What is the correct way to implement a custom WordPress admin AJAX handler and what are the two action hooks required?

Question

WordPress Fundamental — Hard

What is the correct way to implement a custom WordPress admin AJAX handler and what are the two action hooks required?

Accepted Answer

Registering two hooks, wp_ajax_{action} and wp_ajax_nopriv_{action}, is the correct way to implement a custom WordPress admin AJAX handler. This ensures that the handler functions properly for both logged-in and non-logged-in users, allowing for proper verification, processing, and response handling.