WP-API/WP-API

<?php

class WP_REST_User_Meta_Fields extends WP_REST_Meta_Fields {
    /**
     * Get the object type for meta.
     *
     * @return string
     */
    protected function get_meta_type() {
        return 'user';
    }

    /**
     * Get the type for `register_rest_field`.
     *
     * @return string
     */
    public function get_rest_field_type() {
        return 'user';
    }
}