Ship a paid tool in five minutes.

The whole integration.

// app/api/my-tool/route.ts
import { paidHandler } from "@keryxhq/middleware/next";

export const POST = paidHandler({
  price: 0.004,                           // USD per call
  wallet: "0xYourArcWallet...",           // where payment lands
  description: "Web search over indexed docs.",
  handler: async ({ query }: { query: string }) => {
    return { results: await mySearch(query) };
  },
});

Three steps. The SDK does all three.

Same idea, connect-style.

import express from "express";
import { paidExpress } from "@keryxhq/middleware/express";

const app = express();
app.use(express.json());

app.post(
  "/api/my-tool",
  paidExpress({
    price: 0.004,
    wallet: "0xYourArcWallet...",
    description: "Web search over indexed docs.",
  }),
  (req, res) => {
    // req.keryxPayment holds the verified receipt
    res.json({ results: mySearch(req.body.query) });
  },
);

Use the framework-agnostic primitives.

import {
  buildRequirements,
  decodePaymentHeader,
  verifyPayment,
  buildX402Body,
} from "@keryxhq/middleware";

// Use these if you're not on Next.js or Express — Cloudflare Workers,
// Deno, Fastify, Hono, bare Node http.Server, etc.

Arc-native, USDC-priced.