x402 SDK for Developers

Build apps that accept micropayments with one line of code

Quick Start

Get started in under 5 minutes

Install the SDK

npm install @simtrade/x402-sdk

Initialize and accept payments

import { X402 } from '@simtrade/x402-sdk'

const x402 = new X402({ apiKey: 'your-api-key' })

// Accept a payment

const payment = await x402.charge({

amount: 0.10,

description: 'Run simulation'

})

Lightning Fast

Sub-second payment verification

Payments are verified instantly on-chain, enabling real-time micropayment flows

Secure by Default

Built-in fraud protection

Automatic validation, replay protection, and secure key management out of the box

Multi-Chain

Works across all major chains

Support for Ethereum, Polygon, Arbitrum, Optimism, and more coming soon

Multi-Language Support

Use x402 in your preferred language

JavaScript

Available

TypeScript

Available

Python

Available

Coming Soon

Rust

Coming Soon

Java

Coming Soon

Ruby

Coming Soon

PHP

Coming Soon

SDK Pricing

Simple, transparent pricing for developers

Free Tier

Perfect for testing

Up to 1,000 transactions/month

Basic support

Community access

Standard SLA