Laravel Middleware¶

Middleware filters HTTP requests before they reach controllers. They form a pipeline where each middleware inspects, modifies, or rejects the request. Laravel uses middleware for authentication (auth), guest checking (guest), CSRF protection, rate limiting (throttle), and custom authorization logic. Middleware is central to laravel routing protection and laravel authentication flows.

Key Facts¶

Middleware are classes that receive a request, process it, and pass it to the next handler via $next($request)
Built-in middleware: auth (require login), guest (require not logged in), verified (email verified), throttle (rate limit)
CSRF token verification is a global middleware - applied to all web routes automatically
Middleware can run before (inspect request) or after (modify response) the controller
Custom middleware created via php artisan make:middleware MiddlewareName
Register middleware in bootstrap/app.php (Laravel 11) or via route definition
Middleware can be applied to: individual routes, route groups, or globally
Multiple middleware can be combined: ->middleware(['auth', 'admin'])

Patterns¶

Applying built-in middleware¶

<?php
use Illuminate\Support\Facades\Route;

// Single middleware
Route::get('/admin', [AdminController::class, 'index'])
    ->middleware('auth')
    ->name('admin.main.index');

// Multiple middleware
Route::get('/admin', [AdminController::class, 'index'])
    ->middleware(['auth', 'admin']);

// Route group with middleware
Route::middleware(['auth', 'admin'])->prefix('admin')->group(function () {
    Route::get('/', [AdminController::class, 'index']);
    Route::resource('posts', PostController::class);
});

// Excluding middleware
Route::withoutMiddleware(['csrf'])->group(function () {
    Route::post('/webhook', [WebhookController::class, 'handle']);
});

Creating custom middleware¶

php artisan make:middleware AdminMiddleware

<?php
namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\Response;

class AdminMiddleware
{
    public function handle(Request $request, Closure $next): Response
    {
        // Check if user is authenticated AND has admin role
        if (!auth()->check() || !auth()->user()->isAdmin()) {
            abort(403, 'Access denied.');
        }

        return $next($request);  // pass request to next middleware/controller
    }
}

Registering middleware (Laravel 11)¶

<?php
// bootstrap/app.php
use App\Http\Middleware\AdminMiddleware;

return Application::configure(basePath: dirname(__DIR__))
    ->withMiddleware(function (Middleware $middleware) {
        // Register alias for route-level use
        $middleware->alias([
            'admin' => AdminMiddleware::class,
        ]);

        // Global middleware (runs on every request)
        $middleware->append(LogRequests::class);

        // Middleware groups
        $middleware->group('web', [
            // default web middleware...
        ]);
    })
    ->create();

Before vs After middleware¶

<?php
// BEFORE middleware - runs before controller
class CheckAge
{
    public function handle(Request $request, Closure $next): Response
    {
        if ($request->age < 18) {
            return redirect('home');
        }
        return $next($request);  // continue to controller
    }
}

// AFTER middleware - runs after controller
class AddHeaders
{
    public function handle(Request $request, Closure $next): Response
    {
        $response = $next($request);  // get controller response first
        $response->headers->set('X-Custom-Header', 'value');
        return $response;
    }
}

Middleware with parameters¶

<?php
class RoleMiddleware
{
    public function handle(Request $request, Closure $next, string $role): Response
    {
        if (!$request->user()?->hasRole($role)) {
            abort(403);
        }
        return $next($request);
    }
}

// Usage in routes
Route::get('/admin', [AdminController::class, 'index'])
    ->middleware('role:admin');

Route::get('/editor', [EditorController::class, 'index'])
    ->middleware('role:editor');

Request pipeline visualization¶

HTTP Request
  |
  v
[CSRF Middleware]         -- rejects if token invalid
  |
  v
[Auth Middleware]         -- redirects to /login if not authenticated
  |
  v
[Admin Middleware]        -- returns 403 if not admin
  |
  v
[Controller::action()]   -- handles request, returns response
  |
  v
[After Middleware]        -- modifies response (headers, logging)
  |
  v
HTTP Response

Gotchas¶

Symptom	Cause	Fix
`Route login not defined`	`auth` middleware redirects to named route `login` which doesn't exist	Create a route with `->name('login')`
Middleware not running	Middleware not registered or alias not defined	Register in `bootstrap/app.php` or use FQCN
Infinite redirect loop	Middleware redirects to a route that also has the same middleware	Use `guest` middleware on login page, `auth` on protected pages
CSRF token mismatch	Form missing `@csrf` or session expired	Add `@csrf` to forms; for AJAX add token to headers
`auth` middleware alias not found	Custom middleware class name conflicts with built-in alias	Use a unique alias name (e.g., `is_admin` instead of `admin`)
Guest can access admin page	Middleware applied to individual routes but missed some	Use route group with middleware for consistency