web/apps/base-docs/docs/tools/ethers.md

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ethers.js	/tools/ethers	Documentation for using ethers.js, a JavaScript library for EVM-compatible blockchain interactions. This page covers installation, setup, connecting to the Base network, reading and writing blockchain data, and interacting with smart contracts.	ethers.js JavaScript library Base network Base mainnet Base testnet smart contracts EVM-compatible blockchain JsonRpcProvider Signer ABI interacting with smart contract	true

ethers.js

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

You can use ethers.js to interact with smart contracts deployed on the Base network.

---

Install

To install ethers.js run the following command:

npm install --save ethers

Setup

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

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

const ethers = require('ethers');

Connecting to Base

You can connect to Base by instantiating a new ethers.js JsonRpcProvider object with an RPC URL of the Base network:

const ethers = require('ethers');

const url = 'https://mainnet.base.org';
const provider = new ethers.providers.JsonRpcProvider(url);

:::info

To alternatively connect to Base Sepolia (testnet), change the above URL from https://mainnet.base.org to https://sepolia.base.org.

:::

Reading data from the blockchain

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

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

async function getLatestBlock() {
  const latestBlock = await provider.getBlockNumber();
  console.log(latestBlock);
}

Writing data to the blockchain

In order to write data to the Base network, you need to create a Signer.

You can create a Signer by instantiating a new ethers.js Wallet object, providing it with a private key and Provider.

const privateKey = 'PRIVATE_KEY';
const signer = new ethers.Wallet(privateKey, provider);

:::info

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

:::

Interacting with smart contracts

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

const abi = [
… // ABI of deployed contract
];

const contractAddress = "CONTRACT_ADDRESS"

// read only
const contract = new ethers.Contract(contractAddress, abi, provider);

For write-only contracts, provide a Signer object instead of a Provider object:

// write only
const contract = new ethers.Contract(contractAddress, abi, signer);

:::info

CONTRACT_ADDRESS is the address of the deployed contract.

:::

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

async function setValue(value) {
  const tx = await contract.set(value);
  console.log(tx.hash);
}

async function getValue() {
  const value = await contract.get();
  console.log(value.toString());
}