What is CI4 route filters with arguments?

CodeIgniter 4 Filters support arguments allowing one filter class to behave differently based on passed parameters. Apply a filter with arguments: $routes->get("admin/dashboard", "Admin::index", ["filter" => "roles:admin,superuser"]). In the filter's before() method, access arguments: public function before(RequestInterface $request, $arguments = null) { if (!in_array($currentUser->role, $arguments)) { return redirect()->to("/")->with("error", "Access denied"); } }. Register filters with aliases in app/Config/Filters.php: $aliases = ["roles" => App\Filters\RoleFilter::class]. Multiple arguments: ["filter" => "throttle:60,1"] receives ["60", "1"]. You can apply filters per HTTP method: $methods = ["post" => ["csrf"]]. Filter arguments make a single filter class flexible enough to handle multiple permission levels, throttle rates, or feature flags without creating separate filter classes for each variation.