Production-Ready Setup

import { paymentMiddleware } from '@x402/express';
import { x402ResourceServer, HTTPFacilitatorClient } from '@x402/core/server';
import { registerExactEvmScheme } from '@x402/evm/exact/server';
import { Ratelimit } from '@upstash/ratelimit';
import { Redis } from '@upstash/redis';
import express from 'express';

// Setup server
const facilitatorClient = new HTTPFacilitatorClient({
  url: 'https://api.cdp.coinbase.com/platform/v2/x402'
});
const server = new x402ResourceServer(facilitatorClient);
registerExactEvmScheme(server);
const app = express();

// Setup rate limiting
const ratelimit = new Ratelimit({
  redis: Redis.fromEnv(),
  limiter: Ratelimit.slidingWindow(10, '10 s'),
});

// Configure payment middleware
app.use(
  paymentMiddleware(
    {
      'GET /api/data': {
        accepts: [{
          scheme: 'exact',
          price: '$0.001',
          network: 'eip155:8453',
          payTo: process.env.RECEIVING_WALLET_ADDRESS!,
        }],
        description: 'Rate-limited data endpoint',
        mimeType: 'application/json',
      },
    },
    server
  )
);

// Handler with rate limiting
app.get('/api/data', async (req, res) => {
  const paymentHeader = req.headers['x-payment'];
  const payer = JSON.parse(Buffer.from(paymentHeader as string, 'base64').toString()).from;

  // Rate limit by payer address
  const { success } = await ratelimit.limit(payer);
  if (!success) {
    return res.status(429).json({ error: 'Rate limit exceeded' });
  }

  // Serve data
  res.json({ data: '...' });
});