Monetize Express.js APIs for AI Agents in 3 Lines of Code with x402

AI agents are increasingly making programmatic requests, but traditional billing (credit cards, OAuth, complex API keys) creates friction for automated microtransactions. With x402-express, you can monetize any Express.js endpoint using HTTP 402 payment requirements on Base in 3 lines of code. 1. Installation bash npm install x402-express 2. Implementation Add the middleware to any route you want to protect: javascript const express = require('express'); const { x402Middleware } = require('x402-express'); const app = express(); app.get('/api/agent-data', x402Middleware({ price: '0.01' }), (req, res) => { res.json({ message: "Payment verified via x402!" }); }); app.listen(3000, () => console.log('Server running on port 3000')); 3. Verification & Registry - GitHub Repository: github.com/IkeHentrel/x402-express - MCP Registry: io.github.ihen404/x402-express When an unauthenticated agent hits your endpoint, x402-express interceptively returns an HTTP 402 Payment Required payload containing payment parameters, verifying settlements autonomously. Top comments (0)