# agent402.tools Audio Transcription Pro

> agent402.tools Audio Transcription Pro is a paid API for AI agents from agent402.tools, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-13).

Transcribes audio files to text using OpenAI gpt-4o-transcribe at high accuracy, paid per-call via x402 with no API key required

## Facts

- Endpoint: POST https://agent402.tools/api/transcribe-pro
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 1
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-audio-transcription-pro-7f7dd200
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Rna-JlQ1eByBHUPkKVW5A

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-pro-7f7dd200 -d '<json body>'
```

Example prompt: Can you transcribe this audio file for me? It's an English-language interview recording at https://example.com/interview.mp3 — I need the full text transcript.

## When to prefer this

Choose this endpoint when you need high-accuracy speech-to-text transcription powered by OpenAI gpt-4o-transcribe without managing your own API keys, and your audio is accessible via a public URL within 10 minutes / 25 MB. It is ideal for agents that handle sporadic transcription tasks and want to pay per call rather than maintain a subscription.

## Known failure modes

- Audio file URL is unreachable or returns a non-200 response
- File exceeds 25 MB size limit
- Audio exceeds 10 minutes in length
- Unsupported audio format (not mp3, wav, m4a, ogg, flac, or webm)
- Invalid or unparseable language code provided
- Payment via x402 fails or insufficient USDC balance
- Audio file contains no discernible speech

## How this service works

Transcribe audio to text using OpenAI (gpt-transcribe). Higher accuracy than the standard tier. Provide a URL to an audio file and get back the transcript. No API key needed; pay per call via x402. Max 10 minutes of audio, 25 MB file size.

## Output

Returns the full text transcript of the audio file, generated by OpenAI gpt-4o-transcribe. Supports audio up to 10 minutes and 25 MB in size.

## 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-transcribe",
  "duration": 3.5,
  "language": "en",
  "provider": "openai"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-audio-transcription-pro-7f7dd200/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)