StepAudio 2.5 ASR Stream

StepFun · Transcription

WEBSOCKET /v1/realtime

Live transcription over a socket, returning partial results as the speaker talks, with voice activity detection marking each sentence.

At a glance

Pricing

Example request

import asyncio, json, os, websockets
URL = "wss://api.empiriolabs.ai/v1/realtime?model=stepaudio-2-5-asr-stream"
async def main():
    async with websockets.connect(
        URL,
        additional_headers=[("Authorization", f"Bearer {os.environ['EMPIRIOLABS_API_KEY']}")],
        max_size=None,
    ) as ws:
        print(json.loads(await ws.recv())["type"])  # session.created
        await ws.send(json.dumps({
            "type": "conversation.item.create",
            "item": {"type": "message", "role": "user",
                     "content": [{"type": "input_text", "text": "Say hello."}]},
        }))
        await ws.send(json.dumps({"type": "response.create"}))
        async for raw in ws:
            event = json.loads(raw)
            if event["type"] == "response.done":
                break
asyncio.run(main())

Parameters

Notes

Live transcription over a WebSocket at wss://api.empiriolabs.ai/v1/realtime?model=stepaudio-2-5-asr-stream, authenticated with the ordinary Authorization Bearer header. Stream 16 kHz pcm16 audio up with input_audio_buffer.append and read partial results back as the speaker is still talking, with server-side voice activity detection marking where each sentence ends. Use this for live captions and voice input; for a finished recording, POST /v1/audio/transcriptions returns the whole transcript in one call. Billing follows the duration of audio you stream, settled when the session closes.

Machine-readable schema: GET https://api.empiriolabs.ai/v1/models/stepaudio-2-5-asr-stream.