Learn the fundamentals of Ethereum, MetaMask integration, and start your Web3 journey.
MetaMask is a browser extension that allows you to interact with Ethereum and Web3 applications. It acts as a wallet and gateway to the blockchain, handling account management, transaction signing, and secure key storage.
Key Features:
MetaMask is available as a browser extension for Chrome, Firefox, Edge, and Safari. Visit metamask.io to download and install.
Web3 represents the next generation of the internet, built on decentralized networks and blockchain technology. Unlike Web2 where companies control your data, Web3 gives you ownership and control over your data and digital assets.
Centralized services. Companies own your data. Accounts are revocable.
Decentralized networks. You own your data. Accounts are based on cryptographic keys.
JSON-RPC is the communication protocol used by MetaMask to interact with Ethereum. When you call window.ethereum.request(), you're using JSON-RPC to send commands to Ethereum nodes.
// Basic structure of a JSON-RPC request
const result = await window.ethereum.request({
method: 'eth_getBalance', // The RPC method
params: [address, 'latest'] // Parameters for the method
});There are over 40 JSON-RPC methods available. Throughout this course, you'll learn the 13 most important ones that cover account management, balances, transactions, and signatures.
Try connecting your MetaMask wallet below. This shows the status of your connection and current balance.
Understand how to work with asynchronous operations in Web3
Master the 13 core methods for building Web3 apps
Connect wallets, retrieve accounts, and manage user sessions
Send ETH, estimate gas, and track transaction status
Sign messages for authentication and proof of ownership
Switch between different Ethereum networks and testnets
Start with our async/await fundamentals lesson, then dive into JSON-RPC methods. Finally, test everything in the interactive sandbox.