captcha-mcp
JSON →L402 Lightning paywall and PoW gate for MCP tool calls. Free tier solves a Hashcash challenge; paid tier pays a Lightning invoice via self-hosted LNBits. No accounts, no API keys.
Install
npx -y @powforge/captcha-mcp Tools · 3
- challenge Request a fresh proof-of-work puzzle. Returns {id, salt, difficulty, signature}.
- verify Submit a solved nonce. Returns a 5-minute HMAC-signed access token.
- status Server health, lifetime stats, L402 endpoint metadata.
Environment variables
CAPTCHA_URL