Add WebSocket broadcast to stt-server.py

Every connection receives the full event stream (vad_start, vad_end,
transcript, error) from the moment it connects — no subscription
handshake required. The asyncio WebSocket server runs in a daemon thread
alongside the VAD loop and transcription thread. Events still go to
stdout unchanged.

Port is configurable via STT_PORT env var (default: 11501).
Add websockets to both setup scripts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

setup-venv-local-build.sh

@@ -57,7 +57,7 @@ fi
 
 echo "==> upgrading pip + build tools"
 "${VENV}/bin/pip" install --upgrade pip wheel setuptools pybind11 --quiet
-"${VENV}/bin/pip" install torch silero-vad
+"${VENV}/bin/pip" install torch silero-vad websockets
 
 # --- clone (skipped if already done) ---
 if [ ! -d "${BUILD_DIR}/src/.git" ]; then

setup-venv.sh

@@ -25,7 +25,7 @@ fi
 
 echo "==> installing torch and faster-whisper"
 "${VENV}/bin/pip" install --upgrade pip --quiet
-"${VENV}/bin/pip" install torch faster-whisper silero-vad
+"${VENV}/bin/pip" install torch faster-whisper silero-vad websockets
 
 echo ""
 echo "==> done. Venv ready at ${VENV}"

stt-server.py

@@ -1,18 +1,25 @@
 #!/usr/bin/env -S bash -c 'exec "$(dirname "$0")/venv/bin/python3" "$0" "$@"'
 """
-STT process: records audio, runs Silero VAD, transcribes with faster-whisper.
+STT server: records audio, runs Silero VAD, transcribes with faster-whisper.
+Broadcasts JSON events to all connected WebSocket clients and to stdout.
 
-Events (JSON lines on stdout):
+Events:
   {"event": "ready"}
   {"event": "vad_start"}
-  {"event": "vad_end",     "duration": 1.23}
-  {"event": "transcript",  "text": "...", "words": [...], "duration": 1.23}
-  {"event": "error",       "message": "..."}
+  {"event": "vad_end",    "duration": 1.23}
+  {"event": "transcript", "text": "...", "words": [...], "duration": 1.23}
+  {"event": "error",      "message": "..."}
 
 word format: {"word": "hello", "start": 0.12, "end": 0.45, "probability": 0.99}
 
+Every WebSocket connection receives the full event stream from the moment it
+connects — no subscription handshake required.
+
 All log/status messages go to stderr. Stdout is machine-readable events only.
 
+Environment:
+  STT_PORT   WebSocket port (default: 11501)
+
 Usage:
   ./stt-server.py
   ./stt-server.py --model large-v3 --device cuda --compute-type int8_float16
@@ -26,13 +33,16 @@ import threading
 import queue
 import subprocess
 import traceback
+import asyncio
+import websockets
 import numpy as np
 import torch
 
-SAMPLE_RATE     = 16000
-VAD_WINDOW      = 512           # samples per VAD chunk (32ms at 16kHz)
-PRE_ROLL_SAMPLES = 3200         # 0.2s of audio prepended to each segment
-HISTORY_SAMPLES  = 960000       # 60s ring buffer for pre-roll
+SAMPLE_RATE      = 16000
+VAD_WINDOW       = 512      # samples per VAD chunk (32ms at 16kHz)
+PRE_ROLL_SAMPLES = 3200     # 0.2s prepended to each segment for context
+HISTORY_SAMPLES  = 960000   # 60s ring buffer for pre-roll
+PORT             = int(__import__('os').environ.get('STT_PORT', 11501))
 
 
 def log(msg):
@@ -40,10 +50,49 @@ def log(msg):
 	sys.stderr.flush()
 
 
-def emit(event):
-	sys.stdout.write(json.dumps(event) + '\n')
-	sys.stdout.flush()
+# --- WebSocket broadcast ---
 
+_ws_loop    = None
+_ws_clients = set()   # set of asyncio.Queue, one per connection
+
+
+def emit(event):
+	line = json.dumps(event)
+	sys.stdout.write(line + '\n')
+	sys.stdout.flush()
+	if _ws_loop is not None:
+		for q in list(_ws_clients):
+			_ws_loop.call_soon_threadsafe(q.put_nowait, line)
+
+
+async def ws_handler(websocket):
+	q = asyncio.Queue()
+	_ws_clients.add(q)
+	log(f'client connected ({len(_ws_clients)} total)')
+	try:
+		while True:
+			msg = await q.get()
+			await websocket.send(msg)
+	except websockets.ConnectionClosed:
+		pass
+	finally:
+		_ws_clients.discard(q)
+		log(f'client disconnected ({len(_ws_clients)} remaining)')
+
+
+async def ws_main():
+	global _ws_loop
+	_ws_loop = asyncio.get_running_loop()
+	async with websockets.serve(ws_handler, '', PORT):
+		log(f'WebSocket listening on port {PORT}')
+		await asyncio.Future()   # run forever
+
+
+def start_ws_server():
+	asyncio.run(ws_main())
+
+
+# --- Mic ---
 
 def find_mic():
 	candidates = [
@@ -63,6 +112,8 @@ def s16le_to_f32(data):
 	return np.frombuffer(data, dtype=np.int16).astype(np.float32) / 32768.0
 
 
+# --- Args + model loading ---
+
 parser = argparse.ArgumentParser()
 parser.add_argument('--model',        default='base.en')
 parser.add_argument('--device',       default='cuda')
@@ -82,25 +133,25 @@ except Exception as e:
 log('loading silero VAD...')
 from silero_vad import load_silero_vad, VADIterator
 vad_model = load_silero_vad()
-vad        = VADIterator(vad_model, sampling_rate=SAMPLE_RATE,
-                         threshold=0.5, min_silence_duration_ms=500)
+vad       = VADIterator(vad_model, sampling_rate=SAMPLE_RATE,
+                        threshold=0.5, min_silence_duration_ms=500)
 log('VAD ready')
 
 
-# Ring buffer for pre-roll context
+# --- Pre-roll ring buffer ---
+
 history     = np.zeros(HISTORY_SAMPLES, dtype=np.float32)
 history_pos = 0
 
 def push_history(samples):
 	global history_pos
-	n    = len(samples)
-	base = history_pos % HISTORY_SAMPLES
-	# May wrap around — handle both cases
+	n     = len(samples)
+	base  = history_pos % HISTORY_SAMPLES
 	space = HISTORY_SAMPLES - base
 	if n <= space:
 		history[base:base + n] = samples
 	else:
-		history[base:]    = samples[:space]
+		history[base:]      = samples[:space]
 		history[:n - space] = samples[space:]
 	history_pos += n
 
@@ -113,7 +164,8 @@ def get_preroll():
 	return out
 
 
-# Transcription runs in a separate thread so VAD is never blocked by GPU
+# --- Transcription thread ---
+
 transcription_queue = queue.Queue()
 
 def transcription_worker():
@@ -152,9 +204,11 @@ def transcription_worker():
 
 
 threading.Thread(target=transcription_worker, daemon=True).start()
+threading.Thread(target=start_ws_server, daemon=True).start()
 
 
-# Main recording + VAD loop
+# --- Main recording + VAD loop ---
+
 cmd, cmd_args = find_mic()
 log(f'mic: {cmd} {" ".join(cmd_args)}')
 mic = subprocess.Popen([cmd] + cmd_args, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)