diff --git a/packages/apps-engine/tests/server/accessors/ModifyDeleter.test.ts b/packages/apps-engine/tests/server/accessors/ModifyDeleter.test.ts
new file mode 100644
index 0000000000000..c40eb55617ad5
--- /dev/null
+++ b/packages/apps-engine/tests/server/accessors/ModifyDeleter.test.ts
@@ -0,0 +1,127 @@
+import * as assert from 'node:assert';
+import { afterEach, beforeEach, describe, it, mock } from 'node:test';
+
+import type { IMessage } from '../../../src/definition/messages';
+import type { IUser } from '../../../src/definition/users';
+import { UserType } from '../../../src/definition/users';
+import { ModifyDeleter } from '../../../src/server/accessors/ModifyDeleter';
+import type { AppBridges, MessageBridge, RoomBridge, UserBridge } from '../../../src/server/bridges';
+import { TestData } from '../../test-data/utilities';
+
+describe('ModifyDeleter', () => {
+	let mockAppId: string;
+	let mockRoomBridge: RoomBridge;
+	let mockMessageBridge: MessageBridge;
+	let mockUserBridge: UserBridge;
+	let mockBridges: AppBridges;
+
+	beforeEach(() => {
+		mockAppId = 'testing-app';
+
+		mockRoomBridge = {
+			doDelete(roomId: string, appId: string): Promise<void> {
+				return Promise.resolve();
+			},
+			doRemoveUsers(roomId: string, usernames: Array<string>, appId: string): Promise<void> {
+				return Promise.resolve();
+			},
+		} as RoomBridge;
+
+		mockMessageBridge = {
+			doDelete(message: IMessage, user: IUser, appId: string): Promise<void> {
+				return Promise.resolve();
+			},
+		} as MessageBridge;
+
+		mockUserBridge = {
+			doDeleteUsersCreatedByApp(appId: string, userType: UserType): Promise<boolean> {
+				return Promise.resolve(true);
+			},
+		} as UserBridge;
+
+		const rmBridge = mockRoomBridge;
+		const msgBridge = mockMessageBridge;
+		const usrBridge = mockUserBridge;
+		mockBridges = {
+			getRoomBridge: () => rmBridge,
+			getMessageBridge: () => msgBridge,
+			getUserBridge: () => usrBridge,
+		} as AppBridges;
+	});
+
+	afterEach(() => {
+		mock.restoreAll();
+	});
+
+	it('deleteRoom delegates to RoomBridge', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockRoomBridge, 'doDelete');
+
+		await md.deleteRoom('room-id');
+
+		assert.strictEqual(spy.mock.calls.length, 1);
+		assert.deepStrictEqual(spy.mock.calls[0].arguments, ['room-id', mockAppId]);
+	});
+
+	it('deleteMessage delegates to MessageBridge', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockMessageBridge, 'doDelete');
+
+		const message = TestData.getMessage();
+		const user = TestData.getUser();
+		await md.deleteMessage(message, user);
+
+		assert.strictEqual(spy.mock.calls.length, 1);
+		assert.deepStrictEqual(spy.mock.calls[0].arguments, [message, user, mockAppId]);
+	});
+
+	it('deleteUsers delegates to UserBridge and returns result', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockUserBridge, 'doDeleteUsersCreatedByApp');
+
+		const result = await md.deleteUsers('app-id', UserType.APP);
+
+		assert.strictEqual(result, true);
+		assert.strictEqual(spy.mock.calls.length, 1);
+		assert.deepStrictEqual(spy.mock.calls[0].arguments, ['app-id', UserType.APP]);
+
+		await md.deleteUsers('app-id', UserType.BOT);
+		assert.strictEqual(spy.mock.calls.length, 2);
+		assert.deepStrictEqual(spy.mock.calls[1].arguments, ['app-id', UserType.BOT]);
+	});
+
+	it('removeUsersFromRoom delegates to RoomBridge', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockRoomBridge, 'doRemoveUsers');
+
+		const usernames = ['user1', 'user2', 'user3'];
+		await md.removeUsersFromRoom('room-id', usernames);
+
+		assert.strictEqual(spy.mock.calls.length, 1);
+		assert.deepStrictEqual(spy.mock.calls[0].arguments, ['room-id', usernames, mockAppId]);
+	});
+
+	it('removeUsersFromRoom accepts exactly 50 users', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockRoomBridge, 'doRemoveUsers');
+
+		const fiftyUsers = Array.from({ length: 50 }, (_, i) => `user${i}`);
+		await md.removeUsersFromRoom('room-id', fiftyUsers);
+
+		assert.strictEqual(spy.mock.calls.length, 1);
+		assert.deepStrictEqual(spy.mock.calls[0].arguments, ['room-id', fiftyUsers, mockAppId]);
+	});
+
+	it('removeUsersFromRoom throws when exceeding 50 users', async () => {
+		const md = new ModifyDeleter(mockBridges, mockAppId);
+		const spy = mock.method(mockRoomBridge, 'doRemoveUsers');
+
+		const tooManyUsers = Array.from({ length: 51 }, (_, i) => `user${i}`);
+
+		await assert.rejects(
+			() => md.removeUsersFromRoom('room-id', tooManyUsers),
+			{ name: 'Error', message: 'A maximum of 50 members can be removed in a single call' },
+		);
+		assert.strictEqual(spy.mock.calls.length, 0);
+	});
+});