Alibaba Cloud Model Studio:Client events for Qwen-ASR-Realtime

Event lifecycle

A typical session follows this sequence:

1. Establish a WebSocket connection.

2. Send session.update to configure audio format, language, and VAD settings.

3. Send input_audio_buffer.append repeatedly to stream audio data.

4. In Manual mode, send input_audio_buffer.commit to trigger recognition for a complete utterance. In VAD mode, the server triggers recognition automatically.

5. Send session.finish to end the session, then disconnect after receiving the session.finished response.

session.update

Configures the session. Send this immediately after establishing the WebSocket connection to set the audio format, the language, and VAD parameters. If omitted, defaults apply.

The server responds with a session.updated event on success.

{
    "event_id": "event_123",
    "type": "session.update",
    "session": {
        "input_audio_format": "pcm",
        "sample_rate": 16000,
        "input_audio_transcription": {
            "language": "zh"
        },
        "turn_detection": {
            "type": "server_vad",
            "threshold": 0.0,
            "silence_duration_ms": 400
        }
    }
}

input_audio_buffer.append

Streams an audio chunk to the server's input buffer -- the core event for sending audio data.

Behavior differs by interaction mode:

• VAD mode: The server monitors the buffer for voice activity and automatically triggers recognition.

• Manual mode: The client controls utterance boundaries. Send smaller chunks for lower latency.

{
    "event_id": "event_2728",
    "type": "input_audio_buffer.append",
    "audio": "<Base64-encoded-audio-data>"
}

input_audio_buffer.commit

Triggers recognition for all audio in the buffer as a single utterance. Use in Manual mode when your application controls utterance boundaries (e.g., push-to-talk).

Disabled in VAD mode.

The server responds with an input_audio_buffer.committed event on success.

{
    "event_id": "event_789",
    "type": "input_audio_buffer.commit"
}

session.finish

Ends the session. Server response depends on speech detection:

• Speech detected: The server completes final recognition, sends a conversation.item.input_audio_transcription.completed event with the result, then sends a session.finished event.

• No speech detected: The server sends session.finished directly.

After receiving session.finished, disconnect the WebSocket connection.

{
    "event_id": "event_341",
    "type": "session.finish"
}