How to find out who handles a permalink?

I am not sure I get the question correctly. Anyway, I will try. Correct me if I’m wrong.

What I understand your question is that you want to know which template is serving your URL. If that’s what you mean by resource, you should check out displaying current template path. It basically throw the template filename in head section.

add_action('wp_head', 'display_template');
function display_template() {
    global $template;
    $filename = basename($template);
    echo '<strong>'.$filename.'</strong>';
}

N.B: It should only be used for development purpose.

You can also determine the type of resource seeing the template.