npm install selfx402-framework

// src/config/x402.ts
export const x402Config = {
  network: "celo",
  facilitatorUrl: "https://facilitator.selfx402.xyz",
  paymentPrice: "0.001", // $0.001 for verified humans
  walletAddress: process.env.PAYMENT_WALLET_ADDRESS
};

import { celoPaymentMiddleware } from "selfx402-framework/middleware";

const paymentMiddleware = celoPaymentMiddleware({
  facilitatorUrl: x402Config.facilitatorUrl,
  network: x402Config.network,
  paymentPrice: x402Config.paymentPrice,
  walletAddress: x402Config.walletAddress,
  enableSelfProtocol: true, // Enable proof-of-unique-human
});

// Apply to protected routes
app.get("/api/protected", paymentMiddleware, (req, res) => {
  const tier = req.tier; // "verified_human" | "unverified"
  res.json({ message: "Access granted!", tier });
});

app.get("/.well-known/x402", (req, res) => {
  res.json({
    version: 1,
    facilitatorUrl: "https://facilitator.selfx402.xyz",
    payment: {
      network: "celo",
      asset: "0xcebA9300f2b948710d2653dD7B07f33A8B32118C",
      payTo: x402Config.walletAddress,
    },
    verification: {
      enabled: true,
      requirements: {
        minimumAge: 18,
        excludedCountries: [], // ISO 3166-1 alpha-3
        ofac: false,
      },
      scope: "my-api-v1", // Unique identifier
    },
    pricing: {
      tiers: {
        unverified: { price: "1.00", description: "Bot pricing" },
        verified_human: { price: "0.001", description: "1000x cheaper" }
      }
    }
  });
});

• x402 micropayments (EIP-712 signatures)
• Self Protocol verification (proof-of-unique-human)
• Tiered pricing (bots pay 1000x more)
• Deferred payments (99% gas savings)