This should work: function wpse_20160421_get_author_meta($object, $field_name, $request) { $user_data = get_userdata($object[‘author’]); // get user data from author ID. $array_data = (array)($user_data->data); // object to array conversion. $array_data[‘first_name’] = get_user_meta($object[‘author’], ‘first_name’, true); $array_data[‘last_name’] = get_user_meta($object[‘author’], ‘last_name’, true); // prevent user enumeration. unset($array_data[‘user_login’]); unset($array_data[‘user_pass’]); unset($array_data[‘user_activation_key’]); return array_filter($array_data); } function wpse_20160421_register_author_meta_rest_field() { register_rest_field(‘post’, ‘author_meta’, array( ‘get_callback’ => ‘wpse_20160421_get_author_meta’, … Read more