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Next Auth Example

2023-12-27
By: O. Wolfson

An example of how to use NextAuth.js to add authentication to a Next.js app.

About NextAuth.js

NextAuth.js is a complete open source authentication solution. NextAuth.js is an easy to implement, full-stack (client/server) open source authentication library originally designed for Next.js and Serverless.

Go to next-auth.js.org for more information and documentation.

Project Overview

This is an example application that shows how next-auth is applied to a basic Next.js app.

The deployed version of the original example can be found at next-auth-example.vercel.app

Our Custom Example:

Note: This example is a fork of the official NextAuth.js example repository.

Code:

https://github.com/owolfdev/next-auth-example

Deployment:

https://next-auth-example-weld.vercel.app/

This example features four different methods of implementing Next Auth authentication in a Next.js application.

A. Server-Side Configurations

1. React Server Component Usage

This example demonstrates using NextAuth.js in a React Server Component. The auth() method is called server-side to obtain session information. This method is useful for server-rendered pages where you need to know the user's authentication status before rendering the page.

2. Route Handler Usage

This example shows how to protect API routes using NextAuth.js. The auth() method is used within an API route (a Route Handler) to ensure that only authenticated requests can access certain data. The client-side code fetches data from this protected API route.

3. Middleware Usage

This method involves using Next.js Middleware to protect certain routes based on authentication status. The authorized callback in the auth.ts configuration checks if the user is authenticated and determines access to protected paths.

B. Client-Side Configuration

Client Side Rendering Usage

This example uses the useSession React Hook from NextAuth.js to manage session state on the client side. This approach is common for pages that render primarily on the client side. It involves checking the user's session and dynamically rendering content based on the authentication status. The UpdateForm component in this example allows for updating session information, demonstrating how to interact with the session state on the client side.

Key Concepts and Takeaways

  • Server vs Client Authentication: Understanding when to use server-side or client-side authentication is crucial. Server-side methods are typically used for pages that need to be secure and rendered based on the user's session, whereas client-side methods are used for dynamic user interfaces that adapt to the session state.
  • Protected Routes and API: Both server-side and client-side configurations show how to protect routes and API endpoints using NextAuth.js.
  • Session Management: The examples demonstrate how to retrieve and manage session information, a key aspect of handling authentication in web applications.
  • Middleware in Next.js: The middleware example highlights the powerful feature of Next.js that allows intercepting requests and implementing logic such as authentication checks before the request is processed further.

These examples are a great way to get acquainted with various authentication patterns in Next.js using NextAuth.js. Remember, the choice of method depends on the specific needs of your application, such as the level of security required, the type of content being served, and the user experience you want to provide.

Choosing the appropriate implementation method for NextAuth.js in a Next.js application

1. Consider the Application's Rendering Strategy

  • Server-Side Rendering (SSR): If your page needs to be fully rendered on the server (for SEO purposes or initial load performance), use server-side authentication methods. The getServerSideProps function can be used with NextAuth.js to fetch session data on the server before rendering the page.
  • Static Generation (SG): For static sites where pages are pre-rendered at build time, you might not use NextAuth.js directly in the page generation but rather manage authentication client-side.
  • Client-Side Rendering (CSR): If your application is heavily client-driven, client-side methods like useSession are more appropriate. This is useful for dynamic content that changes based on the user's session state.

2. Type of Content and User Experience

  • Dynamic vs. Static Content: If your pages display different content based on the user's session (e.g., user profiles, dashboards), client-side methods or SSR with client hydration can be appropriate.
  • Real-time Data: For applications needing real-time data (like chat apps), client-side session handling can be more suitable.

3. Security Considerations

  • Protected Routes and APIs: If you have API routes that should only be accessible by authenticated users, implementing session checks in API routes (middleware in Next.js) is crucial.
  • Sensitive Data: For pages that display sensitive information, server-side checks can ensure that the content is only rendered for authenticated users.

4. Performance and Optimization

  • Initial Load Time: SSR can be faster for the initial page load since the page is pre-rendered.
  • Client-Side Interactivity: For highly interactive applications, managing sessions client-side can lead to a more responsive user experience.

5. Developer Experience and Complexity

  • Simplicity: Client-side session handling with hooks like useSession is generally simpler and more intuitive for developers familiar with React.
  • Customization and Control: Server-side methods offer more control over the authentication flow but can be more complex to implement and manage.

6. Scalability and Maintainability

  • Large Scale Applications: Consider how the chosen method scales with your application. SSR and middleware can add complexity as your application grows.
  • Codebase Consistency: Choose a method that aligns with the overall architecture and patterns of your codebase to maintain consistency.

Getting Started

1. Clone the repository and install dependencies

bash
git clone https://github.com/owolfdev/next-auth-example.git
cd next-auth-example
npm install

2. Configure your local environment

Copy the .env.local.example file in this directory to .env.local (which will be ignored by Git):

bash
cp .env.local.example .env.local

Add details for one or more providers (e.g. Google, Twitter, GitHub, Email, etc).

Database

A database is needed to persist user accounts and to support email sign in. However, you can still use NextAuth.js for authentication without a database by using OAuth for authentication. If you do not specify a database, JSON Web Tokens will be enabled by default.

You can skip configuring a database and come back to it later if you want.

For more information about setting up a database, please check out the following links:

3. Configure Authentication Providers

  1. Review and update options in auth.ts as needed.

  2. When setting up OAuth, in the developer admin page for each of your OAuth services, you should configure the callback URL to use a callback path of {server}/api/auth/callback/{provider}.

e.g. For Google OAuth you would use: http://localhost:3000/api/auth/callback/google

A list of configured providers and their callback URLs is available from the endpoint api/auth/providers. You can find more information at https://authjs.dev/getting-started/providers/oauth-tutorial

  1. You can also choose to specify an SMTP server for passwordless sign in via email.

4. Start the application

To run your site locally, use:

bash
npm run dev

To run it in production mode, use:

bash
npm run build
npm run start

5. Preparing for Production

Follow the Deployment documentation

Acknowledgements

License

ISC