Audio Streams
Stream real-time audio from active calls over WebSocket for transcription, sentiment analysis, and AI voice agents.
The Audio Streams API lets you fork the audio of a live call to a WebSocket server in near real time. You can start and stop streams dynamically during the call, retrieve the list of active streams, and optionally send audio back into the call using bidirectional streaming.
Real-time Audio
Fork inbound, outbound, or both tracks of a live call to your WebSocket in near real time.
Bidirectional Mode
Enable bidirectional=true to send audio from your server back into the call.
Flexible Codecs
Choose audio/x-l16 or audio/x-mulaw at 8 kHz or 16 kHz sample rates.
Status Callbacks
Receive stream lifecycle events (connected, stopped, timeout, failed) on your callback URL.
Important: Your WebSocket server must accept connections over wss://. Audio packets are delivered as JSON frames containing base64-encoded payloads. See the Stream XML element to start streams from XML instead of the API.
API Endpoint
Authentication Required:
- • X-Auth-ID: Your account ID (e.g., {Auth_ID})
- • X-Auth-Token: Your account Auth Token
- • Content-Type: application/json
Available Operations
The Stream object
Complete structure and attributes of an audio Stream object including status, timing, and configuration fields.
View Documentation →Start an audio stream
Start streaming audio from an active call to your WebSocket server with configurable tracks, codecs, and bidirectional mode.
View Documentation →Retrieve an audio stream
Get details of a specific audio stream on a call using its stream ID.
View Documentation →List all audio streams
Retrieve all audio streams attached to a given call.
View Documentation →Stop a specific audio stream
Stop a single active audio stream on a call by its stream ID.
View Documentation →Stop all audio streams
Stop every active audio stream currently running on a call in one request.
View Documentation →Note: Audio streams are billed per minute of audio forked. Stopping a stream immediately halts billing for that stream.