What is x402r? - x402r Documentation

x402r is a refundable payments protocol extension for x402. It enables secure, reversible transactions with built-in buyer protection through smart contract escrow on Base.

Why x402r

Standard x402 payments are immediate and irreversible. x402r adds:

Escrow deposits: smart contracts hold funds until conditions clear
Refund windows: configurable time periods for buyers to request refunds
Dispute resolution: arbiter system for handling contested transactions

How it works

Who this is for

Merchants (Receivers)

Capture funds, process refunds, and manage escrow periods.

Get started

Protocol Overview

Understand how x402r extends the x402 protocol.

Smart Contracts

Explore the escrow and payment operator contracts.

SDK Quickstart

Start building with the TypeScript SDK.

Deploy an Operator

Deploy your own PaymentOperator on Base.

Architecture

x402r consists of these core components:

Component	Purpose
PaymentOperator	Manages payment authorization, capture, charge, void, and refunds with pluggable conditions
AuthCaptureEscrow	Holds ERC-20 tokens during the payment lifecycle (from commerce-payments)
Conditions & Hooks	Pluggable authorization checks (before action) and state updates (after action)
EscrowPeriod & Freeze	Time-based capture and freeze policies for buyer protection
RefundRequest	Handles refund request lifecycle and approvals

All protocol contracts use universal CREATE2 addresses, same address on every supported chain.

Supported networks

Today, the supported chains in @x402r/core are Base and Base Sepolia. More EVMs land as canonical base/commerce-payments@v1.0.0 coverage extends. See Network support for chain IDs and USDC token addresses.

Resources

GitHub

Source code and examples.

SDK Reference

SDK documentation and API reference.

Support

Get help with integration.

X402 Protocol Overview

​Why x402r

​How it works

​Who this is for