# OpenAI TTS-1 Text-to-Speech (x402)

> OpenAI TTS-1 Text-to-Speech (x402) is a paid API for AI agents from openai.mm.family, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Converts text to speech audio using OpenAI's TTS-1 model, billed per call in USDC via x402 micropayment protocol

## Facts

- Endpoint: POST https://openai.mm.family/x402/v1/models/tts-1/audio/speech?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openai-tts-1-text-to-speech-x402-cdca78c3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2Q_8kQ-WD5ZWjVhD4B_W6

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 openai-tts-1-text-to-speech-x402-cdca78c3 -d '<json body>'
```

Example prompt: Read this product description aloud using the nova voice and give me an MP3: 'Introducing our new smart home hub — seamless control for every device in your home.'

## When to prefer this

Choose this endpoint when you need standard-quality, cost-efficient AI speech synthesis billed per call via USDC micropayments (x402 protocol) without API key management. Prefer tts-1 over tts-1-hd when audio quality is acceptable at lower cost ($15/1M chars vs $30/1M chars). Best for agents needing pay-per-use audio generation without subscription overhead, or when integrating into crypto-native workflows on Base or Solana.

## Known failure modes

- Input text exceeds 4096 character limit — request will be rejected
- Invalid voice enum value — must be one of alloy, ash, coral, echo, fable, onyx, nova, sage, shimmer
- Invalid response_format — must be one of mp3, opus, aac, flac, wav, pcm
- Payment failure via x402 micropayment protocol — USDC payment not accepted or insufficient
- Model field not set to 'tts-1' — only this model is accepted at this endpoint
- Empty input string — no audio generated

## How this service works

tts-1: OpenAI TTS 1 text to speech, paid per call in USDC. OpenAI list $15 per 1M characters, plus $0.0005 (Base) or $0.0005 (Solana) per call; up to 4096 characters; voices: alloy, ash, coral, echo, fable, onyx, nova, sage, shimmer. Returns the audio bytes (mp3 by default). Rates: https://openai.mm.family/x402/pricing

## Output

Binary audio bytes (MP3 by default) containing synthesized speech of the input text. The response content-type is audio/mpeg for MP3, with other formats available (opus, aac, flac, wav, pcm) depending on the response_format parameter. Maximum input is 4096 characters per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string"
  },
  "model": {
   "enum": [
    "tts-1"
   ],
   "type": "string"
  },
  "speed": {
   "type": "number"
  },
  "voice": {
   "enum": [
    "alloy",
    "ash",
    "coral",
    "echo",
    "fable",
    "onyx",
    "nova",
    "sage",
    "shimmer"
   ],
   "type": "string"
  },
  "instructions": {
   "type": "string"
  },
  "response_format": {
   "enum": [
    "mp3",
    "opus",
    "aac",
    "flac",
    "wav",
    "pcm"
   ],
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "body": "binary audio bytes (mp3 by default)",
  "content_type": "audio/mpeg"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/openai-tts-1-text-to-speech-x402-cdca78c3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from openai.mm.family](https://www.zero.xyz/host/openai.mm.family/llms.txt)