feat: refine announcement (#11497)

* wip

* Update read-announcement.ts

* wip

* wip

* wip

* Update index.d.ts

* wip

* Create 1691649257651-refine-announcement.js

* wip

* wip

* wip

* wip

* wip

* wip

* Update announcements.vue

* wip

* wip

* Update announcements.vue

* wip

* Update announcements.vue

* wip

* Update misskey-js.api.md

* Update users.ts

* Create MkAnnouncementDialog.stories.impl.ts

* wip

* wip

* Create AnnouncementService.ts

38 files changed, 1226 insertions, 223 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a5c74258d5..ba9fb8cbcd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,10 @@
 
 ### General
 - OAuth 2.0のサポート
+- お知らせ機能の強化
+	- ユーザー個別のお知らせを作成可能に
+	- お知らせのバナー表示やダイアログ表示が可能に
+	- お知らせのアイコンを設定可能に
 - チャンネルをセンシティブ指定できるようになりました
 
 ### Client
diff --git a/locales/index.d.ts b/locales/index.d.ts
index 4dceec6050..4984dd18ec 100644
--- a/locales/index.d.ts
+++ b/locales/index.d.ts
@@ -1098,6 +1098,22 @@ export interface Locale {
     "doYouAgree": string;
     "beSureToReadThisAsItIsImportant": string;
     "iHaveReadXCarefullyAndAgree": string;
+    "dialog": string;
+    "icon": string;
+    "forYou": string;
+    "currentAnnouncements": string;
+    "pastAnnouncements": string;
+    "youHaveUnreadAnnouncements": string;
+    "_announcement": {
+        "forExistingUsers": string;
+        "forExistingUsersDescription": string;
+        "needConfirmationToRead": string;
+        "needConfirmationToReadDescription": string;
+        "end": string;
+        "tooManyActiveAnnouncementDescription": string;
+        "readConfirmTitle": string;
+        "readConfirmText": string;
+    };
     "_initialAccountSetting": {
         "accountCreated": string;
         "letsStartAccountSetup": string;
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index cab5c8f97a..9089cb1d3b 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -330,7 +330,7 @@ watch: "ウォッチ"
 unwatch: "ウォッチ解除"
 accept: "許可"
 reject: "拒否"
-normal: "正常"
+normal: "通常"
 instanceName: "サーバー名"
 instanceDescription: "サーバーの紹介"
 maintainerName: "管理者の名前"
@@ -1095,6 +1095,22 @@ expired: "期限切れ"
 doYouAgree: "同意しますか？"
 beSureToReadThisAsItIsImportant: "重要ですので必ずお読みください。"
 iHaveReadXCarefullyAndAgree: "「{x}」の内容をよく読み、同意します。"
+dialog: "ダイアログ"
+icon: "アイコン"
+forYou: "あなたへ"
+currentAnnouncements: "現在のお知らせ"
+pastAnnouncements: "過去のお知らせ"
+youHaveUnreadAnnouncements: "未読のお知らせがあります。"
+
+_announcement:
+  forExistingUsers: "既存ユーザーのみ"
+  forExistingUsersDescription: "有効にすると、このお知らせ作成時点で存在するユーザーにのみお知らせが表示されます。無効にすると、このお知らせ作成後にアカウントを作成したユーザーにもお知らせが表示されます。"
+  needConfirmationToRead: "既読にするのに確認が必要"
+  needConfirmationToReadDescription: "有効にすると、このお知らせを既読にする際に確認ダイアログが表示されます。また、一括既読操作の対象になりません。"
+  end: "お知らせを終了"
+  tooManyActiveAnnouncementDescription: "アクティブなお知らせが多いため、UXが低下する可能性があります。終了したお知らせはアーカイブすることを検討してください。"
+  readConfirmTitle: "既読にしますか？"
+  readConfirmText: "「{title}」の内容を読み、既読にします。"
 
 _initialAccountSetting:
   accountCreated: "アカウントの作成が完了しました！"
diff --git a/packages/backend/migration/1691649257651-refine-announcement.js b/packages/backend/migration/1691649257651-refine-announcement.js
new file mode 100644
index 0000000000..d8d63f3103
--- /dev/null
+++ b/packages/backend/migration/1691649257651-refine-announcement.js
@@ -0,0 +1,27 @@
+export class RefineAnnouncement1691649257651 {
+    name = 'RefineAnnouncement1691649257651'
+
+    async up(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "display" character varying(256) NOT NULL DEFAULT 'normal'`);
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "needConfirmationToRead" boolean NOT NULL DEFAULT false`);
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "isActive" boolean NOT NULL DEFAULT true`);
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "forExistingUsers" boolean NOT NULL DEFAULT false`);
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "userId" character varying(32)`);
+        await queryRunner.query(`CREATE INDEX "IDX_bc1afcc8ef7e9400cdc3c0a87e" ON "announcement" ("isActive") `);
+        await queryRunner.query(`CREATE INDEX "IDX_da795d3a83187e8832005ba19d" ON "announcement" ("forExistingUsers") `);
+        await queryRunner.query(`CREATE INDEX "IDX_fd25dfe3da37df1715f11ba6ec" ON "announcement" ("userId") `);
+        await queryRunner.query(`ALTER TABLE "announcement" ADD CONSTRAINT "FK_fd25dfe3da37df1715f11ba6ec8" FOREIGN KEY ("userId") REFERENCES "user"("id") ON DELETE CASCADE ON UPDATE NO ACTION`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "announcement" DROP CONSTRAINT "FK_fd25dfe3da37df1715f11ba6ec8"`);
+        await queryRunner.query(`DROP INDEX "public"."IDX_fd25dfe3da37df1715f11ba6ec"`);
+        await queryRunner.query(`DROP INDEX "public"."IDX_da795d3a83187e8832005ba19d"`);
+        await queryRunner.query(`DROP INDEX "public"."IDX_bc1afcc8ef7e9400cdc3c0a87e"`);
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "userId"`);
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "forExistingUsers"`);
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "isActive"`);
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "needConfirmationToRead"`);
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "display"`);
+    }
+}
diff --git a/packages/backend/migration/1691657412740-refine-announcement-2.js b/packages/backend/migration/1691657412740-refine-announcement-2.js
new file mode 100644
index 0000000000..8791f99f44
--- /dev/null
+++ b/packages/backend/migration/1691657412740-refine-announcement-2.js
@@ -0,0 +1,11 @@
+export class RefineAnnouncement21691657412740 {
+    name = 'RefineAnnouncement21691657412740'
+
+    async up(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "announcement" ADD "icon" character varying(256) NOT NULL DEFAULT 'info'`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "announcement" DROP COLUMN "icon"`);
+    }
+}
diff --git a/packages/backend/src/core/AnnouncementService.ts b/packages/backend/src/core/AnnouncementService.ts
new file mode 100644
index 0000000000..482aeee39f
--- /dev/null
+++ b/packages/backend/src/core/AnnouncementService.ts
@@ -0,0 +1,135 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Inject, Injectable } from '@nestjs/common';
+import { Brackets } from 'typeorm';
+import { DI } from '@/di-symbols.js';
+import type { User } from '@/models/entities/User.js';
+import type { AnnouncementReadsRepository, AnnouncementsRepository, Announcement, AnnouncementRead } from '@/models/index.js';
+import { bindThis } from '@/decorators.js';
+import { Packed } from '@/misc/json-schema.js';
+import { IdService } from '@/core/IdService.js';
+import { GlobalEventService } from '@/core/GlobalEventService.js';
+
+@Injectable()
+export class AnnouncementService {
+	constructor(
+		@Inject(DI.announcementsRepository)
+		private announcementsRepository: AnnouncementsRepository,
+
+		@Inject(DI.announcementReadsRepository)
+		private announcementReadsRepository: AnnouncementReadsRepository,
+
+		private idService: IdService,
+		private globalEventService: GlobalEventService,
+	) {
+	}
+
+	@bindThis
+	public async getReads(userId: User['id']): Promise<AnnouncementRead[]> {
+		return this.announcementReadsRepository.findBy({
+			userId: userId,
+		});
+	}
+
+	@bindThis
+	public async getUnreadAnnouncements(user: User): Promise<Announcement[]> {
+		const readsQuery = this.announcementReadsRepository.createQueryBuilder('read')
+			.select('read.announcementId')
+			.where('read.userId = :userId', { userId: user.id });
+
+		const q = this.announcementsRepository.createQueryBuilder('announcement')
+			.where('announcement.isActive = true')
+			.andWhere(new Brackets(qb => {
+				qb.orWhere('announcement.userId = :userId', { userId: user.id });
+				qb.orWhere('announcement.userId IS NULL');
+			}))
+			.andWhere(new Brackets(qb => {
+				qb.orWhere('announcement.forExistingUsers = false');
+				qb.orWhere('announcement.createdAt > :createdAt', { createdAt: user.createdAt });
+			}))
+			.andWhere(`announcement.id NOT IN (${ readsQuery.getQuery() })`);
+
+		q.setParameters(readsQuery.getParameters());
+
+		return q.getMany();
+	}
+
+	@bindThis
+	public async create(values: Partial<Announcement>): Promise<{ raw: Announcement; packed: Packed<'Announcement'> }> {
+		const announcement = await this.announcementsRepository.insert({
+			id: this.idService.genId(),
+			createdAt: new Date(),
+			updatedAt: null,
+			title: values.title,
+			text: values.text,
+			imageUrl: values.imageUrl,
+			icon: values.icon,
+			display: values.display,
+			forExistingUsers: values.forExistingUsers,
+			needConfirmationToRead: values.needConfirmationToRead,
+			userId: values.userId,
+		}).then(x => this.announcementsRepository.findOneByOrFail(x.identifiers[0]));
+
+		const packed = (await this.packMany([announcement]))[0];
+
+		if (values.userId) {
+			this.globalEventService.publishMainStream(values.userId, 'announcementCreated', {
+				announcement: packed,
+			});
+		} else {
+			this.globalEventService.publishBroadcastStream('announcementCreated', {
+				announcement: packed,
+			});
+		}
+
+		return {
+			raw: announcement,
+			packed: packed,
+		};
+	}
+
+	@bindThis
+	public async read(user: User, announcementId: Announcement['id']): Promise<void> {
+		try {
+			await this.announcementReadsRepository.insert({
+				id: this.idService.genId(),
+				createdAt: new Date(),
+				announcementId: announcementId,
+				userId: user.id,
+			});
+		} catch (e) {
+			return;
+		}
+
+		if ((await this.getUnreadAnnouncements(user)).length === 0) {
+			this.globalEventService.publishMainStream(user.id, 'readAllAnnouncements');
+		}
+	}
+
+	@bindThis
+	public async packMany(
+		announcements: Announcement[],
+		me?: { id: User['id'] } | null | undefined,
+		options?: {
+			reads?: AnnouncementRead[];
+		},
+	): Promise<Packed<'Announcement'>[]> {
+		const reads = me ? (options?.reads ?? await this.getReads(me.id)) : [];
+		return announcements.map(announcement => ({
+			id: announcement.id,
+			createdAt: announcement.createdAt.toISOString(),
+			updatedAt: announcement.updatedAt?.toISOString() ?? null,
+			text: announcement.text,
+			title: announcement.title,
+			imageUrl: announcement.imageUrl,
+			icon: announcement.icon,
+			display: announcement.display,
+			needConfirmationToRead: announcement.needConfirmationToRead,
+			forYou: announcement.userId === me?.id,
+			isRead: reads.some(read => read.announcementId === announcement.id),
+		}));
+	}
+}
diff --git a/packages/backend/src/core/CoreModule.ts b/packages/backend/src/core/CoreModule.ts
index 9d6fb87923..51d4f9cfa9 100644
--- a/packages/backend/src/core/CoreModule.ts
+++ b/packages/backend/src/core/CoreModule.ts
@@ -7,6 +7,7 @@ import { Module } from '@nestjs/common';
 import { AccountMoveService } from './AccountMoveService.js';
 import { AccountUpdateService } from './AccountUpdateService.js';
 import { AiService } from './AiService.js';
+import { AnnouncementService } from './AnnouncementService.js';
 import { AntennaService } from './AntennaService.js';
 import { AppLockService } from './AppLockService.js';
 import { AchievementService } from './AchievementService.js';
@@ -130,6 +131,7 @@ const $LoggerService: Provider = { provide: 'LoggerService', useExisting: Logger
 const $AccountMoveService: Provider = { provide: 'AccountMoveService', useExisting: AccountMoveService };
 const $AccountUpdateService: Provider = { provide: 'AccountUpdateService', useExisting: AccountUpdateService };
 const $AiService: Provider = { provide: 'AiService', useExisting: AiService };
+const $AnnouncementService: Provider = { provide: 'AnnouncementService', useExisting: AnnouncementService };
 const $AntennaService: Provider = { provide: 'AntennaService', useExisting: AntennaService };
 const $AppLockService: Provider = { provide: 'AppLockService', useExisting: AppLockService };
 const $AchievementService: Provider = { provide: 'AchievementService', useExisting: AchievementService };
@@ -257,6 +259,7 @@ const $ApQuestionService: Provider = { provide: 'ApQuestionService', useExisting
 		AccountMoveService,
 		AccountUpdateService,
 		AiService,
+		AnnouncementService,
 		AntennaService,
 		AppLockService,
 		AchievementService,
@@ -377,6 +380,7 @@ const $ApQuestionService: Provider = { provide: 'ApQuestionService', useExisting
 		$AccountMoveService,
 		$AccountUpdateService,
 		$AiService,
+		$AnnouncementService,
 		$AntennaService,
 		$AppLockService,
 		$AchievementService,
@@ -498,6 +502,7 @@ const $ApQuestionService: Provider = { provide: 'ApQuestionService', useExisting
 		AccountMoveService,
 		AccountUpdateService,
 		AiService,
+		AnnouncementService,
 		AntennaService,
 		AppLockService,
 		AchievementService,
@@ -617,6 +622,7 @@ const $ApQuestionService: Provider = { provide: 'ApQuestionService', useExisting
 		$AccountMoveService,
 		$AccountUpdateService,
 		$AiService,
+		$AnnouncementService,
 		$AntennaService,
 		$AppLockService,
 		$AchievementService,
diff --git a/packages/backend/src/core/entities/UserEntityService.ts b/packages/backend/src/core/entities/UserEntityService.ts
index 1959224227..7be547fbb9 100644
--- a/packages/backend/src/core/entities/UserEntityService.ts
+++ b/packages/backend/src/core/entities/UserEntityService.ts
@@ -4,7 +4,6 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { In, Not } from 'typeorm';
 import * as Redis from 'ioredis';
 import _Ajv from 'ajv';
 import { ModuleRef } from '@nestjs/core';
@@ -16,13 +15,13 @@ import { awaitAll } from '@/misc/prelude/await-all.js';
 import { USER_ACTIVE_THRESHOLD, USER_ONLINE_THRESHOLD } from '@/const.js';
 import type { LocalUser, PartialLocalUser, PartialRemoteUser, RemoteUser, User } from '@/models/entities/User.js';
 import { birthdaySchema, descriptionSchema, localUsernameSchema, locationSchema, nameSchema, passwordSchema } from '@/models/entities/User.js';
-import type { UsersRepository, UserSecurityKeysRepository, FollowingsRepository, FollowRequestsRepository, BlockingsRepository, MutingsRepository, DriveFilesRepository, NoteUnreadsRepository, UserNotePiningsRepository, UserProfilesRepository, AnnouncementReadsRepository, AnnouncementsRepository, UserProfile, RenoteMutingsRepository, UserMemoRepository } from '@/models/index.js';
+import type { UsersRepository, UserSecurityKeysRepository, FollowingsRepository, FollowRequestsRepository, BlockingsRepository, MutingsRepository, DriveFilesRepository, NoteUnreadsRepository, UserNotePiningsRepository, UserProfilesRepository, AnnouncementReadsRepository, AnnouncementsRepository, UserProfile, RenoteMutingsRepository, UserMemoRepository, Announcement } from '@/models/index.js';
 import { bindThis } from '@/decorators.js';
 import { RoleService } from '@/core/RoleService.js';
 import { ApPersonService } from '@/core/activitypub/models/ApPersonService.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
 import type { OnModuleInit } from '@nestjs/common';
-import type { AntennaService } from '../AntennaService.js';
+import type { AnnouncementService } from '../AnnouncementService.js';
 import type { CustomEmojiService } from '../CustomEmojiService.js';
 import type { NoteEntityService } from './NoteEntityService.js';
 import type { DriveFileEntityService } from './DriveFileEntityService.js';
@@ -58,7 +57,7 @@ export class UserEntityService implements OnModuleInit {
 	private driveFileEntityService: DriveFileEntityService;
 	private pageEntityService: PageEntityService;
 	private customEmojiService: CustomEmojiService;
-	private antennaService: AntennaService;
+	private announcementService: AnnouncementService;
 	private roleService: RoleService;
 	private federatedInstanceService: FederatedInstanceService;
 
@@ -128,7 +127,7 @@ export class UserEntityService implements OnModuleInit {
 		this.driveFileEntityService = this.moduleRef.get('DriveFileEntityService');
 		this.pageEntityService = this.moduleRef.get('PageEntityService');
 		this.customEmojiService = this.moduleRef.get('CustomEmojiService');
-		this.antennaService = this.moduleRef.get('AntennaService');
+		this.announcementService = this.moduleRef.get('AnnouncementService');
 		this.roleService = this.moduleRef.get('RoleService');
 		this.federatedInstanceService = this.moduleRef.get('FederatedInstanceService');
 	}
@@ -209,19 +208,6 @@ export class UserEntityService implements OnModuleInit {
 	}
 
 	@bindThis
-	public async getHasUnreadAnnouncement(userId: User['id']): Promise<boolean> {
-		const reads = await this.announcementReadsRepository.findBy({
-			userId: userId,
-		});
-
-		const count = await this.announcementsRepository.countBy(reads.length > 0 ? {
-			id: Not(In(reads.map(read => read.announcementId))),
-		} : {});
-
-		return count > 0;
-	}
-
-	@bindThis
 	public async getHasUnreadAntenna(userId: User['id']): Promise<boolean> {
 		/*
 		const myAntennas = (await this.antennaService.getAntennas()).filter(a => a.userId === userId);
@@ -347,6 +333,7 @@ export class UserEntityService implements OnModuleInit {
 
 		const isModerator = isMe && opts.detail ? this.roleService.isModerator(user) : null;
 		const isAdmin = isMe && opts.detail ? this.roleService.isAdministrator(user) : null;
+		const unreadAnnouncements = isMe && opts.detail ? await this.announcementService.getUnreadAnnouncements(user) : null;
 
 		const falsy = opts.detail ? false : undefined;
 
@@ -456,7 +443,8 @@ export class UserEntityService implements OnModuleInit {
 					where: { userId: user.id, isMentioned: true },
 					take: 1,
 				}).then(count => count > 0),
-				hasUnreadAnnouncement: this.getHasUnreadAnnouncement(user.id),
+				hasUnreadAnnouncement: unreadAnnouncements!.length > 0,
+				unreadAnnouncements,
 				hasUnreadAntenna: this.getHasUnreadAntenna(user.id),
 				hasUnreadChannel: false, // 後方互換性のため
 				hasUnreadNotification: this.getHasUnreadNotification(user.id),
diff --git a/packages/backend/src/misc/json-schema.ts b/packages/backend/src/misc/json-schema.ts
index ca8a030a62..80c1041c62 100644
--- a/packages/backend/src/misc/json-schema.ts
+++ b/packages/backend/src/misc/json-schema.ts
@@ -35,6 +35,7 @@ import { packedQueueCountSchema } from '@/models/json-schema/queue.js';
 import { packedGalleryPostSchema } from '@/models/json-schema/gallery-post.js';
 import { packedEmojiDetailedSchema, packedEmojiSimpleSchema } from '@/models/json-schema/emoji.js';
 import { packedFlashSchema } from '@/models/json-schema/flash.js';
+import { packedAnnouncementSchema } from '@/models/json-schema/announcement.js';
 
 export const refs = {
 	UserLite: packedUserLiteSchema,
@@ -46,6 +47,7 @@ export const refs = {
 	User: packedUserSchema,
 
 	UserList: packedUserListSchema,
+	Announcement: packedAnnouncementSchema,
 	App: packedAppSchema,
 	Note: packedNoteSchema,
 	NoteReaction: packedNoteReactionSchema,
diff --git a/packages/backend/src/models/entities/Announcement.ts b/packages/backend/src/models/entities/Announcement.ts
index 99cdf89330..18c26faab0 100644
--- a/packages/backend/src/models/entities/Announcement.ts
+++ b/packages/backend/src/models/entities/Announcement.ts
@@ -3,8 +3,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { Entity, Index, Column, PrimaryColumn } from 'typeorm';
+import { Entity, Index, Column, PrimaryColumn, ManyToOne, JoinColumn } from 'typeorm';
 import { id } from '../id.js';
+import { User } from './User.js';
 
 @Entity()
 export class Announcement {
@@ -38,6 +39,52 @@ export class Announcement {
 	})
 	public imageUrl: string | null;
 
+	// info, warning, error, success
+	@Column('varchar', {
+		length: 256, nullable: false,
+		default: 'info',
+	})
+	public icon: string;
+
+	// normal ... お知らせページ掲載
+	// banner ... お知らせページ掲載 + バナー表示
+	// dialog ... お知らせページ掲載 + ダイアログ表示
+	@Column('varchar', {
+		length: 256, nullable: false,
+		default: 'normal',
+	})
+	public display: string;
+
+	@Column('boolean', {
+		default: false,
+	})
+	public needConfirmationToRead: boolean;
+
+	@Index()
+	@Column('boolean', {
+		default: true,
+	})
+	public isActive: boolean;
+
+	@Index()
+	@Column('boolean', {
+		default: false,
+	})
+	public forExistingUsers: boolean;
+
+	@Index()
+	@Column({
+		...id(),
+		nullable: true,
+	})
+	public userId: User['id'] | null;
+
+	@ManyToOne(type => User, {
+		onDelete: 'CASCADE',
+	})
+	@JoinColumn()
+	public user: User | null;
+
 	constructor(data: Partial<Announcement>) {
 		if (data == null) return;
 
diff --git a/packages/backend/src/models/json-schema/announcement.ts b/packages/backend/src/models/json-schema/announcement.ts
new file mode 100644
index 0000000000..c7e24c7f29
--- /dev/null
+++ b/packages/backend/src/models/json-schema/announcement.ts
@@ -0,0 +1,58 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export const packedAnnouncementSchema = {
+	type: 'object',
+	properties: {
+		id: {
+			type: 'string',
+			optional: false, nullable: false,
+			format: 'id',
+			example: 'xxxxxxxxxx',
+		},
+		createdAt: {
+			type: 'string',
+			optional: false, nullable: false,
+			format: 'date-time',
+		},
+		updatedAt: {
+			type: 'string',
+			optional: false, nullable: true,
+			format: 'date-time',
+		},
+		text: {
+			type: 'string',
+			optional: false, nullable: false,
+		},
+		title: {
+			type: 'string',
+			optional: false, nullable: false,
+		},
+		imageUrl: {
+			type: 'string',
+			optional: false, nullable: true,
+		},
+		icon: {
+			type: 'string',
+			optional: false, nullable: false,
+		},
+		display: {
+			type: 'string',
+			optional: false, nullable: false,
+		},
+		forYou: {
+			type: 'boolean',
+			optional: false, nullable: false,
+		},
+		needConfirmationToRead: {
+			type: 'boolean',
+			optional: false, nullable: false,
+		},
+		isRead: {
+			type: 'boolean',
+			optional: true, nullable: false,
+		},
+	},
+} as const;
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/create.ts b/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
index 8addffc6a8..6c5520c2ef 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/create.ts
@@ -3,11 +3,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { Inject, Injectable } from '@nestjs/common';
+import { Injectable } from '@nestjs/common';
 import { Endpoint } from '@/server/api/endpoint-base.js';
-import type { AnnouncementsRepository } from '@/models/index.js';
-import { IdService } from '@/core/IdService.js';
-import { DI } from '@/di-symbols.js';
+import { AnnouncementService } from '@/core/AnnouncementService.js';
 
 export const meta = {
 	tags: ['admin'],
@@ -57,6 +55,11 @@ export const paramDef = {
 		title: { type: 'string', minLength: 1 },
 		text: { type: 'string', minLength: 1 },
 		imageUrl: { type: 'string', nullable: true, minLength: 1 },
+		icon: { type: 'string', enum: ['info', 'warning', 'error', 'success'], default: 'info' },
+		display: { type: 'string', enum: ['normal', 'banner', 'dialog'], default: 'normal' },
+		forExistingUsers: { type: 'boolean', default: false },
+		needConfirmationToRead: { type: 'boolean', default: false },
+		userId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
 	},
 	required: ['title', 'text', 'imageUrl'],
 } as const;
@@ -65,22 +68,23 @@ export const paramDef = {
 @Injectable()
 export default class extends Endpoint<typeof meta, typeof paramDef> {
 	constructor(
-		@Inject(DI.announcementsRepository)
-		private announcementsRepository: AnnouncementsRepository,
-
-		private idService: IdService,
+		private announcementService: AnnouncementService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
-			const announcement = await this.announcementsRepository.insert({
-				id: this.idService.genId(),
+			const { raw, packed } = await this.announcementService.create({
 				createdAt: new Date(),
 				updatedAt: null,
 				title: ps.title,
 				text: ps.text,
 				imageUrl: ps.imageUrl,
-			}).then(x => this.announcementsRepository.findOneByOrFail(x.identifiers[0]));
+				icon: ps.icon,
+				display: ps.display,
+				forExistingUsers: ps.forExistingUsers,
+				needConfirmationToRead: ps.needConfirmationToRead,
+				userId: ps.userId,
+			});
 
-			return Object.assign({}, announcement, { createdAt: announcement.createdAt.toISOString(), updatedAt: null });
+			return packed;
 		});
 	}
 }
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/list.ts b/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
index ec0d4061a6..4da3f457f9 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/list.ts
@@ -66,6 +66,7 @@ export const paramDef = {
 		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
 		sinceId: { type: 'string', format: 'misskey:id' },
 		untilId: { type: 'string', format: 'misskey:id' },
+		userId: { type: 'string', format: 'misskey:id', nullable: true },
 	},
 	required: [],
 } as const;
@@ -84,6 +85,11 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			const query = this.queryService.makePaginationQuery(this.announcementsRepository.createQueryBuilder('announcement'), ps.sinceId, ps.untilId);
+			if (ps.userId) {
+				query.andWhere('announcement.userId = :userId', { userId: ps.userId });
+			} else {
+				query.andWhere('announcement.userId IS NULL');
+			}
 
 			const announcements = await query.limit(ps.limit).getMany();
 
@@ -102,6 +108,12 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 				title: announcement.title,
 				text: announcement.text,
 				imageUrl: announcement.imageUrl,
+				icon: announcement.icon,
+				display: announcement.display,
+				isActive: announcement.isActive,
+				forExistingUsers: announcement.forExistingUsers,
+				needConfirmationToRead: announcement.needConfirmationToRead,
+				userId: announcement.userId,
 				reads: reads.get(announcement)!,
 			}));
 		});
diff --git a/packages/backend/src/server/api/endpoints/admin/announcements/update.ts b/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
index b3df14320f..7efc7c0402 100644
--- a/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
+++ b/packages/backend/src/server/api/endpoints/admin/announcements/update.ts
@@ -31,8 +31,13 @@ export const paramDef = {
 		title: { type: 'string', minLength: 1 },
 		text: { type: 'string', minLength: 1 },
 		imageUrl: { type: 'string', nullable: true, minLength: 0 },
+		icon: { type: 'string', enum: ['info', 'warning', 'error', 'success'] },
+		display: { type: 'string', enum: ['normal', 'banner', 'dialog'] },
+		forExistingUsers: { type: 'boolean' },
+		needConfirmationToRead: { type: 'boolean' },
+		isActive: { type: 'boolean' },
 	},
-	required: ['id', 'title', 'text', 'imageUrl'],
+	required: ['id'],
 } as const;
 
 // eslint-disable-next-line import/no-default-export
@@ -53,6 +58,11 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 				text: ps.text,
 				/* eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing -- 空の文字列の場合、nullを渡すようにするため */
 				imageUrl: ps.imageUrl || null,
+				display: ps.display,
+				icon: ps.icon,
+				forExistingUsers: ps.forExistingUsers,
+				needConfirmationToRead: ps.needConfirmationToRead,
+				isActive: ps.isActive,
 			});
 		});
 	}
diff --git a/packages/backend/src/server/api/endpoints/announcements.ts b/packages/backend/src/server/api/endpoints/announcements.ts
index df0a0afb09..070e6f0d77 100644
--- a/packages/backend/src/server/api/endpoints/announcements.ts
+++ b/packages/backend/src/server/api/endpoints/announcements.ts
@@ -4,8 +4,10 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
+import { Brackets } from 'typeorm';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { QueryService } from '@/core/QueryService.js';
+import { AnnouncementService } from '@/core/AnnouncementService.js';
 import { DI } from '@/di-symbols.js';
 import type { AnnouncementReadsRepository, AnnouncementsRepository } from '@/models/index.js';
 
@@ -20,40 +22,7 @@ export const meta = {
 		items: {
 			type: 'object',
 			optional: false, nullable: false,
-			properties: {
-				id: {
-					type: 'string',
-					optional: false, nullable: false,
-					format: 'id',
-					example: 'xxxxxxxxxx',
-				},
-				createdAt: {
-					type: 'string',
-					optional: false, nullable: false,
-					format: 'date-time',
-				},
-				updatedAt: {
-					type: 'string',
-					optional: false, nullable: true,
-					format: 'date-time',
-				},
-				text: {
-					type: 'string',
-					optional: false, nullable: false,
-				},
-				title: {
-					type: 'string',
-					optional: false, nullable: false,
-				},
-				imageUrl: {
-					type: 'string',
-					optional: false, nullable: true,
-				},
-				isRead: {
-					type: 'boolean',
-					optional: true, nullable: false,
-				},
-			},
+			ref: 'Announcement',
 		},
 	},
 } as const;
@@ -62,9 +31,9 @@ export const paramDef = {
 	type: 'object',
 	properties: {
 		limit: { type: 'integer', minimum: 1, maximum: 100, default: 10 },
-		withUnreads: { type: 'boolean', default: false },
 		sinceId: { type: 'string', format: 'misskey:id' },
 		untilId: { type: 'string', format: 'misskey:id' },
+		isActive: { type: 'boolean', default: true },
 	},
 	required: [],
 } as const;
@@ -80,27 +49,19 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 		private announcementReadsRepository: AnnouncementReadsRepository,
 
 		private queryService: QueryService,
+		private announcementService: AnnouncementService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
-			const query = this.queryService.makePaginationQuery(this.announcementsRepository.createQueryBuilder('announcement'), ps.sinceId, ps.untilId);
+			const query = this.queryService.makePaginationQuery(this.announcementsRepository.createQueryBuilder('announcement'), ps.sinceId, ps.untilId)
+				.where('announcement.isActive = :isActive', { isActive: ps.isActive })
+				.andWhere(new Brackets(qb => {
+					if (me) qb.orWhere('announcement.userId = :meId', { meId: me.id });
+					qb.orWhere('announcement.userId IS NULL');
+				}));
 
 			const announcements = await query.limit(ps.limit).getMany();
 
-			if (me) {
-				const reads = (await this.announcementReadsRepository.findBy({
-					userId: me.id,
-				})).map(x => x.announcementId);
-
-				for (const announcement of announcements) {
-					(announcement as any).isRead = reads.includes(announcement.id);
-				}
-			}
-
-			return (ps.withUnreads ? announcements.filter((a: any) => !a.isRead) : announcements).map((a) => ({
-				...a,
-				createdAt: a.createdAt.toISOString(),
-				updatedAt: a.updatedAt?.toISOString() ?? null,
-			}));
+			return this.announcementService.packMany(announcements, me);
 		});
 	}
 }
diff --git a/packages/backend/src/server/api/endpoints/i/read-announcement.ts b/packages/backend/src/server/api/endpoints/i/read-announcement.ts
index 7bda6e2627..412532939c 100644
--- a/packages/backend/src/server/api/endpoints/i/read-announcement.ts
+++ b/packages/backend/src/server/api/endpoints/i/read-announcement.ts
@@ -3,14 +3,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { Inject, Injectable } from '@nestjs/common';
+import { Injectable } from '@nestjs/common';
 import { Endpoint } from '@/server/api/endpoint-base.js';
-import { IdService } from '@/core/IdService.js';
-import type { AnnouncementReadsRepository, AnnouncementsRepository } from '@/models/index.js';
-import { GlobalEventService } from '@/core/GlobalEventService.js';
-import { UserEntityService } from '@/core/entities/UserEntityService.js';
-import { DI } from '@/di-symbols.js';
-import { ApiError } from '../../error.js';
+import { AnnouncementService } from '@/core/AnnouncementService.js';
 
 export const meta = {
 	tags: ['account'],
@@ -20,11 +15,6 @@ export const meta = {
 	kind: 'write:account',
 
 	errors: {
-		noSuchAnnouncement: {
-			message: 'No such announcement.',
-			code: 'NO_SUCH_ANNOUNCEMENT',
-			id: '184663db-df88-4bc2-8b52-fb85f0681939',
-		},
 	},
 } as const;
 
@@ -40,47 +30,10 @@ export const paramDef = {
 @Injectable()
 export default class extends Endpoint<typeof meta, typeof paramDef> {
 	constructor(
-		@Inject(DI.announcementsRepository)
-		private announcementsRepository: AnnouncementsRepository,
-
-		@Inject(DI.announcementReadsRepository)
-		private announcementReadsRepository: AnnouncementReadsRepository,
-
-		private userEntityService: UserEntityService,
-		private idService: IdService,
-		private globalEventService: GlobalEventService,
+		private announcementService: AnnouncementService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
-			// Check if announcement exists
-			const announcementExist = await this.announcementsRepository.exist({ where: { id: ps.announcementId } });
-
-			if (!announcementExist) {
-				throw new ApiError(meta.errors.noSuchAnnouncement);
-			}
-
-			// Check if already read
-			const alreadyRead = await this.announcementReadsRepository.exist({
-				where: {
-					announcementId: ps.announcementId,
-					userId: me.id,
-				},
-			});
-
-			if (alreadyRead) {
-				return;
-			}
-
-			// Create read
-			await this.announcementReadsRepository.insert({
-				id: this.idService.genId(),
-				createdAt: new Date(),
-				announcementId: ps.announcementId,
-				userId: me.id,
-			});
-
-			if (!await this.userEntityService.getHasUnreadAnnouncement(me.id)) {
-				this.globalEventService.publishMainStream(me.id, 'readAllAnnouncements');
-			}
+			await this.announcementService.read(me, ps.announcementId);
 		});
 	}
 }
diff --git a/packages/backend/src/server/api/stream/types.ts b/packages/backend/src/server/api/stream/types.ts
index 82ccd91c88..751a23de8d 100644
--- a/packages/backend/src/server/api/stream/types.ts
+++ b/packages/backend/src/server/api/stream/types.ts
@@ -64,6 +64,9 @@ export interface BroadcastTypes {
 			[other: string]: any;
 		}[];
 	};
+	announcementCreated: {
+		announcement: Packed<'Announcement'>;
+	};
 }
 
 export interface MainStreamTypes {
@@ -105,6 +108,9 @@ export interface MainStreamTypes {
 	driveFileCreated: Packed<'DriveFile'>;
 	readAntenna: Antenna;
 	receiveFollowRequest: Packed<'User'>;
+	announcementCreated: {
+		announcement: Packed<'Announcement'>;
+	};
 }
 
 export interface DriveStreamTypes {
diff --git a/packages/backend/test/e2e/users.ts b/packages/backend/test/e2e/users.ts
index 0530b44ce4..8afbcbe322 100644
--- a/packages/backend/test/e2e/users.ts
+++ b/packages/backend/test/e2e/users.ts
@@ -160,6 +160,7 @@ describe('ユーザー', () => {
 			hasUnreadChannel: user.hasUnreadChannel,
 			hasUnreadNotification: user.hasUnreadNotification,
 			hasPendingReceivedFollowRequest: user.hasPendingReceivedFollowRequest,
+			unreadAnnouncements: user.unreadAnnouncements,
 			mutedWords: user.mutedWords,
 			mutedInstances: user.mutedInstances,
 			mutingNotificationTypes: user.mutingNotificationTypes,
@@ -405,6 +406,7 @@ describe('ユーザー', () => {
 		assert.strictEqual(response.hasUnreadChannel, false);
 		assert.strictEqual(response.hasUnreadNotification, false);
 		assert.strictEqual(response.hasPendingReceivedFollowRequest, false);
+		assert.deepStrictEqual(response.unreadAnnouncements, []);
 		assert.deepStrictEqual(response.mutedWords, []);
 		assert.deepStrictEqual(response.mutedInstances, []);
 		assert.deepStrictEqual(response.mutingNotificationTypes, []);
diff --git a/packages/backend/test/unit/AnnouncementService.ts b/packages/backend/test/unit/AnnouncementService.ts
new file mode 100644
index 0000000000..c97e081ba5
--- /dev/null
+++ b/packages/backend/test/unit/AnnouncementService.ts
@@ -0,0 +1,194 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+process.env.NODE_ENV = 'test';
+
+import { jest } from '@jest/globals';
+import { ModuleMocker } from 'jest-mock';
+import { Test } from '@nestjs/testing';
+import { GlobalModule } from '@/GlobalModule.js';
+import { AnnouncementService } from '@/core/AnnouncementService.js';
+import type { Announcement, AnnouncementsRepository, AnnouncementReadsRepository, UsersRepository, User } from '@/models/index.js';
+import { DI } from '@/di-symbols.js';
+import { genAid } from '@/misc/id/aid.js';
+import { CacheService } from '@/core/CacheService.js';
+import { IdService } from '@/core/IdService.js';
+import { GlobalEventService } from '@/core/GlobalEventService.js';
+import { secureRndstr } from '@/misc/secure-rndstr.js';
+import type { TestingModule } from '@nestjs/testing';
+import type { MockFunctionMetadata } from 'jest-mock';
+
+const moduleMocker = new ModuleMocker(global);
+
+describe('AnnouncementService', () => {
+	let app: TestingModule;
+	let announcementService: AnnouncementService;
+	let usersRepository: UsersRepository;
+	let announcementsRepository: AnnouncementsRepository;
+	let announcementReadsRepository: AnnouncementReadsRepository;
+	let globalEventService: jest.Mocked<GlobalEventService>;
+
+	function createUser(data: Partial<User> = {}) {
+		const un = secureRndstr(16);
+		return usersRepository.insert({
+			id: genAid(new Date()),
+			createdAt: new Date(),
+			username: un,
+			usernameLower: un,
+			...data,
+		})
+			.then(x => usersRepository.findOneByOrFail(x.identifiers[0]));
+	}
+
+	function createAnnouncement(data: Partial<Announcement> = {}) {
+		return announcementsRepository.insert({
+			id: genAid(new Date()),
+			createdAt: new Date(),
+			updatedAt: null,
+			title: 'Title',
+			text: 'Text',
+			...data,
+		})
+			.then(x => announcementsRepository.findOneByOrFail(x.identifiers[0]));
+	}
+
+	beforeEach(async () => {
+		app = await Test.createTestingModule({
+			imports: [
+				GlobalModule,
+			],
+			providers: [
+				AnnouncementService,
+				CacheService,
+				IdService,
+			],
+		})
+			.useMocker((token) => {
+				if (token === GlobalEventService) {
+					return {
+						publishMainStream: jest.fn(),
+						publishBroadcastStream: jest.fn(),
+					};
+				}
+				if (typeof token === 'function') {
+					const mockMetadata = moduleMocker.getMetadata(token) as MockFunctionMetadata<any, any>;
+					const Mock = moduleMocker.generateFromMetadata(mockMetadata);
+					return new Mock();
+				}
+			})
+			.compile();
+
+		app.enableShutdownHooks();
+
+		announcementService = app.get<AnnouncementService>(AnnouncementService);
+		usersRepository = app.get<UsersRepository>(DI.usersRepository);
+		announcementsRepository = app.get<AnnouncementsRepository>(DI.announcementsRepository);
+		announcementReadsRepository = app.get<AnnouncementReadsRepository>(DI.announcementReadsRepository);
+		globalEventService = app.get<GlobalEventService>(GlobalEventService) as jest.Mocked<GlobalEventService>;
+	});
+
+	afterEach(async () => {
+		await Promise.all([
+			app.get(DI.metasRepository).delete({}),
+			usersRepository.delete({}),
+			announcementsRepository.delete({}),
+			announcementReadsRepository.delete({}),
+		]);
+
+		await app.close();
+	});
+
+	describe('getUnreadAnnouncements', () => {
+		test('通常', async () => {
+			const user = await createUser();
+			const announcement = await createAnnouncement({
+				title: '1',
+			});
+
+			const result = await announcementService.getUnreadAnnouncements(user);
+
+			expect(result.length).toBe(1);
+			expect(result[0].title).toBe(announcement.title);
+		});
+
+		test('isActiveがfalseは除外', async () => {
+			const user = await createUser();
+			await createAnnouncement({
+				isActive: false,
+			});
+
+			const result = await announcementService.getUnreadAnnouncements(user);
+
+			expect(result.length).toBe(0);
+		});
+
+		test('forExistingUsers', async () => {
+			const user = await createUser();
+			const [announcementAfter, announcementBefore, announcementBefore2] = await Promise.all([
+				createAnnouncement({
+					title: 'after',
+					createdAt: new Date(),
+					forExistingUsers: true,
+				}),
+				createAnnouncement({
+					title: 'before',
+					createdAt: new Date(Date.now() - 1000),
+					forExistingUsers: true,
+				}),
+				createAnnouncement({
+					title: 'before2',
+					createdAt: new Date(Date.now() - 1000),
+					forExistingUsers: false,
+				}),
+			]);
+
+			const result = await announcementService.getUnreadAnnouncements(user);
+
+			expect(result.length).toBe(2);
+			expect(result.some(a => a.title === announcementAfter.title)).toBe(true);
+			expect(result.some(a => a.title === announcementBefore.title)).toBe(false);
+			expect(result.some(a => a.title === announcementBefore2.title)).toBe(true);
+		});
+	});
+
+	describe('create', () => {
+		test('通常', async () => {
+			const result = await announcementService.create({
+				title: 'Title',
+				text: 'Text',
+			});
+
+			expect(result.raw.title).toBe('Title');
+			expect(result.packed.title).toBe('Title');
+
+			expect(globalEventService.publishBroadcastStream).toHaveBeenCalled();
+			expect(globalEventService.publishBroadcastStream.mock.lastCall![0]).toBe('announcementCreated');
+			expect((globalEventService.publishBroadcastStream.mock.lastCall![1] as any).announcement).toBe(result.packed);
+		});
+
+		test('ユーザー指定', async () => {
+			const user = await createUser();
+			const result = await announcementService.create({
+				title: 'Title',
+				text: 'Text',
+				userId: user.id,
+			});
+
+			expect(result.raw.title).toBe('Title');
+			expect(result.packed.title).toBe('Title');
+
+			expect(globalEventService.publishBroadcastStream).not.toHaveBeenCalled();
+			expect(globalEventService.publishMainStream).toHaveBeenCalled();
+			expect(globalEventService.publishMainStream.mock.lastCall![0]).toBe(user.id);
+			expect(globalEventService.publishMainStream.mock.lastCall![1]).toBe('announcementCreated');
+			expect((globalEventService.publishMainStream.mock.lastCall![2] as any).announcement).toBe(result.packed);
+		});
+	});
+
+	describe('read', () => {
+		// TODO
+	});
+});
+
diff --git a/packages/frontend/src/account.ts b/packages/frontend/src/account.ts
index c3f3337c9d..634084c750 100644
--- a/packages/frontend/src/account.ts
+++ b/packages/frontend/src/account.ts
@@ -96,7 +96,6 @@ export async function removeAccount(idOrToken: Account['id']) {
 
 function fetchAccount(token: string, id?: string, forceShowDialog?: boolean): Promise<Account> {
 	return new Promise((done, fail) => {
-		// Fetch user
 		window.fetch(`${apiUrl}/i`, {
 			method: 'POST',
 			body: JSON.stringify({
@@ -108,8 +107,8 @@ function fetchAccount(token: string, id?: string, forceShowDialog?: boolean): Pr
 		})
 			.then(res => new Promise<Account | { error: Record<string, any> }>((done2, fail2) => {
 				if (res.status >= 500 && res.status < 600) {
-				// サーバーエラー(5xx)の場合をrejectとする
-				// （認証エラーなど4xxはresolve）
+					// サーバーエラー(5xx)の場合をrejectとする
+					// （認証エラーなど4xxはresolve）
 					return fail2(res);
 				}
 				res.json().then(done2, fail2);
diff --git a/packages/frontend/src/boot/main-boot.ts b/packages/frontend/src/boot/main-boot.ts
index 7459ea0fa5..9ab1f6e14c 100644
--- a/packages/frontend/src/boot/main-boot.ts
+++ b/packages/frontend/src/boot/main-boot.ts
@@ -83,6 +83,21 @@ export async function mainBoot() {
 			}
 		});
 
+		for (const announcement of ($i.unreadAnnouncements ?? []).filter(x => x.display === 'dialog')) {
+			popup(defineAsyncComponent(() => import('@/components/MkAnnouncementDialog.vue')), {
+				announcement,
+			}, {}, 'closed');
+		}
+
+		stream.on('announcementCreated', (ev) => {
+			const announcement = ev.announcement;
+			if (announcement.display === 'dialog') {
+				popup(defineAsyncComponent(() => import('@/components/MkAnnouncementDialog.vue')), {
+					announcement,
+				}, {}, 'closed');
+			}
+		});
+
 		if ($i.isDeleted) {
 			alert({
 				type: 'warning',
diff --git a/packages/frontend/src/components/MkAnnouncementDialog.stories.impl.ts b/packages/frontend/src/components/MkAnnouncementDialog.stories.impl.ts
new file mode 100644
index 0000000000..42cfb90f7c
--- /dev/null
+++ b/packages/frontend/src/components/MkAnnouncementDialog.stories.impl.ts
@@ -0,0 +1,47 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/* eslint-disable @typescript-eslint/explicit-function-return-type */
+import { StoryObj } from '@storybook/vue3';
+import MkAnnouncementDialog from './MkAnnouncementDialog.vue';
+export const Default = {
+	render(args) {
+		return {
+			components: {
+				MkAnnouncementDialog,
+			},
+			setup() {
+				return {
+					args,
+				};
+			},
+			computed: {
+				props() {
+					return {
+						...this.args,
+					};
+				},
+			},
+			template: '<MkAnnouncementDialog v-bind="props" />',
+		};
+	},
+	args: {
+		announcement: {
+			id: '1',
+			title: 'Title',
+			text: 'Text',
+			createdAt: new Date().toISOString(),
+			updatedAt: null,
+			icon: 'info',
+			imageUrl: null,
+			display: 'dialog',
+			needConfirmationToRead: false,
+			forYou: true,
+		},
+	},
+	parameters: {
+		layout: 'centered',
+	},
+} satisfies StoryObj<typeof MkAnnouncementDialog>;
diff --git a/packages/frontend/src/components/MkAnnouncementDialog.vue b/packages/frontend/src/components/MkAnnouncementDialog.vue
new file mode 100644
index 0000000000..8e11053813
--- /dev/null
+++ b/packages/frontend/src/components/MkAnnouncementDialog.vue
@@ -0,0 +1,104 @@
+<!--
+SPDX-FileCopyrightText: syuilo and other misskey contributors
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+<MkModal ref="modal" :zPriority="'middle'" @closed="$emit('closed')" @click="onBgClick">
+	<div ref="rootEl" :class="$style.root">
+		<div :class="$style.header">
+			<span :class="$style.icon">
+				<i v-if="announcement.icon === 'info'" class="ti ti-info-circle"></i>
+				<i v-else-if="announcement.icon === 'warning'" class="ti ti-alert-triangle" style="color: var(--warn);"></i>
+				<i v-else-if="announcement.icon === 'error'" class="ti ti-circle-x" style="color: var(--error);"></i>
+				<i v-else-if="announcement.icon === 'success'" class="ti ti-check" style="color: var(--success);"></i>
+			</span>
+			<span :class="$style.title">{{ announcement.title }}</span>
+		</div>
+		<div :class="$style.text"><Mfm :text="announcement.text"/></div>
+		<MkButton primary full @click="ok">{{ i18n.ts.ok }}</MkButton>
+	</div>
+</MkModal>
+</template>
+
+<script lang="ts" setup>
+import { onMounted, shallowRef } from 'vue';
+import * as misskey from 'misskey-js';
+import * as os from '@/os';
+import MkModal from '@/components/MkModal.vue';
+import MkButton from '@/components/MkButton.vue';
+import { i18n } from '@/i18n';
+import { $i, updateAccount } from '@/account';
+
+const props = withDefaults(defineProps<{
+	announcement: misskey.entities.Announcement;
+}>(), {
+});
+
+const rootEl = shallowRef<HTMLDivElement>();
+const modal = shallowRef<InstanceType<typeof MkModal>>();
+
+async function ok() {
+	if (props.announcement.needConfirmationToRead) {
+		const confirm = await os.confirm({
+			type: 'question',
+			title: i18n.ts._announcement.readConfirmTitle,
+			text: i18n.t('_announcement.readConfirmText', { title: props.announcement.title }),
+		});
+		if (confirm.canceled) return;
+	}
+
+	modal.value.close();
+	os.api('i/read-announcement', { announcementId: props.announcement.id });
+	updateAccount({
+		unreadAnnouncements: $i!.unreadAnnouncements.filter(a => a.id !== props.announcement.id),
+	});
+}
+
+function onBgClick() {
+	rootEl.value.animate([{
+		offset: 0,
+		transform: 'scale(1)',
+	}, {
+		offset: 0.5,
+		transform: 'scale(1.1)',
+	}, {
+		offset: 1,
+		transform: 'scale(1)',
+	}], {
+		duration: 100,
+	});
+}
+
+onMounted(() => {
+});
+</script>
+
+<style lang="scss" module>
+.root {
+	margin: auto;
+	position: relative;
+	padding: 32px;
+	min-width: 320px;
+	max-width: 480px;
+	box-sizing: border-box;
+	background: var(--panel);
+	border-radius: var(--radius);
+}
+
+.header {
+	font-size: 120%;
+}
+
+.icon {
+	margin-right: 0.5em;
+}
+
+.title {
+	font-weight: bold;
+}
+
+.text {
+	margin: 1em 0;
+}
+</style>
diff --git a/packages/frontend/src/components/MkNoteDetailed.vue b/packages/frontend/src/components/MkNoteDetailed.vue
index 8acd4e4707..2a00b8db8e 100644
--- a/packages/frontend/src/components/MkNoteDetailed.vue
+++ b/packages/frontend/src/components/MkNoteDetailed.vue
@@ -172,7 +172,6 @@ import { showMovedDialog } from '@/scripts/show-moved-dialog';
 
 const props = defineProps<{
 	note: misskey.entities.Note;
-	pinned?: boolean;
 }>();
 
 const inChannel = inject('inChannel', null);
diff --git a/packages/frontend/src/components/MkNoteHeader.vue b/packages/frontend/src/components/MkNoteHeader.vue
index 559133ef46..fcde45405e 100644
--- a/packages/frontend/src/components/MkNoteHeader.vue
+++ b/packages/frontend/src/components/MkNoteHeader.vue
@@ -37,7 +37,6 @@ import { userPage } from '@/filters/user';
 
 defineProps<{
 	note: misskey.entities.Note;
-	pinned?: boolean;
 }>();
 </script>
 
diff --git a/packages/frontend/src/components/MkNoteSimple.vue b/packages/frontend/src/components/MkNoteSimple.vue
index 9648b7230a..e3c9e2bd5f 100644
--- a/packages/frontend/src/components/MkNoteSimple.vue
+++ b/packages/frontend/src/components/MkNoteSimple.vue
@@ -31,7 +31,6 @@ import { $i } from '@/account';
 
 const props = defineProps<{
 	note: misskey.entities.Note;
-	pinned?: boolean;
 }>();
 
 const showContent = $ref(false);
diff --git a/packages/frontend/src/components/MkSwitch.vue b/packages/frontend/src/components/MkSwitch.vue
index 96e2bad49f..8e946e7437 100644
--- a/packages/frontend/src/components/MkSwitch.vue
+++ b/packages/frontend/src/components/MkSwitch.vue
@@ -12,10 +12,15 @@ SPDX-License-Identifier: AGPL-3.0-only
 		:class="$style.input"
 		@keydown.enter="toggle"
 	>
-	<XButton :checked="checked" :disabled="disabled" @toggle="toggle" />
+	<XButton :checked="checked" :disabled="disabled" @toggle="toggle"/>
 	<span :class="$style.body">
 		<!-- TODO: 無名slotの方は廃止 -->
-		<span :class="$style.label" @click="toggle"><slot name="label"></slot><slot></slot></span>
+		<span :class="$style.label">
+			<span @click="toggle">
+				<slot name="label"></slot><slot></slot>
+			</span>
+			<span v-if="helpText" v-tooltip:dialog="helpText" class="_button _help" :class="$style.help"><i class="ti ti-help-circle"></i></span>
+		</span>
 		<p :class="$style.caption"><slot name="caption"></slot></p>
 	</span>
 </div>
@@ -28,6 +33,7 @@ import XButton from '@/components/MkSwitch.button.vue';
 const props = defineProps<{
 	modelValue: boolean | Ref<boolean>;
 	disabled?: boolean;
+	helpText?: string;
 }>();
 
 const emit = defineEmits<{
@@ -38,10 +44,6 @@ const checked = toRefs(props).modelValue;
 const toggle = () => {
 	if (props.disabled) return;
 	emit('update:modelValue', !checked.value);
-
-	if (!checked.value) {
-
-	}
 };
 </script>
 
@@ -98,4 +100,10 @@ const toggle = () => {
 		display: none;
 	}
 }
+
+.help {
+	margin-left: 0.5em;
+	font-size: 85%;
+	vertical-align: top;
+}
 </style>
diff --git a/packages/frontend/src/components/MkUserAnnouncementEditDialog.vue b/packages/frontend/src/components/MkUserAnnouncementEditDialog.vue
new file mode 100644
index 0000000000..ce41b3116d
--- /dev/null
+++ b/packages/frontend/src/components/MkUserAnnouncementEditDialog.vue
@@ -0,0 +1,145 @@
+<!--
+SPDX-FileCopyrightText: syuilo and other misskey contributors
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+<MkModalWindow
+	ref="dialog"
+	:width="400"
+	@close="dialog.close()"
+	@closed="$emit('closed')"
+>
+	<template v-if="announcement" #header>:{{ announcement.title }}:</template>
+	<template v-else #header>New announcement</template>
+
+	<div>
+		<MkSpacer :marginMin="20" :marginMax="28">
+			<div class="_gaps_m">
+				<MkInput v-model="title">
+					<template #label>{{ i18n.ts.title }}</template>
+				</MkInput>
+				<MkTextarea v-model="text">
+					<template #label>{{ i18n.ts.text }}</template>
+				</MkTextarea>
+				<MkRadios v-model="icon">
+					<template #label>{{ i18n.ts.icon }}</template>
+					<option value="info"><i class="ti ti-info-circle"></i></option>
+					<option value="warning"><i class="ti ti-alert-triangle" style="color: var(--warn);"></i></option>
+					<option value="error"><i class="ti ti-circle-x" style="color: var(--error);"></i></option>
+					<option value="success"><i class="ti ti-check" style="color: var(--success);"></i></option>
+				</MkRadios>
+				<MkRadios v-model="display">
+					<template #label>{{ i18n.ts.display }}</template>
+					<option value="normal">{{ i18n.ts.normal }}</option>
+					<option value="banner">{{ i18n.ts.banner }}</option>
+					<option value="dialog">{{ i18n.ts.dialog }}</option>
+				</MkRadios>
+				<MkSwitch v-model="needConfirmationToRead">
+					{{ i18n.ts._announcement.needConfirmationToRead }}
+					<template #caption>{{ i18n.ts._announcement.needConfirmationToReadDescription }}</template>
+				</MkSwitch>
+				<MkButton v-if="announcement" danger @click="del()"><i class="ti ti-trash"></i> {{ i18n.ts.delete }}</MkButton>
+			</div>
+		</MkSpacer>
+		<div :class="$style.footer">
+			<MkButton primary rounded style="margin: 0 auto;" @click="done"><i class="ti ti-check"></i> {{ props.announcement ? i18n.ts.update : i18n.ts.create }}</MkButton>
+		</div>
+	</div>
+</MkModalWindow>
+</template>
+
+<script lang="ts" setup>
+import { } from 'vue';
+import * as misskey from 'misskey-js';
+import MkModalWindow from '@/components/MkModalWindow.vue';
+import MkButton from '@/components/MkButton.vue';
+import MkInput from '@/components/MkInput.vue';
+import * as os from '@/os';
+import { i18n } from '@/i18n';
+import MkTextarea from '@/components/MkTextarea.vue';
+import MkSwitch from '@/components/MkSwitch.vue';
+import MkRadios from '@/components/MkRadios.vue';
+
+const props = defineProps<{
+	user: misskey.entities.User,
+	announcement?: any,
+}>();
+
+let dialog = $ref(null);
+let title: string = $ref(props.announcement ? props.announcement.title : '');
+let text: string = $ref(props.announcement ? props.announcement.text : '');
+let icon: string = $ref(props.announcement ? props.announcement.icon : 'info');
+let display: string = $ref(props.announcement ? props.announcement.display : 'dialog');
+let needConfirmationToRead = $ref(props.announcement ? props.announcement.needConfirmationToRead : false);
+
+const emit = defineEmits<{
+	(ev: 'done', v: { deleted?: boolean; updated?: any; created?: any }): void,
+	(ev: 'closed'): void
+}>();
+
+async function done() {
+	const params = {
+		title: title,
+		text: text,
+		icon: icon,
+		imageUrl: null,
+		display: display,
+		needConfirmationToRead: needConfirmationToRead,
+		userId: props.user.id,
+	};
+
+	if (props.announcement) {
+		await os.apiWithDialog('admin/announcements/update', {
+			id: props.announcement.id,
+			...params,
+		});
+
+		emit('done', {
+			updated: {
+				id: props.announcement.id,
+				...params,
+			},
+		});
+
+		dialog.close();
+	} else {
+		const created = await os.apiWithDialog('admin/announcements/create', params);
+
+		emit('done', {
+			created: created,
+		});
+
+		dialog.close();
+	}
+}
+
+async function del() {
+	const { canceled } = await os.confirm({
+		type: 'warning',
+		text: i18n.t('removeAreYouSure', { x: title }),
+	});
+	if (canceled) return;
+
+	os.api('admin/announcements/delete', {
+		id: props.announcement.id,
+	}).then(() => {
+		emit('done', {
+			deleted: true,
+		});
+		dialog.close();
+	});
+}
+</script>
+
+<style lang="scss" module>
+.footer {
+	position: sticky;
+	bottom: 0;
+	left: 0;
+	padding: 12px;
+	border-top: solid 0.5px var(--divider);
+	-webkit-backdrop-filter: var(--blur, blur(15px));
+	backdrop-filter: var(--blur, blur(15px));
+}
+</style>
diff --git a/packages/frontend/src/pages/admin/announcements.vue b/packages/frontend/src/pages/admin/announcements.vue
index 2e80d028f7..bb903af459 100644
--- a/packages/frontend/src/pages/admin/announcements.vue
+++ b/packages/frontend/src/pages/admin/announcements.vue
@@ -7,9 +7,20 @@ SPDX-License-Identifier: AGPL-3.0-only
 <MkStickyContainer>
 	<template #header><XHeader :actions="headerActions" :tabs="headerTabs"/></template>
 	<MkSpacer :contentMax="900">
-		<div class="_gaps_m">
-			<section v-for="announcement in announcements" class="">
-				<div class="_panel _gaps_m" style="padding: 24px;">
+		<div class="_gaps">
+			<MkInfo v-if="announcements.length > 5" warn>{{ i18n.ts._announcement.tooManyActiveAnnouncementDescription }}</MkInfo>
+
+			<MkFolder v-for="announcement in announcements" :key="announcement.id ?? announcement._id" :defaultOpen="announcement.id == null">
+				<template #label>{{ announcement.title }}</template>
+				<template #icon>
+					<i v-if="announcement.icon === 'info'" class="ti ti-info-circle"></i>
+					<i v-else-if="announcement.icon === 'warning'" class="ti ti-alert-triangle" style="color: var(--warn);"></i>
+					<i v-else-if="announcement.icon === 'error'" class="ti ti-circle-x" style="color: var(--error);"></i>
+					<i v-else-if="announcement.icon === 'success'" class="ti ti-check" style="color: var(--success);"></i>
+				</template>
+				<template #caption>{{ announcement.text }}</template>
+
+				<div class="_gaps_m">
 					<MkInput v-model="announcement.title">
 						<template #label>{{ i18n.ts.title }}</template>
 					</MkInput>
@@ -19,13 +30,33 @@ SPDX-License-Identifier: AGPL-3.0-only
 					<MkInput v-model="announcement.imageUrl">
 						<template #label>{{ i18n.ts.imageUrl }}</template>
 					</MkInput>
+					<MkRadios v-model="announcement.icon">
+						<template #label>{{ i18n.ts.icon }}</template>
+						<option value="info"><i class="ti ti-info-circle"></i></option>
+						<option value="warning"><i class="ti ti-alert-triangle" style="color: var(--warn);"></i></option>
+						<option value="error"><i class="ti ti-circle-x" style="color: var(--error);"></i></option>
+						<option value="success"><i class="ti ti-check" style="color: var(--success);"></i></option>
+					</MkRadios>
+					<MkRadios v-model="announcement.display">
+						<template #label>{{ i18n.ts.display }}</template>
+						<option value="normal">{{ i18n.ts.normal }}</option>
+						<option value="banner">{{ i18n.ts.banner }}</option>
+						<option value="dialog">{{ i18n.ts.dialog }}</option>
+					</MkRadios>
+					<MkSwitch v-model="announcement.forExistingUsers" :helpText="i18n.ts._announcement.forExistingUsersDescription">
+						{{ i18n.ts._announcement.forExistingUsers }}
+					</MkSwitch>
+					<MkSwitch v-model="announcement.needConfirmationToRead" :helpText="i18n.ts._announcement.needConfirmationToReadDescription">
+						{{ i18n.ts._announcement.needConfirmationToRead }}
+					</MkSwitch>
 					<p v-if="announcement.reads">{{ i18n.t('nUsersRead', { n: announcement.reads }) }}</p>
 					<div class="buttons _buttons">
 						<MkButton class="button" inline primary @click="save(announcement)"><i class="ti ti-device-floppy"></i> {{ i18n.ts.save }}</MkButton>
-						<MkButton class="button" inline danger @click="remove(announcement)"><i class="ti ti-trash"></i> {{ i18n.ts.remove }}</MkButton>
+						<MkButton v-if="announcement.id != null" class="button" inline @click="archive(announcement)"><i class="ti ti-check"></i> {{ i18n.ts._announcement.end }} ({{ i18n.ts.archive }})</MkButton>
+						<MkButton v-if="announcement.id != null" class="button" inline danger @click="del(announcement)"><i class="ti ti-trash"></i> {{ i18n.ts.delete }}</MkButton>
 					</div>
 				</div>
-			</section>
+			</MkFolder>
 		</div>
 	</MkSpacer>
 </MkStickyContainer>
@@ -37,9 +68,13 @@ import XHeader from './_header_.vue';
 import MkButton from '@/components/MkButton.vue';
 import MkInput from '@/components/MkInput.vue';
 import MkTextarea from '@/components/MkTextarea.vue';
+import MkSwitch from '@/components/MkSwitch.vue';
+import MkRadios from '@/components/MkRadios.vue';
+import MkInfo from '@/components/MkInfo.vue';
 import * as os from '@/os';
 import { i18n } from '@/i18n';
 import { definePageMetadata } from '@/scripts/page-metadata';
+import MkFolder from '@/components/MkFolder.vue';
 
 let announcements: any[] = $ref([]);
 
@@ -49,17 +84,22 @@ os.api('admin/announcements/list').then(announcementResponse => {
 
 function add() {
 	announcements.unshift({
+		_id: Math.random().toString(36),
 		id: null,
-		title: '',
+		title: 'New announcement',
 		text: '',
 		imageUrl: null,
+		icon: 'info',
+		display: 'normal',
+		forExistingUsers: false,
+		needConfirmationToRead: false,
 	});
 }
 
-function remove(announcement) {
+function del(announcement) {
 	os.confirm({
 		type: 'warning',
-		text: i18n.t('removeAreYouSure', { x: announcement.title }),
+		text: i18n.t('deleteAreYouSure', { x: announcement.title }),
 	}).then(({ canceled }) => {
 		if (canceled) return;
 		announcements = announcements.filter(x => x !== announcement);
@@ -67,32 +107,20 @@ function remove(announcement) {
 	});
 }
 
-function save(announcement) {
+async function archive(announcement) {
+	await os.apiWithDialog('admin/announcements/update', {
+		...announcement,
+		isActive: false,
+	});
+	refresh();
+}
+
+async function save(announcement) {
 	if (announcement.id == null) {
-		os.api('admin/announcements/create', announcement).then(() => {
-			os.alert({
-				type: 'success',
-				text: i18n.ts.saved,
-			});
-			refresh();
-		}).catch(err => {
-			os.alert({
-				type: 'error',
-				text: err,
-			});
-		});
+		await os.apiWithDialog('admin/announcements/create', announcement);
+		refresh();
 	} else {
-		os.api('admin/announcements/update', announcement).then(() => {
-			os.alert({
-				type: 'success',
-				text: i18n.ts.saved,
-			});
-		}).catch(err => {
-			os.alert({
-				type: 'error',
-				text: err,
-			});
-		});
+		os.apiWithDialog('admin/announcements/update', announcement);
 	}
 }
 
diff --git a/packages/frontend/src/pages/announcements.vue b/packages/frontend/src/pages/announcements.vue
index dd166d3c51..9937eb4cbf 100644
--- a/packages/frontend/src/pages/announcements.vue
+++ b/packages/frontend/src/pages/announcements.vue
@@ -5,20 +5,36 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <MkStickyContainer>
-	<template #header><MkPageHeader :actions="headerActions" :tabs="headerTabs"/></template>
+	<template #header><MkPageHeader v-model:tab="tab" :actions="headerActions" :tabs="headerTabs"/></template>
 	<MkSpacer :contentMax="800">
-		<MkPagination ref="paginationEl" v-slot="{items}" :pagination="pagination" class="ruryvtyk _gaps_m">
-			<section v-for="announcement in items" :key="announcement.id" class="announcement _panel">
-				<div class="header"><span v-if="$i && !announcement.isRead">🆕 </span>{{ announcement.title }}</div>
-				<div class="content">
-					<Mfm :text="announcement.text"/>
-					<img v-if="announcement.imageUrl" :src="announcement.imageUrl"/>
-				</div>
-				<div v-if="$i && !announcement.isRead" class="footer">
-					<MkButton primary @click="read(announcement.id)"><i class="ti ti-check"></i> {{ i18n.ts.gotIt }}</MkButton>
-				</div>
-			</section>
-		</MkPagination>
+		<div class="_gaps">
+			<MkInfo v-if="$i && $i.hasUnreadAnnouncement && tab === 'current'" warn>{{ i18n.ts.youHaveUnreadAnnouncements }}</MkInfo>
+			<MkPagination ref="paginationEl" :key="tab" v-slot="{items}" :pagination="tab === 'current' ? paginationCurrent : paginationPast" class="_gaps">
+				<section v-for="announcement in items" :key="announcement.id" class="_panel" :class="$style.announcement">
+					<div v-if="announcement.forYou" :class="$style.forYou"><i class="ti ti-pin"></i> {{ i18n.ts.forYou }}</div>
+					<div :class="$style.header">
+						<span v-if="$i && !announcement.isRead" style="margin-right: 0.5em;">🆕</span>
+						<span style="margin-right: 0.5em;">
+							<i v-if="announcement.icon === 'info'" class="ti ti-info-circle"></i>
+							<i v-else-if="announcement.icon === 'warning'" class="ti ti-alert-triangle" style="color: var(--warn);"></i>
+							<i v-else-if="announcement.icon === 'error'" class="ti ti-circle-x" style="color: var(--error);"></i>
+							<i v-else-if="announcement.icon === 'success'" class="ti ti-check" style="color: var(--success);"></i>
+						</span>
+						<span>{{ announcement.title }}</span>
+					</div>
+					<div :class="$style.content">
+						<Mfm :text="announcement.text"/>
+						<img v-if="announcement.imageUrl" :src="announcement.imageUrl"/>
+						<div style="opacity: 0.7; font-size: 85%;">
+							<MkTime :time="announcement.updatedAt ?? announcement.createdAt" mode="detail"/>
+						</div>
+					</div>
+					<div v-if="tab !== 'past' && $i && !announcement.isRead" :class="$style.footer">
+						<MkButton primary @click="read(announcement)"><i class="ti ti-check"></i> {{ i18n.ts.gotIt }}</MkButton>
+					</div>
+				</section>
+			</MkPagination>
+		</div>
 	</MkSpacer>
 </MkStickyContainer>
 </template>
@@ -27,30 +43,64 @@ SPDX-License-Identifier: AGPL-3.0-only
 import { ref } from 'vue';
 import MkPagination from '@/components/MkPagination.vue';
 import MkButton from '@/components/MkButton.vue';
+import MkInfo from '@/components/MkInfo.vue';
 import * as os from '@/os';
 import { i18n } from '@/i18n';
 import { definePageMetadata } from '@/scripts/page-metadata';
-import { $i } from '@/account';
+import { $i, updateAccount } from '@/account';
 
-const pagination = {
+const paginationCurrent = {
 	endpoint: 'announcements' as const,
 	limit: 10,
+	params: {
+		isActive: true,
+	},
+};
+
+const paginationPast = {
+	endpoint: 'announcements' as const,
+	limit: 10,
+	params: {
+		isActive: false,
+	},
 };
 
 const paginationEl = ref<InstanceType<typeof MkPagination>>();
 
-function read(id: string) {
+const tab = ref('current');
+
+async function read(announcement) {
+	if (announcement.needConfirmationToRead) {
+		const confirm = await os.confirm({
+			type: 'question',
+			title: i18n.ts._announcement.readConfirmTitle,
+			text: i18n.t('_announcement.readConfirmText', { title: announcement.title }),
+		});
+		if (confirm.canceled) return;
+	}
+
 	if (!paginationEl.value) return;
-	paginationEl.value.updateItem(id, announcement => {
-		announcement.isRead = true;
-		return announcement;
+	paginationEl.value.updateItem(announcement.id, a => {
+		a.isRead = true;
+		return a;
+	});
+	os.api('i/read-announcement', { announcementId: announcement.id });
+	updateAccount({
+		unreadAnnouncements: $i!.unreadAnnouncements.filter(a => a.id !== announcement.id),
 	});
-	os.api('i/read-announcement', { announcementId: id });
 }
 
 const headerActions = $computed(() => []);
 
-const headerTabs = $computed(() => []);
+const headerTabs = $computed(() => [{
+	key: 'current',
+	title: i18n.ts.currentAnnouncements,
+	icon: 'ti ti-flare',
+}, {
+	key: 'past',
+	title: i18n.ts.pastAnnouncements,
+	icon: 'ti ti-point',
+}]);
 
 definePageMetadata({
 	title: i18n.ts.announcements,
@@ -58,27 +108,34 @@ definePageMetadata({
 });
 </script>
 
-<style lang="scss" scoped>
-.ruryvtyk {
-	> .announcement {
-		padding: 16px;
+<style lang="scss" module>
+.announcement {
+	padding: 16px;
+}
 
-		> .header {
-			margin-bottom: 16px;
-			font-weight: bold;
-		}
+.forYou {
+	display: flex;
+	align-items: center;
+	line-height: 24px;
+	font-size: 90%;
+	white-space: pre;
+	color: #d28a3f;
+}
 
-		> .content {
-			> img {
-				display: block;
-				max-height: 300px;
-				max-width: 100%;
-			}
-		}
+.header {
+	margin-bottom: 16px;
+	font-weight: bold;
+}
 
-		> .footer {
-			margin-top: 16px;
-		}
+.content {
+	> img {
+		display: block;
+		max-height: 300px;
+		max-width: 100%;
 	}
 }
+
+.footer {
+	margin-top: 16px;
+}
 </style>
diff --git a/packages/frontend/src/pages/emoji-edit-dialog.vue b/packages/frontend/src/pages/emoji-edit-dialog.vue
index 19c63f8000..7e91805a12 100644
--- a/packages/frontend/src/pages/emoji-edit-dialog.vue
+++ b/packages/frontend/src/pages/emoji-edit-dialog.vue
@@ -63,7 +63,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				</MkFolder>
 				<MkSwitch v-model="isSensitive">isSensitive</MkSwitch>
 				<MkSwitch v-model="localOnly">{{ i18n.ts.localOnly }}</MkSwitch>
-				<MkButton danger @click="del()"><i class="ti ti-trash"></i> {{ i18n.ts.delete }}</MkButton>
+				<MkButton v-if="emoji" danger @click="del()"><i class="ti ti-trash"></i> {{ i18n.ts.delete }}</MkButton>
 			</div>
 		</MkSpacer>
 		<div :class="$style.footer">
diff --git a/packages/frontend/src/pages/gallery/index.vue b/packages/frontend/src/pages/gallery/index.vue
index e7c4ae88b5..af0ac2191b 100644
--- a/packages/frontend/src/pages/gallery/index.vue
+++ b/packages/frontend/src/pages/gallery/index.vue
@@ -86,7 +86,7 @@ const tagUsersPagination = $computed(() => ({
 	endpoint: 'hashtags/users' as const,
 	limit: 30,
 	params: {
-		tag: this.tag,
+		tag: props.tag,
 		origin: 'combined',
 		sort: '+follower',
 	},
diff --git a/packages/frontend/src/pages/user-info.vue b/packages/frontend/src/pages/user-info.vue
index 42b561cfe2..35cd116fad 100644
--- a/packages/frontend/src/pages/user-info.vue
+++ b/packages/frontend/src/pages/user-info.vue
@@ -132,6 +132,31 @@ SPDX-License-Identifier: AGPL-3.0-only
 					</div>
 				</MkFolder>
 
+				<MkFolder v-if="user.host == null && iAmModerator">
+					<template #icon><i class="ti ti-speakerphone"></i></template>
+					<template #label>{{ i18n.ts.announcements }}</template>
+					<div class="_gaps">
+						<MkButton primary rounded @click="createAnnouncement"><i class="ti ti-plus"></i> {{ i18n.ts.new }}</MkButton>
+
+						<MkPagination :pagination="announcementsPagination">
+							<template #default="{ items }">
+								<div class="_gaps_s">
+									<div v-for="announcement in items" :key="announcement.id" v-panel :class="$style.announcementItem" @click="editAnnouncement(announcement)">
+										<span style="margin-right: 0.5em;">
+											<i v-if="announcement.icon === 'info'" class="ti ti-info-circle"></i>
+											<i v-else-if="announcement.icon === 'warning'" class="ti ti-alert-triangle" style="color: var(--warn);"></i>
+											<i v-else-if="announcement.icon === 'error'" class="ti ti-circle-x" style="color: var(--error);"></i>
+											<i v-else-if="announcement.icon === 'success'" class="ti ti-check" style="color: var(--success);"></i>
+										</span>
+										<span>{{ announcement.title }}</span>
+										<span v-if="announcement.reads > 0" style="margin-left: auto; opacity: 0.7;">{{ i18n.ts.messageRead }}</span>
+									</div>
+								</div>
+							</template>
+						</MkPagination>
+					</div>
+				</MkFolder>
+
 				<MkFolder>
 					<template #icon><i class="ti ti-password"></i></template>
 					<template #label>IP</template>
@@ -185,7 +210,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 </template>
 
 <script lang="ts" setup>
-import { computed, watch } from 'vue';
+import { computed, defineAsyncComponent, watch } from 'vue';
 import * as misskey from 'misskey-js';
 import MkChart from '@/components/MkChart.vue';
 import MkObjectView from '@/components/MkObjectView.vue';
@@ -207,6 +232,7 @@ import { definePageMetadata } from '@/scripts/page-metadata';
 import { i18n } from '@/i18n';
 import { iAmAdmin, iAmModerator, $i } from '@/account';
 import MkRolePreview from '@/components/MkRolePreview.vue';
+import MkPagination, { Paging } from '@/components/MkPagination.vue';
 
 const props = withDefaults(defineProps<{
 	userId: string;
@@ -233,6 +259,13 @@ const filesPagination = {
 		userId: props.userId,
 	})),
 };
+const announcementsPagination = {
+	endpoint: 'admin/announcements/list' as const,
+	limit: 10,
+	params: computed(() => ({
+		userId: props.userId,
+	})),
+};
 let expandedRoles = $ref([]);
 
 function createFetcher() {
@@ -406,6 +439,19 @@ function toggleRoleItem(role) {
 	}
 }
 
+function createAnnouncement() {
+	os.popup(defineAsyncComponent(() => import('@/components/MkUserAnnouncementEditDialog.vue')), {
+		user,
+	}, {}, 'closed');
+}
+
+function editAnnouncement(announcement) {
+	os.popup(defineAsyncComponent(() => import('@/components/MkUserAnnouncementEditDialog.vue')), {
+		user,
+		announcement,
+	}, {}, 'closed');
+}
+
 watch(() => props.userId, () => {
 	init = createFetcher();
 }, {
@@ -569,4 +615,11 @@ definePageMetadata(computed(() => ({
 	margin-left: 8px;
 	align-self: center;
 }
+
+.announcementItem {
+	display: flex;
+	padding: 8px 12px;
+	border-radius: 6px;
+	cursor: pointer;
+}
 </style>
diff --git a/packages/frontend/src/ui/_common_/announcements.vue b/packages/frontend/src/ui/_common_/announcements.vue
new file mode 100644
index 0000000000..cd8b4e5275
--- /dev/null
+++ b/packages/frontend/src/ui/_common_/announcements.vue
@@ -0,0 +1,80 @@
+<!--
+SPDX-FileCopyrightText: syuilo and other misskey contributors
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+<div :class="$style.root">
+	<MkA
+		v-for="announcement in $i.unreadAnnouncements.filter(x => x.display === 'banner')"
+		:key="announcement.id"
+		:class="$style.item"
+		to="/announcements"
+	>
+		<span :class="$style.icon">
+			<i v-if="announcement.icon === 'info'" class="ti ti-info-circle"></i>
+			<i v-else-if="announcement.icon === 'warning'" class="ti ti-alert-triangle" style="color: var(--warn);"></i>
+			<i v-else-if="announcement.icon === 'error'" class="ti ti-circle-x" style="color: var(--error);"></i>
+			<i v-else-if="announcement.icon === 'success'" class="ti ti-check" style="color: var(--success);"></i>
+		</span>
+		<span :class="$style.title">{{ announcement.title }}</span>
+		<span :class="$style.body">{{ announcement.text }}</span>
+	</MkA>
+</div>
+</template>
+
+<script lang="ts" setup>
+import { $i } from '@/account';
+</script>
+
+<style lang="scss" module>
+.root {
+	font-size: 15px;
+	background: var(--panel);
+}
+
+.item {
+	--height: 24px;
+	font-size: 0.85em;
+
+	display: flex;
+	vertical-align: bottom;
+	width: 100%;
+	line-height: var(--height);
+	height: var(--height);
+	overflow: clip;
+	contain: strict;
+	background: var(--accent);
+	color: var(--fgOnAccent);
+
+	@container (max-width: 1000px) {
+		display: block;
+		text-align: center;
+
+		> .body {
+			display: none;
+		}
+	}
+}
+
+.icon {
+	margin-left: 10px;
+}
+
+.title {
+	padding: 0 10px;
+	font-weight: bold;
+
+	&:empty {
+		display: none;
+	}
+}
+
+.body {
+	min-width: 0;
+	flex: 1;
+	overflow: clip;
+	white-space: nowrap;
+	text-overflow: ellipsis;
+}
+</style>
diff --git a/packages/frontend/src/ui/deck.vue b/packages/frontend/src/ui/deck.vue
index f047474741..3518891811 100644
--- a/packages/frontend/src/ui/deck.vue
+++ b/packages/frontend/src/ui/deck.vue
@@ -8,6 +8,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 	<XSidebar v-if="!isMobile"/>
 
 	<div :class="$style.main">
+		<XAnnouncements v-if="$i" :class="$style.announcements"/>
 		<XStatusBars/>
 		<div ref="columnsEl" :class="[$style.sections, { [$style.center]: deckStore.reactiveState.columnAlign.value === 'center', [$style.snapScroll]: snapScroll }]" @contextmenu.self.prevent="onContextmenu" @wheel.self="onWheel">
 			<!-- sectionを利用しているのは、deck.vue側でcolumnに対してfirst-of-typeを効かせるため -->
@@ -113,6 +114,7 @@ import XMentionsColumn from '@/ui/deck/mentions-column.vue';
 import XDirectColumn from '@/ui/deck/direct-column.vue';
 import XRoleTimelineColumn from '@/ui/deck/role-timeline-column.vue';
 const XStatusBars = defineAsyncComponent(() => import('@/ui/_common_/statusbars.vue'));
+const XAnnouncements = defineAsyncComponent(() => import('@/ui/_common_/announcements.vue'));
 
 const columnComponents = {
 	main: XMainColumn,
diff --git a/packages/frontend/src/ui/universal.vue b/packages/frontend/src/ui/universal.vue
index 1c09df8394..d9cb81b5ef 100644
--- a/packages/frontend/src/ui/universal.vue
+++ b/packages/frontend/src/ui/universal.vue
@@ -8,7 +8,12 @@ SPDX-License-Identifier: AGPL-3.0-only
 	<XSidebar v-if="!isMobile" :class="$style.sidebar"/>
 
 	<MkStickyContainer ref="contents" :class="$style.contents" style="container-type: inline-size;" @contextmenu.stop="onContextmenu">
-		<template #header><XStatusBars :class="$style.statusbars"/></template>
+		<template #header>
+			<div>
+				<XAnnouncements v-if="$i" :class="$style.announcements"/>
+				<XStatusBars :class="$style.statusbars"/>
+			</div>
+		</template>
 		<RouterView/>
 		<div :class="$style.spacer"></div>
 	</MkStickyContainer>
@@ -105,6 +110,7 @@ import { useScrollPositionManager } from '@/nirax';
 const XWidgets = defineAsyncComponent(() => import('./universal.widgets.vue'));
 const XSidebar = defineAsyncComponent(() => import('@/ui/_common_/navbar.vue'));
 const XStatusBars = defineAsyncComponent(() => import('@/ui/_common_/statusbars.vue'));
+const XAnnouncements = defineAsyncComponent(() => import('@/ui/_common_/announcements.vue'));
 
 const DESKTOP_THRESHOLD = 1100;
 const MOBILE_THRESHOLD = 500;
diff --git a/packages/misskey-js/etc/misskey-js.api.md b/packages/misskey-js/etc/misskey-js.api.md
index 9d872f98e7..9c598a090e 100644
--- a/packages/misskey-js/etc/misskey-js.api.md
+++ b/packages/misskey-js/etc/misskey-js.api.md
@@ -30,6 +30,10 @@ type Announcement = {
     text: string;
     title: string;
     imageUrl: string | null;
+    display: 'normal' | 'banner' | 'dialog';
+    icon: 'info' | 'warning' | 'error' | 'success';
+    needConfirmationToRead: boolean;
+    forYou: boolean;
     isRead?: boolean;
 };
 
@@ -2453,6 +2457,7 @@ type MeDetailed = UserDetailed & {
     noCrawle: boolean;
     receiveAnnouncementEmail: boolean;
     usePasswordLessLogin: boolean;
+    unreadAnnouncements: Announcement[];
     [other: string]: any;
 };
 
diff --git a/packages/misskey-js/src/entities.ts b/packages/misskey-js/src/entities.ts
index b9771d1964..f0c6104ed3 100644
--- a/packages/misskey-js/src/entities.ts
+++ b/packages/misskey-js/src/entities.ts
@@ -104,6 +104,7 @@ export type MeDetailed = UserDetailed & {
 	noCrawle: boolean;
 	receiveAnnouncementEmail: boolean;
 	usePasswordLessLogin: boolean;
+	unreadAnnouncements: Announcement[];
 	[other: string]: any;
 };
 
@@ -413,6 +414,10 @@ export type Announcement = {
 	text: string;
 	title: string;
 	imageUrl: string | null;
+	display: 'normal' | 'banner' | 'dialog';
+	icon: 'info' | 'warning' | 'error' | 'success';
+	needConfirmationToRead: boolean;
+	forYou: boolean;
 	isRead?: boolean;
 };