# x402 Shop — Text-to-Speech (TTS) via Kokoro-82M · USDC on Base

> x402 Shop — Text-to-Speech (TTS) via Kokoro-82M · USDC on Base is a paid API for AI agents from x402.stan01.xyz, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Synthesizes natural-sounding MP3 audio from input text using the Kokoro-82M model, billed per job in USDC on Base via x402.

## Facts

- Endpoint: POST https://x402.stan01.xyz/v1/terminal/tts
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-shop-text-to-speech-tts-via-kokoro-82m-usdc-on-base-4bf59a05
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jc-2HbHzTGnjSxbZzzVb8

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 x402-shop-text-to-speech-tts-via-kokoro-82m-usdc-on-base-4bf59a05 -d '<json body>'
```

Example prompt: Can you synthesize this script into spoken audio using the af_heart voice at normal speed: 'Welcome to our weekly briefing. Here's what happened this week in AI.'

## When to prefer this

Choose this endpoint when you need pay-per-use, per-job TTS synthesis using the Kokoro-82M model and want to pay in USDC on Base with no subscription — ideal for AI agents that need occasional or bursty audio generation without committing to a recurring API plan. Prefer it over general TTS APIs when the x402 micropayment flow fits your agent architecture.

## Known failure modes

- Missing required text or text_url field — returns validation error
- chars estimate missing when text_url is provided — required for pricing/quoting
- Speed value out of range (below 0.5 or above 2) — rejected with validation error
- Invalid or unreachable text_url — job may fail or timeout
- Payment challenge not met — 402 returned until USDC payment on Base is completed
- Unknown or unsupported voice name — may fall back to default or return error

## How this service works

Pay-per-use ASR and TTS for AI agents. ASR: send a podcast feed (RSS) or any audio URL, get back a clean timestamped transcript, optionally plus an AI synthesis (thesis, keypoints, verbatim quotes, takeaways). Modes: synthesis or transcript. TTS: text in -> synthesized mp3 out (Kokoro-82M). Exact USDC price quoted in the 402 challenge; pay per job on Base.

## Output

Returns a JSON object with a job_id (UUID) and a status field (e.g. 'running'), indicating the TTS job has been queued. The agent would poll or retrieve the completed MP3 once the job finishes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "Inline text to synthesize"
  },
  "chars": {
   "type": "integer",
   "minimum": 1,
   "description": "Estimated char count for text_url (required for URL input)"
  },
  "speed": {
   "type": "number",
   "default": 1,
   "maximum": 2,
   "minimum": 0.5
  },
  "voice": {
   "type": "string",
   "description": "Kokoro voice, e.g. af_heart (default)"
  },
  "text_url": {
   "type": "string",
   "format": "uri",
   "description": "https URL to a text file (requires \"chars\" estimate)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "job_id": "00000000-0000-0000-0000-000000000000",
  "status": "running"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-shop-text-to-speech-tts-via-kokoro-82m-usdc-on-base-4bf59a05/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.stan01.xyz](https://www.zero.xyz/host/x402.stan01.xyz/llms.txt)