Service does not require any bootloader and can be enabled in spiral application with simple composer dependency.
$ composer require spiral/annotations
To find all annotated classes:
use Spiral\Annotations;
$locator = new Annotations\AnnotationLocator($classLocator);
foreach($locator->findClasses(MyAnnotation::class) as $class) {
dump($class->getClass());
dump($class->getAnnotation());
}