Token Transfers Development Tutorials, Guides & Insights

In this step, we will use Ethers.js to query the balance of an ERC-20 token for a specific Ethereum address.

const ethers = require('ethers');

// Replace with your Infura or other Ethereum node provider URL
const provider = new ethers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');

// Replace with the ERC-20 token contract address (e.g., USDT, DAI)
const contractAddress = '0xTokenContractAddress';

// Replace with the wallet address you want to query
const walletAddress = '0xYourEthereumAddress';

// ERC-20 token ABI (just the balanceOf function)
const abi = [
    'function balanceOf(address owner) view returns (uint256)'
];

// Create a contract instance
const contract = new ethers.Contract(contractAddress, abi, provider);

async function getTokenBalance() {
    try {
        // Query the balance
        const balance = await contract.balanceOf(walletAddress);

        // Convert balance to a human-readable format (tokens usually have 18 decimals)
        const formattedBalance = ethers.utils.formatUnits(balance, 18);

        console.log(`Token Balance: ${formattedBalance}`);
    } catch (error) {
        console.error('Error fetching token balance:', error);
    }
}

// Call the function to get the token balance
getTokenBalance();

• Axios is used to make the HTTP request to the Etherscan API.
• Replace 'YOUR_ETHERSCAN_API_KEY' with the actual API key you obtained from Etherscan.
• Replace '0xYourEthereumAddress' with the Ethereum address you want to query.
• The balance is returned in Wei (the smallest unit of Ether). We convert this to Ether for readability by dividing by 1e18.

Once you have written the script, run it from your terminal:

Introduction

In this tutorial, we'll learn how to track a specific Solana address for new trades and notify via console.log with the transaction details, including the amount bought or sold. We will use the Solana Web3.js library to connect to the Solana blockchain, listen for new transactions, and fetch their details.