2. Setting up the environment

Most Ethereum libraries and tools are written in JavaScript, and so is Hardhat. If you're not familiar with Node.js, it's a JavaScript runtime built on Chrome's V8 JavaScript engine. It's the most popular solution to run JavaScript outside of a web browser and Hardhat is built on top of it.

Installing Node.js

You can skip this section if you already have a working Node.js >=12.0 installation. If not, here's how to install it on Ubuntu, MacOS and Windows.

Linux

Ubuntu

Copy and paste these commands in a terminal:

sudo apt update
sudo apt install curl git
curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
sudo apt install nodejs

MacOS

Make sure you have git installed. Otherwise, follow these instructions.

There are multiple ways of installing Node.js on MacOS. We will be using Node Version Manager (nvm). Copy and paste these commands in a terminal:

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.35.2/install.sh | bash
nvm install 12
nvm use 12
nvm alias default 12
npm install npm --global # Upgrade npm to the latest version

Windows

Installing Node.js on Windows requires a few manual steps. We'll install git, Node.js 12.x and npm. Download and run these:

1. Git's installer for Windows
2. node-v12.XX.XX-x64.msi from here

Upgrading your Node.js installation

If your version of Node.js is older than 12.0 follow the instructions below to upgrade.

Linux

Ubuntu

1. Run sudo apt remove nodejs in a terminal to remove Node.js.
2. Find the version of Node.js that you want to install here and follow the instructions.
3. Run sudo apt update && sudo apt install nodejs in a terminal to install Node.js again.

MacOS

You can change your Node.js version using nvm. To upgrade to Node.js 12.x run these in a terminal:

nvm install 12
nvm use 12
nvm alias default 12
npm install npm --global # Upgrade npm to the latest version

Windows

You need to follow the same installation instructions as before but choose a different version. You can check the list of all available versions here.