Pay Anything.
Instantly.
Programmatically.

import express from "express";
import { paywall } from "@xpay/sdk";

const app = express();

// price this route, that is the whole integration
app.use("/v1/summarize", paywall({
  price:   "$0.002",
  network: "base",
  payTo:   "0xA1c4…9F2b",
}));

app.post("/v1/summarize", (req, res) => {
  res.json({ summary: summarize(req.body.text) });
});

import { XPayWallet } from "@xpay/sdk";

const wallet = new XPayWallet({
  sessionKey: process.env.XPAY_SESSION_KEY,
  limits: { perCall: "$0.05", daily: "$25" },
});

// 402 is caught, paid and retried automatically
const res = await wallet.fetch(
  "https://api.acme.dev/v1/summarize",
  { method: "POST", body: JSON.stringify({ text }) }
);

console.log(res.payment.amount, res.payment.tx);
// "$0.002"  "0x7d1e…"

from xpay import paywall, XPayWallet

# sell, FastAPI
app.add_middleware(
    paywall(price="$0.002", network="base",
            pay_to="0xA1c4…9F2b")
)

# buy, any agent
wallet = XPayWallet(
    session_key=os.environ["XPAY_SESSION_KEY"],
    limits={"per_call": "$0.05", "daily": "$25"},
)

r = wallet.get("https://api.acme.dev/v1/quote")
print(r.payment.tx)

# 1. unpaid request
GET /v1/quote HTTP/1.1
Host: api.acme.dev

# 2. the price, in machine readable form
HTTP/1.1 402 Payment Required
X-Payment-Required: {"scheme":"exact","amount":"2000",
  "asset":"USDC","network":"base","payTo":"0xA1c4…9F2b"}

# 3. retry with a signed authorization
GET /v1/quote HTTP/1.1
X-Payment: eyJzaWduYXR1cmUiOiIweGFm…

# 4. response plus settlement receipt
HTTP/1.1 200 OK
X-Payment-Response: {"settled":true,"tx":"0x7d1e…"}