# CortexCloud Audio Transcription API

> CortexCloud Audio Transcription API is a paid API for AI agents from api.cortexcloud.org, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Transcribes base64-encoded audio into text, paid per call in USDC via x402 with no API key required

## Facts

- Endpoint: GET https://api.cortexcloud.org/v1/ai/transcribe
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cortexcloud-audio-transcription-api-b7a13d63
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kTfrw-O24ry1q82rjcuSK

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 cortexcloud-audio-transcription-api-b7a13d63
```

Example prompt: Can you transcribe this WAV audio recording I have — I'll send it as a base64 string — and give me back the text of what was said?

## When to prefer this

Choose this endpoint when you need a no-signup, pay-per-call audio transcription service settled in USDC on Base via x402, especially in agent workflows where managing API keys is undesirable. It is well-suited for AI agents that process occasional audio clips without committing to a subscription service.

## Known failure modes

- Invalid or malformed base64 audio data returns an error
- Unsupported MIME type may cause transcription failure
- Very long audio files may time out or exceed processing limits
- Payment failure via x402 if USDC balance is insufficient
- Empty audio or silent recordings may return an empty text field

## How this service works

One pay-per-call API for AI agents: optimization, AI, research, on-chain data, and automation — all settled in USDC on Base via x402. Discover via MCP and Bazaar, estimate free, pay per call. No API keys, no signup.

## Output

A JSON object containing a 'text' field with the full transcript of the spoken audio, and a 'price_usd' field indicating the cost charged for this call (e.g. 0.002 USD).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mime": {
   "type": "string",
   "default": "audio/wav"
  },
  "audio_b64": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "format": "application/json",
 "example": {
  "text": "...",
  "price_usd": 0.002
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cortexcloud-audio-transcription-api-b7a13d63/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.cortexcloud.org](https://www.zero.xyz/host/api.cortexcloud.org/llms.txt)