General

The Pulse STT WebSocket accepts a new query parameter, vad_events. When set to true, the server emits two additional JSON message types: speech_started and speech_ended. They are interleaved with the transcription stream on the same connection.

Usage

Set vad_events=true on the WebSocket URL. Default is false. vad=true is accepted as an alias; when both are set, vad_events takes precedence and vad is ignored.

1
const url = new URL("wss://api.smallest.ai/waves/v1/stt/live?model=pulse");
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url.searchParams.append("vad_events", "true");

Event payloads

1
{ "type": "speech_started", "session_id": "a1b2c3d4", "timestamp": 1.84 }
2
{ "type": "speech_ended",   "session_id": "a1b2c3d4", "timestamp": 4.52 }

timestamp is measured in seconds from the first audio frame received on the connection. Boundaries are acoustic and independent of transcript finalization (is_final).

Full reference: VAD Events.