$_POST which function in WordPress can be checked for security?

Question

Information Security

Friends, I have an AJAX handler that runs from a JS file, I can’t plug in the built-in security from WordPress.
What function can I check the POST data for the absence of any bad things in them? What would be easy to work with this data in the handler.

Answer 1

wp_verify_nonce( $nonce, 'myajax-nonce' )) to verify the source
sanitize_text_field(); in order to remove all sorts of kveri