feat: fin de phrase Silero, vision d'écran et actions locales (v2.3.0) (#13)

Écoute permanente
- Silero VAD dans le worker sherpa-onnx (vad.start/audio/stop) ; le renderer
  envoie des trames de 128 ms pendant la commande et reçoit le segment WAV
  complet (speech-start / segment). Repli sur le VAD énergétique si le modèle
  n'est pas installé ou si l'option est désactivée.
- Modèle « silero-vad » (0,6 Mo) dans le catalogue, section « Fin de phrase »
  dans Modèles locaux, réglage dans Paramètres → Micro.

Vision d'écran
- IPC system:screen-capture (desktopCapturer, JPEG 1600 px) ; bouton dans la
  barre de commande ; « regarde mon écran… » joint la capture à la question
  envoyée à Hermes (transport chat completions pour les images).

Actions locales
- IPC system:action à liste blanche : verrouiller la session, touches média
  (volume, mute, lecture, piste), ouvrir une application connue ou une URL
  http(s), presse-papiers, recherche de fichiers dans les dossiers utilisateur.
- Routeur d'intentions FR/EN exécuté avant Hermes (« coupe le son », « ouvre
  Spotify », « verrouille la session »…), résultat affiché et lu ; désactivable.

Correctif
- Chat completions : les premiers fragments SSE arrivés avant l'événement de
  démarrage étaient perdus (premier mot manquant) ; ils sont maintenant rejoués.

Tests : 26 tests unitaires (intentions locales ajoutées), e2e Electron sous
Xvfb avec les vrais modèles (Silero : un segment par phrase, 6,7 s d'audio
traités en 190 ms ; capture 109 ko reçue par Hermes ; intention locale
traitée sans Hermes).


Claude-Session: https://claude.ai/code/session_017Wn5VX9HNbJ7N54hR24u9Y

Co-authored-by: Claude <noreply@anthropic.com>

electron/ipc/system.ts

@@ -0,0 +1,184 @@
+/**
+ * Local "JARVIS" actions: screenshot for vision, and an allow-list of system actions
+ * (lock, open an application or URL, media keys, clipboard, file search).
+ */
+import { app, clipboard, desktopCapturer, ipcMain, screen, shell } from 'electron';
+import { execFile } from 'node:child_process';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { IPC } from '../../shared/ipc';
+import type { SystemAction, SystemActionResult } from '../../shared/bridge';
+import { log } from '../logger';
+
+const MEDIA_KEYS: Record<string, number> = {
+  'volume-up': 175,
+  'volume-down': 174,
+  mute: 173,
+  'play-pause': 179,
+  next: 176,
+  previous: 177
+};
+
+/** Applications the assistant may launch by name (Windows aliases + common Linux/macOS names). */
+const APP_ALIASES: Record<string, string[]> = {
+  'bloc-notes': ['notepad.exe', 'gedit', 'TextEdit'],
+  notepad: ['notepad.exe', 'gedit', 'TextEdit'],
+  calculatrice: ['calc.exe', 'gnome-calculator', 'Calculator'],
+  calc: ['calc.exe', 'gnome-calculator', 'Calculator'],
+  explorateur: ['explorer.exe', 'nautilus', 'Finder'],
+  explorer: ['explorer.exe', 'nautilus', 'Finder'],
+  terminal: ['wt.exe', 'cmd.exe', 'gnome-terminal', 'Terminal'],
+  cmd: ['cmd.exe'],
+  powershell: ['powershell.exe'],
+  paint: ['mspaint.exe'],
+  chrome: ['chrome', 'google-chrome', 'Google Chrome'],
+  edge: ['msedge', 'microsoft-edge', 'Microsoft Edge'],
+  firefox: ['firefox', 'Firefox'],
+  vscode: ['code', 'Visual Studio Code'],
+  code: ['code', 'Visual Studio Code'],
+  spotify: ['spotify', 'Spotify'],
+  discord: ['discord', 'Discord'],
+  steam: ['steam', 'Steam'],
+  word: ['winword', 'Microsoft Word'],
+  excel: ['excel', 'Microsoft Excel'],
+  outlook: ['outlook', 'Microsoft Outlook'],
+  teams: ['ms-teams', 'Microsoft Teams'],
+  'task manager': ['taskmgr.exe'],
+  'gestionnaire des tâches': ['taskmgr.exe'],
+  paramètres: ['ms-settings:'],
+  settings: ['ms-settings:']
+};
+
+function run(cmd: string, args: string[], timeoutMs = 8000): Promise<{ code: number; out: string }> {
+  return new Promise((resolve) => {
+    execFile(cmd, args, { timeout: timeoutMs, windowsHide: true }, (err, stdout, stderr) => {
+      resolve({ code: err ? 1 : 0, out: `${stdout}${stderr}`.trim() });
+    });
+  });
+}
+
+async function openApp(name: string): Promise<SystemActionResult> {
+  const key = name.trim().toLowerCase();
+  if (!key || key.length > 40) return { ok: false, message: 'Nom d’application invalide' };
+  const candidates = APP_ALIASES[key] ?? [key.replace(/[^a-z0-9 ._-]/gi, '')];
+  if (process.platform === 'win32') {
+    for (const candidate of candidates) {
+      if (candidate.endsWith(':')) {
+        await shell.openExternal(candidate);
+        return { ok: true, message: `${name} ouvert` };
+      }
+      // `start` resolves App Paths, PATH and Start Menu names.
+      const result = await run('cmd.exe', ['/c', 'start', '', candidate]);
+      if (result.code === 0) return { ok: true, message: `${name} lancé` };
+    }
+    return { ok: false, message: `Impossible de lancer ${name}` };
+  }
+  for (const candidate of candidates) {
+    const result = process.platform === 'darwin' ? await run('open', ['-a', candidate]) : await run('sh', ['-c', `command -v ${JSON.stringify(candidate)} >/dev/null && (nohup ${JSON.stringify(candidate)} >/dev/null 2>&1 &)`]);
+    if (result.code === 0) return { ok: true, message: `${name} lancé` };
+  }
+  return { ok: false, message: `Application introuvable : ${name}` };
+}
+
+async function lockSession(): Promise<SystemActionResult> {
+  if (process.platform === 'win32') {
+    const r = await run('rundll32.exe', ['user32.dll,LockWorkStation']);
+    return { ok: r.code === 0, message: r.code === 0 ? 'Session verrouillée' : r.out };
+  }
+  if (process.platform === 'darwin') {
+    const r = await run('osascript', ['-e', 'tell application "System Events" to keystroke "q" using {command down, control down}']);
+    return { ok: r.code === 0, message: r.out };
+  }
+  const r = await run('sh', ['-c', 'loginctl lock-session || xdg-screensaver lock || gnome-screensaver-command -l']);
+  return { ok: r.code === 0, message: r.code === 0 ? 'Session verrouillée' : r.out };
+}
+
+async function mediaKey(key: string): Promise<SystemActionResult> {
+  const code = MEDIA_KEYS[key];
+  if (!code) return { ok: false, message: 'Touche inconnue' };
+  if (process.platform === 'win32') {
+    const script = `$s=Add-Type -MemberDefinition '[DllImport("user32.dll")] public static extern void keybd_event(byte b,byte s,uint f,UIntPtr e);' -Name K -Namespace W -PassThru; $s::keybd_event(${code},0,0,[UIntPtr]::Zero); $s::keybd_event(${code},0,2,[UIntPtr]::Zero)`;
+    const r = await run('powershell.exe', ['-NoProfile', '-NonInteractive', '-Command', script]);
+    return { ok: r.code === 0, message: r.code === 0 ? key : r.out };
+  }
+  const xdo: Record<string, string> = { 'volume-up': 'XF86AudioRaiseVolume', 'volume-down': 'XF86AudioLowerVolume', mute: 'XF86AudioMute', 'play-pause': 'XF86AudioPlay', next: 'XF86AudioNext', previous: 'XF86AudioPrev' };
+  const r = await run('sh', ['-c', `xdotool key ${xdo[key]}`]);
+  return { ok: r.code === 0, message: r.code === 0 ? key : 'xdotool indisponible' };
+}
+
+async function findFiles(query: string): Promise<SystemActionResult> {
+  const needle = query.trim().toLowerCase();
+  if (needle.length < 2) return { ok: false, message: 'Recherche trop courte' };
+  const roots = ['Documents', 'Desktop', 'Downloads', 'Pictures'].map((d) => path.join(os.homedir(), d));
+  const hits: string[] = [];
+  const deadline = Date.now() + 4000;
+  const walk = async (dir: string, depth: number) => {
+    if (depth > 4 || hits.length >= 25 || Date.now() > deadline) return;
+    let entries: fs.Dirent[] = [];
+    try {
+      entries = await fs.promises.readdir(dir, { withFileTypes: true });
+    } catch {
+      return;
+    }
+    for (const entry of entries) {
+      if (entry.name.startsWith('.') || entry.name === 'node_modules') continue;
+      const full = path.join(dir, entry.name);
+      if (entry.name.toLowerCase().includes(needle)) hits.push(full);
+      if (entry.isDirectory()) await walk(full, depth + 1);
+      if (hits.length >= 25) return;
+    }
+  };
+  for (const root of roots) await walk(root, 0);
+  return { ok: true, message: `${hits.length} résultat(s)`, data: hits };
+}
+
+export async function captureScreen(maxWidth = 1600): Promise<string> {
+  const display = screen.getPrimaryDisplay();
+  const scale = Math.min(1, maxWidth / display.size.width);
+  const sources = await desktopCapturer.getSources({
+    types: ['screen'],
+    thumbnailSize: { width: Math.round(display.size.width * scale), height: Math.round(display.size.height * scale) }
+  });
+  const primary = sources.find((s) => s.display_id === String(display.id)) ?? sources[0];
+  if (!primary) throw new Error('Aucun écran capturable');
+  return primary.thumbnail.toJPEG(82).toString('base64').replace(/^/, 'data:image/jpeg;base64,');
+}
+
+export async function runSystemAction(action: SystemAction): Promise<SystemActionResult> {
+  switch (action.type) {
+    case 'lock':
+      return lockSession();
+    case 'open-app':
+      return openApp(String(action.name ?? ''));
+    case 'open-url': {
+      const url = String(action.url ?? '');
+      if (!/^https?:\/\//i.test(url) || url.length > 2048) return { ok: false, message: 'URL refusée' };
+      await shell.openExternal(url);
+      return { ok: true, message: 'Ouvert dans le navigateur' };
+    }
+    case 'media':
+      return mediaKey(String(action.key));
+    case 'clipboard-read':
+      return { ok: true, data: (await clipboard.readText()).slice(0, 20_000) };
+    case 'clipboard-write':
+      await clipboard.writeText(String(action.text ?? '').slice(0, 100_000));
+      return { ok: true, message: 'Copié dans le presse-papiers' };
+    case 'find-files':
+      return findFiles(String(action.query ?? ''));
+    default:
+      return { ok: false, message: 'Action inconnue' };
+  }
+}
+
+export function registerSystemIpc(): void {
+  ipcMain.handle(IPC.screenCapture, (_e, maxWidth?: number) => captureScreen(Number(maxWidth) || 1600));
+  ipcMain.handle(IPC.systemAction, async (_e, action: SystemAction) => {
+    if (!action || typeof action.type !== 'string') throw new Error('Action invalide');
+    log('INFO', 'system', `action ${action.type}`);
+    const result = await runSystemAction(action);
+    if (!result.ok) log('WARN', 'system', `action ${action.type} failed: ${result.message}`);
+    return result;
+  });
+  void app;
+}

electron/main.ts

@@ -9,6 +9,7 @@ import { getSharedDirectory, registerFilesIpc } from './ipc/files';
 import { createMainWindow, getMainWindow, getWindowMode, setWindowMode, toggleWindowVisibility, windowEvents } from './window';
 import { getWebhookStatus, startWebhookServer, stopWebhookServer } from './webhook';
 import { registerVoiceIpc } from './voice/ipc';
+import { registerSystemIpc } from './ipc/system';
 import { stopEngine } from './voice/engine';
 
 // Audio playback must never be blocked behind a user gesture (TTS starts on incoming events).
@@ -159,6 +160,7 @@ async function boot(): Promise<void> {
   registerFilesIpc();
   registerCoreIpc();
   registerVoiceIpc();
+  registerSystemIpc();
   createMainWindow();
   createTray();
   registerShortcuts();

electron/preload.ts

@@ -13,8 +13,8 @@ import {
   type WebhookStatus,
   type WindowMode
 } from '../shared/ipc';
-import type { EveFlowBridge, Unsubscribe } from '../shared/bridge';
-import { VOICE_IPC, type KwsDetection, type KwsStartRequest, type SynthesizeRequest, type SynthesizeResult, type TranscribeRequest, type TranscribeResult, type VoiceDownloadProgress, type VoiceEngineStatus, type VoiceModelStatus } from '../shared/voice';
+import type { EveFlowBridge, SystemAction, SystemActionResult, Unsubscribe } from '../shared/bridge';
+import { VOICE_IPC, type KwsDetection, type KwsStartRequest, type VadEvent, type VadStartRequest, type SynthesizeRequest, type SynthesizeResult, type TranscribeRequest, type TranscribeResult, type VoiceDownloadProgress, type VoiceEngineStatus, type VoiceModelStatus } from '../shared/voice';
 
 function subscribe<T>(channel: string, callback: (payload: T) => void): Unsubscribe {
   const listener = (_event: Electron.IpcRendererEvent, payload: T) => callback(payload);
@@ -43,7 +43,9 @@ const api: EveFlowBridge = {
   },
   system: {
     metrics: () => ipcRenderer.invoke(IPC.metrics) as Promise<SystemMetrics>,
-    appInfo: () => ipcRenderer.invoke(IPC.appInfo) as Promise<AppInfo>
+    appInfo: () => ipcRenderer.invoke(IPC.appInfo) as Promise<AppInfo>,
+    captureScreen: (maxWidth?: number) => ipcRenderer.invoke(IPC.screenCapture, maxWidth) as Promise<string>,
+    action: (action: SystemAction) => ipcRenderer.invoke(IPC.systemAction, action) as Promise<SystemActionResult>
   },
   files: {
     readLocal: (filePath: string) => ipcRenderer.invoke(IPC.readLocalFile, filePath) as Promise<string>,
@@ -73,7 +75,11 @@ const api: EveFlowBridge = {
     kwsStart: (req: KwsStartRequest) => ipcRenderer.invoke(VOICE_IPC.kwsStart, req) as Promise<{ accepted: string[]; rejected: string[] }>,
     kwsStop: () => ipcRenderer.invoke(VOICE_IPC.kwsStop) as Promise<void>,
     kwsAudio: (pcm: Uint8Array, sampleRate: number) => ipcRenderer.send(VOICE_IPC.kwsAudio, pcm, sampleRate),
-    onKwsDetected: (cb: (detection: KwsDetection) => void) => subscribe<KwsDetection>(VOICE_IPC.kwsDetected, cb)
+    onKwsDetected: (cb: (detection: KwsDetection) => void) => subscribe<KwsDetection>(VOICE_IPC.kwsDetected, cb),
+    vadStart: (req: VadStartRequest) => ipcRenderer.invoke(VOICE_IPC.vadStart, req) as Promise<void>,
+    vadStop: () => ipcRenderer.invoke(VOICE_IPC.vadStop) as Promise<void>,
+    vadAudio: (pcm: Uint8Array, sampleRate: number) => ipcRenderer.send(VOICE_IPC.vadAudio, pcm, sampleRate),
+    onVadEvent: (cb: (event: VadEvent) => void) => subscribe<VadEvent>(VOICE_IPC.vadEvent, cb)
   }
 };
 

electron/voice/catalog.ts

@@ -86,6 +86,19 @@ export const VOICE_CATALOG: VoiceModelSpec[] = [
     ],
     recommended: true
   },
+  {
+    id: 'silero-vad',
+    kind: 'vad',
+    engine: 'silero',
+    name: 'Silero VAD (fin de phrase neuronale, 0,6 Mo)',
+    description: 'Détecte précisément le début et la fin de la parole pendant l’écoute permanente ; moins de faux départs sur le bruit.',
+    languages: ['multi'],
+    sizeMb: 1,
+    url: `${ASR}/silero_vad.onnx`,
+    dir: 'silero-vad',
+    files: ['silero_vad.onnx'],
+    recommended: true
+  },
   {
     id: 'kokoro-v1',
     kind: 'tts',

electron/voice/engine.ts

@@ -6,7 +6,7 @@ import { utilityProcess, type UtilityProcess, type WebContents } from 'electron'
 import { createHash } from 'node:crypto';
 import fs from 'node:fs';
 import path from 'node:path';
-import { VOICE_IPC, type KwsDetection, type KwsStartRequest, type SynthesizeRequest, type SynthesizeResult, type TranscribeRequest, type TranscribeResult, type VoiceEngineStatus } from '../../shared/voice';
+import { VOICE_IPC, type KwsDetection, type KwsStartRequest, type SynthesizeRequest, type SynthesizeResult, type TranscribeRequest, type TranscribeResult, type VadEvent, type VadStartRequest, type VoiceEngineStatus } from '../../shared/voice';
 import { buildKeywordsFile, parseTokens } from '../../shared/keywords';
 import { findModel } from './catalog';
 import { isInstalled, modelDir, modelsDir } from './models';
@@ -16,6 +16,8 @@ import { log } from '../logger';
 let kwsSubscriber: WebContents | null = null;
 let kwsActive = false;
 let kwsRequest: KwsStartRequest | null = null;
+let vadSubscriber: WebContents | null = null;
+let vadActive = false;
 
 interface Pending {
   resolve: (value: unknown) => void;
@@ -42,7 +44,20 @@ function spawn(): UtilityProcess {
   child = proc;
   proc.stdout?.on('data', (d: Buffer) => log('DEBUG', 'voice-worker', d.toString().trim()));
   proc.stderr?.on('data', (d: Buffer) => log('WARN', 'voice-worker', d.toString().trim()));
-  proc.on('message', (msg: { id?: number; type?: string; ok?: boolean; result?: unknown; error?: string; keyword?: string; at?: number }) => {
+  proc.on('message', (msg: { id?: number; type?: string; ok?: boolean; result?: unknown; error?: string; keyword?: string; at?: number; event?: { type: string; wav?: string; durationSec?: number } }) => {
+    if (msg.type === 'vad.event' && msg.event) {
+      if (vadSubscriber && !vadSubscriber.isDestroyed()) {
+        const ev = msg.event;
+        const payload: VadEvent =
+          ev.type === 'segment' && ev.wav
+            ? { type: 'segment', wav: new Uint8Array(Buffer.from(ev.wav, 'base64')), durationSec: ev.durationSec ?? 0 }
+            : ev.type === 'speech-start'
+              ? { type: 'speech-start' }
+              : { type: 'error', message: 'événement VAD inconnu' };
+        vadSubscriber.send(VOICE_IPC.vadEvent, payload);
+      }
+      return;
+    }
     if (msg.type === 'kws.detected') {
       if (kwsSubscriber && !kwsSubscriber.isDestroyed()) {
         kwsSubscriber.send(VOICE_IPC.kwsDetected, { keyword: msg.keyword ?? '', at: msg.at ?? Date.now() } satisfies KwsDetection);
@@ -180,6 +195,35 @@ export function kwsFeed(pcm: Uint8Array, sampleRate: number): void {
   }
 }
 
+/** Neural end-of-speech detection (Silero) on frames streamed by the renderer. */
+export async function vadStart(req: VadStartRequest, sender: WebContents): Promise<void> {
+  const spec = findModel(req.modelId);
+  if (!spec || spec.kind !== 'vad') throw new Error('Modèle VAD introuvable');
+  if (!isInstalled(spec)) throw new Error('Silero VAD non installé (Paramètres → Modèles locaux).');
+  vadSubscriber = sender;
+  await request(
+    { type: 'vad.start', model: { id: spec.id, engine: spec.engine, dir: modelDir(spec), files: spec.files }, silenceMs: req.silenceMs, threshold: req.threshold, maxUtteranceSec: req.maxUtteranceSec },
+    30_000
+  );
+  vadActive = true;
+}
+
+export async function vadStop(): Promise<void> {
+  vadActive = false;
+  vadSubscriber = null;
+  if (child) await request({ type: 'vad.stop' }, 10_000).catch(() => undefined);
+}
+
+export function vadFeed(pcm: Uint8Array, sampleRate: number): void {
+  if (!vadActive || !child) return;
+  const b64 = Buffer.from(pcm.buffer, pcm.byteOffset, pcm.byteLength).toString('base64');
+  try {
+    child.postMessage({ id: -1, type: 'vad.audio', pcm: b64, sampleRate });
+  } catch (err) {
+    log('WARN', 'voice', `vad feed failed: ${(err as Error).message}`);
+  }
+}
+
 /** Native model memory is only released deterministically by restarting the worker. */
 export function unload(_modelId?: string): Promise<unknown> {
   stopEngine();

electron/voice/ipc.ts

@@ -1,6 +1,6 @@
 import { ipcMain } from 'electron';
-import { VOICE_IPC, type KwsStartRequest, type SynthesizeRequest, type TranscribeRequest } from '../../shared/voice';
-import { engineStatus, kwsFeed, kwsStart, kwsStop, synthesize, transcribe, unload } from './engine';
+import { VOICE_IPC, type KwsStartRequest, type SynthesizeRequest, type TranscribeRequest, type VadStartRequest } from '../../shared/voice';
+import { engineStatus, kwsFeed, kwsStart, kwsStop, synthesize, transcribe, unload, vadFeed, vadStart, vadStop } from './engine';
 import { cancelDownload, downloadModel, listModels, removeModel } from './models';
 
 export function registerVoiceIpc(): void {
@@ -32,6 +32,15 @@ export function registerVoiceIpc(): void {
     return kwsStart({ ...req, keywords: req.keywords.filter((k) => typeof k === 'string'), sensitivity: Number(req.sensitivity) || 3 }, event.sender);
   });
   ipcMain.handle(VOICE_IPC.kwsStop, () => kwsStop());
+  ipcMain.handle(VOICE_IPC.vadStart, (event, req: VadStartRequest) => {
+    if (!req || typeof req.modelId !== 'string') throw new Error('Requête invalide');
+    return vadStart({ modelId: req.modelId, silenceMs: Number(req.silenceMs) || 700, threshold: Number(req.threshold) || 0.5, maxUtteranceSec: Number(req.maxUtteranceSec) || 30 }, event.sender);
+  });
+  ipcMain.handle(VOICE_IPC.vadStop, () => vadStop());
+  ipcMain.on(VOICE_IPC.vadAudio, (_e, pcm: unknown, sampleRate: unknown) => {
+    if (!(pcm instanceof Uint8Array) || pcm.byteLength === 0 || pcm.byteLength > 1024 * 1024) return;
+    vadFeed(pcm, typeof sampleRate === 'number' && sampleRate > 0 ? sampleRate : 16000);
+  });
   ipcMain.on(VOICE_IPC.kwsAudio, (_e, pcm: unknown, sampleRate: unknown) => {
     if (!(pcm instanceof Uint8Array) || pcm.byteLength === 0 || pcm.byteLength > 1024 * 1024) return;
     kwsFeed(pcm, typeof sampleRate === 'number' && sampleRate > 0 ? sampleRate : 16000);

electron/voice/worker.ts

@@ -21,7 +21,10 @@ type Request =
   | { id: number; type: 'unload'; modelId?: string }
   | { id: number; type: 'kws.start'; model: ModelRef; keywordsFile: string; threshold: number; score: number }
   | { id: number; type: 'kws.audio'; pcm: string; sampleRate: number }
-  | { id: number; type: 'kws.stop' };
+  | { id: number; type: 'kws.stop' }
+  | { id: number; type: 'vad.start'; model: ModelRef; silenceMs: number; threshold: number; maxUtteranceSec: number }
+  | { id: number; type: 'vad.audio'; pcm: string; sampleRate: number }
+  | { id: number; type: 'vad.stop' };
 
 type Response = { id: number; ok: true; result: unknown } | { id: number; ok: false; error: string };
 
@@ -32,6 +35,16 @@ type Sherpa = {
     decode: (s: unknown) => void;
     getResult: (s: unknown) => { text: string; lang?: string };
   };
+  Vad: new (config: unknown, bufferSizeInSeconds: number) => {
+    acceptWaveform: (samples: Float32Array) => void;
+    isEmpty: () => boolean;
+    isDetected: () => boolean;
+    pop: () => void;
+    clear: () => void;
+    front: (enableExternalBuffer?: boolean) => { start: number; samples: Float32Array };
+    reset: () => void;
+    flush: () => void;
+  };
   KeywordSpotter: new (config: unknown) => {
     createStream: () => KwsStream;
     isReady: (s: KwsStream) => boolean;
@@ -50,6 +63,7 @@ type Sherpa = {
 type KwsStream = { acceptWaveform: (w: { sampleRate: number; samples: Float32Array }) => void };
 let sherpa: Sherpa | null = null;
 let kws: { spotter: InstanceType<Sherpa['KeywordSpotter']>; stream: KwsStream } | null = null;
+let vad: { detector: InstanceType<Sherpa['Vad']>; speaking: boolean; windowSize: number; carry: Float32Array } | null = null;
 let notify: ((message: unknown) => void) | null = null;
 let loadError: string | null = null;
 
@@ -275,9 +289,74 @@ function feedKws(pcmBase64: string, sampleRate: number): void {
   }
 }
 
+function startVad(model: ModelRef, silenceMs: number, threshold: number, maxUtteranceSec: number): void {
+  const s = loadSherpa();
+  const windowSize = 512;
+  const detector = new s.Vad(
+    {
+      sileroVad: {
+        model: path.join(model.dir, 'silero_vad.onnx'),
+        threshold: Math.max(0.1, Math.min(0.95, threshold)),
+        minSilenceDuration: Math.max(0.15, silenceMs / 1000),
+        minSpeechDuration: 0.2,
+        windowSize,
+        maxSpeechDuration: Math.max(3, maxUtteranceSec)
+      },
+      sampleRate: 16000,
+      numThreads: 1,
+      provider: 'cpu',
+      debug: 0
+    },
+    Math.max(10, maxUtteranceSec + 5)
+  );
+  vad = { detector, speaking: false, windowSize, carry: new Float32Array(0) };
+}
+
+function feedVad(pcmBase64: string, sampleRate: number): void {
+  if (!vad) return;
+  const bytes = Buffer.from(pcmBase64, 'base64');
+  const int16 = new Int16Array(bytes.buffer, bytes.byteOffset, Math.floor(bytes.byteLength / 2));
+  let samples: Float32Array = new Float32Array(int16.length);
+  for (let i = 0; i < int16.length; i++) samples[i] = int16[i] / 32768;
+  if (sampleRate !== 16000) samples = resampleTo16k(samples, sampleRate);
+  // Silero expects fixed windows: keep the remainder for the next frame.
+  const merged = new Float32Array(vad.carry.length + samples.length);
+  merged.set(vad.carry, 0);
+  merged.set(samples, vad.carry.length);
+  const usable = merged.length - (merged.length % vad.windowSize);
+  for (let i = 0; i < usable; i += vad.windowSize) {
+    vad.detector.acceptWaveform(merged.subarray(i, i + vad.windowSize));
+    const detected = vad.detector.isDetected();
+    if (detected && !vad.speaking) {
+      vad.speaking = true;
+      notify?.({ type: 'vad.event', event: { type: 'speech-start' } });
+    }
+    while (!vad.detector.isEmpty()) {
+      const segment = vad.detector.front(false);
+      vad.detector.pop();
+      vad.speaking = false;
+      const wav = encodeWav(segment.samples, 16000);
+      notify?.({
+        type: 'vad.event',
+        event: { type: 'segment', wav: Buffer.from(wav.buffer, wav.byteOffset, wav.byteLength).toString('base64'), durationSec: segment.samples.length / 16000 }
+      });
+    }
+  }
+  vad.carry = merged.slice(usable);
+}
+
 // ── request handling ───────────────────────────────────────────────────────
 function handle(req: Request): unknown {
   switch (req.type) {
+    case 'vad.start':
+      startVad(req.model, req.silenceMs, req.threshold, req.maxUtteranceSec);
+      return { ok: true };
+    case 'vad.audio':
+      feedVad(req.pcm, req.sampleRate);
+      return { ok: true };
+    case 'vad.stop':
+      vad = null;
+      return { ok: true };
     case 'kws.start':
       startKws(req.model, req.keywordsFile, req.threshold, req.score);
       return { ok: true };
@@ -331,6 +410,7 @@ function handle(req: Request): unknown {
         recognizers.clear();
         synthesizers.clear();
         kws = null;
+        vad = null;
       }
       return { ok: true };
     }