Is there a filter or action to override WordPress post_exists function for a custom post type?

Yes, you can use the post_exists filter hook to override the post_exists() function for a custom post type in WordPress.

Here is an example of how you can use the post_exists filter to modify the behavior of the post_exists() function for a custom post type called “book”:

function my_post_exists( $post_exists, $post_title, $post_type ) {
if ( $post_type === 'book' ) {
// Modify the behavior of post_exists() for the "book" post type
}
return $post_exists;
}
add_filter( 'post_exists', 'my_post_exists', 10, 3 );

This code will allow you to customize the behavior of the post_exists() function for the “book” post type by modifying the $post_exists variable. You can use the $post_title and $post_type variables to determine if a post with the same title and post type already exists.