diff --git a/packages/backend/src/server/api/AuthenticateService.ts b/packages/backend/src/server/api/AuthenticateService.ts
index 601618553e..397626c49d 100644
--- a/packages/backend/src/server/api/AuthenticateService.ts
+++ b/packages/backend/src/server/api/AuthenticateService.ts
@@ -84,6 +84,8 @@ export class AuthenticateService implements OnApplicationShutdown {
 				return [user, {
 					id: accessToken.id,
 					permission: app.permission,
+					appId: app.id,
+					app,
 				} as MiAccessToken];
 			} else {
 				return [user, accessToken];
diff --git a/packages/backend/src/server/api/endpoint-list.ts b/packages/backend/src/server/api/endpoint-list.ts
index 1c5a781fd9..a78c3e9ae6 100644
--- a/packages/backend/src/server/api/endpoint-list.ts
+++ b/packages/backend/src/server/api/endpoint-list.ts
@@ -128,6 +128,7 @@ export * as 'antennas/update' from './endpoints/antennas/update.js';
 export * as 'ap/get' from './endpoints/ap/get.js';
 export * as 'ap/show' from './endpoints/ap/show.js';
 export * as 'app/create' from './endpoints/app/create.js';
+export * as 'app/current' from './endpoints/app/current.js';
 export * as 'app/show' from './endpoints/app/show.js';
 export * as 'auth/accept' from './endpoints/auth/accept.js';
 export * as 'auth/session/generate' from './endpoints/auth/session/generate.js';
diff --git a/packages/backend/src/server/api/endpoints/app/current.ts b/packages/backend/src/server/api/endpoints/app/current.ts
new file mode 100644
index 0000000000..39b5ef347c
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/app/current.ts
@@ -0,0 +1,73 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Inject, Injectable } from '@nestjs/common';
+import { Endpoint } from '@/server/api/endpoint-base.js';
+import type { AppsRepository } from '@/models/_.js';
+import { AppEntityService } from '@/core/entities/AppEntityService.js';
+import { DI } from '@/di-symbols.js';
+import { ApiError } from '../../error.js';
+
+export const meta = {
+	tags: ['app'],
+
+	errors: {
+		credentialRequired: {
+			message: 'Credential required.',
+			code: 'CREDENTIAL_REQUIRED',
+			id: '1384574d-a912-4b81-8601-c7b1c4085df1',
+			httpStatusCode: 401,
+		},
+		noAppLogin: {
+			message: 'Not logged in with an app.',
+			code: 'NO_APP_LOGIN',
+			id: '339a4ad2-48c3-47fc-bd9d-2408f05120f8',
+		},
+	},
+
+	res: {
+		type: 'object',
+		optional: false, nullable: false,
+		ref: 'App',
+	},
+
+	// 10 calls per 5 seconds
+	limit: {
+		duration: 1000 * 5,
+		max: 10,
+	},
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {},
+	required: [],
+} as const;
+
+@Injectable()
+export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-disable-line import/no-default-export
+	constructor(
+		@Inject(DI.appsRepository)
+		private appsRepository: AppsRepository,
+
+		private appEntityService: AppEntityService,
+	) {
+		super(meta, paramDef, async (_, user, token) => {
+			if (!user) {
+				throw new ApiError(meta.errors.credentialRequired);
+			}
+			if (!token || !token.appId) {
+				throw new ApiError(meta.errors.noAppLogin);
+			}
+
+			const app = token.app ?? await this.appsRepository.findOneByOrFail({ id: token.appId });
+
+			return await this.appEntityService.pack(app, user, {
+				detail: true,
+				includeSecret: false,
+			});
+		});
+	}
+}
diff --git a/packages/backend/src/server/api/mastodon/MastodonConverters.ts b/packages/backend/src/server/api/mastodon/MastodonConverters.ts
index cf625d6e94..375ea1ef08 100644
--- a/packages/backend/src/server/api/mastodon/MastodonConverters.ts
+++ b/packages/backend/src/server/api/mastodon/MastodonConverters.ts
@@ -4,7 +4,7 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { Entity, MastodonEntity } from 'megalodon';
+import { Entity, MastodonEntity, MisskeyEntity } from 'megalodon';
 import mfm from '@transfem-org/sfm-js';
 import { MastodonNotificationType } from 'megalodon/lib/src/mastodon/notification.js';
 import { NotificationType } from 'megalodon/lib/src/notification.js';
@@ -369,6 +369,15 @@ export class MastodonConverters {
 			type: convertNotificationType(notification.type as NotificationType),
 		};
 	}
+
+	public convertApplication(app: MisskeyEntity.App): MastodonEntity.Application {
+		return {
+			name: app.name,
+			scopes: app.permission,
+			redirect_uri: app.callbackUrl,
+			redirect_uris: [app.callbackUrl],
+		};
+	}
 }
 
 function simpleConvert<T>(data: T): T {
@@ -459,4 +468,3 @@ export function convertRelationship(relationship: Partial<Entity.Relationship> &
 		note: relationship.note ?? '',
 	};
 }
-
diff --git a/packages/backend/src/server/api/mastodon/endpoints/apps.ts b/packages/backend/src/server/api/mastodon/endpoints/apps.ts
index 5fce838f47..72b520c74a 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/apps.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/apps.ts
@@ -5,6 +5,7 @@
 
 import { Injectable } from '@nestjs/common';
 import { MastodonClientService } from '@/server/api/mastodon/MastodonClientService.js';
+import { MastodonConverters } from '@/server/api/mastodon/MastodonConverters.js';
 import type { FastifyInstance } from 'fastify';
 
 const readScope = [
@@ -59,6 +60,7 @@ type AuthMastodonRoute = { Body?: AuthPayload, Querystring: AuthPayload };
 export class ApiAppsMastodon {
 	constructor(
 		private readonly clientService: MastodonClientService,
+		private readonly mastoConverters: MastodonConverters,
 	) {}
 
 	public register(fastify: FastifyInstance): void {
@@ -108,6 +110,13 @@ export class ApiAppsMastodon {
 
 			return reply.send(response);
 		});
+
+		fastify.get('/v1/apps/verify_credentials', async (_request, reply) => {
+			const client = this.clientService.getClient(_request);
+			const data = await client.verifyAppCredentials();
+			const response = this.mastoConverters.convertApplication(data.data);
+			return reply.send(response);
+		});
 	}
 }
 
diff --git a/packages/megalodon/src/index.ts b/packages/megalodon/src/index.ts
index 50663c3ce5..bacd0574d4 100644
--- a/packages/megalodon/src/index.ts
+++ b/packages/megalodon/src/index.ts
@@ -9,6 +9,7 @@ import * as NotificationType from './notification'
 import FilterContext from './filter_context'
 import Converter from './converter'
 import MastodonEntity from './mastodon/entity';
+import MisskeyEntity from './misskey/entity';
 
 export {
   Response,
@@ -23,4 +24,5 @@ export {
   Entity,
   Converter,
 	MastodonEntity,
+	MisskeyEntity,
 }
diff --git a/packages/megalodon/src/mastodon/entities/application.ts b/packages/megalodon/src/mastodon/entities/application.ts
index a3f07997ee..f402152bf6 100644
--- a/packages/megalodon/src/mastodon/entities/application.ts
+++ b/packages/megalodon/src/mastodon/entities/application.ts
@@ -3,5 +3,8 @@ namespace MastodonEntity {
     name: string
     website?: string | null
     vapid_key?: string | null
+		scopes: string[]
+		redirect_uris: string[]
+		redirect_uri?: string
   }
 }
diff --git a/packages/megalodon/src/misskey.ts b/packages/megalodon/src/misskey.ts
index 669eb0f106..bc38e27ce5 100644
--- a/packages/megalodon/src/misskey.ts
+++ b/packages/megalodon/src/misskey.ts
@@ -102,7 +102,7 @@ export default class Misskey implements MegalodonInterface {
         website: null,
         redirect_uri: res.data.callbackUrl,
         client_id: '',
-        client_secret: res.data.secret
+        client_secret: res.data.secret!
       }
       return OAuth.AppData.from(appData)
     })
@@ -122,11 +122,8 @@ export default class Misskey implements MegalodonInterface {
   // ======================================
   // apps
   // ======================================
-  public async verifyAppCredentials(): Promise<Response<Entity.Application>> {
-    return new Promise((_, reject) => {
-      const err = new NoImplementedError('misskey does not support')
-      reject(err)
-    })
+  public async verifyAppCredentials(): Promise<Response<MisskeyAPI.Entity.App>> {
+		return await this.client.post<MisskeyAPI.Entity.App>('/api/app/current');
   }
 
   // ======================================
diff --git a/packages/megalodon/src/misskey/entities/app.ts b/packages/megalodon/src/misskey/entities/app.ts
index 40a704b944..49c431596f 100644
--- a/packages/megalodon/src/misskey/entities/app.ts
+++ b/packages/megalodon/src/misskey/entities/app.ts
@@ -4,6 +4,6 @@ namespace MisskeyEntity {
     name: string
     callbackUrl: string
     permission: Array<string>
-    secret: string
+    secret?: string
   }
 }
diff --git a/packages/misskey-js/etc/misskey-js.api.md b/packages/misskey-js/etc/misskey-js.api.md
index 18cb070af5..44700add31 100644
--- a/packages/misskey-js/etc/misskey-js.api.md
+++ b/packages/misskey-js/etc/misskey-js.api.md
@@ -552,6 +552,9 @@ type AppCreateRequest = operations['app___create']['requestBody']['content']['ap
 // @public (undocumented)
 type AppCreateResponse = operations['app___create']['responses']['200']['content']['application/json'];
 
+// @public (undocumented)
+type AppCurrentResponse = operations['app___current']['responses']['200']['content']['application/json'];
+
 // @public (undocumented)
 type AppShowRequest = operations['app___show']['requestBody']['content']['application/json'];
 
@@ -1643,6 +1646,7 @@ declare namespace entities {
         ApShowResponse,
         AppCreateRequest,
         AppCreateResponse,
+        AppCurrentResponse,
         AppShowRequest,
         AppShowResponse,
         AuthAcceptRequest,
diff --git a/packages/misskey-js/src/autogen/apiClientJSDoc.ts b/packages/misskey-js/src/autogen/apiClientJSDoc.ts
index 75b3c5769e..0dfe042811 100644
--- a/packages/misskey-js/src/autogen/apiClientJSDoc.ts
+++ b/packages/misskey-js/src/autogen/apiClientJSDoc.ts
@@ -1313,6 +1313,17 @@ declare module '../api.js' {
       credential?: string | null,
     ): Promise<SwitchCaseResponseType<E, P>>;
 
+    /**
+     * No description provided.
+     * 
+     * **Credential required**: *No*
+     */
+    request<E extends 'app/current', P extends Endpoints[E]['req']>(
+      endpoint: E,
+      params: P,
+      credential?: string | null,
+    ): Promise<SwitchCaseResponseType<E, P>>;
+
     /**
      * No description provided.
      * 
diff --git a/packages/misskey-js/src/autogen/endpoint.ts b/packages/misskey-js/src/autogen/endpoint.ts
index 9293a5e950..b424927316 100644
--- a/packages/misskey-js/src/autogen/endpoint.ts
+++ b/packages/misskey-js/src/autogen/endpoint.ts
@@ -159,6 +159,7 @@ import type {
 	ApShowResponse,
 	AppCreateRequest,
 	AppCreateResponse,
+	AppCurrentResponse,
 	AppShowRequest,
 	AppShowResponse,
 	AuthAcceptRequest,
@@ -778,6 +779,7 @@ export type Endpoints = {
 	'ap/get': { req: ApGetRequest; res: ApGetResponse };
 	'ap/show': { req: ApShowRequest; res: ApShowResponse };
 	'app/create': { req: AppCreateRequest; res: AppCreateResponse };
+	'app/current': { req: EmptyRequest; res: AppCurrentResponse };
 	'app/show': { req: AppShowRequest; res: AppShowResponse };
 	'auth/accept': { req: AuthAcceptRequest; res: EmptyResponse };
 	'auth/session/generate': { req: AuthSessionGenerateRequest; res: AuthSessionGenerateResponse };
diff --git a/packages/misskey-js/src/autogen/entities.ts b/packages/misskey-js/src/autogen/entities.ts
index f71407a6ae..39359e3cfa 100644
--- a/packages/misskey-js/src/autogen/entities.ts
+++ b/packages/misskey-js/src/autogen/entities.ts
@@ -162,6 +162,7 @@ export type ApShowRequest = operations['ap___show']['requestBody']['content']['a
 export type ApShowResponse = operations['ap___show']['responses']['200']['content']['application/json'];
 export type AppCreateRequest = operations['app___create']['requestBody']['content']['application/json'];
 export type AppCreateResponse = operations['app___create']['responses']['200']['content']['application/json'];
+export type AppCurrentResponse = operations['app___current']['responses']['200']['content']['application/json'];
 export type AppShowRequest = operations['app___show']['requestBody']['content']['application/json'];
 export type AppShowResponse = operations['app___show']['responses']['200']['content']['application/json'];
 export type AuthAcceptRequest = operations['auth___accept']['requestBody']['content']['application/json'];
diff --git a/packages/misskey-js/src/autogen/types.ts b/packages/misskey-js/src/autogen/types.ts
index 57e98f2f88..077ea35729 100644
--- a/packages/misskey-js/src/autogen/types.ts
+++ b/packages/misskey-js/src/autogen/types.ts
@@ -1086,6 +1086,15 @@ export type paths = {
      */
     post: operations['app___create'];
   };
+  '/app/current': {
+    /**
+     * app/current
+     * @description No description provided.
+     *
+     * **Credential required**: *No*
+     */
+    post: operations['app___current'];
+  };
   '/app/show': {
     /**
      * app/show
@@ -13071,6 +13080,58 @@ export type operations = {
       };
     };
   };
+  /**
+   * app/current
+   * @description No description provided.
+   *
+   * **Credential required**: *No*
+   */
+  app___current: {
+    responses: {
+      /** @description OK (with results) */
+      200: {
+        content: {
+          'application/json': components['schemas']['App'];
+        };
+      };
+      /** @description Client error */
+      400: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+      /** @description Authentication error */
+      401: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+      /** @description Forbidden error */
+      403: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+      /** @description I'm Ai */
+      418: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+      /** @description Too many requests */
+      429: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+      /** @description Internal server error */
+      500: {
+        content: {
+          'application/json': components['schemas']['Error'];
+        };
+      };
+    };
+  };
   /**
    * app/show
    * @description No description provided.