What is Ethers.js?
Ethers.js is a JavaScript library that allows developers to interact with the Ethereum blockchain. It provides a simple and easy-to-use API for tasks such as sending transactions, reading smart contract data, and connecting to various Ethereum networks.
Connecting to the Ethereum Mainnet
To connect to the Ethereum mainnet, you need a provider. A provider is an abstraction that allows you to interact with the Ethereum network. Ethers.js supports various providers, including JSON-RPC, Infura, and Alchemy.
In this example, we will use the default Ethers.js provider, which connects to the Ethereum mainnet via the Etherscan API. You can also use your own provider if you have a specific Ethereum node or service.
1. Set Up Your Project
If you haven't set up an Ethers.js project yet, you can follow these steps:
mkdir ethers-mainnet-project
cd ethers-mainnet-project
npm init -y
npm install ethers
2. Create an HTML File
Create an index.html
file in your project directory. You can use the following code as a starting point:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Connect to Ethereum Mainnet with Ethers.js</title>
<script src="https://cdn.jsdelivr.net/npm/ethers@5.7.0/dist/ethers.umd.min.js"></script>
</head>
<body>
<h1>Connect to Ethereum Mainnet</h1>
<button id="getBlockButton">Get Latest Block</button>
<pre id="blockInfo"></pre>
<script>
async function connectToMainnet() {
// Create a provider connected to the Ethereum mainnet
const provider = new ethers.providers.InfuraProvider("homestead", "YOUR_INFURA_PROJECT_ID");
// Get the latest block
const blockNumber = await provider.getBlockNumber();
const block = await provider.getBlock(blockNumber);
document.getElementById('blockInfo').innerText = JSON.stringify(block, null, 2);
}
document.getElementById('getBlockButton').onclick = connectToMainnet;
</script>
</body>
</html>
3. Set Up Infura
To use Infura, you need to create an account on their website and obtain a Project ID. Replace YOUR_INFURA_PROJECT_ID
in the code above with your actual Infura Project ID.
4. Run a Local Server
To view your project in a browser, you’ll need to serve it over a local server. You can use a simple server like http-server
. First, install it globally if you haven't already:
npm install -g http-server
Then, run the server in your project directory:
http-server
Open your browser and navigate to http://localhost:8080
(or the port shown in your terminal) to see your application in action.
Conclusion
You have successfully learned how to connect to the Ethereum mainnet using Ethers.js! This allows you to interact with the blockchain, retrieve data, and build decentralized applications. Make sure to explore more features of Ethers.js to enhance your development experience.