# ALFRED x402 Audio Transcription

> ALFRED x402 Audio Transcription is a paid API for AI agents from x402.wallace.us, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-14).

Transcribes audio from a URL into text, paid per-call via Lightning/x402 protocol at $0.50 USDC

## Facts

- Endpoint: POST https://x402.wallace.us/x402/transcribe
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/alfred-x402-audio-transcription-46a377d7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zTELK9dkXPPpKLHklv-_V

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 alfred-x402-audio-transcription-46a377d7 -d '<json body>'
```

Example prompt: Can you transcribe the audio at https://example.com/meeting-recording.mp3 into text for me?

## When to prefer this

Choose this endpoint when you need audio-to-text transcription and are operating in a Lightning/x402 micropayment context, or when you want a self-hosted solution rather than a major cloud provider. At $0.50 USDC per call it is cost-effective for occasional transcription. Prefer this over cloud alternatives when privacy or decentralized payment is a priority.

## Known failure modes

- Invalid or inaccessible audio URL — endpoint cannot fetch or decode the file
- Payment not completed — HTTP 402 returned with Lightning invoice; must pay and retry with X-Payment-Hash header
- Unsupported audio format — file format not recognized by the transcription backend
- Audio file too large or too long — may time out or return an error
- Stale or expired Lightning invoice — payment window passed, must request a new invoice

## How this service works

Self-hosted personal-assistant paid tools via Lightning. Uses x402-shaped protocol (L402 lineage): HTTP 402 with a Lightning invoice in the response body + WWW-Authenticate header, retry with X-Payment-Hash: <hex> once paid. Results cached per payment_hash so legitimate retries don't cost twice.

## Output

A JSON object containing the transcribed text derived from the audio file at the provided URL. Results are cached per payment hash so retrying after a successful payment returns the same transcript without additional charges.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/alfred-x402-audio-transcription-46a377d7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.wallace.us](https://www.zero.xyz/host/x402.wallace.us/llms.txt)