Text-to-speech (HD)

Convert text to speech using OpenAI TTS-1-HD (higher fidelity). Returns base64-encoded audio. Same interface as /api/tts but with better audio quality. No API key needed; pay per call via x402. Text capped at 2000 chars.

Input

Field	Type	Description
text *	string	Text to convert to speech (max 2000 chars)
voice	string	Voice: alloy, ash, ballad, coral, echo, fable, nova, onyx, sage, shimmer (default: alloy)
format	string	Audio format: mp3, opus, aac, flac, wav, pcm (default: mp3)

Example output

{
  "model": "tts-1-hd",
  "provider": "openai",
  "voice": "alloy",
  "format": "mp3",
  "audio": "<base64-encoded audio>",
  "chars": 20
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/tts-hd \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello from Agent402!","voice":"alloy","format":"mp3"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/tts-hd", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "text": "Hello from Agent402!",
    "voice": "alloy",
    "format": "mp3"
  }),
});

Wallet-only. This tool reaches the network/browser/storage, so it is paid in USDC via x402 (no proof-of-work tier).

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