Monetize Any HTTP Application with x402 and CloudFront + Lambda@Edge

┌─────────┐     ┌──────────────────────────┐     ┌─────────────┐
│  Client │────▶│ CloudFront + Lambda@Edge │────▶│ Your Origin │
└─────────┘     │    (x402 verification)   │     │ (unchanged) │
                └──────────────────────────┘     └─────────────┘

Client                CloudFront              Origin
  │                       │                     │
  │──── Request ─────────▶│                     │
  │                       │                     │
  │◀─── 402 Payment ──────│                     │
  │     Required          │                     │
  │                       │                     │
  │──── Request + ───────▶│                     │
  │     Payment Signature │                     │
  │                       │──── Forward ───────▶│
  │                       │                     │
  │                       │◀─── Response ───────│
  │                       │                     │
  │                       │ (settle payment     │
  │                       │  if status < 400)   │
  │                       │                     │
  │◀─── Response ─────────│                     │

// config.ts
import type { RoutesConfig } from '@x402/core/server';

export const FACILITATOR_URL = 'https://x402.org/facilitator';
export const PAY_TO = '0xYourWalletAddress';
export const NETWORK = 'eip155:84532'; // Base Sepolia (testnet)

export const ROUTES: RoutesConfig = {
  '/api/*': {
    accepts: {
      scheme: 'exact',
      network: NETWORK,
      payTo: PAY_TO,
      price: '$0.001',
    },
    description: 'API access',
  },
  '/api/premium/**': {
    accepts: {
      scheme: 'exact',
      network: NETWORK,
      payTo: PAY_TO,
      price: '$0.01',
    },
    description: 'Premium API access',
  },
};

import { originRequestHandler, originResponseHandler } from './index';

import { createX402Middleware, MiddlewareResultType } from './lib';

const x402 = createX402Middleware({
  facilitatorUrl: 'https://x402.org/facilitator',
  network: 'eip155:84532',
  routes: ROUTES,
});

export const handler = async (event: CloudFrontRequestEvent) => {
  const request = event.Records[0].cf.request;
  
  // Your custom logic first (auth, WAF, logging, etc.)
  if (request.headers['x-api-key']?.[0]?.value !== 'secret') {
    return { status: '401', body: 'Unauthorized' };
  }
  
  // x402 payment check
  const result = await x402.processOriginRequest(
    request, 
    event.Records[0].cf.config.distributionDomainName
  );
  
  if (result.type === MiddlewareResultType.RESPOND) {
    return result.response; // 402 Payment Required
  }
  
  return result.request;
};

export const handler = async (event: CloudFrontRequestEvent) => {
  const request = event.Records[0].cf.request;
  
  // WAF can be configured to add custom headers based on bot labels
  // Example: x-bot-category header added by WAF rule action
  const botCategory = request.headers['x-bot-category']?.[0]?.value;
  const isVerifiedBot = request.headers['x-verified-bot']?.[0]?.value === 'true';
  
  // Free pass for humans (no bot label)
  if (!botCategory) {
    return request;
  }
  
  // Free pass for verified good bots (Googlebot, etc.)
  if (isVerifiedBot) {
    return request;
  }
  
  // Require payment for unverified bots and AI agents
  const result = await x402.processOriginRequest(request, distributionDomain);
  
  if (result.type === MiddlewareResultType.RESPOND) {
    return result.response; // 402 Payment Required for bots
  }
  
  return result.request;
};