How to Convert Text to Speech with Bitcoin Lightning
3 tiers. 332+ voices. 602+ languages. Per-character pricing. No signup.
For Humans
Use the web UI — no setup required.
Quality TTS services charge $5-33/month with character limits and mandatory accounts. Free tools sound robotic. Sats4AI gives you studio-quality speech across 3 tiers and 332+ voices covering 602+ languages with per-character pricing — you pay only for the text you convert. Nothing to sign up for, nothing stored.
One-off voiceovers
Need narration for a video, a presentation, or a demo? Pay 300 sats once and download a studio-quality audio file — no subscription to cancel afterward.
Multilingual content
Generate speech in 602+ languages from the same interface. The OmniVoice tier reaches underserved languages like Yoruba, Marathi, and Cebuano that frontier models can't touch.
Expressive characters
Set emotional tone — happy, calm, angry, fearful, surprised — with Inworld Max Premium, the #1 ranked TTS. 332 voices across 40+ languages. Ideal for audiobooks, game dialogue, or educational content.
Speak in your own voice
Want the audio to sound like you? Use voice cloning to capture your voice once, then generate speech in it anytime — consistent branding or personal content.
3 Quality Tiers
All tiers use per-character pricing — you pay only for the text you convert. The price is calculated automatically based on your input length.
OmniVoice
602+ languages including Yoruba, Marathi, Tagalog, Swahili, Cebuano, and hundreds more that frontier models can't reach. Zero-shot voice cloning and voice design via text prompts.
- 602+ languages (underserved included)
- Zero-shot voice cloning
- 100 chars/sat — most affordable
Inworld Max
#1 ranked TTS model (ELO 1217). Natural cadence, rich audio, and emotion control — the default tier for most use cases.
- 332 voices across 40+ languages
- Emotion control (happy, calm, angry, etc.)
- 50 chars/sat
Minimax
Highest quality with voice cloning from a reference audio clip. Upload a sample, get speech that sounds like you.
- Voice cloning from reference clip
- 40+ languages
- 10 chars/sat — highest quality
For Agents
Integrate via L402, MCP, or OpenClaw — no account, no API key.
The TTS endpoint supports L402 authentication: your script or agent sends the text, pays a Lightning invoice proportional to the character count, and receives the audio file. No billing account, no API key rotation, no rate limit surprises. Per-character cost, every time.
Spoken alerts and notifications
A monitoring agent converts server alerts or status updates to speech and delivers them as audio — useful for voice interfaces or accessibility workflows.
Automated audio content
An agent generates article summaries with AI chat, then calls TTS to produce podcast-style audio — full pipeline, no human in the loop.
Multilingual voice pipelines
Translate text with AI chat, then synthesize speech in the target language. 602+ languages from the same endpoint — no per-language integration needed.
Voice call delivery
Chain TTS with the phone call service: generate the audio, then deliver it to any phone number worldwide — automated voice broadcasts with no telephony setup.
L402 Authentication Flow
Send the request without auth
POST your text, voice, and format parameters to the endpoint. The server responds with HTTP 402 + a 300-sat Lightning invoice in the WWW-Authenticate header.
Pay the Lightning invoice
Your agent pays the invoice using a Lightning wallet or library. Save the preimage from the payment result.
Resend with the preimage
Repeat the identical request, adding an Authorization: L402 <macaroon>:<preimage> header. The server validates and returns your audio file.
# Text-to-speech is available via the MCP server or web UI.
# Your MCP-connected agent calls synthesize_speech with your
# text — Lightning payment handled automatically.
#
# MCP setup (add to your MCP settings JSON):
{
"mcpServers": {
"sats4ai": { "url": "https://sats4ai.com/api/mcp" }
}
}
# Then ask your agent: "Convert this text to speech"
# The agent uses synthesize_speech — 300 sats per generation.Connect any MCP-compatible AI assistant. TTS is one of 10+ tools available through a single connection.
View MCP docs →One-line MCP setup. Your agent speaks with Lightning — no API key, no billing account.
Setup OpenClaw →Chain with Other Services
Try It Now — No Signup Required
3 tiers, 332+ voices, 602+ languages. Per-character pricing. All you need is a Lightning wallet.