Introduction
# OpenRouter Audio Transcription
Transcribe audio files using OpenRouter's chat completions API with `input_audio` content type. Works with any audio-capable model.
## Quick start
```bash {baseDir}/scripts/transcribe.sh /path/to/audio.m4a ```
Output goes to stdout.
## Useful flags
```bash # Custom model (default: google/gemini-2.5-flash) {baseDir}/scripts/transcribe.sh audio.ogg --model openai/gpt-4o-audio-preview
# Custom instructions {baseDir}/scripts/transcribe.sh audio.m4a --prompt "Transcribe with speaker labels"
# Save to file {baseDir}/scripts/transcribe.sh audio.m4a --out /tmp/transcript.txt
# Custom caller identifier (for OpenRouter dashboard) {baseDir}/scripts/transcribe.sh audio.m4a --title "MyApp" ```
## How it works
1. Converts audio to WAV (mono, 16kHz) using ffmpeg 2. Base64 encodes the audio 3. Sends to OpenRouter chat completions with `input_audio` content 4. Extracts transcript from response
## API key
Set `OPENROUTER_API_KEY` env var, or configure in `~/.clawdbot/clawdbot.json`:
```json5 { skills: { "openrouter-transcribe": { apiKey: "YOUR_OPENROUTER_KEY" } } } ```
## Headers
The script sends identification headers to OpenRouter: - `X-Title`: Caller name (default: "Peanut/Clawdbot") - `HTTP-Referer`: Reference URL (default: "https://clawdbot.com")
These show up in your OpenRouter dashboard for tracking.
## Troubleshooting
**ffmpeg format errors**: The script uses a temp directory (not `mktemp -t file.wav`) because macOS's mktemp adds random suffixes after the extension, breaking format detection.
**Argument list too long**: Large audio files produce huge base64 strings that exceed shell argument limits. The script writes to temp files (`--rawfile` for jq, `@file` for curl) instead of passing data as arguments.
**Empty response**: If you get "Empty response from API", the script will dump the raw response for debugging. Common causes: - Invalid API key - Model doesn't support audio input - Audio file too large or corrupted