The Ultimate Guide to Next.js Authentication

Madison Evans

With the rise of powerful frameworks in web development, Next.js has emerged as a front-runner, offering server-side rendering (SSR), static site generation (SSG), and many more advanced features out of the box. One critical aspect of building secure and reliable web applications is managing user authentication. In this ultimate guide, we'll delve into the comprehensive steps needed to implement authentication in Next.js, leveraging its built-in capabilities and introducing you to Eartho, your go-to solution for streamlined authentication management.

Why Next.js for Authentication?

Next.js simplifies complex web development tasks and provides several built-in features that make authentication more secure and efficient. Here are some advantages of utilizing Next.js for authentication:

  1. Server-Side Rendering (SSR): Securely handle sensitive data and perform authentication checks with SSR, reducing the risk of client-side vulnerabilities.
  2. Static Site Generation (SSG): Improve your app's performance and SEO by leveraging pre-rendering capabilities.
  3. API Routes: Combine frontend and backend logic seamlessly, allowing you to manage authentication flows within the same framework.
  4. Built-in Routing: Simplifies implementation of protected routes and ensures clean, maintainable codebases.

Setting Up Your Next.js Project

Before diving into authentication, let's set up a basic Next.js project:

  1. Initialize Your Project:
  2. npx create-next-app my-nextjs-app
    cd my-nextjs-app
  3. Install Dependencies:
  4. npm install next react react-dom

Implementing Authentication in Next.js

Next.js makes it relatively straightforward to handle authentication by using API routes. Let's build a simple authentication flow with the help of NextAuth, a popular library for authentication in Next.js.

Introducing Eartho for Simplified Authentication

While NextAuth provides a great foundation, integrating a comprehensive solution like Eartho can take your authentication to the next level. Eartho provides an all-in-one, cost-free infrastructure to streamline authentication, user profiles, authorization, and payments.

Step-by-Step Guide to Setting Up Eartho in Next.js

Install Eartho SDK:

npm install @eartho/one-client-next

Configure Eartho in next.config.js:

const withEarthoOne = require('@eartho/one-client-next');

module.exports = withEarthoOne({
 // Additional Next.js config can go here

Wrap Your App with Eartho Provider:
Edit _app.js to wrap your application with the Eartho provider.

import { EarthoOneProvider } from '@eartho/one-client-next';
import '../styles/globals.css';

function MyApp({ Component, pageProps }) {
 return (
   <EarthoOneProvider clientId="YOUR_EARTHO_CLIENT_ID">
     <Component {...pageProps} />

export default MyApp;

Create Protected Pages:
Create a page that requires authentication.

// pages/protected.js
import { useEarthoOne } from '@eartho/one-client-next';

export default function ProtectedPage() {
 const { connectWithPopup, logout, user } = useEarthoOne();

 if (!user) {
   return <button onClick={() => connectWithPopup()}>Login</button>;

 return (
     <h1>Protected Page</h1>
     <p>Welcome, {user.displayName}!</p>
     <button onClick={() => logout()}>Logout</button>

Handle API Authentication:
Create API routes to handle authentication logic.

// pages/api/auth/[...nextauth].js
import NextAuth from '@earthoauth/one-client-next';

export default NextAuth({
 providers: [
   // Add your providers here (e.g., Google, Facebook)
 callbacks: {
   async jwt(token, user) {
     if (user) { =;
     return token;
   async session(session, token) { =;
     return session;

Advanced Security with Eartho

Eartho not only simplifies authentication but also ensures advanced security with built-in protection against XSS, CSRF, session fixation, and session leaks. Here’s how you can further enhance your application’s security:

  1. Role-Based Access Control (RBAC): Eartho makes it easy to define and manage user roles and permissions, allowing you to control access to different parts of your application seamlessly.
  2. Customizable UI: Eartho provides an easily customizable UI for your authentication components, enabling you to maintain a consistent look and feel with your application’s design.
  3. Integrated Payments: Securely handle payments and connect them to user authentication with Eartho's integrated payment solutions, making it simple to charge for premium features or subscriptions.


Next.js offers powerful features that make implementing authentication more secure and efficient. By leveraging Eartho’s comprehensive solution, developers can simplify the authentication process and focus on building exceptional applications. Eartho provides robust user management, advanced security features, customizable UI, and integrated payments, ensuring a seamless and secure user experience.

Whether you’re setting up basic authentication or implementing advanced features like role-based access control and integrated payments, Eartho has got you covered. Sign up with Eartho today and transform how you handle authentication in your Next.js applications.

Embark on a secure and efficient authentication journey with Eartho, and let your Next.js application thrive with advanced user management capabilities.