query + '%' });
+
+			if (ps.origin === 'local') {
+				profQuery.andWhere('prof.userHost IS NULL');
+			} else if (ps.origin === 'remote') {
+				profQuery.andWhere('prof.userHost IS NOT NULL');
+			}
+
+			const query = Users.createQueryBuilder('user')
+				.where(`user.id IN (${ profQuery.getQuery() })`)
+				.andWhere(new Brackets(qb => { qb
+					.where('user.updatedAt IS NULL')
+					.orWhere('user.updatedAt > :activeThreshold', { activeThreshold: activeThreshold });
+				}))
+				.andWhere('user.isSuspended = FALSE')
+				.setParameters(profQuery.getParameters());
+
+			users = users.concat(await query
+				.orderBy('user.updatedAt', 'DESC', 'NULLS LAST')
+				.take(ps.limit!)
+				.skip(ps.offset)
+				.getMany()
+			);
+		}
+	}
+
+	return await Users.packMany(users, me, { detail: ps.detail });
+});
diff --git a/packages/backend/src/server/api/endpoints/users/show.ts b/packages/backend/src/server/api/endpoints/users/show.ts
new file mode 100644
index 0000000000..f056983636
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/show.ts
@@ -0,0 +1,105 @@
+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';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	params: {
+		userId: {
+			validator: $.optional.type(ID),
+		},
+
+		userIds: {
+			validator: $.optional.arr($.type(ID)).unique(),
+		},
+
+		username: {
+			validator: $.optional.str
+		},
+
+		host: {
+			validator: $.optional.nullable.str
+		}
+	},
+
+	res: {
+		type: 'object' as const,
+		optional: false as const, nullable: false as const,
+		ref: 'User',
+	},
+
+	errors: {
+		failedToResolveRemoteUser: {
+			message: 'Failed to resolve remote user.',
+			code: 'FAILED_TO_RESOLVE_REMOTE_USER',
+			id: 'ef7b9be4-9cba-4e6f-ab41-90ed171c7d3c',
+			kind: 'server' as const
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '4362f8dc-731f-4ad8-a694-be5a88922a24'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	let user;
+
+	const isAdminOrModerator = me && (me.isAdmin || me.isModerator);
+
+	if (ps.userIds) {
+		if (ps.userIds.length === 0) {
+			return [];
+		}
+
+		const users = await Users.find(isAdminOrModerator ? {
+			id: In(ps.userIds)
+		} : {
+			id: In(ps.userIds),
+			isSuspended: false
+		});
+
+		// リクエストされた通りに並べ替え
+		const _users: User[] = [];
+		for (const id of ps.userIds) {
+			_users.push(users.find(x => x.id === id)!);
+		}
+
+		return await Promise.all(_users.map(u => Users.pack(u, me, {
+			detail: true
+		})));
+	} else {
+		// Lookup user
+		if (typeof ps.host === 'string' && typeof ps.username === 'string') {
+			user = await resolveUser(ps.username, ps.host).catch(e => {
+				apiLogger.warn(`failed to resolve remote user: ${e}`);
+				throw new ApiError(meta.errors.failedToResolveRemoteUser);
+			});
+		} else {
+			const q: any = ps.userId != null
+				? { id: ps.userId }
+				: { usernameLower: ps.username!.toLowerCase(), host: null };
+
+			user = await Users.findOne(q);
+		}
+
+		if (user == null || (!isAdminOrModerator && user.isSuspended)) {
+			throw new ApiError(meta.errors.noSuchUser);
+		}
+
+		return await Users.pack(user, me, {
+			detail: true
+		});
+	}
+});
diff --git a/packages/backend/src/server/api/endpoints/users/stats.ts b/packages/backend/src/server/api/endpoints/users/stats.ts
new file mode 100644
index 0000000000..ef8afd5625
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/users/stats.ts
@@ -0,0 +1,144 @@
+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, ReversiGames, Users } from '@/models/index';
+
+export const meta = {
+	tags: ['users'],
+
+	requireCredential: false as const,
+
+	params: {
+		userId: {
+			validator: $.type(ID),
+		},
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '9e638e45-3b25-4ef7-8f95-07e8498f1819'
+		},
+	}
+};
+
+export default define(meta, async (ps, me) => {
+	const user = await Users.findOne(ps.userId);
+	if (user == null) {
+		throw new ApiError(meta.errors.noSuchUser);
+	}
+
+	const [
+		notesCount,
+		repliesCount,
+		renotesCount,
+		repliedCount,
+		renotedCount,
+		pollVotesCount,
+		pollVotedCount,
+		localFollowingCount,
+		remoteFollowingCount,
+		localFollowersCount,
+		remoteFollowersCount,
+		sentReactionsCount,
+		receivedReactionsCount,
+		noteFavoritesCount,
+		pageLikesCount,
+		pageLikedCount,
+		driveFilesCount,
+		driveUsage,
+		reversiCount,
+	] = await Promise.all([
+		Notes.createQueryBuilder('note')
+			.where('note.userId = :userId', { userId: user.id })
+			.getCount(),
+		Notes.createQueryBuilder('note')
+			.where('note.userId = :userId', { userId: user.id })
+			.andWhere('note.replyId IS NOT NULL')
+			.getCount(),
+		Notes.createQueryBuilder('note')
+			.where('note.userId = :userId', { userId: user.id })
+			.andWhere('note.renoteId IS NOT NULL')
+			.getCount(),
+		Notes.createQueryBuilder('note')
+			.where('note.replyUserId = :userId', { userId: user.id })
+			.getCount(),
+		Notes.createQueryBuilder('note')
+			.where('note.renoteUserId = :userId', { userId: user.id })
+			.getCount(),
+		PollVotes.createQueryBuilder('vote')
+			.where('vote.userId = :userId', { userId: user.id })
+			.getCount(),
+		PollVotes.createQueryBuilder('vote')
+			.innerJoin('vote.note', 'note')
+			.where('note.userId = :userId', { userId: user.id })
+			.getCount(),
+		Followings.createQueryBuilder('following')
+			.where('following.followerId = :userId', { userId: user.id })
+			.andWhere('following.followeeHost IS NULL')
+			.getCount(),
+		Followings.createQueryBuilder('following')
+			.where('following.followerId = :userId', { userId: user.id })
+			.andWhere('following.followeeHost IS NOT NULL')
+			.getCount(),
+		Followings.createQueryBuilder('following')
+			.where('following.followeeId = :userId', { userId: user.id })
+			.andWhere('following.followerHost IS NULL')
+			.getCount(),
+		Followings.createQueryBuilder('following')
+			.where('following.followeeId = :userId', { userId: user.id })
+			.andWhere('following.followerHost IS NOT NULL')
+			.getCount(),
+		NoteReactions.createQueryBuilder('reaction')
+			.where('reaction.userId = :userId', { userId: user.id })
+			.getCount(),
+		NoteReactions.createQueryBuilder('reaction')
+			.innerJoin('reaction.note', 'note')
+			.where('note.userId = :userId', { userId: user.id })
+			.getCount(),
+		NoteFavorites.createQueryBuilder('favorite')
+			.where('favorite.userId = :userId', { userId: user.id })
+			.getCount(),
+		PageLikes.createQueryBuilder('like')
+			.where('like.userId = :userId', { userId: user.id })
+			.getCount(),
+		PageLikes.createQueryBuilder('like')
+			.innerJoin('like.page', 'page')
+			.where('page.userId = :userId', { userId: user.id })
+			.getCount(),
+		DriveFiles.createQueryBuilder('file')
+			.where('file.userId = :userId', { userId: user.id })
+			.getCount(),
+		DriveFiles.calcDriveUsageOf(user),
+		ReversiGames.createQueryBuilder('game')
+			.where('game.user1Id = :userId', { userId: user.id })
+			.orWhere('game.user2Id = :userId', { userId: user.id })
+			.getCount(),
+	]);
+
+	return {
+		notesCount,
+		repliesCount,
+		renotesCount,
+		repliedCount,
+		renotedCount,
+		pollVotesCount,
+		pollVotedCount,
+		localFollowingCount,
+		remoteFollowingCount,
+		localFollowersCount,
+		remoteFollowersCount,
+		followingCount: localFollowingCount + remoteFollowingCount,
+		followersCount: localFollowersCount + remoteFollowersCount,
+		sentReactionsCount,
+		receivedReactionsCount,
+		noteFavoritesCount,
+		pageLikesCount,
+		pageLikedCount,
+		driveFilesCount,
+		driveUsage,
+		reversiCount,
+	};
+});