Quick Start

Get up and running with T402 in under 5 minutes.

Overview

T402 enables HTTP-native payments using USDT and USDT0. Here’s what a typical flow looks like:

Client makes a request to a protected resource
Server responds with 402 Payment Required and payment options
Client signs a payment authorization
Server verifies and settles the payment
Client receives the requested resource

Server Setup (Express.js)

import express from 'express'
import { paymentMiddleware } from '@t402/express'
import { ExactEvmScheme } from '@t402/evm'
 
const app = express()
 
// Add payment middleware
app.use(paymentMiddleware({
  'GET /api/premium': {
    price: '$0.01',
    network: 'eip155:8453', // Base
    payTo: '0xYourAddress...',
    description: 'Premium API access'
  }
}))
 
app.get('/api/premium', (req, res) => {
  res.json({ data: 'Premium content!' })
})
 
app.listen(3000)

Client Setup

import { t402Client, wrapFetchWithPayment } from '@t402/fetch'
import { registerExactEvmScheme } from '@t402/evm/exact/client'
import { privateKeyToAccount } from 'viem/accounts'
 
// Create and configure client
const client = new t402Client()
registerExactEvmScheme(client, {
  signer: privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`)
})
 
// Wrap fetch to automatically handle payments
const fetchWithPayment = wrapFetchWithPayment(fetch, client)
 
// Make requests - payments are handled automatically!
const response = await fetchWithPayment('https://api.example.com/api/premium')
const data = await response.json()

What’s Next?

Installation - Detailed installation guide
Core Concepts - Understand how T402 works
Server Integration - Complete server setup
Client Integration - Complete client setup

Installation