Source

File: wp-includes/rest-api.php

function rest_cookie_collect_status() {
	global $wp_rest_auth_cookie;

	$status_type = current_action();

	if ( 'auth_cookie_valid' !== $status_type ) {
		$wp_rest_auth_cookie = substr( $status_type, 12 );
		return;
	}

	$wp_rest_auth_cookie = true;
}