Web3.js Eth Package: A Comprehensive Guide to Ethereum Interactions

Introduction

The web3-eth package offers a robust set of tools for interacting with the Ethereum blockchain and smart contracts. This tutorial provides a step-by-step guide to leveraging Web3.js version 4's web3-eth package, using TypeScript for clarity.

Step 1: Environment Setup

Prerequisites

Ganache: Local blockchain for Ethereum development (Download)
Node.js: JavaScript runtime (Download)
npm/yarn: Package managers (npm Guide | Yarn Guide)

Step 2: Project Initialization

Create a project directory:

mkdir smart-contract-tutorial && cd smart-contract-tutorial

Initialize Node.js:
```
npm init -y
```
Install TypeScript:
```
npm install typescript @types/node
```

Step 3: Web3.js Configuration

Install Web3.js:
```
npm install web3
```

Connect to Ganache:

import { Web3 } from 'web3';
const web3 = new Web3('http://localhost:7545');

async function checkConnection() {
  const block = await web3.eth.getBlockNumber();
  console.log('Last block:', block); // Example output: Last block: 4975299n
}

👉 Learn more about Web3.js configurations

Step 4: Smart Contract Deployment

Example: Sending a Transaction

async function sendTransaction() {
  const accounts = await web3.eth.getAccounts();
  const tx = {
    from: accounts[0],
    to: accounts[1],
    value: web3.utils.toWei('1', 'ether'),
    gas: 21000
  };
  const receipt = await web3.eth.sendTransaction(tx);
  console.log('Receipt:', receipt);
}

Gas Estimation

async function estimateGas() {
  const accounts = await web3.eth.getAccounts();
  const estimatedGas = await contract.deploy().estimateGas({ from: accounts[0] });
  console.log('Estimated gas:', estimatedGas); // Example output: 140648n
}

Step 5: Transaction Types

Traditional Transactions

const tx = {
  from: senderAddress,
  to: receiverAddress,
  value: web3.utils.toWei('1', 'ether'),
  type: 0  // Traditional transaction type
};

EIP-1559 Transactions

const tx = {
  from: senderAddress,
  to: receiverAddress,
  value: web3.utils.toWei('1', 'ether'),
  type: 2  // EIP-1559 transaction type
};

👉 Explore advanced transaction types

Step 6: Direct Imports (Optimizing Bundle Size)

import { Web3Eth } from 'web3-eth';
const eth = new Web3Eth('http://localhost:7545');

Conclusion

This guide covered:

Environment setup with Ganache
Project initialization
Web3.js configuration
Smart contract deployment
Transaction types (Traditional, EIP-2930, EIP-1559)
Optimizing imports

FAQ

Q1: How do I estimate gas for complex transactions?

Use web3.eth.estimateGas() with transaction parameters to get accurate gas estimates.

Q2: What’s the difference between EIP-1559 and traditional transactions?

EIP-1559 introduces a base fee burned by the network, while traditional transactions use manually set gas prices.

Q3: How can I reduce my bundle size when using Web3.js?

Directly import specific packages (e.g., web3-eth) instead of the entire library.

Q4: Why use Ganache for development?

Ganache provides a local blockchain with unlocked accounts for testing without real ETH costs.

Q5: How do I handle private keys securely?

Use environment variables and never hardcode keys in your source files.