4 files changed, 57 insertions, 0 deletions
diff --git a/packages/backend/src/core/ChatService.ts b/packages/backend/src/core/ChatService.ts
index 4e81847a52..5cd336a097 100644
--- a/packages/backend/src/core/ChatService.ts
+++ b/packages/backend/src/core/ChatService.ts
@@ -332,6 +332,16 @@ export class ChatService {
 	}
 
 	@bindThis
+	public async readAllChatMessages(
+		readerId: MiUser['id'],
+	): Promise<void> {
+		const redisPipeline = this.redisClient.pipeline();
+		// TODO: newUserChatMessageExists とか newRoomChatMessageExists も消したい(けどキーの列挙が必要になって面倒)
+		redisPipeline.del(`newChatMessagesExists:${readerId}`);
+		await redisPipeline.exec();
+	}
+
+	@bindThis
 	public findMessageById(messageId: MiChatMessage['id']) {
 		return this.chatMessagesRepository.findOneBy({ id: messageId });
 	}
diff --git a/packages/backend/src/server/api/endpoint-list.ts b/packages/backend/src/server/api/endpoint-list.ts
index 1fdd000fdf..092d296bd3 100644
--- a/packages/backend/src/server/api/endpoint-list.ts
+++ b/packages/backend/src/server/api/endpoint-list.ts
@@ -428,4 +428,5 @@ export * as 'chat/rooms/invitations/ignore' from './endpoints/chat/rooms/invitat
 export * as 'chat/rooms/invitations/inbox' from './endpoints/chat/rooms/invitations/inbox.js';
 export * as 'chat/rooms/invitations/outbox' from './endpoints/chat/rooms/invitations/outbox.js';
 export * as 'chat/history' from './endpoints/chat/history.js';
+export * as 'chat/read-all' from './endpoints/chat/read-all.js';
 export * as 'v2/admin/emoji/list' from './endpoints/v2/admin/emoji/list.js';
diff --git a/packages/backend/src/server/api/endpoints/chat/read-all.ts b/packages/backend/src/server/api/endpoints/chat/read-all.ts
new file mode 100644
index 0000000000..2ed9497eef
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/chat/read-all.ts
@@ -0,0 +1,38 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Inject, Injectable } from '@nestjs/common';
+import { Endpoint } from '@/server/api/endpoint-base.js';
+import { DI } from '@/di-symbols.js';
+import { ChatService } from '@/core/ChatService.js';
+import { ApiError } from '@/server/api/error.js';
+
+export const meta = {
+	tags: ['chat'],
+
+	requireCredential: true,
+
+	kind: 'write:chat',
+
+	errors: {
+	},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+	},
+} as const;
+
+@Injectable()
+export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-disable-line import/no-default-export
+	constructor(
+		private chatService: ChatService,
+	) {
+		super(meta, paramDef, async (ps, me) => {
+			await this.chatService.readAllChatMessages(me.id);
+		});
+	}
+}
diff --git a/packages/frontend/src/pages/settings/other.vue b/packages/frontend/src/pages/settings/other.vue
index f09cc9c9bc..9459a9b326 100644
--- a/packages/frontend/src/pages/settings/other.vue
+++ b/packages/frontend/src/pages/settings/other.vue
@@ -128,6 +128,10 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 		<hr>
 
+		<MkButton @click="readAllChatMessages">Read all chat messages</MkButton>
+
+		<hr>
+
 		<FormSlot>
 			<MkButton danger @click="migrate"><i class="ti ti-refresh"></i> {{ i18n.ts.migrateOldSettings }}</MkButton>
 			<template #caption>{{ i18n.ts.migrateOldSettings_description }}</template>
@@ -214,6 +218,10 @@ function hideAllTips() {
 	os.success();
 }
 
+function readAllChatMessages() {
+	os.apiWithDialog('chat/read-all', {});
+}
+
 const headerActions = computed(() => []);
 
 const headerTabs = computed(() => []);