Convert text to speech audio -- 20+ languages, base64 MP3 output. Google TTS engine, fast and reliable. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

json

{
  "mcpServers": {
    "text-to-speech": {
      "url": "https://text-to-speech.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

bash

curl -X POST "https://text-to-speech.api.klymax402.com/api/speak" \
  -H "Content-Type: application/json" \
  -d '{"text":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

Tool	Method	Path	Price	Description
`media_text_to_speech`	POST	`/api/speak`	$0.012	Convert text to speech audio

`media_text_to_speech`

Use this when you need to convert text to speech audio. Returns base64-encoded MP3 audio in JSON.

Parameters

Name	Type	Required	Description
`text`	string	yes	The text to convert to speech (max 200 characters per request)
`language`	string	no	Language code: en, fr, es, de, it, pt, ja, ko, zh, ar, ru, hi, etc. (default: en)

Example response:

json

{"audio":"SUQzBAAAAAAAI1RTU0UAAAAP...","language":"en","textLength":45,"durationEstimate":3.2,"format":"mp3"}

When to use: generating audio narration, building voice assistants, creating audio versions of articles, accessibility features, and language learning apps.

Not for: language detection (use text_detect_language), text translation (use text_translate), OCR from images (use media_extract_text_from_image).

Example agent prompts

"Convert text to speech audio"

Payment

Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
Network: Base L2 (eip155:8453)
Asset: USDC
Facilitator: Coinbase CDP (primary), PayAI (fallback)
Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)