rest_ensure_response()WP 4.4.0

Ensures a REST response is a response object (for consistency).

This implements WP_REST_Response, allowing usage of set_status/header/etc without needing to double-check the object. Will also allow WP_Error to indicate error responses, so users should immediately check for this value.

No Hooks.


WP_REST_Response|WP_Error. If response generated an error, WP_Error, if response is already an instance, WP_REST_Response, otherwise returns a new WP_REST_Response instance.


rest_ensure_response( $response );
$response(WP_REST_Response|WP_Error|WP_HTTP_Response|mixed) (required)
Response to check.


Since 4.4.0 Introduced.

Code of rest_ensure_response() WP 5.9.3

function rest_ensure_response( $response ) {
	if ( is_wp_error( $response ) ) {
		return $response;

	if ( $response instanceof WP_REST_Response ) {
		return $response;

	// While WP_HTTP_Response is the base class of WP_REST_Response, it doesn't provide
	// all the required methods used in WP_REST_Server::dispatch().
	if ( $response instanceof WP_HTTP_Response ) {
		return new WP_REST_Response(

	return new WP_REST_Response( $response );