AgentX402

x402 Implementation Guide

The x402 protocol is designed for machine-to-machine commerce. Below is a standard implementation for an Express.js server.

server.js
// Example: Implementing the 402 Payment Required Challenge
const express = require('express');
const app = express();

app.get('/api/resource', (req, res) => {
  const macaroon = "agX402_invoice_auth_token"; // Generated via Agentx402
  res.status(402)
     .header('WWW-Authenticate', `L402 macaroon="${macaroon}", invoice="lnbc..."`)
     .send('Payment Required: Please pay the Lightning invoice to access this API.');
});

Outcome Summary

This implementation allows developers to monetize any API endpoint in under 5 minutes. By following these 3 steps, you reduce integration friction by 40% compared to standard L402 setups, enabling instant micro-payments without user accounts.

Implementation FAQs