@pay-skill/express

Express.js middleware for x402 payments — both consumer and provider sides. Thin adapter over @pay-skill/sdk for Express 4 and 5.

Full docs: https://pay-skill.com/docs/middleware/express

Install

npm install @pay-skill/sdk @pay-skill/express express

Provider — Gate a route behind an x402 paywall

import express from "express";
import { requirePayment } from "@pay-skill/express";

const app = express();

app.get("/api/data", requirePayment({
  price: 0.01,
  settlement: "tab",
  providerAddress: "0xYourProviderWallet...",
}), (req, res) => {
  res.json({ data: "premium", paidBy: req.payment!.from });
});

Unpaid requests receive a 402 with the PAYMENT-REQUIRED header. Verified requests have req.payment populated (from, amount, settlement) and X-Pay-Verified / X-Pay-From / X-Pay-Amount / X-Pay-Settlement headers set for downstream middleware.

Consumer — Auto-pay outbound x402 calls

import express from "express";
import { Wallet } from "@pay-skill/sdk";
import { payMiddleware } from "@pay-skill/express";

const wallet = await Wallet.create();
const app = express();

app.use(payMiddleware(wallet, {
  maxPerRequest: 1.00,
  maxTotal: 100.00,
}));

app.get("/forecast", async (req, res) => {
  const data = await req.pay!.fetch("https://api.example.com/forecast");
  res.json(await data.json());
});

req.pay.fetch is a pay-enabled fetch backed by createPayFetch. It auto-settles x402 402 responses via tab or direct and retries — your handler never sees the 402.

License

MIT