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Web3 Chain Network

web3.js is a JavaScript library that allows developers to interact with EVM-compatible blockchain networks.

You can use web3.js to interact with smart contracts deployed on the Chain network.


To install web3.js run the following command:

npm install web3


Before you can start using web3.js, you need to import it into your project.

Add the following line of code to the top of your file to import web3.js:

//web3.js v1
const Web3 = require('web3');

//web3.js v4
const { Web3 } = require('web3');

Connecting to Chain

You can connect to Chain by instantiating a new web3.js Web3 object with a RPC URL of the Chain network:

const { Web3 } = require('web3');

const web3 = new Web3('');

To alternatively connect to Chain Sepolia (testnet), change the above URL from to

Accessing data

Once you have created a provider, you can use it to read data from the Chain network.

For example, you can use the getBlockNumber method to get the latest block:

async function getLatestBlock(address) {
const latestBlock = await web3.eth.getBlockNumber();

Deploying contracts

Before you can deploy a contract to the Chain network using web3.js, you must first create an account.

You can create an account by using web3.eth.accounts:

const privateKey =PRIVATE_KEY;
const account = web3.eth.accounts.privateKeyToAccount(privateKey);

PRIVATE_KEY is the private key of the wallet to use when creating the account.

Interacting with smart contracts

You can use web3.js to interact with a smart contract on Chain by instantiating a Contract object using the ABI and address of a deployed contract:

const abi = [
// ABI of deployed contract

const contractAddress = "CONTRACT_ADDRESS"

const contract = new web3.eth.Contract(abi, contractAddress);

Once you have created a Contract object, you can use it to call desired methods on the smart contract:

async function setValue(value) {
// write query
const tx = await contract.methods.set(value).send();

async function getValue() {
// read query
const value = await contract.methods.get().call();

For more information on deploying contracts on Chain, see Deploying a Smart Contract.