# agent402.tools Audio Transcription

> agent402.tools Audio Transcription is a paid API for AI agents from agent402.tools, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-16, last successful call 2026-07-23).

Transcribes an audio file (given by URL) to text using OpenAI gpt-4o-mini-transcribe, with per-call payment via x402

## Facts

- Endpoint: POST https://agent402.tools/api/transcribe
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Last successful call: 2026-07-23
- Success rate: 95% of calls made through Zero
- Activations on Zero: 269
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-audio-transcription-5bf2bf36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_W5VuTrHmnctX0gQMOAdZO

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agent402-tools-audio-transcription-5bf2bf36 -d '<json body>'
```

Example prompt: Can you transcribe this audio file for me? It's an English podcast clip at https://example.com/clip.mp3 — just give me the full text of what's said.

## When to prefer this

Choose this endpoint when you need quick, pay-per-call audio transcription with no API key setup, for audio files accessible via a public URL, up to 5 minutes long and 25 MB in size. Ideal for agents that handle occasional or one-off transcription tasks without committing to a subscription or managing OpenAI credentials directly.

## Known failure modes

- Audio file URL is unreachable or returns a non-200 response — transcription fails
- File format not supported (only mp3, wav, m4a, ogg, flac, webm accepted)
- File exceeds 25 MB size limit — request rejected
- Audio duration exceeds 5 minutes — request rejected
- Invalid or unsupported ISO-639-1 language code provided — may fall back to auto-detect or error
- Payment via x402 not completed or insufficient — request blocked

## How this service works

Transcribe audio to text using OpenAI (gpt-4o-mini-transcribe). Provide a URL to an audio file (mp3, wav, m4a, etc.) and get back the transcript. No API key needed; pay per call via x402. Max 5 minutes of audio, 25 MB file size.

## Output

A plain-text transcript of the spoken content in the provided audio file, extracted using OpenAI's gpt-4o-mini-transcribe model. Covers up to 5 minutes of audio and files up to 25 MB.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "URL of the audio file to transcribe (mp3, wav, m4a, ogg, flac, webm)"
  },
  "language": {
   "type": "string",
   "description": "Optional ISO-639-1 language code (e.g. 'en', 'es', 'fr') for better accuracy"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "text": "Hello, this is a sample transcription.",
  "model": "gpt-4o-mini-transcribe",
  "duration": 3.5,
  "language": "en",
  "provider": "openai"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-audio-transcription-5bf2bf36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)