T402 Documentation

The Official Payment Protocol for USDT

T402 is an open standard for HTTP-native stablecoin payments. It enables seamless USDT and USDT0 payments across multiple blockchains with a single HTTP header.

Why T402?

  • HTTP Native: Pay for any HTTP resource with a single header
  • Multi-Chain: Support for Ethereum, Arbitrum, Base, TON, TRON, Solana, and more
  • Gasless: ERC-4337 account abstraction for zero-gas user experience
  • Cross-Chain: LayerZero OFT bridging for USDT0 transfers
  • AI Ready: MCP server for AI agent payments

Quick Install

# TypeScript
pnpm add @t402/core @t402/evm
 
# Python
pip install t402
 
# Go
go get github.com/t402-io/t402/go

Packages

PackageDescription
@t402/coreProtocol types and HTTP utilities
@t402/evmEVM chains (Ethereum, Arbitrum, Base, etc.)
@t402/tonTON blockchain support
@t402/tronTRON blockchain support
@t402/wdkTether WDK integration
@t402/wdk-gaslessGasless payments with WDK + ERC-4337
@t402/wdk-bridgeCross-chain bridging with WDK + LayerZero
@t402/mcpMCP server for AI agents

Supported Networks

  • EVM: Ethereum, Arbitrum, Base, Optimism, Polygon, Ink, Berachain, Unichain
  • TON: TON Mainnet and Testnet
  • TRON: TRON Mainnet and Testnets
  • Solana: Mainnet and Devnet

See Chains for detailed information.

Get Started

Ready to integrate T402? Start with our Quick Start Guide.