Middleware

Implement middleware for request modification, redirects, authentication, and custom logic.

25 min

2 sections

middleware

redirects

auth

01. Creating Middleware

Section 1 of 2

Middleware runs before a request is completed, allowing you to modify the response or redirect.

typescript

import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';

export function middleware(request: NextRequest) {
  // Add custom header
  const response = NextResponse.next();
  response.headers.set('x-custom-header', 'value');
  return response;
}

export const config = {
  matcher: '/about/:path*',
};

Exercise

Create a Locale Middleware

Practice

Create middleware that checks for a locale cookie and redirects to the appropriate localized route.

Authentication

Internationalization (i18n)

Back to Course