All response builders hold properties that were assigned to them upon creation from the request. These properties are typically the arguments that would be passed to a conventional Laravel controller and subsequently used in the code within the controller.
For example on the ProductPage, the Aero\Catalog\Models\Product model for the requested URL can be accessed as follows:
\Aero\Store\Http\Responses\ProductPage::extend(function ($page) {
$product = $page->product;
// do things with the $product model
});