WordPress get post data via ajax with json

gistfile1.php

<?php

// Make ajax requests to /wp-admin/admin-ajax.php?action=get_post&id=127

add_action('wp_ajax_get_post', 'figgis_get_post_json');
add_action('wp_ajax_nopriv_get_post', 'figgis_get_post_json');

function get_post_json() {
  header('Cache-Control: no-cache, must-revalidate');
  header('Expires: '.gmdate('D, d M Y H:i:s \G\M\T', time() + 3600));
  header('Content-type: application/json');
	
  $post_id = htmlspecialchars($_GET["id"]);
  $post = get_post($post_id); 
  $title = $post->post_title;
	
  echo json_encode($post);
	
  die();
}