StepAudio 2.5 ASR API

About StepAudio 2.5 ASR

StepFun streaming speech recognition model for Chinese and English audio transcription.

EmpirioLabs exposes the standard /v1/audio/transcriptions endpoint and returns the final transcript in the normal transcription response format.

Also known as StepAudio ASR, StepFun StepAudio 2.5 ASR, StepAudio-2.5-ASR, stepaudio-2-5-asr

StepAudio 2.5 ASR specs

Model ID

stepaudio-2-5-asr

Provider

StepFun

Category

Transcription

Released

Apr 24, 2026

Input

Audio

Output

Text

Region

International

Endpoints

POST/v1/audio/transcriptions

Alternate model IDs

stepaudio-2.5-asrstepfun/stepaudio-2-5-asrstepfun/stepaudio-2.5-asr

StepAudio 2.5 ASR API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

How to call the StepAudio 2.5 ASR API

StepAudio 2.5 ASR runs through POST /v1/audio/transcriptions. The request returns a job_id right away; poll GET /v1/jobs/{job_id} until the job completes and read the output URLs from the result. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/audio/transcriptions \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "stepaudio-2-5-asr",
    "audio_url": "https://example.com/meeting-recording.mp3"
  }'

curl https://api.empiriolabs.ai/v1/jobs/JOB_ID \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY"

import requests

response = requests.post(
    "https://api.empiriolabs.ai/v1/audio/transcriptions",
    headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    json={
        "model": "stepaudio-2-5-asr",
        "audio_url": "https://example.com/meeting-recording.mp3",
    },
)
job = response.json()

# Generation runs as an async job. Poll until it completes.
import time
while True:
    status = requests.get(
        f"https://api.empiriolabs.ai/v1/jobs/{job['job_id']}",
        headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    ).json()
    if status.get("status") in ("completed", "failed"):
        print(status)
        break
    time.sleep(5)

StepAudio 2.5 ASR API parameters

Request parameters supported by the StepAudio 2.5 ASR API on EmpirioLabs. Defaults apply when a field is omitted.

Good to know

Supports wav, mp3, ogg, and pcm input. PCM requests should include codec, sample rate, bit depth, and channel count. Recognition language supports Chinese and English. Timestamp output is available through enable_timestamp.

StepAudio 2.5 ASR API: common questions

How much does the StepAudio 2.5 ASR API cost?

On EmpirioLabs, StepAudio 2.5 ASR is billed pay as you go: Transcription $0.022 per hour of audio. The live rate card on this page always matches what the API charges.

Which endpoint does StepAudio 2.5 ASR use?

StepAudio 2.5 ASR is served through POST /v1/audio/transcriptions on api.empiriolabs.ai with standard bearer-token authentication.

Can I try StepAudio 2.5 ASR in the browser before integrating?

Yes. The EmpirioLabs playground runs StepAudio 2.5 ASR in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a StepAudio 2.5 ASR API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.