x402 Discovery - Navigate and Discover the x402 Protocol

TypeScript Client Quickstart

Get started making payments with TypeScript in 5 minutes

typescriptclient

TypeScript Server Quickstart

Accept payments for your API in 5 minutes

typescriptserver

Fetch API Client Example

Use x402 with the native Fetch API

typescriptfetchclient

Axios Client Example

Use x402 with Axios HTTP client

typescriptaxiosclient

Advanced Client Patterns

Lifecycle hooks, network preferences, and custom validation

typescriptclienthooksnetwork-preferences

Custom Client Implementation

Manual implementation using only @x402/core

typescriptclient

MCP Server Example

Build an MCP server that makes paid API requests

typescriptclientmcp

Express Server Example

Protect Express.js routes with x402 middleware

typescriptexpressserver

Hono Server Example

Protect Hono routes with x402 middleware

typescripthonoserver

Advanced Server Patterns

Lifecycle hooks, dynamic pricing, custom tokens, and Bazaar discovery

typescriptserverhooksdynamic-pricing+2 more

Custom Server Implementation

Manual implementation using only @x402/core

typescriptserver

TypeScript Facilitator

Run your own payment facilitator with /verify and /settle endpoints

typescriptfacilitator

Next.js Fullstack App

Full Next.js app with protected routes

typescriptnextjsserver

Farcaster Mini App

Farcaster Mini App with x402 payments

typescriptserverfarcaster

Go HTTP Client Example

Use x402 with Go's standard HTTP client

Go Advanced Client

Advanced client patterns with hooks, error recovery, and multi-network priority

goclienthookserror-recovery+1 more

Go Custom Client

Manual client implementation

Gin Server Example

Protect Gin routes with x402 middleware

Go Advanced Server

Advanced server patterns with hooks, dynamic pricing, custom tokens, and Bazaar discovery

goserverhooksdynamic-pricing+2 more

Go Custom Server

Manual server implementation

Run a payment facilitator in Go

HTTP 402 Protocol

How x402 uses the HTTP 402 status code

Client & Server Architecture

How clients and servers interact

Facilitator Role

What facilitators do and how they work

Wallet Management

How wallets work in x402

Network & Token Support

Supported blockchain networks and tokens

Bazaar Discovery Layer

Discover x402-enabled services

bazaar-discovery

Building MCP Servers with x402

Create Model Context Protocol servers that make payments

Migration Guide: v1 to v2

Upgrade from x402 v1 to v2

x402 Specification v2

Technical specification for x402 v2

x402 Specification v1

Technical specification for x402 v1 (legacy)

Exact Scheme - EVM

Exact payment scheme for EVM chains

Exact Scheme - SVM

Exact payment scheme for Solana

Exact Scheme - Sui

Exact payment scheme for Sui

@x402/core Package

Core TypeScript package for x402

@x402/axios Package

Axios client integration

typescriptaxiosclient

@x402/fetch Package

Fetch API integration

typescriptfetchclient

@x402/express Package

Express.js middleware

typescriptexpressserver

@x402/hono Package

Hono middleware

typescripthonoserver

@x402/next Package

Next.js middleware

typescriptnextjsserver

Go Package Documentation

Go SDK documentation

Python Package Documentation

Python SDK documentation

Java Package Documentation

Java SDK documentation

Welcome to x402

Introduction to x402 and overview of the open payment standard

Frequently Asked Questions

Common questions about x402, facilitators, networks, and troubleshooting

Go Client Implementation Guide

Comprehensive guide to implementing x402 clients in Go

Go Server Implementation Guide

Comprehensive guide to implementing x402 servers in Go

Go Facilitator Implementation Guide

Comprehensive guide to implementing x402 facilitators in Go

Go Extensions Overview

Go SDK extensions and middleware

Go Payment Mechanisms

Payment mechanism implementations in Go

Go EVM Mechanism

EVM payment mechanism for Go SDK

Go SVM Mechanism

Solana payment mechanism for Go SDK

Go EVM Exact Scheme v1

EVM exact payment scheme v1 implementation

Go SVM Exact Scheme v1

Solana exact payment scheme v1 implementation

Go Gin Framework Integration

Gin framework integration guide

Specifications Overview

Overview of x402 technical specifications

Exact Scheme Overview

General overview of the exact payment scheme

HTTP Transport v1

HTTP transport protocol specification v1

MCP Transport v1

Model Context Protocol transport specification v1

Agent-to-Agent Transport v1

Agent-to-Agent communication protocol specification v1

HTTP Transport v2

HTTP transport protocol specification v2

MCP Transport v2

Model Context Protocol transport specification v2

Agent-to-Agent Transport v2

Agent-to-Agent communication protocol specification v2

TypeScript Extensions

TypeScript SDK extensions and middleware

TypeScript EVM Mechanism

EVM payment mechanism for TypeScript SDK

TypeScript SVM Mechanism

Solana payment mechanism for TypeScript SDK

@x402/paywall Package

Paywall utilities for TypeScript HTTP servers

typescriptserver

TypeScript Demo Site

Demo website showcasing x402 integration

TypeScript v2 Changelog

Version 2 changelog and migration notes

Welcome to x402

Introduction to the x402 payment protocol

Complete payment flow from request to settlement

Networks & Token Support

Supported blockchain networks and tokens

Building Miniapps with x402

Build miniapps with x402 payments using our template

x402 Facilitator API

Facilitator API overview and endpoints

Verify Payment Endpoint

Verify x402 payments with specific schemes and networks

Settle Payment Endpoint

Settle x402 payments on-chain

Get Supported Schemes Endpoint

Get supported payment schemes and networks