# AgentData Speech-to-Text Transcription

> AgentData Speech-to-Text Transcription is a paid API for AI agents from agentdata-api.sander-van-aard.workers.dev, paid per call via x402, $0.3/call, status unknown (last checked 2026-10-30).

Transcribes audio files (MP3, WAV, M4A, OGG, FLAC, WebM) into text with timed segments, detected language, and optional WebVTT subtitles, paid per-call in USDC on Base.

## Facts

- Endpoint: POST https://agentdata-api.sander-van-aard.workers.dev/media/transcribe?utm_source=zero.xyz
- Price: $0.3/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentdata-speech-to-text-transcription-f9a59c19
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qq_b4I9wqFA86JatDiWiT

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 agentdata-speech-to-text-transcription-f9a59c19 -d '<json body>'
```

Example prompt: Transcribe this audio file for me — here's the URL: https://example.com/meeting.mp3 — I need the full transcript with timed segments and the detected language.

## When to prefer this

Choose this endpoint when you need a single synchronous call to transcribe a short audio file (up to 5 MB / ~5 minutes) without managing API keys or accounts. It is ideal for agent workflows that need timed segments and language detection together, and where you only want to pay per successful transcription. Avoid it for files larger than 5 MB, audio longer than ~5 minutes, or when you need batch/streaming transcription.

## Known failure modes

- No speech detected in audio — returns 400, no charge
- Audio file exceeds 5 MB size limit — rejected
- Unsupported audio format submitted — rejected
- Audio URL unreachable or returns error — request fails
- Audio duration exceeds ~5 minutes — may be rejected
- Invalid base64 encoding — request fails
- Insufficient USDC balance for payment — transaction fails

## How this service works

Speech to text for AI agents, $0.30 per file: MP3, WAV, M4A, OGG, FLAC or WebM audio (max 5 MB, about 5 minutes) to a transcript with timed segments, detected language and optional WebVTT subtitles. One call: send a url or base64 — no upload step, no polling. No speech found means a 400 and you pay nothing. USDC on Base, no account, no API key.

## Output

Returns a transcript with the full spoken text, timed segments (each with start/end timestamps and the corresponding text), the automatically detected language code, and optionally WebVTT subtitle content. If no speech is detected, returns a 400 error and no charge is applied.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentdata-speech-to-text-transcription-f9a59c19/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentdata-api.sander-van-aard.workers.dev](https://www.zero.xyz/host/agentdata-api.sander-van-aard.workers.dev/llms.txt)