Pay-per-use APIs for AI agents.

One npm install, automatic USDC micropayments on Base.

• ✓ No API key — pay per call with USDC, no subscription required
• ✓ Free test mode — no wallet needed to start
• ✓ Single env var — add X402_PRIVATE_KEY and go
• ✓ Micropayments — $0.01 to $0.10 per request, no subscriptions