OpenAI-compatible text-to-speech over x402
OpenAI-compatible text-to-speech over x402 - point any OpenAI SDK's audio.speech.create() at base_url https://agent402.tools/v1 and pay $0.06 per call in USDC, no API key, no signup. Served by Voxtral Mini TTS behind a five-model failover chain (xAI Grok Voice, Kokoro, MAI-Voice-2 Flash, MAI-Voice-2), every link proven by a real paid canary - a provider outage never becomes your failure. Up to 2,000 chars in, raw mp3 (default) or pcm bytes out - the same wire shape as OpenAI's endpoint.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://agent402.tools/v1/audio/speech
| Category | Image and media |
|---|---|
| Provider host | agent402.tools |
| Networks | algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=, eip155:10, eip155:1329, eip155:137, eip155:143, eip155:42161, eip155:42220, eip155:43114, eip155:4663, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp, stellar:pubnet |
| Payment schemes | exact, upto |
| Self-reported calls, 30 days | 49 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.06 | 917 ms |
Example input (from the provider)
{
"body": {
"input": "Agent402 serves fourteen hundred tools, paid per call.",
"voice": "alloy"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"input": {
"description": "Text to speak (up to 2,000 chars)",
"type": "string"
},
"model": {
"description": "Optional - pin a chain model (e.g. mistralai/voxtral-mini-tts-2603); the rest stay as fallbacks",
"type": "string"
},
"response_format": {
"description": "\"mp3\" (default) or \"pcm\"",
"type": "string"
},
"speed": {
"description": "Optional 0.25\u20134 playback speed (providers that don't support it ignore it)",
"type": "number"
},
"voice": {
"description": "OpenAI voice name - alloy (default), ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse - or a native voice id from GET /v1/models (e.g. en_paul_cheerful)",
"type": "string"
},
"zdr": {
"description": "Optional - true routes only to zero-data-retention providers",
"type": "boolean"
}
},
"required": [
"input"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "string"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}