diff --git a/apps/desktop/docs/aiturk-macos-native-menu.md b/apps/desktop/docs/aiturk-macos-native-menu.md
new file mode 100644
index 0000000..fc52bd9
--- /dev/null
+++ b/apps/desktop/docs/aiturk-macos-native-menu.md
@@ -0,0 +1,35 @@
+# macOS yerel menüsünün Türkçe desteği
+
+Dosya, Düzen, Görünüm, Pencere, Yardım ve uygulama menüsündeki komutlar
+Türkçe gösterilir. Ana pencerenin dil seçimi mevcut `display.language`
+ayarından gelir. Dar kapsamlı `setUiLanguage` köprüsü yalnızca menü
+etiketlerini günceller; ayrı bir tercih dosyası veya sunucu ayarı oluşturmaz.
+Dil kaydı başarısız olursa arayüzle birlikte menü dili de geri alınır.
+Yardımcı pencereler ana pencerenin menü dilini değiştiremez.
+
+Menü öğelerinin eylemleri, Electron rolleri ve klavye kısayolları korunur.
+Özellikle renderer tarafından yönetilen yeni pencere, klasör açma, sekme
+kapatma ve sayfa yenileme komutlarına yerel kısayol eklenmez. İngilizce
+seçilince özgün İngilizce şablon kullanılır; diğer diller yerel menüde
+mevcut İngilizce desteğini kullanmaya devam eder.
+
+Paket doğrulama yolları `package.json` içindeki AITURK ürün ve çalıştırılabilir
+dosya adlarını kullanır. Intel Mac için `release/mac`, Apple Silicon için
+`release/mac-arm64` aranır. Temiz kurulum denemesi açıkça izole
+`AITURK_IDE_HOME` ve Electron kullanıcı dizini seçer. Başka bir Hermes
+kurulumunun çalışma dizinine yönelmez.
+
+## Kanıt ve yayın sınırı
+
+- Menü birim testleri eylem, rol ve kısayol bütünlüğünü; kaynak pencere ve
+  dil doğrulamasını kontrol eder.
+- React testi yüklenen dil, iyimser geçiş ve kayıt hatasında geri dönüşün
+  yerel köprüye iletildiğini doğrular.
+- Gerçek Electron E2E testi köprüyü kullanır. macOS'ta yerel menü etiketlerini,
+  Windows'ta uygulama menüsünün kapalı kalmasını kontrol eder.
+- Windows üzerinde Türkçe ayar kaydı ve köprü testleri geçti. Paket yolu,
+  mevcut Windows beta.5 dosyası üzerinde açılış ve içerik kontrolüyle doğrulandı.
+
+Bu kaynak değişikliği, yayımlanan Windows beta.5 dosyasını değiştirmez.
+macOS dalındaki E2E testi, DMG/ZIP derlemesi ve gerçek Mac'te çalıştırma henüz
+doğrulanmadı. Mac paketi bu kanıtlar tamamlanmadan yayımlanmış sayılmaz.
diff --git a/apps/desktop/e2e/fixtures.ts b/apps/desktop/e2e/fixtures.ts
index 030dbe9..4a8b3f5 100644
--- a/apps/desktop/e2e/fixtures.ts
+++ b/apps/desktop/e2e/fixtures.ts
@@ -33,6 +33,9 @@ import { installErrorBannerGuard } from './test'
 const DESKTOP_ROOT = path.resolve(import.meta.dirname, '..')
 const REPO_ROOT = path.resolve(DESKTOP_ROOT, '..', '..')
 const RELEASE_ROOT = path.join(DESKTOP_ROOT, 'release')
+const PACKAGE_CONFIG = JSON.parse(fs.readFileSync(path.join(DESKTOP_ROOT, 'package.json'), 'utf8')).build as {
+  executableName: string
+}
 
 // ─── Credential stripping (matches launch.spec.ts) ──────────────────────
 
@@ -519,16 +522,19 @@ providers:
  */
 function resolvePackagedBinaryPath(): string {
   if (process.platform === 'win32') {
-    return path.join(RELEASE_ROOT, 'win-unpacked', 'Hermes.exe')
+    return path.join(RELEASE_ROOT, 'win-unpacked', `${PACKAGE_CONFIG.executableName}.exe`)
   }
 
   if (process.platform === 'darwin') {
     const arch = process.arch === 'arm64' ? 'arm64' : 'x64'
 
-    return path.join(RELEASE_ROOT, `mac-${arch}`, 'Hermes.app', 'Contents', 'MacOS', 'Hermes')
+    return path.join(
+      RELEASE_ROOT, arch === 'x64' ? 'mac' : `mac-${arch}`,
+      `${PACKAGE_CONFIG.executableName}.app`, 'Contents', 'MacOS', PACKAGE_CONFIG.executableName
+    )
   }
 
-  return path.join(RELEASE_ROOT, 'linux-unpacked', 'hermes')
+  return path.join(RELEASE_ROOT, 'linux-unpacked', PACKAGE_CONFIG.executableName)
 }
 
 export const PACKAGED_BINARY_PATH = resolvePackagedBinaryPath()
diff --git a/apps/desktop/e2e/launch-packaged-app.spec.ts b/apps/desktop/e2e/launch-packaged-app.spec.ts
index d52b261..912f9ef 100644
--- a/apps/desktop/e2e/launch-packaged-app.spec.ts
+++ b/apps/desktop/e2e/launch-packaged-app.spec.ts
@@ -34,9 +34,9 @@ test.afterAll(async () => {
   fixture = null
 })
 
-test('window opens with the Hermes title', async () => {
+test('window opens with the AITURK title', async () => {
   const title = await fixture!.page.title()
-  expect(title).toContain('Hermes')
+  expect(title).toContain('AITURK')
 })
 
 test('renderer loads and shows DOM content', async () => {
diff --git a/apps/desktop/e2e/turkish-settings.spec.ts b/apps/desktop/e2e/turkish-settings.spec.ts
index aa4a665..ccd7454 100644
--- a/apps/desktop/e2e/turkish-settings.spec.ts
+++ b/apps/desktop/e2e/turkish-settings.spec.ts
@@ -6,7 +6,10 @@ import { expect, test } from './test'
 
 let fixture: MockBackendFixture | null = null
 type DesktopTestWindow = Window & {
-  hermesDesktop: { api<T = unknown>(request: { path: string }): Promise<T> }
+  hermesDesktop: {
+    api<T = unknown>(request: { path: string }): Promise<T>
+    setUiLanguage(locale: string): void
+  }
 }
 
 test.beforeAll(async () => {
@@ -75,3 +78,20 @@ test('Turkish safety settings persist the backend enum through the real desktop
   await expect(approvals.getByRole('combobox')).toContainText('Elle onayla')
   await page.screenshot({ path: test.info().outputPath('turkish-safety-settings.png'), fullPage: true })
 })
+
+test('native language bridge updates the Mac menu and preserves menu-free Windows', async () => {
+  const { app, page } = fixture!
+  const platform = await app.evaluate(() => process.platform)
+  for (const locale of ['en', 'tr']) {
+    await page.evaluate(language => {
+      ;(window as unknown as DesktopTestWindow).hermesDesktop.setUiLanguage(language)
+    }, locale)
+    await expect
+      .poll(() => app.evaluate(({ Menu }) => Menu.getApplicationMenu()?.items.map((item: { label: string }) => item.label) ?? null))
+      .toEqual(
+        platform === 'darwin'
+          ? expect.arrayContaining([locale === 'tr' ? 'Dosya' : 'File', locale === 'tr' ? 'Düzen' : 'Edit'])
+          : null
+      )
+  }
+})
diff --git a/apps/desktop/electron/main.ts b/apps/desktop/electron/main.ts
index e724d5a..707f888 100644
--- a/apps/desktop/electron/main.ts
+++ b/apps/desktop/electron/main.ts
@@ -261,6 +261,7 @@ import {
   resolveOauthRestAuth,
   resolveReadinessProbeAuth
 } from './native-auth-decisions'
+import { localizeNativeMenu, type NativeMenuLocale, resolveNativeMenuLocale } from './native-menu-locale'
 import {
   nativeRefreshUrl,
   type NativeTokenSet,
@@ -6755,11 +6756,13 @@ function sendWindowStateChanged(nextIsFullscreen?: boolean, target = mainWindow)
   webContents.send('hermes:window-state-changed', state)
 }
 
+let nativeMenuLocale: NativeMenuLocale = 'tr'
+
 function buildApplicationMenu() {
   const template = []
 
   const checkForUpdatesItem = {
-    label: 'AITURK IDE güncellemeleri…',
+    label: 'Check for Updates…',
     click: () => IS_PACKAGED ? void shell.openExternal(AITURK_PRODUCT.downloads) : sendOpenUpdatesRequested()
   }
 
@@ -6886,7 +6889,7 @@ function buildApplicationMenu() {
     submenu: [checkForUpdatesItem]
   })
 
-  return Menu.buildFromTemplate(template)
+  return Menu.buildFromTemplate(localizeNativeMenu(template, nativeMenuLocale, APP_NAME))
 }
 
 function toggleDevTools(window) {
@@ -16955,6 +16958,22 @@ ipcMain.on('hermes:titlebar-theme', (_event, payload) => {
   }
 })
 
+// Language stays in backend display.language; this only updates native labels.
+ipcMain.on('hermes:ui-language', (event, locale) => {
+  if (!IS_MAC) {
+    return
+  }
+
+  const next = resolveNativeMenuLocale(locale, event.sender.id, mainWindow?.webContents.id)
+
+  if (next === null || next === nativeMenuLocale) {
+    return
+  }
+
+  nativeMenuLocale = next
+  Menu.setApplicationMenu(buildApplicationMenu())
+})
+
 // Pin the native appearance to the app theme (see NATIVE_THEME_CONFIG_PATH).
 ipcMain.on('hermes:native-theme', (_event, mode) => {
   if (!THEME_SOURCES.has(mode)) {
diff --git a/apps/desktop/electron/native-menu-locale.test.ts b/apps/desktop/electron/native-menu-locale.test.ts
new file mode 100644
index 0000000..2d99305
--- /dev/null
+++ b/apps/desktop/electron/native-menu-locale.test.ts
@@ -0,0 +1,53 @@
+import type { MenuItemConstructorOptions } from 'electron'
+import { describe, expect, it, vi } from 'vitest'
+
+import { localizeNativeMenu, resolveNativeMenuLocale } from './native-menu-locale'
+
+describe('native menu language', () => {
+  it('translates nested labels without changing actions, roles or keyboard ownership', () => {
+    const openFolder = vi.fn()
+    const zoom = vi.fn()
+
+    const template: MenuItemConstructorOptions[] = [
+      {
+        label: 'File',
+        submenu: [{ label: 'Open Folder…', click: openFolder }, { type: 'separator' }, { role: 'quit' }]
+      },
+      {
+        label: 'View',
+        submenu: [{ label: 'Zoom In', accelerator: 'CommandOrControl+Plus', click: zoom }, { role: 'togglefullscreen' }]
+      },
+      { label: 'My custom action', enabled: false }
+    ]
+
+    const translated = localizeNativeMenu(template, 'tr', 'AITURK IDE')
+    const file = translated[0].submenu as MenuItemConstructorOptions[]
+    const view = translated[1].submenu as MenuItemConstructorOptions[]
+    expect(translated[0].label).toBe('Dosya')
+    expect(file[0]).toEqual({ label: 'Klasör aç…', click: openFolder })
+    expect(file[1]).toEqual({ type: 'separator' })
+    expect(file[2]).toEqual({ role: 'quit', label: 'AITURK IDE uygulamasından çık' })
+    expect(view[0]).toEqual({ label: 'Yakınlaştır', accelerator: 'CommandOrControl+Plus', click: zoom })
+    expect(view[1].role).toBe('togglefullscreen')
+    expect(translated[2]).toEqual(template[2])
+    expect(localizeNativeMenu(template, 'en', 'AITURK IDE')).toBe(template)
+    expect((template[0].submenu as MenuItemConstructorOptions[])[0].label).toBe('Open Folder…')
+    expect(openFolder).not.toHaveBeenCalled()
+    expect(zoom).not.toHaveBeenCalled()
+  })
+
+  it('accepts only supported language messages from the primary renderer', () => {
+    expect(resolveNativeMenuLocale('tr', 42, 42)).toBe('tr')
+    expect(resolveNativeMenuLocale('en', 42, 42)).toBe('en')
+    expect(resolveNativeMenuLocale('ja', 42, 42)).toBe('en')
+
+    for (const locale of ['tr', 'en']) {
+      expect(resolveNativeMenuLocale(locale, 43, 42)).toBeNull()
+      expect(resolveNativeMenuLocale(locale, 42, undefined)).toBeNull()
+    }
+
+    for (const value of [null, {}, ['tr'], 'unsupported', '__proto__']) {
+      expect(resolveNativeMenuLocale(value, 42, 42)).toBeNull()
+    }
+  })
+})
diff --git a/apps/desktop/electron/native-menu-locale.ts b/apps/desktop/electron/native-menu-locale.ts
new file mode 100644
index 0000000..eb5e191
--- /dev/null
+++ b/apps/desktop/electron/native-menu-locale.ts
@@ -0,0 +1,90 @@
+import type { MenuItemConstructorOptions } from 'electron'
+
+export type NativeMenuLocale = 'en' | 'tr'
+
+// Only the primary settings surface owns the app-wide menu language. Utility
+// windows have their own I18nProvider and must not overwrite that preference.
+export function resolveNativeMenuLocale(
+  value: unknown,
+  senderId: number,
+  primaryId: number | undefined
+): NativeMenuLocale | null {
+  if (primaryId === undefined || senderId !== primaryId) {
+    return null
+  }
+
+  if (value === 'tr') {
+    return 'tr'
+  }
+
+  if (typeof value === 'string' && ['en', 'zh', 'zh-hant', 'ja', 'ar', 'ru'].includes(value)) {
+    return 'en'
+  }
+
+  return null
+}
+
+export function localizeNativeMenu(
+  template: MenuItemConstructorOptions[],
+  locale: NativeMenuLocale,
+  appName: string
+): MenuItemConstructorOptions[] {
+  if (locale !== 'tr') {
+    return template
+  }
+
+  const labels: Record<string, string> = {
+    [`About ${appName}`]: `${appName} Hakkında`,
+    'Check for Updates…': 'Güncellemeleri kontrol et…',
+    File: 'Dosya',
+    'New Window': 'Yeni pencere',
+    'Open Folder…': 'Klasör aç…',
+    Close: 'Kapat',
+    Edit: 'Düzen',
+    View: 'Görünüm',
+    Reload: 'Yenile',
+    'Toggle Developer Tools': 'Geliştirici araçlarını aç/kapat',
+    'Actual Size': 'Gerçek boyut',
+    'Zoom In': 'Yakınlaştır',
+    'Zoom Out': 'Uzaklaştır',
+    Window: 'Pencere',
+    Help: 'Yardım'
+  }
+
+  const roles: Partial<Record<NonNullable<MenuItemConstructorOptions['role']>, string>> = {
+    services: 'Servisler',
+    hide: `${appName} uygulamasını gizle`,
+    hideOthers: 'Diğerlerini gizle',
+    unhide: 'Tümünü göster',
+    quit: `${appName} uygulamasından çık`,
+    undo: 'Geri al',
+    redo: 'Yinele',
+    cut: 'Kes',
+    copy: 'Kopyala',
+    paste: 'Yapıştır',
+    pasteAndMatchStyle: 'Biçimlendirmeden yapıştır',
+    delete: 'Sil',
+    selectAll: 'Tümünü seç',
+    forceReload: 'Uygulamayı zorla yenile',
+    togglefullscreen: 'Tam ekranı aç/kapat',
+    minimize: 'Simge durumuna küçült',
+    zoom: 'Pencereyi büyüt/küçült',
+    front: 'Tümünü öne getir',
+    close: 'Kapat'
+  }
+
+  return template.map(item => {
+    const label =
+      item.label !== undefined
+        ? Object.hasOwn(labels, item.label)
+          ? labels[item.label]
+          : item.label
+        : item.role && roles[item.role]
+
+    return {
+      ...item,
+      ...(label !== undefined && { label }),
+      ...(Array.isArray(item.submenu) && { submenu: localizeNativeMenu(item.submenu, locale, appName) })
+    }
+  })
+}
diff --git a/apps/desktop/electron/preload.ts b/apps/desktop/electron/preload.ts
index fd96687..68d2d95 100644
--- a/apps/desktop/electron/preload.ts
+++ b/apps/desktop/electron/preload.ts
@@ -13,6 +13,7 @@ const hudNativeDrag = hudWindowing?.nativeDrag === true
 const launchFlags = ipcRenderer.sendSync('hermes:launch-flags')
 
 contextBridge.exposeInMainWorld('hermesDesktop', {
+  setUiLanguage: (locale: string) => ipcRenderer.send('hermes:ui-language', locale),
   glassSupported: translucencySupport?.glass === true,
   translucencySupported: translucencySupport?.translucency === true,
   // Launch-flag fact: the app was started with --local, so the renderer may
diff --git a/apps/desktop/scripts/test-desktop.mjs b/apps/desktop/scripts/test-desktop.mjs
index ec94ddc..faaa2e8 100644
--- a/apps/desktop/scripts/test-desktop.mjs
+++ b/apps/desktop/scripts/test-desktop.mjs
@@ -19,10 +19,10 @@ const PLATFORM = process.platform
 // launch via install.ps1 / install.sh, per the Phase 1 thin-installer flow).
 const APP = (() => {
   if (PLATFORM === 'darwin') {
-    const appPath = path.join(RELEASE_ROOT, `mac-${ARCH}`, 'Hermes.app')
+    const appPath = path.join(RELEASE_ROOT, ARCH === 'x64' ? 'mac' : `mac-${ARCH}`, `${PACKAGE_JSON.build.executableName}.app`)
     return {
       appPath,
-      binary: path.join(appPath, 'Contents', 'MacOS', 'Hermes'),
+      binary: path.join(appPath, 'Contents', 'MacOS', PACKAGE_JSON.build.executableName),
       resourcesPath: path.join(appPath, 'Contents', 'Resources'),
       asarPath: path.join(appPath, 'Contents', 'Resources', 'app.asar'),
       unpackedDistIndex: path.join(appPath, 'Contents', 'Resources', 'app.asar.unpacked', 'dist', 'index.html')
@@ -32,7 +32,7 @@ const APP = (() => {
     const unpacked = path.join(RELEASE_ROOT, 'win-unpacked')
     return {
       appPath: unpacked,
-      binary: path.join(unpacked, 'Hermes.exe'),
+      binary: path.join(unpacked, `${PACKAGE_JSON.build.executableName}.exe`),
       resourcesPath: path.join(unpacked, 'resources'),
       asarPath: path.join(unpacked, 'resources', 'app.asar'),
       unpackedDistIndex: path.join(unpacked, 'resources', 'app.asar.unpacked', 'dist', 'index.html')
@@ -42,24 +42,24 @@ const APP = (() => {
   const unpacked = path.join(RELEASE_ROOT, 'linux-unpacked')
   return {
     appPath: unpacked,
-    binary: path.join(unpacked, 'Hermes'),
+    binary: path.join(unpacked, PACKAGE_JSON.build.executableName),
     resourcesPath: path.join(unpacked, 'resources'),
     asarPath: path.join(unpacked, 'resources', 'app.asar'),
     unpackedDistIndex: path.join(unpacked, 'resources', 'app.asar.unpacked', 'dist', 'index.html')
   }
 })()
 
-// Default HERMES_HOME for non-sandboxed runs -- matches main.ts's
-// resolveHermesHome(). On Windows it's %LOCALAPPDATA%\hermes; elsewhere
-// it's ~/.hermes. The fresh-install sandbox launchFresh() sets its own
-// HERMES_HOME and never touches this.
-const DEFAULT_HERMES_HOME = (() => {
+// Match AITURK's product-owned runtime; never inspect another Hermes install.
+const DEFAULT_AGENT_HOME = (() => {
+  if (process.env.AITURK_IDE_HOME) return path.resolve(process.env.AITURK_IDE_HOME)
+  const userData = process.env.AITURK_IDE_USER_DATA_DIR || process.env.HERMES_DESKTOP_USER_DATA_DIR
+  if (userData) return path.join(path.resolve(userData), 'agent-home')
   if (PLATFORM === 'win32' && process.env.LOCALAPPDATA) {
-    return path.join(process.env.LOCALAPPDATA, 'hermes')
+    return path.join(process.env.LOCALAPPDATA, 'TurkServis', 'AITURK-IDE', 'agent')
   }
-  return path.join(os.homedir(), '.hermes')
+  return path.join(os.homedir(), '.aiturk-ide', 'agent')
 })()
-const VENV_ROOT = path.join(DEFAULT_HERMES_HOME, 'hermes-agent', 'venv')
+const VENV_ROOT = path.join(DEFAULT_AGENT_HOME, 'hermes-agent', 'venv')
 const FRESH_SANDBOX_ROOT = path.join(os.tmpdir(), 'hermes-desktop-fresh-install')
 
 function die(message) {
@@ -124,10 +124,10 @@ function ensurePackagedApp() {
 
 function resolveDmgPath() {
   if (!exists(RELEASE_ROOT)) {
-    return path.join(RELEASE_ROOT, `Hermes-${PACKAGE_JSON.version}-${ARCH}.dmg`)
+    return path.join(RELEASE_ROOT, `AITURK-IDE-${PACKAGE_JSON.version}-mac-${ARCH}.dmg`)
   }
 
-  const prefix = `Hermes-${PACKAGE_JSON.version}`
+  const prefix = `AITURK-IDE-${PACKAGE_JSON.version}-mac-`
   const candidates = fs
     .readdirSync(RELEASE_ROOT)
     .filter(name => name.endsWith('.dmg'))
@@ -141,15 +141,15 @@ function resolveDmgPath() {
 
   return candidates.length > 0
     ? path.join(RELEASE_ROOT, candidates[0])
-    : path.join(RELEASE_ROOT, `Hermes-${PACKAGE_JSON.version}-${ARCH}.dmg`)
+    : path.join(RELEASE_ROOT, `AITURK-IDE-${PACKAGE_JSON.version}-mac-${ARCH}.dmg`)
 }
 
 function resolveNsisPath() {
-  // electron-builder NSIS artifactName template is 'Hermes-${version}-${os}-${arch}.${ext}'
+  // Select only this AITURK release and architecture.
   if (!exists(RELEASE_ROOT)) return null
   const candidates = fs
     .readdirSync(RELEASE_ROOT)
-    .filter(name => /\.exe$/i.test(name) && /win/i.test(name))
+    .filter(name => name === `AITURK-IDE-${PACKAGE_JSON.version}-win-${ARCH}.exe`)
     .sort((a, b) => {
       const aMtime = fs.statSync(path.join(RELEASE_ROOT, a)).mtimeMs
       const bMtime = fs.statSync(path.join(RELEASE_ROOT, b)).mtimeMs
@@ -261,6 +261,9 @@ function launchFresh() {
   env.HERMES_DESKTOP_TEST_MODE = 'fresh-install'
   env.HERMES_DESKTOP_USER_DATA_DIR = userDataDir
   env.HERMES_HOME = hermesHome
+  env.AITURK_IDE_HOME = hermesHome
+  env.AITURK_IDE_USER_DATA_DIR = userDataDir
+  delete env.HERMES_DESKTOP_PYTHON
   delete env.HERMES_DESKTOP_HERMES
   delete env.HERMES_DESKTOP_HERMES_ROOT
 
@@ -275,7 +278,7 @@ function launchFresh() {
   console.log('\nFresh install sandbox:')
   console.log(`  root: ${sandbox}`)
   console.log(`  electron userData: ${userDataDir}`)
-  console.log(`  HERMES_HOME: ${hermesHome}`)
+  console.log(`  AITURK_IDE_HOME: ${hermesHome}`)
   console.log(`  cwd: ${cwd}`)
 
   return { runtimeRoot: path.join(hermesHome, 'hermes-agent', 'venv') }
@@ -399,8 +402,8 @@ function printArtifacts(options = {}) {
 
 function help() {
   console.log(`Usage:
-  npm run test:desktop:existing  # build packaged app, launch with normal PATH/existing Hermes
-  npm run test:desktop:fresh     # build packaged app, launch with temp userData + HERMES_HOME
+  npm run test:desktop:existing  # build packaged app, launch with the existing AITURK profile
+  npm run test:desktop:fresh     # build packaged app, launch with temp userData + AITURK_IDE_HOME
   npm run test:desktop:dmg       # (macOS only) build DMG and open it
   npm run test:desktop:nsis      # (win32 only) build NSIS installer
   npm run test:desktop:all       # build installer, validate app payload, print paths
diff --git a/apps/desktop/src/global.d.ts b/apps/desktop/src/global.d.ts
index 0362b8f..aff6423 100644
--- a/apps/desktop/src/global.d.ts
+++ b/apps/desktop/src/global.d.ts
@@ -17,6 +17,7 @@ export {}
 declare global {
   interface Window {
     hermesDesktop: {
+      setUiLanguage?: (locale: string) => void
       // Resolve a backend connection. Omit `profile` (or pass the primary) for
       // the window's backend; pass a named profile to lazily spawn/reuse that
       // profile's backend from the pool.
diff --git a/apps/desktop/src/i18n/context.test.tsx b/apps/desktop/src/i18n/context.test.tsx
index 7baee22..b770a2b 100644
--- a/apps/desktop/src/i18n/context.test.tsx
+++ b/apps/desktop/src/i18n/context.test.tsx
@@ -30,6 +30,42 @@ describe('I18nProvider', () => {
     vi.restoreAllMocks()
   })
 
+  it('keeps the native menu aligned with loaded, optimistic and rolled-back language', async () => {
+    const original = window.hermesDesktop
+    const setUiLanguage = vi.fn()
+    window.hermesDesktop = { ...original, setUiLanguage }
+    let rejectSave: (error: Error) => void = () => undefined
+
+    const configClient: I18nConfigClient = {
+      getConfig: vi.fn().mockResolvedValue({ display: { language: 'en' } }),
+      saveConfig: vi.fn().mockImplementation(
+        () =>
+          new Promise((_resolve, reject) => {
+            rejectSave = reject
+          })
+      )
+    }
+
+    try {
+      render(
+        <I18nProvider configClient={configClient}>
+          <LanguageProbe target="tr" />
+        </I18nProvider>
+      )
+      await waitFor(() => expect(setUiLanguage).toHaveBeenLastCalledWith('en'))
+      fireEvent.click(screen.getByRole('button', { name: 'switch' }))
+      await waitFor(() => expect(configClient.saveConfig).toHaveBeenCalledTimes(1))
+      expect(setUiLanguage).toHaveBeenLastCalledWith('tr')
+      rejectSave(new Error('Cannot save language'))
+      await waitFor(() => expect(screen.getByTestId('save-error').textContent).toBe('Cannot save language'))
+      expect(setUiLanguage).toHaveBeenLastCalledWith('en')
+      expect(screen.getByTestId('locale').textContent).toBe('en')
+    } finally {
+      cleanup()
+      window.hermesDesktop = original
+    }
+  })
+
   it('defaults to Turkish without a config client', () => {
     render(
       <I18nProvider configClient={null}>
diff --git a/apps/desktop/src/i18n/context.tsx b/apps/desktop/src/i18n/context.tsx
index 87c6337..54e4c86 100644
--- a/apps/desktop/src/i18n/context.tsx
+++ b/apps/desktop/src/i18n/context.tsx
@@ -105,6 +105,10 @@ export function I18nProvider({ children, configClient = defaultConfigClient, ini
     localeRef.current = locale
     setRuntimeI18nLocale(locale)
     applyDocumentLocale(locale)
+
+    if (typeof window !== 'undefined') {
+      window.hermesDesktop?.setUiLanguage?.(locale)
+    }
   }, [locale])
 
   useEffect(() => {