Beta
x402 — The payment layer for autonomous agents
Sui-first, multi-network x402 facilitator for instant stablecoin micropayments. Enable AI agents to pay for API calls without human intervention.
Features
Built for the agentic era.
Sui-first Architecture
Optimized for Sui's parallel execution and low fees — sub-cent micropayments at scale.
Multi-network Support
Extend to Ethereum, Base, and other EVM chains with the same developer experience.
AI Agent Native
Purpose-built for autonomous agent payment flows. No wallets, no approvals, no friction.
Standards-compliant
Implements the x402 payment protocol specification for maximum ecosystem compatibility.
Use cases
What you can build.
API Monetization
Charge per API call without subscriptions. Set any price, get paid per request, no billing infrastructure needed.
AI Agent Payments
Let agents autonomously pay for compute and data. Agents acquire resources and settle costs in real time.
Micropayment Commerce
Enable pay-per-use for digital content, unlocking business models impossible with traditional payment rails.
Integration
Integrate in minutes.
The x402 middleware handles payment verification transparently. Drop it into any Express.js app and start charging per request.
import express from "express";
import { x402Express } from "@bex/x402";
const app = express();
// Protect a route with x402 micropayments
app.use(
"/api/data",
x402Express({
facilitator: "https://x402.bex.co",
price: "0.001", // $0.001 USDC per request
network: "sui",
}),
);
app.get("/api/data", (req, res) => {
res.json({ data: "premium content" });
});
app.listen(3000);Get early access.
We're opening x402 to a limited set of early partners. Join the waitlist to be first in line.
Frequently asked questions
What is x402?
An open protocol that revives HTTP's unused 402 Payment Required status code: a server answers with the price and how to pay, the client pays and retries, and the request succeeds. It makes per-request payments a property of the HTTP exchange rather than something bolted on with accounts and invoices.
Who is it for?
APIs that want to charge per call without onboarding every caller, and autonomous agents that need to pay for something mid-task. Both are cases where signing up, entering a card and waiting for an invoice is not a workable step.
Which chains and tokens does it work with?
The protocol is chain-agnostic; settlement in practice uses stablecoins on low-fee networks, because a payment worth a fraction of a cent only makes sense when the fee to move it is smaller still. The docs cover the currently supported networks.