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DevX Voice Text-to-Speech
x402
DevX Voice Text-to-Speech is a paid API for AI agents from voice.madebydevx.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-28).
Converts text (up to 2,000 characters) into a WAV audio clip using MeloTTS, supporting English, Spanish, French, Chinese, Japanese, and Korean, billed per 1,000 characters on Base via x402.
Price / call$0.001
Success—
StatusUnknown
How this service works
Text to speech for agents: send text (up to 2,000 chars) in English, Spanish, French, Chinese, Japanese or Korean and get a WAV voice clip (base64 in JSON, or raw audio/wav with response_format=wav). $0.001 USDC per started 1,000 characters on Base; failures are not charged. Accepts dTelecom-style text/lang_code fields. MeloTTS. By DevX.
Output
A JSON object containing a base64-encoded WAV audio clip (or raw audio/wav if response_format=wav), along with metadata including MIME type, model name (melotts), language, character count, sample rate (44100 Hz), duration in seconds, billed units, an operation ID, and payment confirmation details including transaction hash and USDC amount charged on Base.
Example use cases
Multilingual voice response for chatbot
“I need you to synthesize this customer support message in Spanish as a WAV audio clip: 'Su pedido ha sido enviado y llegará en 3 a 5 días hábiles. Gracias por su compra.'”
Japanese narration for language learning app
“Generate spoken audio in Japanese for this phrase: '今日の天気はとても良いです。散歩に行きましょう。' — I need the raw WAV audio back.”
English podcast intro voice clip
“Turn this intro text into a spoken WAV clip in English: 'Welcome to the Daily Briefing. Here are today's top stories curated just for you.' Use the default voice.”
Technical details
Endpoint
POSThttps://voice.madebydevx.com/v1/tts?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need lightweight, pay-per-use multilingual TTS (English, Spanish, French, Chinese, Japanese, Korean) billed in USDC on Base via x402 with no subscription required. It is ideal for AI agents needing spoken audio responses in real time, especially when idempotency (via requestKey) matters to avoid double-billing. Prefer it over subscription TTS APIs for low-volume or sporadic agent usage, and when MeloTTS voice quality is acceptable for the use case.
Side effects
- Text exceeds 2,000 characters — request rejected before charge
- Unsupported language code provided — validation error
- Empty or missing text field — 400 error
- Network or upstream MeloTTS failure — error returned, no charge
- Invalid requestKey format — idempotency key rejected
- Payment failure on Base network — audio not returned
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| lang | string | Language (default en). Aliases: language, lang_code (dTelecom/Kokoro letters a, b, e, f, j, z) |
| text | string | Text to speak (max 2,000 characters) |
| speed | number | |
| voice | string | |
| language | string | |
| lang_code | string | |
| requestKey | string | Optional idempotency key: the same payer + requestKey + input within 7 days returns the stored result without a second charge. |
| response_format | string | json (default): base64 WAV inside JSON; wav: raw audio/wav body |
Output
Schema · Response
{
"type": "json",
"example": {
"result": {
"mime": "audio/wav",
"model": "melotts",
"voice": "melotts-default",
"language": "en",
"characters": 22,
"sample_rate": 44100,
"audio_base64": "UklGRl7xAABXQVZFZm10IBAAAAABAAEARKwAAIhYAQACABAAZGF0YQ...",
"billed_units": 1,
"duration_seconds": 1.6
},
"status": "paid",
"payment": {
"status": "paid",
"network": "eip155:8453",
"tx_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
"amount_raw": "1000"
},
"operation_id": "0d7c1f8a-5e2b-4a9c-8f3d-1b6e2c9a7d40"
}
}Tags
x402
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