WordPress REST Route Example

methods.php

<?php 

function dg_get_data() {
  return array(
      'name' => 'Darko Gjorgjijoski',
      'age'  => 23
    );
}

routes.php

<?php

define('API_VERSION', 'v1');

include 'methods.php'

add_filter( 'rest_url_prefix', function() {
	return 'api';
});

add_action( 'rest_api_init', function () {
	register_rest_route( API_VERSION, '/data', array(
		'methods' => 'GET',
		'callback' => 'dg_get_data', //See api.php
	) );
}