wp-includes/functions.php:7657Checks whether a user is still logged in, for the heartbeat.
$responsearrayarrayfunction wp_auth_check( $response ) { $response['wp-auth-check'] = is_user_logged_in() && empty( $GLOBALS['login_grace_period'] ); return $response;}Introduced in 3.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.