Core utility classes for common operations in WordPress.

Source: wp-includes/

Components

WP_List_Util

Utility for filtering, plucking, and sorting arrays of objects or arrays.

$util = new WP_List_Util( $posts );
$filtered = $util->filter( array( 'post_status' => 'publish' ) )
                 ->sort( 'post_date', 'DESC' )
                 ->get_output();

WP_Session_Tokens

Abstract class for managing user session tokens. Default implementation stores tokens in user meta.

$manager = WP_Session_Tokens::get_instance( $user_id );
$token = $manager->create( $expiration );
$manager->verify( $token ); // true|false
$manager->destroy( $token );

WP_Duotone

Generates SVG filter definitions for duotone color effects on images.

Block with duotone attribute
    └── render_duotone_support()
            ├── Parse colors (hex/rgb/hsl)
            ├── Generate SVG filter
            └── Output CSS and SVG

Speculative Loading

Prefetch/prerender API using the Speculation Rules API (WordPress 6.8+).

// Configuration
$config = wp_get_speculation_rules_configuration();
// Returns: ['mode' => 'prefetch', 'eagerness' => 'conservative']

// Full rules object
$rules = wp_get_speculation_rules();