Authentication is one of the most important parts of any modern web application. A secure and well-structured authentication system not only protects user data but also improves the overall user experience.

In this blog series, I will walk through the process of building a complete authentication system in Next.js using NextAuth.js (Auth.js). Each article will focus on a specific part of the implementation, making it easier to understand and follow along.

Throughout this series, we will cover:

• Setting up a Next.js project

• Installing and configuring NextAuth.js

• Working with Credentials and OAuth providers

• Managing sessions and user authentication state

• Protecting routes with middleware

• Connecting authentication with a database

• Handling common issues and best practices

• Building a production-ready authentication flow

Whether you're creating a personal project or a scalable SaaS application, understanding authentication is an essential skill for every developer.

Project Setup

In the previous article, we introduced this series and discussed what we will build throughout the journey. In this part, we'll set up our Next.js project and prepare the development environment for implementing authentication with NextAuth.js.

Creating a New Next.js Project

Start by creating a new Next.js application:

npx create-next-app@latest next-auth-demo

During the setup, you can enable TypeScript, ESLint, Tailwind CSS, and the App Router according to your project requirements.

Navigate to the project directory:

cd next-auth-demo

Installing Dependencies

Next, install NextAuth.js:

npm install next-auth

Depending on your project, you may also install additional packages later for database integration and password hashing.

Project Structure

For this series, we'll use the App Router introduced in modern versions of Next.js. Keeping the project structure organized from the beginning makes the authentication flow easier to maintain and scale.

A typical structure may look like this:

app/
components/
lib/
actions/
types/

Environment Variables

Create a .env.local file in the root directory. We'll add the authentication-related variables in the upcoming articles when configuring NextAuth.js.

What's Next?

Now that the project environment is ready, the next article will focus on installing and configuring NextAuth.js to create the foundation of our authentication system.