x402 is an open, neutral standard for internet-native payments. It absolves the Internet’s original sin by natively making payments possible between clients and servers, creating win-win economies that empower agentic payments at scale. x402 exists to build a more free and fair internet.
app.use(paymentMiddleware({
"GET /weather": {
accepts: [...], // As many networks / schemes as you want to support
description: "Weather data", // What your endpoint does
},
}));
That’s it. Add one line of code to require payment for each incoming request. If a request arrives without payment, the server responds with HTTP 402, prompting the client to pay and retry.
Filling out a form is a human behavior that doesn’t match the programmatic nature of the internet. It’s time for an open, internet-native form of payments. Payments that are amazing for humans and AI agents.
x402 is built-in to existing HTTP requests, with no additional communication required.
x402 is free for the customer and the merchant—just pay nominal payment network fees
Money moves at the speed of the internet
No accounts or personal information needed
Anyone on the internet can build on or extend x402
x402 is a neutral standard, not tied to any specific network
The old way of doing payments is barely working for a human world, let alone an agentic future. x402 does in moments what existing systems can’t do at all.
1. Create account with new API provider
Time consuming setup
2. Add payment method to API provider
KYC required, delaying access and requiring approval
3 Buy credits or subscription
Prepaid commitment → overpay or run out of funds
4 Manage API key
Security risk → must store and rotate keys
5 Make payment
Slow transactions, chargebacks, fees
1. AI agent sends HTTP request and receives 402: Payment Required
No account setup, instant onboarding
2. AI agent pays instantly with stablecoins
No signups or approvals required
3. API access granted
No API key management and related security risks
Join a global community of thousands of builders contributing to an open codebase, faster financial system, and freer internet.
x402 enables instant, low-cost payments for digital services. It’s designed for API monetization, agentic commerce, paywalled content, and any scenario where traditional payment methods are too slow or expensive.
Yes, x402 is production-ready and has processed millions of transactions. The protocol is open-source and has been audited for security.
Integration is simple – add a single line of middleware to your server. Check our documentation for detailed guides and examples in multiple programming languages.
x402 is blockchain-agnostic and supports all EVM-compatible chains, Solana, and more. Stablecoin payments are the primary use case. x402 is also extensible to traditional payment methods.
