This repository is a reference integration project for x402 in GOAT Network.
x402 is a payment standard for crypto-native applications.
It allows an app or API to request token payment in a structured way, so users can complete payment from their wallet and the service can verify settlement.
In short, GOAT Network x402 is used to make blockchain payments a standard part of application access, checkout, and service flows.
This project demonstrates how to integrate x402 in practice, including:
- order creation and payment workflow
- client and server integration patterns
- callback/settlement-related implementation examples
GOAT x402 supports configured EVM mainnet chains. Each merchant still needs per-chain token, fee, receiving-address, and callback-contract configuration before taking payments on a chain.
| Chain | Chain ID | DIRECT | DELEGATE |
|---|---|---|---|
| Ethereum | 1 |
Yes | Yes |
| Polygon | 137 |
Yes | Yes |
| BSC | 56 |
Yes | Yes |
| Arbitrum | 42161 |
Yes | Yes |
| Optimism | 10 |
Yes | Yes |
| Avalanche | 43114 |
Yes | Yes |
| Base | 8453 |
Yes | Yes |
| Berachain | 80094 |
Yes | Yes |
| X Layer | 196 |
Yes | Yes |
| GOAT | 2345 |
Yes | Yes |
| Metis | 1088 |
Yes | No |
| Tempo | 4217 |
Yes | No |
DIRECT means the payer transfers ERC-20 tokens directly to the merchant receiving address. DELEGATE means EIP-3009 or Permit2 settlement through the merchant callback contract and TSS submission; Metis and Tempo are DIRECT-only.
Use docs/README.md as the canonical documentation hub.
Quick references:
DEVELOPER_FAST.md- concise SDK/backend integration guide.API.md- Core API and HMAC authentication reference.docs/README.md- structured public docs index, including QuickPay, QuickPay Products, MPP, and agent integration paths.
Production API base URL: https://api.x402.goat.network.