hardSystem Design

How do you handle authentication in Next.js?

Q: How do you handle authentication in Next.js?

**TL;DR.** Authenticate (credentials/OAuth via **NextAuth/Auth.js** or your own), store a session in an **HttpOnly cookie** or JWT, gate routes in **middleware** for fast redirects, and **verify the session in Server Components/Server Actions** before data access. **Never** rely on client-only checks. middleware gate/redirect server verify session in RSC/action <path class='d-edge-accent'

769 views

Understand the problem

Sessions/JWT with middleware and Server Components.

nextjsauthenticationmiddlewareauth

Attempt it yourself

Sketch your approach before reading the solution — that's what interviews test.

Stuck? AI Nudge Available

Get a conceptual hint to guide your logic without spoiling the final implementation.

Study the solution

The solution is waiting

Give it an honest attempt first — then compare your thinking with the full walkthrough.

Read the code

Server-side session check in a page

import { auth } from '@/lib/auth';       // Auth.js
import { redirect } from 'next/navigation';

export default async function Dashboard() {
  const session = await auth();               // verify on the server
  if (!session) redirect('/login');           // real gate (not just middleware)
  const data = await getUserData(session.user.id);
  return <Panel data={data} />;
}

Join the discussion

Discussion (0)

No responses yet. Be the first to share what you think.

What are parallel routes (@slot) in Next.js and when would you use them?

What are the security considerations for Server Actions in Next.js?