# Agent402 Audio Transcription

> Agent402 Audio Transcription is a paid API for AI agents from agent402.tools, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-12).

Transcribes an uploaded audio file to text using GPT-based speech recognition, returning the transcript, model used, and audio duration.

## Facts

- Endpoint: POST https://agent402.tools/v1/pro/audio/transcriptions?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-audio-transcription-b3362234
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_44NK6X44qOK9qsf2psFHi

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-audio-transcription-b3362234 -d '<json body>'
```

Example prompt: Can you transcribe this audio file for me? It's an English interview recording — I need the full text transcript back.

## When to prefer this

Choose this endpoint when you need pay-per-call audio transcription with no API key or signup required, especially in agentic workflows using x402 or MPP micropayment protocols. Ideal for one-off or low-volume transcription tasks where setting up a full OpenAI account is unnecessary. Prefer this over raw OpenAI API when you want metered, per-call billing in USDC without managing API credentials.

## Known failure modes

- Unsupported audio format — endpoint may reject non-standard file types
- Audio too long or too large — may timeout or return an error for very large files
- Invalid or missing file part in multipart request — returns error
- Unrecognized language hint — may fall back to auto-detection or return an error
- Insufficient payment (x402) — call rejected if USDC balance is insufficient

## How this service works

OpenAI's transcription wire on the ten-minute tier: POST multipart/form-data with a `file` part. Same model as /v1/audio/transcriptions with a longer cap, for a recording a four-minute route refuses.

## Output

Returns a JSON object containing: 'text' (the full transcript of the audio), 'model' (the transcription model used, e.g. 'gpt-transcribe'), and 'duration' (the length of the audio in seconds as a float).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "file": {
   "type": "string",
   "description": "The audio file, as a multipart part named `file`"
  },
  "diarize": {
   "type": "string",
   "description": "\"true\" for speaker labels and word timestamps (the scribe-v2 model)"
  },
  "language": {
   "type": "string",
   "description": "Optional ISO-639-1 hint"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "text": "Example transcript.",
  "model": "gpt-transcribe",
  "duration": 420.5
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-audio-transcription-b3362234/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)