USDC Quick Start

USDC is a digital dollar issued by Circle, also known as a stablecoin, designed to represent US dollars on the internet and operate seamlessly across many of the world’s leading blockchains, including World Chain. Backed 100% by highly liquid cash and cash-equivalent assets, USDC is always redeemable 1:1 for USD. Circle provides monthly attestation reports for USDC reserve holdings on its Transparency page. On World Chain, USDC can be transferred using its token contract, enabling fast, secure, and programmable digital dollar transactions. This guide will walk you through building a simple script to perform your first USDC transaction on World Chain.

Prerequisites

Node.js (v16 or higher)
npm or yarn

Part 1: Setup up your project

Step 1: Create a new project directory:

mkdir usdc-world-transfer
cd usdc-world-transfer
npm init -y

Step 2: Enable ES module support:

In your package.json, add the following line:

{
  "type": "module"
}

This allows you to use the modern ES module syntax (import/export) in your script. Tip: Alternatively, you can use the following command to set "type": "module" directly:

Step 3: Install required dependencies:

npm install viem @inquirer/prompts

Step 4: Create your script file:

Create a new file called index.js:

touch index.js

Part 2: Build the script

Open index.js and complete the following sections:

Step 1: Import Dependencies

import { createWalletClient, http, formatEther, createPublicClient } from 'viem';
import { privateKeyToAccount, generatePrivateKey } from 'viem/accounts';
import { worldchainSepolia } from 'viem/chains';
import { input } from '@inquirer/prompts';
import fs from 'fs';
import path from 'path';

These imports include:

viem for blockchain interactions
@inquirer/prompts for interactive CLI prompts
fs and path for saving private key backups

Step 2: Define Constants

// USDC contract address on World Chain Sepolia
const USDC_CONTRACT = '0x66145f38cBAC35Ca6F1Dfb4914dF98F1614aeA88';
const USDC_DECIMALS = 6;

USDC_CONTRACT is the address of the USDC token on World Chain Sepolia
USDC_DECIMALS is the number of decimals used in USDC calculations

// USDC ABI (minimal for transfer)
const USDC_ABI = [
  {
    name: 'transfer',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'to', type: 'address' },
      { name: 'amount', type: 'uint256' }
    ],
    outputs: [{ name: '', type: 'bool' }]
  },
  {
    name: 'balanceOf',
    type: 'function',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ name: '', type: 'uint256' }]
  },
  {
    name: 'decimals',
    type: 'function',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: '', type: 'uint8' }]
  }
];

The above ABI defines the minimum required functions for:

Transferring USDC
Checking USDC balance
Getting USDC decimals

Step 3: Add Helper Functions

async function generateWallet() {
  const privateKey = generatePrivateKey();
  const account = privateKeyToAccount(privateKey);
  return { privateKey, address: account.address };
}

async function savePrivateKeyBackup(sourceWallet, destinationWallet) {
  const timestamp = new Date().toISOString().replace(/[:.]/g, '-');
  const backupDir = path.join(process.cwd(), 'backups');

  if (!fs.existsSync(backupDir)) {
    fs.mkdirSync(backupDir);
  }

  const backupFile = path.join(backupDir, `wallet-backup-${timestamp}.txt`);
  const content = `Wallet Backup (${timestamp})

Source Wallet:
Address: ${sourceWallet.address}
Private Key: ${sourceWallet.privateKey}

Destination Wallet:
Address: ${destinationWallet.address}
Private Key: ${destinationWallet.privateKey}

⚠️ IMPORTANT: Keep this file secure and delete it after use.
`;

  fs.writeFileSync(backupFile, content);
  return backupFile;
}

These functions:

Generate new wallets
Save them as JSON files for backup

Step 4: Add Main Function

async function main() {
  try {
    console.log('\n1. Creating source wallet...');
    await input({ message: 'Press Enter to generate source wallet...' });
    const sourceWallet = await generateWallet();
    console.log('Source Address:', sourceWallet.address);
    await input({ message: 'Press Enter to continue...' });

    console.log('\n2. Creating destination wallet...');
    await input({ message: 'Press Enter to generate destination wallet...' });
    const destinationWallet = await generateWallet();
    console.log('Destination Address:', destinationWallet.address);
    await input({ message: 'Press Enter to continue...' });

    console.log('\n3. Saving wallet information...');
    const backupFile = await savePrivateKeyBackup(sourceWallet, destinationWallet);
    console.log('Backup saved to:', backupFile);

    console.log('\n4. Fund your source wallet:');
    console.log('Get testnet ETH from: https://www.alchemy.com/faucets/world-chain-sepolia');
    console.log('Get testnet USDC from: https://faucet.circle.com');
    console.log('Source Wallet Address:', sourceWallet.address);
    
    await input({ message: 'Press Enter after funding your wallet...' });

    console.log('\n5. Checking wallet balances...');
    const publicClient = createPublicClient({
      chain: worldchainSepolia,
      transport: http()
    });

    let ethBalance, usdcBalance;
    let isFunded = false;

    while (!isFunded) {
      ethBalance = await publicClient.getBalance({ address: sourceWallet.address });
      usdcBalance = await publicClient.readContract({
        address: USDC_CONTRACT,
        abi: USDC_ABI,
        functionName: 'balanceOf',
        args: [sourceWallet.address]
      });

      console.log('ETH Balance:', formatEther(ethBalance), 'ETH');
      console.log('USDC Balance:', Number(usdcBalance) / 10 ** USDC_DECIMALS, 'USDC');

      if (ethBalance === 0n || usdcBalance === 0n) {
        console.log('\nPlease fund your wallet with testnet ETH and USDC before proceeding.');
        await input({ message: 'Press Enter after funding your wallet...' });
      } else {
        isFunded = true;
      }
    }

    console.log('\n6. Ready to transfer USDC to Destination Address:', destinationWallet.address);
    const amount = await input({
      message: 'Enter amount of USDC to transfer:',
      validate: (value) => {
        const num = Number(value);
        if (isNaN(num) || num <= 0) return 'Please enter a valid positive number';
        if (num > Number(usdcBalance) / 10 ** USDC_DECIMALS) return 'Insufficient USDC balance';
        return true;
      }
    });

    const amountInDecimals = BigInt(Math.floor(Number(amount) * 10 ** USDC_DECIMALS));
    
    const walletClient = createWalletClient({
      account: privateKeyToAccount(sourceWallet.privateKey),
      chain: worldchainSepolia,
      transport: http()
    });

    console.log('\nExecuting transfer...');
    const hash = await walletClient.writeContract({
      address: USDC_CONTRACT,
      abi: USDC_ABI,
      functionName: 'transfer',
      args: [destinationWallet.address, amountInDecimals]
    });

    console.log('\nTransfer successful!');
    console.log('Transaction Hash:', hash);
    console.log('View on Explorer:', `https://sepolia.worldscan.org/tx/${hash}`);

  } catch (error) {
    console.error('\nError:', error.message);
  }
}

main();

This function drives the full flow to:

Create wallets
Back up credentials
Prompt you to fund the source wallet
Send USDC to the destination
Print the transaction hash

Part 3: Run the Script

Enter the following command:

node index.js

Follow the prompts in your terminal.

What This Script Does

Creates source and destination wallets
Saves wallet information securely
Prompts you to fund the source wallet
Transfers USDC between wallets
Displays the transaction hash and link to the explorer

Important Notes

Keep your private keys secure
Delete backup files after use
Always test with small amounts first
This script uses World Chain Sepolia testnet, not mainnet

About World Chain

Using World Chain

Building on World Chain

Infrastructure Providers

Technical Reference

Tokens

Further Reading

Prerequisites

Part 1: Setup up your project

Step 1: Create a new project directory:

Step 2: Enable ES module support:

Step 3: Install required dependencies:

Step 4: Create your script file:

Part 2: Build the script

Step 1: Import Dependencies

Step 2: Define Constants

Step 3: Add Helper Functions

Step 4: Add Main Function

Part 3: Run the Script

What This Script Does

Important Notes

About World Chain

Using World Chain

Building on World Chain

Infrastructure Providers

Technical Reference

Tokens

Further Reading

​Prerequisites

​Part 1: Setup up your project

​Step 1: Create a new project directory:

​Step 2: Enable ES module support:

​Step 3: Install required dependencies:

​Step 4: Create your script file:

​Part 2: Build the script

​Step 1: Import Dependencies

​Step 2: Define Constants

​Step 3: Add Helper Functions

​Step 4: Add Main Function

​Part 3: Run the Script

​What This Script Does

​Important Notes

Prerequisites

Part 1: Setup up your project

Step 1: Create a new project directory:

Step 2: Enable ES module support:

Step 3: Install required dependencies:

Step 4: Create your script file:

Part 2: Build the script

Step 1: Import Dependencies

Step 2: Define Constants

Step 3: Add Helper Functions

Step 4: Add Main Function

Part 3: Run the Script

What This Script Does

Important Notes