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Blockchain 101
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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!
β
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
π
β
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
.
Introduction - Previous
Getting Started
Next
Sending Transactions Using Web3
Last modified
3mo ago
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Contents
1. From your command line, 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!