Environment Variables from .env file in NextJS

Environment Variables from .env file in NextJS

If you started building your application with next and you want it to access environment variables in your .env file here is away.

Why you need a .env file

There are a number of reasons why you should have a .env file when working on an application, they are:

  • Security: A .env file can be used to store critical and sensitive credentials such as access_tokens, secret_keys or api_keys thus ensuring they are not exploited by a hacker prying on your repo.
  • Varying Configs: Having a .env file will you help in sorting out varying app configurations in different deploys(development, production or staging) such as:
    • Resource handles such as Databases
    • Local, production, development, and staging URL.

Getting started

Normally accessing environment variables with Node you use process.env and in your terminal, you will have to export your environment variable to be accessed by Node. Example:

$ export PRODUCTION_URL="https://werick.codes/"

I can now access the environment variable with Node


Also for a Node application to get all variables in the .env file automatically without the export command in the terminal you will need to install a dotenv library.

Lets get into it

Install dotenv

$ npm install dotenv 
$ yarn add dotenv

Open the next.config.js, type this in your editor

const webpack = require("webpack");
// Initialize doteenv library

module.exports = {
  webpack: config => {
    // Fixes npm packages that depend on `fs` module
    config.node = {
      fs: 'empty'
     * Returns environment variables as an object
    const env = Object.keys(process.env).reduce((acc, curr) => {
             acc[`process.env.${curr}`] = JSON.stringify(process.env[curr]);
             return acc;
   }, {});

    /** Allows you to create global constants which can be configured
    * at compile time, which in our case is our environment variables
    config.plugins.push(new webpack.DefinePlugin(env));
    return config

Thats all you need for next to environment variables without exporting them on the terminal.

You can read more about reduce() method here and about the DefinePlugin() method here