diff --git a/src/main/ipc/settingsApi.ts b/src/main/ipc/settingsApi.ts
index 1d51f7f..121e949 100644
--- a/src/main/ipc/settingsApi.ts
+++ b/src/main/ipc/settingsApi.ts
@@ -8,6 +8,7 @@ import type { ExportService } from '../services/ExportService.js';
 import type { ImportService } from '../services/ImportService.js';
 import type { SyncService } from '../services/SyncService.js';
 import type { TelemetryService } from '../services/TelemetryService.js';
+import { collectAutostartState } from '../services/AutostartDiagnostic.js';
 import { getInboxWindow as getInboxWindowSingleton } from '../windows/inboxWindow.js';
 
 /**
@@ -58,6 +59,13 @@ export function registerSettingsApi(deps?: SettingsIpcDeps): void {
     return { openAtLogin: r.openAtLogin };
   });
 
+  // v0.2.7 F12 deeper fix (Task 21) — 진단 정보 포함된 정식 autostart 상태 조회.
+  // Task 22 에서 옛 'settings:get-autostart' 를 제거하고 본 채널로 통일 예정.
+  ipcMain.handle('settings:autostart-state', async () => {
+    const diag = await collectAutostartState();
+    return { openAtLogin: diag.withArgs.openAtLogin, diagnostic: diag };
+  });
+
   // v0.2.7 정보 섹션 (Task 11) — 트레이 showAboutDialog 의 detail 형식 그대로 (clipboard 일관성).
   // 트레이 showAboutDialog 자체 제거는 Task 25 (Phase 6 cleanup) — 본 task 는 추가만.
   ipcMain.handle('settings:get-app-info', () => ({
diff --git a/tests/unit/settingsApi.test.ts b/tests/unit/settingsApi.test.ts
new file mode 100644
index 0000000..9688850
--- /dev/null
+++ b/tests/unit/settingsApi.test.ts
@@ -0,0 +1,68 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+const { handlers, mockApp, mockCollectAutostartState } = vi.hoisted(() => ({
+  handlers: {} as Record<string, (...args: unknown[]) => unknown>,
+  mockApp: {
+    getLoginItemSettings: vi.fn(),
+    setLoginItemSettings: vi.fn(),
+    getVersion: vi.fn(() => '0.2.7'),
+    getPath: vi.fn(() => '/profile')
+  },
+  mockCollectAutostartState: vi.fn()
+}));
+
+vi.mock('electron', () => ({
+  default: {
+    ipcMain: {
+      handle: (ch: string, fn: (...args: unknown[]) => unknown) => {
+        handlers[ch] = fn;
+      }
+    },
+    app: mockApp,
+    dialog: {},
+    Notification: vi.fn(function (this: unknown) {
+      Object.assign(this as object, { show: vi.fn() });
+    }),
+    shell: { openPath: vi.fn() },
+    clipboard: { writeText: vi.fn() }
+  }
+}));
+
+vi.mock('../../src/main/services/AutostartDiagnostic', () => ({
+  collectAutostartState: mockCollectAutostartState
+}));
+
+vi.mock('../../src/main/windows/inboxWindow.js', () => ({
+  getInboxWindow: vi.fn(() => null)
+}));
+
+import { registerSettingsApi } from '../../src/main/ipc/settingsApi';
+
+describe('settingsApi — autostart IPC', () => {
+  beforeEach(() => {
+    Object.keys(handlers).forEach((k) => delete handlers[k]);
+    mockApp.getLoginItemSettings.mockReset();
+    mockApp.setLoginItemSettings.mockReset();
+    mockCollectAutostartState.mockReset();
+  });
+
+  it('settings:autostart-state returns AutostartState wrapped with openAtLogin', async () => {
+    mockCollectAutostartState.mockResolvedValue({
+      withArgs: { openAtLogin: true, executableWillLaunchAtLogin: true },
+      noArgs: { openAtLogin: false, executableWillLaunchAtLogin: true },
+      execPath: '/path/to/exe'
+    });
+
+    registerSettingsApi();
+
+    const r = await handlers['settings:autostart-state']!() as {
+      openAtLogin: boolean;
+      diagnostic: { withArgs: { openAtLogin: boolean } };
+    };
+
+    expect(r.openAtLogin).toBe(true);
+    expect(r.diagnostic.withArgs.openAtLogin).toBe(true);
+    expect(r.diagnostic).toHaveProperty('noArgs');
+    expect(r.diagnostic).toHaveProperty('execPath');
+  });
+});