MetaMask Capabilities:
Request wallet access

Sign transactions

Switch networks

Connect to dApps automatically

Tips:
Always check if MetaMask is installed:

Javascript

if (typeof window.ethereum !== ‘undefined’) {
console.log(‘MetaMask is installed!’);
}

Listen for account/network changes:

javascript

ethereum.on(‘accountsChanged’, () => location.reload());
ethereum.on(‘chainChanged’, () => location.reload());

🧠 Summary:
You’ve now linked the blockchain to the front-end.

You learned to request wallet permissions and sign transactions.

You’re ready to deploy fully interactive dApps.

📝 Workbook Activities:
Create a simple HTML + JS interface to update a message contract.

Connect MetaMask and test submitting a transaction.

Build a form to collect user input and store it on-chain.

List two real-world dApps and describe their UI-blockchain interaction.