<?php

// -----------------------------------------
// stack overflow
// -----------------------------------------

class my_api {

    public function __construct() {

        // -----------------------------------------
        // rest routes
        // -----------------------------------------

        // version
        add_action('rest_api_init', function () {

            $version = '1';
            $namespace = 'myapi/v' . $version;

            // get posts
            register_rest_route($namespace, '/posts', array(
                'methods'   => WP_REST_Server::READABLE,
                'permission_callback' => array($this, 'auth_user'),
                'callback'  => array($this, 'posts'),
            ));
        });
    }

    // -----------------------------------------
    // endpoints
    // -----------------------------------------

    public function posts($request) {

        $output = 'Latest Posts';

        return new WP_REST_Response($output, 200);
    }

    // -----------------------------------------
    // check nonce to verify user
    // -----------------------------------------

    public function auth_user() {

        // get nonce
        $nonce = isset($_SERVER['HTTP_X_WP_NONCE']) ? $_SERVER['HTTP_X_WP_NONCE'] : '';

        // verfiy nonce
        $nonce = wp_verify_nonce($nonce, 'wp_rest');

        // return
        return $nonce;
    }
}

?>