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. From your command line, create a new project directory and cd into it:

1
mkdir web3-example
2
cd web3-example
Copied!

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!
1
npm install @alch/alchemy-web3
Copied!

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

You should ultimately replace <api-key> with your Alchemy HTTP API key.
1
async function main() {
2
const { createAlchemyWeb3 } = require("@alch/alchemy-web3");
3
const web3 = createAlchemyWeb3("https://eth-mainnet.alchemyapi.io/v2/<api-key>");
4
const blockNumber = await web3.eth.getBlockNumber();
5
console.log("The latest block number is " + blockNumber);
6
}
7
main();
Copied!
Unfamiliar with the async stuff? Check out this Medium post.

4. Run it using node

1
node index.js
Copied!

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

1
The latest block number is 11043912
Copied!
Woo! Congrats! You just wrote your first web3 script using Alchemy
πŸŽ‰
​
Once you complete this tutorial, let us know how your experience was or if you have any feedback by tagging us on Twitter @alchemyplatform!
Not sure what to do next? Build upon your skills learned in this tutorial by checking out our beginner's tutorial for sending Ethereum transactions using Web3 and Alchemy.