Step Asr

Transcribe audio files to text via Step ASR streaming API (HTTP SSE). Supports Chinese and English, multiple audio formats (PCM, WAV, MP3, OGG/OPUS), real-time streaming output, and terminology correction prompts.

Step ASR - Streaming Speech-to-Text

Transcribe audio files using the Step (StepFun) ASR API with HTTP SSE streaming.

Quick start

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.wav

Usage examples

Basic transcription (Chinese, streaming output):

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.wav

Specify language and save to file:

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.mp3 --language en --out /tmp/transcript.txt

Use a prompt for terminology correction:

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.pcm --prompt "Related terms: OpenClaw, StepFun, ASR"

Output as JSON (includes usage stats):

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.ogg --json

Non-streaming mode (only print final result):

bash

python3 {baseDir}/scripts/transcribe.py /path/to/audio.wav --no-stream

Specify audio format explicitly (for raw PCM files without extension):

bash

python3 {baseDir}/scripts/transcribe.py /path/to/raw_audio --format-type pcm --sample-rate 16000

Supported audio formats

Format	Extensions	Notes
PCM	.pcm, .raw	Raw PCM, default codec pcm_s16le
WAV	.wav	WAV container format
MP3	.mp3
OGG/OPUS	.ogg, .opus

All options

Flag	Default	Description
--language	zh	Language code (zh or en)
--model	step-asr	ASR model name
--out	(stdout)	Save transcription to file
--prompt	(none)	Hint text to improve accuracy for domain-specific terms
--format-type	(auto)	Audio format: pcm, mp3, ogg (auto-detected from extension)
--sample-rate	16000	Audio sample rate in Hz
--no-stream	false	Only print the final complete result
--json	false	Output as JSON with usage statistics
--no-itn	false	Disable inverse text normalization
--no-rerun	false	Disable second-pass error correction

API key

Set STEPFUN_API_KEY environment variable, or configure it in ~/.openclaw/openclaw.json:

json5

{
  skills: {
    "step-asr": {
      apiKey: "YOUR_STEPFUN_API_KEY"
    }
  }
}

Get your API key from Step Platform.