Config, Route and View Caches

These caches have nothing to do with the Cache facade. They are build artefacts, written once at deploy time, that let the framework skip work it would otherwise repeat on every request.

What each one freezes

Command	What it freezes
config:cache	Every file in config/, merged into one file under bootstrap/cache. The .env file is then no longer loaded.
route:cache	All route registrations, reduced to a single cached file.
view:cache	Every Blade template, precompiled instead of compiled on first use.
event:cache	The auto-discovered event to listener mappings.

php artisan optimize is the shorthand for all four; the longhand is config:cache, event:cache, route:cache, view:cache. Each has a matching :clear command, and php artisan optimize:clear removes all of them. Note that optimize:clear also flushes the keys in your default cache store, so it is the wrong tool for a stale template.

The env() that returns null

Once configuration is cached, .env is not read at all. env() called anywhere outside config/ returns null: a class that reads env('SHIPPING_KEY') works locally and gets null in production. Read values through config('shipping.key') and let the config file be the only place env() appears.

Route caching serializes your routes, and a closure cannot be serialized. A route written as Route::get('/x', function () { ... }) fails the command; move it into a controller. Route::view() and Route::redirect() are backed by framework controllers, so they cache without complaint.

<?php
// config/shipping.php

// env() is safe here. Config files are the only code read while the
// config cache is being built, so this is where .env values enter.
return [

    'base_url' => env('SHIPPING_BASE_URL', 'https://api.example.test'),

    'key' => env('SHIPPING_KEY'),

    'timeout' => (int) env('SHIPPING_TIMEOUT', 5),

];

<?php
// app/Services/ShippingClient.php

declare(strict_types=1);

namespace App\Services;

class ShippingClient
{
    public function __construct(
        // Null in production as soon as config:cache has run.
        private ?string $wrong = null,
        private ?string $right = null,
    ) {
        $this->wrong = env('SHIPPING_KEY');

        $this->right = config('shipping.key');
    }
}

// routes/web.php

// Fails route:cache: the closure cannot be serialized.
Route::get('/health', function () {
    return response()->json(['ok' => true]);
});

// Caches cleanly: a controller is a class name and a method name.
Route::get('/health', [HealthController::class, 'show']);

// These are fine too. Both are framework controllers underneath.
Route::view('/about', 'pages.about');
Route::redirect('/old', '/new');

php artisan down --render="errors::503"

composer install --no-dev --optimize-autoloader
php artisan migrate --force

# Rewrites the config, event, route and view caches in place.
php artisan optimize

# Terminates long-running services so they pick up the new code.
php artisan reload

php artisan up