Stream Events Overview

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Stream
bidirectional="true"
keepCallAlive="true"
contentType="audio/x-l16;rate=8000">
wss://stream.vobiz.ai/stream
    </Stream>
</Response>

{
  sequenceNumber: 274,
  streamId: "7f169b6e-130d-46a3-b135-e1cc342c1ca2",
  event: "media",
  media: {
    track: "inbound",
    timestamp: "1778574098786",
    chunk: 274,
    payload: "/////////////////////////////////////////////////////////8="
  },
  extra_headers: "{}"
}
WAV recording saved: /home/user/bun/recordings/call-2026-05-12T08-21-33-347Z.wav

stop_event = {
    "event": "stop",
    "streamId": self.stream_id,
}
await websocket.send_text(json.dumps(stop_event))

const WebSocket = require('ws');

let streamId = null;

wss.on('connection', (ws) => {
  ws.on('message', (message) => {
    const data = JSON.parse(message);

    if (data.event === 'start') {
      streamId = data.start.streamId;
      console.log('Stream started:', streamId);

      // Play a greeting audio
      sendPlayAudio(ws, greetingAudioBase64);

      // Send checkpoint to track when greeting finishes
      sendCheckpoint(ws, streamId, 'greeting-complete');
    }

    if (data.event === 'playedStream') {
      console.log('Checkpoint reached:', data.name);
      // Greeting played successfully - continue with next action
    }

    if (data.event === 'media') {
      // Process incoming audio
      const audioData = Buffer.from(data.media.payload, 'base64');
      // ... analyze, transcribe, etc.
    }
  });

  ws.on('close', () => {
    // End-of-stream signal - flush recordings/transcripts here.
    console.log('Stream ended:', streamId);
  });
});

function sendPlayAudio(ws, audioBase64) {
  ws.send(JSON.stringify({
    event: 'playAudio',
    media: {
      contentType: 'audio/x-l16',
      sampleRate: 8000,
      payload: audioBase64
    }
  }));
}

function sendCheckpoint(ws, streamId, checkpointName) {
  ws.send(JSON.stringify({
    event: 'checkpoint',
    streamId: streamId,
    name: checkpointName
  }));
}

function sendClearAudio(ws, streamId) {
  ws.send(JSON.stringify({
    event: 'clearAudio',
    streamId: streamId
  }));
}

function sendStop(ws, streamId) {
  ws.send(JSON.stringify({
    event: 'stop',
    streamId: streamId
  }));
}