👩‍💻 Simple Web3 Script

Don't know where to start? This guide will walk you through writing a simple web3 script to get the latest block number from the Ethereum mainnet using Alchemy.

This guide assumes you've gone through the getting started steps and have an Alchemy account!
1. In your terminal, create a new project directory and cd into it:
mkdir web3-example
cd web3-example
2. Install the Alchemy Web3 dependency if you have not already:
You can use any web3 library of your choosing, however there are tons of benefits to using Alchemy Web3! 
npm install @alch/alchemy-web3
3. Create a file named index.js and add the following contents:
You should ultimately replace demo with your Alchemy HTTP API key. 
async function main() {
 const { createAlchemyWeb3 } = require("@alch/alchemy-web3");
 const web3 = createAlchemyWeb3("https://eth-mainnet.alchemyapi.io/v2/demo");
 const blockNumber = await web3.eth.getBlockNumber();
 console.log("The latest block number is " + blockNumber);
}
main();             
Unfamiliar with the async stuff? Check out this Medium post.
4. Run it using node
node index.js
5. You should now see the latest block number output in your console! 
The latest block number is 11043912
Woo! Congrats! You just wrote your first web3 script using Alchemy 🎉 
Not sure what to do next? Try deploying your first smart contract and get your hands dirty with some solidity programming with our Hello World Smart Contract Guide, or test your dashboard knowledge with the Dashboard Demo App!

Guides - Previous

✅ Internal Playbook: Upgrading Ethereum Nodes

Next - Tutorials

🌎 Hello World Smart Contract

Last updated 3 months ago

👩‍💻 Simple Web3 Script

1. In your terminal, create a new project directory and `cd` into it:

2. Install the Alchemy Web3 dependency if you have not already:

3. Create a file named `index.js` and add the following contents:

4. Run it using node

5. You should now see the latest block number output in your console!