captureAudio - Cognigy Documentation

Emitted when the SDK receives a remote audio track. The event is emitted once for each remote audio track. This event exposes the raw MediaStream for advanced audio processing such as visualization, recording, or custom routing. This event is opt-in. To enable it, set captureAudio: true in the client configuration.

The SDK plays remote audio automatically via an internal Audio element. You don’t need to handle the captureAudio event for basic playback — it’s only needed for advanced use cases.

Category

Audio

Callback Parameters

Parameter	Type	Description
`stream`	`MediaStream`	The remote audio stream.

Example

const client = await createWebRTCClient({
  endpointUrl: 'https://your-cognigy-environment.com/token',
  userId: 'user-123',
  captureAudio: true,
});

client.on('captureAudio', (stream) => {
  console.log('Audio stream available:', stream.getAudioTracks());
});

Advanced: Audio Processing with Web Audio API

client.on('captureAudio', (stream) => {
  const audioContext = new AudioContext();
  const source = audioContext.createMediaStreamSource(stream);

  const analyser = audioContext.createAnalyser();
  source.connect(analyser);
  // Don't connect to destination — the SDK already handles playback
});

More Information

Last modified on November 3, 2026