Network Setup

Avalanche Networks Overview

Avalanche provides two networks for x402 development:

Network	Purpose	Chain ID	RPC URL
Mainnet	Production	43114	https://api.avax.network/ext/bc/C/rpc
Fuji Testnet	Development	43113	https://api.avax-test.network/ext/bc/C/rpc

Fuji Testnet Setup

Step 1: Configure Network in Wallet

Add Fuji testnet to MetaMask or Core wallet:

// Network configuration
{
  networkName: "Avalanche Fuji Testnet",
  rpcUrl: "https://api.avax-test.network/ext/bc/C/rpc",
  chainId: 43113,
  symbol: "AVAX",
  explorerUrl: "https://testnet.snowtrace.io/"
}

Add Fuji to your wallet using the configuration above. Core Wallet has Fuji pre-configured.

Step 2: Get Test AVAX

Get free test AVAX for gas fees:

Navigate to the Console Faucet
Connect your wallet
Request test AVAX

Step 3: Get Test USDC

Get free test USDC from Circle's official faucet:

Visit https://faucet.circle.com/
Select "Avalanche Fuji"
Enter your wallet address
Receive test USDC

Contract Addresses

Mainnet Addresses

const AVALANCHE_MAINNET = {
  chainId: 43114,
  rpc: "https://api.avax.network/ext/bc/C/rpc",
  usdc: "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E",
  usdt: "0x9702230A8Ea53601f5cD2dc00fDBc13d4dF4A8c7",
  wavax: "0xB31f66AA3C1e785363F0875A1B74E27b85FD66c7"
};

Fuji Testnet Addresses

const AVALANCHE_FUJI = {
  chainId: 43113,
  rpc: "https://api.avax-test.network/ext/bc/C/rpc",
  usdc: "0x5425890298aed601595a70AB815c96711a31Bc65",
};

Environment Configuration

For x402 development, configure your environment variables:

# .env file
AVALANCHE_RPC_FUJI=https://api.avax-test.network/ext/bc/C/rpc
USDC_FUJI=0x5425890298aed601595a70AB815c96711a31Bc65
PRIVATE_KEY=your_private_key_here

For mainnet deployment, use:

AVALANCHE_RPC_MAINNET=https://api.avax.network/ext/bc/C/rpc
USDC_MAINNET=0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E

Setting up x402 on Avalanche Fuji testnet requires three steps: configure your wallet with Fuji network, get free test AVAX from Core Wallet console, and get free test USDC from Circle's faucet. With these resources, you're ready to integrate x402 facilitators and start building payment-enabled applications.