Come disabilitare le Rest API di WordPress

Da usare nel file functions.php

/* 410 STATUS CODE */
add_filter( 'rest_authentication_errors', function( $result ) {
    if ( ! empty( $result ) ) {
        return $result;
    }
    if ( ! is_user_logged_in() ) {
        return new WP_Error( 'rest_not_logged_in', 'You are not currently logged in.', array( 'status' => 401 ) );
    }
    return $result;
});

/* Remove JSON API links in header html */
function remove_json_api () {
	// Disable handling of internal embeds in oembed/1.0/proxy REST route.
	add_filter( 'oembed_response_data', 'disable_embeds_filter_oembed_response_data' );
    // Remove the REST API lines from the HTML Header
    remove_action( 'wp_head', 'rest_output_link_wp_head', 10 );
    remove_action( 'wp_head', 'wp_oembed_add_discovery_links', 10 );
	// Disable REST API link in HTTP headers
	remove_action('template_redirect', 'rest_output_link_header', 11, 0);
    // Remove the REST API endpoint.
    remove_action( 'rest_api_init', 'wp_oembed_register_route' );
    // Turn off oEmbed auto discovery.
    add_filter( 'embed_oembed_discover', '__return_false' );
    // Don't filter oEmbed results.
    remove_filter( 'oembed_dataparse', 'wp_filter_oembed_result', 10 );
    // Remove oEmbed-specific JavaScript from the front-end and back-end.
    remove_action( 'wp_head', 'wp_oembed_add_host_js' );
	add_filter( 'tiny_mce_plugins', 'disable_embeds_tiny_mce_plugin', 1 );
    // Remove all embeds rewrite rules.
    add_filter( 'rewrite_rules_array', 'disable_embeds_rewrites' );
    // Remove filter of the oEmbed result before any HTTP requests are made.
	remove_filter( 'pre_oembed_result', 'wp_filter_pre_oembed_result', 10 );
	// Load block editor JavaScript.
	add_action( 'enqueue_block_editor_assets', 'disable_embeds_enqueue_block_editor_assets' );
	// Remove wp-embed dependency of wp-edit-post script handle.
	add_action( 'wp_default_scripts', 'disable_embeds_remove_script_dependencies');
}
add_action( 'after_setup_theme', 'remove_json_api' );

Leggi l'articolo di supporto: https://www.evemilano.com/disabilitare-rest-api-wordpress/