diff --git a/app/src-tauri/Cargo.lock b/app/src-tauri/Cargo.lock
index ee102721b5..9204d46616 100644
--- a/app/src-tauri/Cargo.lock
+++ b/app/src-tauri/Cargo.lock
@@ -3564,6 +3564,12 @@ dependencies = [
  "windows-link 0.2.1",
 ]
 
+[[package]]
+name = "hound"
+version = "3.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62adaabb884c94955b19907d60019f4e145d091c75345379e70d1ee696f7854f"
+
 [[package]]
 name = "html5ever"
 version = "0.29.1"
@@ -5608,9 +5614,11 @@ dependencies = [
  "hkdf",
  "hmac 0.12.1",
  "hostname",
+ "hound",
  "iana-time-zone",
  "image",
  "keyring",
+ "lettre",
  "libc",
  "log",
  "mail-parser",
diff --git a/app/src-tauri/Cargo.toml b/app/src-tauri/Cargo.toml
index 2af2f6a3e3..dbf447cd81 100644
--- a/app/src-tauri/Cargo.toml
+++ b/app/src-tauri/Cargo.toml
@@ -137,11 +137,25 @@ cef = { version = "=146.4.1", default-features = false }
 # gates existed) means the embedded core does NOT inherit the root crate's
 # default gate set, so each default-ON gate must be forwarded explicitly to
 # keep the shipped desktop build byte-identical (AGENTS.md "Compile-time
-# domain gates"). `media` re-registers the `media_generate_*` agent tools
-# that #4804 moved behind `#[cfg(feature = "media")]`; it sheds no deps, so
-# this only restores the pre-gate desktop tool surface.
+# domain gates").
+#
+# This list is NOT optional polish — a gate missing here vanishes from the
+# shipped app silently, with no build error and no test failure:
+#
+# - `voice` — without it the `#[cfg(feature = "voice")]` controllers in
+#   `src/core/all.rs` are never registered, so the whole `openhuman.voice_*`
+#   namespace answers "unknown method" at runtime. This shipped broken from
+#   v0.58.19 to v0.61.x (#4901); the `VOICE_COMPILED_IN` const assert at the
+#   top of `src/lib.rs` now fails the build if it is dropped again.
+# - `media` — re-registers the `media_generate_*` agent tools that #4804 moved
+#   behind `#[cfg(feature = "media")]`; it sheds no deps, so this only restores
+#   the pre-gate desktop tool surface.
+#
+# `tokenjuice-treesitter` is the remaining un-forwarded default — tracked in
+# #4918, deliberately not bundled here because dropping it may be intentional.
 openhuman_core = { path = "../..", package = "openhuman", default-features = false, features = [
     "media",
+    "voice",
 ] }
 tinyjuice = { version = "0.2.1", default-features = false }
 
diff --git a/app/src-tauri/src/lib.rs b/app/src-tauri/src/lib.rs
index 5ca2b6375b..ee15b7897e 100644
--- a/app/src-tauri/src/lib.rs
+++ b/app/src-tauri/src/lib.rs
@@ -3,6 +3,20 @@
 #[cfg(not(any(target_os = "windows", target_os = "macos", target_os = "linux")))]
 compile_error!("src-tauri host supports desktop (Windows/macOS/Linux) only. Mobile lives in app/src-tauri-mobile.");
 
+// The shipped desktop app must always embed the real voice domain. Cargo
+// features are per-crate, so `#[cfg(feature = "voice")]` here would test THIS
+// crate's features, not the core's — a voice-less core is only observable via
+// the core's own always-compiled facade. Without this assert the failure is
+// silent and runtime-only: every `openhuman.voice_*` RPC answers "unknown
+// method" and the UI blames a stale sidecar (#4901). Keep `voice` in the
+// `openhuman_core` feature list in Cargo.toml to satisfy this.
+const _: () = assert!(
+    openhuman_core::openhuman::voice::VOICE_COMPILED_IN,
+    "openhuman_core must be built with the `voice` feature: the desktop app ships voice, \
+     and without it every openhuman.voice_* controller is unregistered (#4901). \
+     Add \"voice\" to the openhuman_core `features` list in app/src-tauri/Cargo.toml."
+);
+
 mod app_update;
 // Artifact export commands (#2779, #3162) — both cross-platform
 // (macOS/Windows/Linux): native Save-As dialog (rfd) + Downloads copy.
diff --git a/app/src/components/flows/canvas/__tests__/EditableFlowCanvas.validation.test.tsx b/app/src/components/flows/canvas/__tests__/EditableFlowCanvas.validation.test.tsx
index 9a1a6450dc..bee206af37 100644
--- a/app/src/components/flows/canvas/__tests__/EditableFlowCanvas.validation.test.tsx
+++ b/app/src/components/flows/canvas/__tests__/EditableFlowCanvas.validation.test.tsx
@@ -100,7 +100,13 @@ describe('EditableFlowCanvas — validation + dirty state', () => {
     // The host header reads `hasErrors` off `onSaveMetaChange` to disable its
     // Save button; the canvas itself also refuses to fire `onSave` through
     // the imperative handle while hard errors exist, even though dirty.
-    expect(lastSaveMeta(onSaveMetaChange)).toMatchObject({ dirty: true, hasErrors: true });
+    // `hasErrors` reaches the host via a follow-up effect that can lag the
+    // error-banner render (see `onSaveMetaChange` in EditableFlowCanvas), so
+    // poll the reported meta rather than reading it once — under a loaded
+    // full-suite run the synchronous read can still see the pre-validation meta.
+    await waitFor(() =>
+      expect(lastSaveMeta(onSaveMetaChange)).toMatchObject({ dirty: true, hasErrors: true })
+    );
     act(() => ref.current?.save());
     expect(onSave).not.toHaveBeenCalled();
 
diff --git a/app/src/features/human/MicComposer.test.tsx b/app/src/features/human/MicComposer.test.tsx
index 42d418cf10..da5411b31d 100644
--- a/app/src/features/human/MicComposer.test.tsx
+++ b/app/src/features/human/MicComposer.test.tsx
@@ -7,12 +7,19 @@ import {
   MicComposer,
   STT_MAX_RETRIES,
 } from './MicComposer';
+import { VoiceNotCompiledError } from './voice/sttClient';
 
 // transcribeWithFactory + encodeBlobToWav are the network/heavy boundaries —
 // mock them here so we can drive the state machine without touching real APIs.
 const transcribeWithFactoryMock = vi.fn();
 const encodeBlobToWavMock = vi.fn();
-vi.mock('./voice/sttClient', () => ({
+// Spread the real module so `VoiceNotCompiledError` / `isVoiceNotCompiledError`
+// keep their real behaviour; only the network-touching call is stubbed. A
+// factory listing exports by hand silently yields `undefined` for anything it
+// forgets, which fails as a TypeError at the call site rather than a clear mock
+// error.
+vi.mock('./voice/sttClient', async importOriginal => ({
+  ...(await importOriginal<typeof import('./voice/sttClient')>()),
   transcribeWithFactory: (...args: unknown[]) => transcribeWithFactoryMock(...args),
 }));
 vi.mock('./voice/wavEncoder', () => ({
@@ -794,10 +801,11 @@ describe('MicComposer', () => {
     expect(onError).not.toHaveBeenCalled();
   });
 
-  it('does not retry permanent errors (stale sidecar)', async () => {
+  it('does not retry permanent errors (voice not compiled into the core)', async () => {
     transcribeWithFactoryMock.mockRejectedValueOnce(
       new Error(
-        'Voice transcription is unavailable in this build. Restart the OpenHuman desktop app to pick up the latest core sidecar.'
+        'Voice transcription is unavailable in this build — the voice module was not compiled into the app. ' +
+          'Update OpenHuman to the latest version; restarting will not help.'
       )
     );
     const onError = vi.fn();
@@ -816,6 +824,31 @@ describe('MicComposer', () => {
     expect(onSubmit).not.toHaveBeenCalled();
   });
 
+  // #4901: the raw error text is untranslated developer copy, so a
+  // VoiceNotCompiledError must surface the localized `mic.voiceNotCompiled`
+  // string instead of being spliced into the `{message}` slot.
+  it('renders translated copy for a voice-not-compiled error, not the raw message', async () => {
+    transcribeWithFactoryMock.mockRejectedValueOnce(new VoiceNotCompiledError());
+    const onError = vi.fn();
+    const onSubmit = vi.fn();
+    render(<MicComposer disabled={false} onSubmit={onSubmit} onError={onError} />);
+
+    fireEvent.click(screen.getByRole('button', { name: /start recording/i }));
+    await waitFor(() => expect(getUserMediaMock).toHaveBeenCalled());
+    await waitFor(() =>
+      expect(screen.getByRole('button', { name: /stop recording and send/i })).toBeInTheDocument()
+    );
+    fireEvent.click(screen.getByRole('button', { name: /stop recording and send/i }));
+
+    await waitFor(() => expect(onError).toHaveBeenCalled());
+    const shown = onError.mock.calls[0][0] as string;
+    // The English `mic.voiceNotCompiled` value, resolved through useT().
+    expect(shown).toMatch(/not included in this version/i);
+    // The untranslated developer copy must not leak into the UI.
+    expect(shown).not.toMatch(/not compiled into the app/i);
+    expect(onSubmit).not.toHaveBeenCalled();
+  });
+
   // ── Low-confidence transcript detection (#1206) ────────────────────────────
 
   it('rejects a single-character transcript as low confidence', async () => {
diff --git a/app/src/features/human/MicComposer.tsx b/app/src/features/human/MicComposer.tsx
index 992a83f014..b843cac268 100644
--- a/app/src/features/human/MicComposer.tsx
+++ b/app/src/features/human/MicComposer.tsx
@@ -3,7 +3,7 @@ import { useCallback, useEffect, useLayoutEffect, useRef, useState } from 'react
 import { createPortal } from 'react-dom';
 
 import { useT } from '../../lib/i18n/I18nContext';
-import { transcribeWithFactory } from './voice/sttClient';
+import { isVoiceNotCompiledError, transcribeWithFactory } from './voice/sttClient';
 import { encodeBlobToWav } from './voice/wavEncoder';
 
 /** Minimal descriptor for an audio input device. */
@@ -33,7 +33,7 @@ const STT_RETRY_BASE_MS = 500;
  * Matched case-insensitively against the error message.
  */
 const PERMANENT_ERROR_PATTERNS = [
-  'unknown method', // stale sidecar
+  'unknown method', // core built without the `voice` feature (#4901)
   'audio blob is empty',
   'unavailable in this build',
 ];
@@ -576,6 +576,13 @@ export function MicComposer({
       }
       const msg = err instanceof Error ? err.message : String(err);
       composerLog('transcribe failed: %s', msg);
+      // The core has no voice domain compiled in (#4901). `msg` is untranslated
+      // developer copy, so render the localized string rather than splicing it
+      // into the `{message}` slot.
+      if (isVoiceNotCompiledError(err)) {
+        onError?.(t('mic.voiceNotCompiled'));
+        return;
+      }
       onError?.(t('mic.transcriptionFailed').replace('{message}', msg));
     } finally {
       if (!disposedRef.current) setState('idle');
diff --git a/app/src/features/human/voice/sttClient.test.ts b/app/src/features/human/voice/sttClient.test.ts
index b4d93cc942..924bc98a8d 100644
--- a/app/src/features/human/voice/sttClient.test.ts
+++ b/app/src/features/human/voice/sttClient.test.ts
@@ -93,14 +93,31 @@ describe('transcribeCloud', () => {
     expect(await transcribeCloud(blob)).toBe('');
   });
 
-  // Issue #1289: stale sidecar binaries surface a generic
-  // "unknown method" error. Frontend rewrites it to an actionable
-  // message so users know to restart the desktop app.
-  it('rewrites "unknown method" errors to an actionable restart hint', async () => {
+  // #4901: a core built without the `voice` feature never registers the
+  // `openhuman.voice_*` controllers, so they answer "unknown method". That is a
+  // compile-time property of the binary, so the message must NOT tell users to
+  // restart (the pre-#4901 copy did, which could never work).
+  it('rewrites "unknown method" errors to a not-compiled-in message', async () => {
     const mock = callCoreRpc as ReturnType<typeof vi.fn>;
     mock.mockRejectedValueOnce(new Error('unknown method: openhuman.voice_cloud_transcribe'));
     const blob = new Blob([new Uint8Array([1])], { type: 'audio/webm' });
-    await expect(transcribeCloud(blob)).rejects.toThrow(/Restart the OpenHuman desktop app/i);
+    await expect(transcribeCloud(blob)).rejects.toThrow(/not compiled into the app/i);
+  });
+
+  it('does not advise restarting for a compile-time voice gate', async () => {
+    const mock = callCoreRpc as ReturnType<typeof vi.fn>;
+    mock.mockRejectedValueOnce(new Error('unknown method: openhuman.voice_cloud_transcribe'));
+    const blob = new Blob([new Uint8Array([1])], { type: 'audio/webm' });
+    await expect(transcribeCloud(blob)).rejects.not.toThrow(/restart the openhuman desktop app/i);
+  });
+
+  // `MicComposer`'s PERMANENT_ERROR_PATTERNS matches this substring to skip the
+  // retry/backoff loop — a compile-time gate can never succeed on retry.
+  it('keeps the "unavailable in this build" substring for retry suppression', async () => {
+    const mock = callCoreRpc as ReturnType<typeof vi.fn>;
+    mock.mockRejectedValueOnce(new Error('unknown method: openhuman.voice_cloud_transcribe'));
+    const blob = new Blob([new Uint8Array([1])], { type: 'audio/webm' });
+    await expect(transcribeCloud(blob)).rejects.toThrow(/unavailable in this build/i);
   });
 
   it('passes through non-unknown-method errors verbatim', async () => {
@@ -148,11 +165,21 @@ describe('transcribeWithFactory', () => {
     expect(mock).not.toHaveBeenCalled();
   });
 
-  it('rewrites stale-sidecar "unknown method" errors', async () => {
+  // #4901 — same compile-time gate as the cloud path above.
+  it('rewrites "unknown method" errors to a not-compiled-in message', async () => {
+    const mock = callCoreRpc as ReturnType<typeof vi.fn>;
+    mock.mockRejectedValueOnce(new Error('unknown method: openhuman.voice_stt_dispatch'));
+    const blob = new Blob([new Uint8Array([1])], { type: 'audio/webm' });
+    await expect(transcribeWithFactory(blob)).rejects.toThrow(/not compiled into the app/i);
+  });
+
+  it('does not advise restarting for a compile-time voice gate', async () => {
     const mock = callCoreRpc as ReturnType<typeof vi.fn>;
     mock.mockRejectedValueOnce(new Error('unknown method: openhuman.voice_stt_dispatch'));
     const blob = new Blob([new Uint8Array([1])], { type: 'audio/webm' });
-    await expect(transcribeWithFactory(blob)).rejects.toThrow(/Restart the OpenHuman desktop app/i);
+    await expect(transcribeWithFactory(blob)).rejects.not.toThrow(
+      /restart the openhuman desktop app/i
+    );
   });
 
   it('passes through non-unknown-method errors verbatim', async () => {
diff --git a/app/src/features/human/voice/sttClient.ts b/app/src/features/human/voice/sttClient.ts
index 1700b067d0..4432a69a10 100644
--- a/app/src/features/human/voice/sttClient.ts
+++ b/app/src/features/human/voice/sttClient.ts
@@ -4,6 +4,52 @@ import { callCoreRpc } from '../../../services/coreRpcClient';
 
 const sttLog = debug('human:stt');
 
+/**
+ * Stable identifier for "the core has no voice domain compiled in" (#4901).
+ *
+ * Callers must branch on this code rather than on the message text: the message
+ * is untranslated developer/log copy, and the UI is responsible for rendering
+ * translated copy via `useT()` (see `MicComposer`'s `mic.voiceNotCompiled`).
+ */
+export const VOICE_NOT_COMPILED_CODE = 'voice_not_compiled';
+
+/**
+ * Thrown when the core answers `unknown method` for a `voice_*` RPC — i.e. the
+ * core was compiled without the `voice` feature, so the domain is absent from
+ * the binary entirely (#4901).
+ *
+ * The `message` is English on purpose: it is what reaches debug logs and Sentry.
+ * User-facing copy is resolved from `code` at the UI boundary.
+ *
+ * Keep the `unavailable in this build` substring: `MicComposer`'s
+ * `PERMANENT_ERROR_PATTERNS` matches on it to skip the retry/backoff loop,
+ * which can never succeed for a compile-time gate.
+ */
+export class VoiceNotCompiledError extends Error {
+  readonly code = VOICE_NOT_COMPILED_CODE;
+
+  constructor() {
+    super(
+      'Voice transcription is unavailable in this build — the voice module was not compiled into the app. ' +
+        'Update OpenHuman to the latest version; restarting will not help.'
+    );
+    this.name = 'VoiceNotCompiledError';
+  }
+}
+
+/**
+ * Duck-typed on `code` rather than `instanceof`: the error crosses async +
+ * retry boundaries, and structured-clone/serialization paths can strip the
+ * prototype while preserving own properties.
+ */
+export function isVoiceNotCompiledError(err: unknown): err is VoiceNotCompiledError {
+  return (
+    typeof err === 'object' &&
+    err !== null &&
+    (err as { code?: unknown }).code === VOICE_NOT_COMPILED_CODE
+  );
+}
+
 export interface CloudTranscribeOptions {
   /** Override the backend STT model id. Default is whatever the backend
    *  resolves `whisper-v1` to today. */
@@ -64,17 +110,16 @@ export async function transcribeCloud(
       params,
     });
   } catch (err) {
-    // Issue #1289: an "unknown method" error means the bundled core
-    // sidecar is older than the frontend (e.g. a stale dev build, or a
-    // cached binary the desktop auto-update hasn't refreshed yet).
-    // The raw "unknown method: openhuman.voice_cloud_transcribe" string
-    // is opaque to end users — surface an actionable message instead.
+    // An "unknown method" error means the core serving this app was built
+    // without the `voice` Cargo feature, so the `openhuman.voice_*`
+    // controllers were never registered (#4901). This is a compile-time
+    // property of the binary — restarting cannot change it, which is why the
+    // old #1289-era "restart to pick up the latest core sidecar" copy was
+    // unactionable (and the sidecar itself is gone since #1061).
     const msg = err instanceof Error ? err.message : String(err);
     if (msg.includes('unknown method')) {
-      sttLog('transcribe rpc stale-sidecar path hit; rewriting unknown-method error: %s', msg);
-      throw new Error(
-        'Voice transcription is unavailable in this build. Restart the OpenHuman desktop app to pick up the latest core sidecar.'
-      );
+      sttLog('[voice-stt] transcribe rpc: voice domain absent from core build: %s', msg);
+      throw new VoiceNotCompiledError();
     }
     sttLog('transcribe rpc failed (passthrough): %O', err);
     throw err;
@@ -149,10 +194,8 @@ export async function transcribeWithFactory(
   } catch (err) {
     const msg = err instanceof Error ? err.message : String(err);
     if (msg.includes('unknown method')) {
-      sttLog('[voice-stt] dispatch stale-sidecar path: %s', msg);
-      throw new Error(
-        'Voice transcription is unavailable in this build. Restart the OpenHuman desktop app to pick up the latest core sidecar.'
-      );
+      sttLog('[voice-stt] dispatch: voice domain absent from core build: %s', msg);
+      throw new VoiceNotCompiledError();
     }
     sttLog('[voice-stt] dispatch failed (passthrough): %O', err);
     throw err;
diff --git a/app/src/lib/i18n/ar.ts b/app/src/lib/i18n/ar.ts
index a86721859b..9b9662d400 100644
--- a/app/src/lib/i18n/ar.ts
+++ b/app/src/lib/i18n/ar.ts
@@ -3163,6 +3163,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'تعذّر فهم الصوت بوضوح: يرجى المحاولة مرة أخرى',
   'mic.failedToStopRecording': 'فشل إيقاف التسجيل: {message}',
   'mic.transcriptionFailed': 'فشل النسخ: {message}',
+  'mic.voiceNotCompiled':
+    'خاصية تحويل الصوت إلى نص غير متوفرة في هذا الإصدار من التطبيق. حدّث OpenHuman لتفعيلها.',
   'reflections.kind.retrospective': 'مراجعة',
   'reflections.kind.derivedFact': 'حقيقة مستنتجة',
   'reflections.kind.moodInsight': 'رؤية المزاج',
diff --git a/app/src/lib/i18n/bn.ts b/app/src/lib/i18n/bn.ts
index 340eb931f6..1e34ff6cc7 100644
--- a/app/src/lib/i18n/bn.ts
+++ b/app/src/lib/i18n/bn.ts
@@ -3238,6 +3238,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'অডিও স্পষ্টভাবে বোঝা যায়নি: আবার চেষ্টা করুন',
   'mic.failedToStopRecording': 'রেকর্ডিং বন্ধ করতে ব্যর্থ: {message}',
   'mic.transcriptionFailed': 'ট্রান্সক্রিপশন ব্যর্থ: {message}',
+  'mic.voiceNotCompiled':
+    'অ্যাপের এই সংস্করণে ভয়েস ট্রান্সক্রিপশন অন্তর্ভুক্ত নেই। এটি চালু করতে OpenHuman আপডেট করুন।',
   'reflections.kind.retrospective': 'পূর্বদর্শন',
   'reflections.kind.derivedFact': 'ডেরাইভড ফ্যাক্ট',
   'reflections.kind.moodInsight': 'মুড ইনসাইট',
diff --git a/app/src/lib/i18n/de.ts b/app/src/lib/i18n/de.ts
index 77cc64948d..871f54a665 100644
--- a/app/src/lib/i18n/de.ts
+++ b/app/src/lib/i18n/de.ts
@@ -3328,6 +3328,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'Audio konnte nicht klar verstanden werden: bitte erneut versuchen',
   'mic.failedToStopRecording': 'Aufzeichnung konnte nicht gestoppt werden: {message}',
   'mic.transcriptionFailed': 'Transkription fehlgeschlagen: {message}',
+  'mic.voiceNotCompiled':
+    'Sprachtranskription ist in dieser App-Version nicht enthalten. Aktualisiere OpenHuman, um sie zu aktivieren.',
   'reflections.kind.retrospective': 'Retrospektive',
   'reflections.kind.derivedFact': 'Abgeleitete Tatsache',
   'reflections.kind.moodInsight': 'Stimmungseinsicht',
diff --git a/app/src/lib/i18n/en.ts b/app/src/lib/i18n/en.ts
index a1dfc6742f..0291d524c1 100644
--- a/app/src/lib/i18n/en.ts
+++ b/app/src/lib/i18n/en.ts
@@ -3629,6 +3629,8 @@ const en: TranslationMap = {
   'mic.lowConfidenceResult': 'Could not understand the audio clearly: please try again',
   'mic.failedToStopRecording': 'Failed to stop recording: {message}',
   'mic.transcriptionFailed': 'Transcription failed: {message}',
+  'mic.voiceNotCompiled':
+    'Voice transcription is not included in this version of the app. Update OpenHuman to enable it.',
 
   // Reflections: kind labels
   'reflections.kind.retrospective': 'Retrospective',
diff --git a/app/src/lib/i18n/es.ts b/app/src/lib/i18n/es.ts
index d8d676616a..b41d056590 100644
--- a/app/src/lib/i18n/es.ts
+++ b/app/src/lib/i18n/es.ts
@@ -3299,6 +3299,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'No se pudo entender el audio con claridad: intenta de nuevo',
   'mic.failedToStopRecording': 'No se pudo detener la grabación: {message}',
   'mic.transcriptionFailed': 'Transcripción fallida: {message}',
+  'mic.voiceNotCompiled':
+    'La transcripción de voz no está incluida en esta versión de la aplicación. Actualiza OpenHuman para activarla.',
   'reflections.kind.retrospective': 'Retrospectiva',
   'reflections.kind.derivedFact': 'Hecho derivado',
   'reflections.kind.moodInsight': 'Insight de ánimo',
diff --git a/app/src/lib/i18n/fr.ts b/app/src/lib/i18n/fr.ts
index c6a8907d4f..4d34ed6dfa 100644
--- a/app/src/lib/i18n/fr.ts
+++ b/app/src/lib/i18n/fr.ts
@@ -3323,6 +3323,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': "Impossible de comprendre l'audio clairement: réessaie",
   'mic.failedToStopRecording': "Échec de l'arrêt de l'enregistrement : {message}",
   'mic.transcriptionFailed': 'Échec de la transcription : {message}',
+  'mic.voiceNotCompiled':
+    "La transcription vocale n'est pas incluse dans cette version de l'application. Mettez à jour OpenHuman pour l'activer.",
   'reflections.kind.retrospective': 'Rétrospective',
   'reflections.kind.derivedFact': 'Fait dérivé',
   'reflections.kind.moodInsight': 'Insight émotionnel',
diff --git a/app/src/lib/i18n/hi.ts b/app/src/lib/i18n/hi.ts
index 32c565246a..ce2250f929 100644
--- a/app/src/lib/i18n/hi.ts
+++ b/app/src/lib/i18n/hi.ts
@@ -3236,6 +3236,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'ऑडियो स्पष्ट रूप से समझ नहीं आया: कृपया पुनः प्रयास करें',
   'mic.failedToStopRecording': 'रिकॉर्डिंग रोकने में दिक्कत: {message}',
   'mic.transcriptionFailed': 'ट्रांसक्रिप्शन विफल: {message}',
+  'mic.voiceNotCompiled':
+    'इस ऐप संस्करण में वॉइस ट्रांसक्रिप्शन शामिल नहीं है। इसे चालू करने के लिए OpenHuman को अपडेट करें।',
   'reflections.kind.retrospective': 'रेट्रोस्पेक्टिव',
   'reflections.kind.derivedFact': 'डिराइव्ड फैक्ट',
   'reflections.kind.moodInsight': 'मूड इनसाइट',
diff --git a/app/src/lib/i18n/id.ts b/app/src/lib/i18n/id.ts
index 71dcb44573..2c9eddecaf 100644
--- a/app/src/lib/i18n/id.ts
+++ b/app/src/lib/i18n/id.ts
@@ -3248,6 +3248,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'Tidak dapat memahami audio dengan jelas: silakan coba lagi',
   'mic.failedToStopRecording': 'Gagal menghentikan perekaman: {message}',
   'mic.transcriptionFailed': 'Transkripsi gagal: {message}',
+  'mic.voiceNotCompiled':
+    'Transkripsi suara tidak tersedia di versi aplikasi ini. Perbarui OpenHuman untuk mengaktifkannya.',
   'reflections.kind.retrospective': 'Retrospektif',
   'reflections.kind.derivedFact': 'Fakta Turunan',
   'reflections.kind.moodInsight': 'Wawasan Suasana Hati',
diff --git a/app/src/lib/i18n/it.ts b/app/src/lib/i18n/it.ts
index 92c48d9082..6ca7a6820e 100644
--- a/app/src/lib/i18n/it.ts
+++ b/app/src/lib/i18n/it.ts
@@ -3297,6 +3297,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': "Impossibile comprendere l'audio chiaramente: riprova",
   'mic.failedToStopRecording': 'Impossibile fermare la registrazione: {message}',
   'mic.transcriptionFailed': 'Trascrizione fallita: {message}',
+  'mic.voiceNotCompiled':
+    "La trascrizione vocale non è inclusa in questa versione dell'app. Aggiorna OpenHuman per attivarla.",
   'reflections.kind.retrospective': 'Retrospettiva',
   'reflections.kind.derivedFact': 'Fatto derivato',
   'reflections.kind.moodInsight': "Insight sull'umore",
diff --git a/app/src/lib/i18n/ko.ts b/app/src/lib/i18n/ko.ts
index 77a920ae01..0f484310e5 100644
--- a/app/src/lib/i18n/ko.ts
+++ b/app/src/lib/i18n/ko.ts
@@ -3201,6 +3201,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': '오디오를 명확하게 이해할 수 없습니다: 다시 시도해 주세요',
   'mic.failedToStopRecording': '녹음을 중지하지 못했습니다: {message}',
   'mic.transcriptionFailed': '전사에 실패했습니다: {message}',
+  'mic.voiceNotCompiled':
+    '이 버전의 앱에는 음성 받아쓰기가 포함되어 있지 않습니다. OpenHuman을 업데이트하면 사용할 수 있습니다.',
   'reflections.kind.retrospective': '회고',
   'reflections.kind.derivedFact': '파생된 사실',
   'reflections.kind.moodInsight': '기분 인사이트',
diff --git a/app/src/lib/i18n/pl.ts b/app/src/lib/i18n/pl.ts
index 26d6481937..71a6700c09 100644
--- a/app/src/lib/i18n/pl.ts
+++ b/app/src/lib/i18n/pl.ts
@@ -3274,6 +3274,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'Nie udało się wyraźnie zrozumieć dźwięku: spróbuj ponownie',
   'mic.failedToStopRecording': 'Nie udało się zatrzymać nagrywania: {message}',
   'mic.transcriptionFailed': 'Transkrypcja nie powiodła się: {message}',
+  'mic.voiceNotCompiled':
+    'Transkrypcja głosu nie jest dostępna w tej wersji aplikacji. Zaktualizuj OpenHuman, aby ją włączyć.',
   'reflections.kind.retrospective': 'Retrospektywa',
   'reflections.kind.derivedFact': 'Wywiedziony fakt',
   'reflections.kind.moodInsight': 'Wnioski o nastroju',
diff --git a/app/src/lib/i18n/pt.ts b/app/src/lib/i18n/pt.ts
index 8ed1b3f750..f88efaeb90 100644
--- a/app/src/lib/i18n/pt.ts
+++ b/app/src/lib/i18n/pt.ts
@@ -3291,6 +3291,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'Não foi possível entender o áudio com clareza: tente novamente',
   'mic.failedToStopRecording': 'Falha ao parar a gravação: {message}',
   'mic.transcriptionFailed': 'Falha na transcrição: {message}',
+  'mic.voiceNotCompiled':
+    'A transcrição de voz não está incluída nesta versão do aplicativo. Atualize o OpenHuman para ativá-la.',
   'reflections.kind.retrospective': 'Retrospectiva',
   'reflections.kind.derivedFact': 'Fato Derivado',
   'reflections.kind.moodInsight': 'Insight de Humor',
diff --git a/app/src/lib/i18n/ru.ts b/app/src/lib/i18n/ru.ts
index 897d272052..45ea259140 100644
--- a/app/src/lib/i18n/ru.ts
+++ b/app/src/lib/i18n/ru.ts
@@ -3264,6 +3264,8 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': 'Не удалось чётко распознать аудио: попробуйте ещё раз',
   'mic.failedToStopRecording': 'Не удалось остановить запись: {message}',
   'mic.transcriptionFailed': 'Ошибка транскрипции: {message}',
+  'mic.voiceNotCompiled':
+    'Расшифровка речи не включена в эту версию приложения. Обновите OpenHuman, чтобы включить её.',
   'reflections.kind.retrospective': 'Ретроспектива',
   'reflections.kind.derivedFact': 'Выведенный факт',
   'reflections.kind.moodInsight': 'Инсайт о настроении',
diff --git a/app/src/lib/i18n/zh-CN.ts b/app/src/lib/i18n/zh-CN.ts
index 23d8f0446c..517b1b8fc0 100644
--- a/app/src/lib/i18n/zh-CN.ts
+++ b/app/src/lib/i18n/zh-CN.ts
@@ -3065,6 +3065,7 @@ const messages: TranslationMap = {
   'mic.lowConfidenceResult': '无法清楚地理解音频：请重试',
   'mic.failedToStopRecording': '停止录音失败: {message}',
   'mic.transcriptionFailed': '转录失败: {message}',
+  'mic.voiceNotCompiled': '此版本的应用未包含语音转文字功能。请更新 OpenHuman 后再使用。',
   'reflections.kind.retrospective': '回顾',
   'reflections.kind.derivedFact': '派生事实',
   'reflections.kind.moodInsight': '情绪洞察',
diff --git a/src/openhuman/voice/compile_status.rs b/src/openhuman/voice/compile_status.rs
new file mode 100644
index 0000000000..c4973cd244
--- /dev/null
+++ b/src/openhuman/voice/compile_status.rs
@@ -0,0 +1,49 @@
+//! Compile-time visibility into the `voice` gate.
+//!
+//! Deliberately **ungated**: unlike the rest of the domain, this module is
+//! compiled in both feature states, because its whole purpose is to report
+//! which state the binary ended up in. It is part of the always-compiled facade
+//! described in [`super`], alongside `stub`.
+
+/// Whether the real voice domain was compiled into this binary.
+///
+/// Cargo features are per-crate and invisible to dependents' `#[cfg]`, so a
+/// consumer that *requires* voice (the desktop shell) has no other way to detect
+/// that it silently got the stubbed build — which is exactly how #4901 shipped:
+/// `app/src-tauri/Cargo.toml` set `default-features = false`, dropping the
+/// default-ON `voice` feature, so every `openhuman.voice_*` controller went
+/// unregistered and answered "unknown method" at runtime.
+///
+/// The shell asserts this at compile time (`const _: () = assert!(...)` in
+/// `app/src-tauri/src/lib.rs`), turning that silent runtime failure into a build
+/// failure.
+pub const VOICE_COMPILED_IN: bool = cfg!(feature = "voice");
+
+#[cfg(test)]
+mod tests {
+    use super::VOICE_COMPILED_IN;
+
+    /// Pins the constant to the gate rather than to a hardcoded value: the
+    /// assertion inverts with the feature, so it holds for both the default
+    /// build and the slim (`--no-default-features`) build.
+    #[test]
+    fn reports_the_compiled_gate_state() {
+        assert_eq!(VOICE_COMPILED_IN, cfg!(feature = "voice"));
+    }
+
+    /// The default build ships voice; this is the state the desktop app
+    /// requires (#4901). Skipped when the slim build is under test.
+    #[test]
+    #[cfg(feature = "voice")]
+    fn is_true_when_the_voice_feature_is_on() {
+        assert!(VOICE_COMPILED_IN);
+    }
+
+    /// The slim build must report honestly, otherwise the shell's const assert
+    /// would pass against a stubbed core and #4901 could ship again.
+    #[test]
+    #[cfg(not(feature = "voice"))]
+    fn is_false_when_the_voice_feature_is_off() {
+        assert!(!VOICE_COMPILED_IN);
+    }
+}
diff --git a/src/openhuman/voice/mod.rs b/src/openhuman/voice/mod.rs
index 993dca1479..50b3508d5d 100644
--- a/src/openhuman/voice/mod.rs
+++ b/src/openhuman/voice/mod.rs
@@ -23,6 +23,12 @@
 //! (`cargo check --no-default-features --features "<all-but-voice>"`): any
 //! signature drift fails that build.
 
+// Ungated — part of the always-compiled facade (see the module docs above): it
+// reports which side of the gate this binary landed on, so it must exist in
+// both states.
+pub mod compile_status;
+pub use compile_status::VOICE_COMPILED_IN;
+
 #[cfg(feature = "voice")]
 pub mod always_on;
 #[cfg(feature = "voice")]