admin_ajax.php

<?php 

/**
  * 
  * add in a simple endpoint
  * 
  ***/
  add_action('wp_ajax_nopriv_add_user_from_minecraft', array($this, 'add_user_from_minecraft') );
  add_action( 'wp_ajax_add_user_from_minecraft', array($this,  'add_user_from_minecraft');
  
  function add_user_from_minecraft(){
    $request_body			= file_get_contents( 'php://input' );
    $decodeit					= json_decode( $request_body ); // Decode it is now a php object available to you like so $decodeit->UUID
    /// grab the user data the user is sending from script craft here either via the $_GET['uuid  OR any get parameter sent']
    //  or via the $decodit like so : $decodeit->uuid ; Decodit is from the json body POST request went sent via ajax 
    
    // Add a user here like so: 
    $user_id = username_exists( $user_name );
    if ( !$user_id and email_exists($user_email) == false ) {
    	$random_password = wp_generate_password( $length=12, $include_standard_special_chars=false );
    	$user_id = wp_create_user( $user_name, $random_password, $user_email );
    //Update the users meat after the user has been created by hooking into the user_register action :D  <-- SCRAP THIS I'M TALKING OUT OF MY ASS
    // USE THIS INSTEAD HERE :D https://codex.wordpress.org/Function_Reference/update_user_meta
     
    } else {
    	$random_password = __('User already exists.  Password inherited.');
    }
      echo "<pre>";
        var_dump($decodeit);
      echo "</pre>";
      echo "<pre>";
        var_dump($_GET);
      echo "</pre>";
      die();
  }