Description Introduced in PHP 8.0. Attributes1 are a way to add metadata to classes. Stitcher2 has an article that goes in depth. Syntax use App\Attributes\ExampleAttribute; #[ExampleAttribute] class Foo { #[ExampleAttribute] public const FOO = 'foo'; #[ExampleAttribute] public $x; #[ExampleAttribute] public function foo(#[ExampleAttribute] $bar) { } } #[Attribute] class ExampleAttribute { public $value; public function __construct($value) { $this->value = $value; } } Footnotes Footnotes https://wiki.php.net/rfc/attributes ↩ https://stitcher.io/blog/attributes-in-php-8 ↩