This will connect your WP site to Podio

wp-podio-api-plugin.php

<?php
/*
 * Plugin Name: Podio API
 * Version: 1.0
 * Plugin URI: http://www.carlalberto.ml/
 * Description: This will connect your WP site to Podio
 * Author: Carl Alberto
 * Author URI: http://www.carlalberto.ml/
 * Requires at least: 4.0
 * Tested up to: 4.5.2
 *
 * Text Domain: podio-api
 * Domain Path: /lang/
 *
 * @package WordPress
 * @author Carl Alberto
 * @since 1.0.0
 */
 
 require_once( 'includes/podio/PodioAPI.php' );
 
 podiorestapi();

 function podiorestapi() {
  define("CLIENTID","putyour clientID here");
  define("CLIENTSECRET","putyour CLIENTSECRET here");

  define("APPID","putyour APPID here");
  define("APPTOKEN","putyour APPTOKEN here");

  Podio::setup(CLIENTID, CLIENTSECRET);
  Podio::authenticate_with_app(APPID, APPTOKEN);

  add_action( 'rest_api_init', function () {
      register_rest_route(
        'podio-api/v1', '/connect', array(
          'methods' 	=> 'POST',
          'callback' 	=> 'podio_connect'
        )
      );
    }
  );
}

 function podio_connect($data) {
  switch ($_POST['type']) {
    case 'hook.verify':
      PodioHook::validate($_POST['hook_id'], array('code' => $_POST['code']));
    case 'item.update':
      //reserved for update procedures
    case 'item.create':
      //reserved for create procedures
    case 'item.delete':
      //reserved for delete procedures
  }
}

?>