function CreateHTTPListener(prefix) {

    // Create a listener.
    sp.StoreObject("HTTPListener", new clr.System.Net.HttpListener());
    var listener = sp.GetStoredObject("HTTPListener");
    // Add the prefix, e.g. "Http://localhost:8080/" (must end with /)
    listener.Prefixes.Add(prefix);
    // Start listening
    listener.Start();

    // Note: The GetContext method blocks while waiting for a request.
    var context = listener.GetContext();

    // Handle when S+ reloaded, to prevent error message when listener stopped
    try{
        // Here is after a request is received
        var request = context.Request;

        // Create stream to receive request body
        var body = host.newVar(clr.System.IO.Stream);
        body = request.InputStream;
        var data = new clr.System.IO.StreamReader(body, request.ContentEncoding)

        // Obtain a response object.
        var response = context.Response;
        var jsonin = JSON.parse(data.ReadToEnd());

        sp.MessageBox(jsonin.Message, jsonin.Title);

        // Construct a response, below is just echoing the entire body of the POST request
        var responseString = '{ "Status": "OK" }';

        var buffer = clr.System.Text.Encoding.UTF8.GetBytes(responseString);
        response.ContentLength64 = buffer.Length;
        response.Close(buffer, true);

        // Seemed to need a delay before closing the connection, research further
        // Would result in random valid response, or connection reset without sleep
        sp.Sleep(200);
        listener.Stop();
    }
    catch(err) 
    {
        sp.MessageBox(err.message, "err");
    }

	// Create a new timer to wait for the next request

    // To allow the ability to bind to the prefix below, I ran this in an admin CMD prompt:
    // netsh http add urlacl url="http://rob-sager:8081/" user=everyone
    // You can use localhost without needing to do this

    // Use Windows Firewall to allow connections to port 8081 from other computers

	sp.CreateTimer("HTTPListenerTimer", 0, -1, `CreateHTTPListener('${prefix}');`);

}

if(__spEngineWrapper.Engine.Name == sp.EngineList().Last().Engine.Name)
{
    //Only create one instance of an HTTP Listener, close and restart on reload
    if(sp.GetStoredObject("HTTPListener").GetType().ToString() == "System.Net.HttpListener")
    {
        try {
            sp.DeleteTimer("HTTPListenerTimer");
            sp.GetStoredObject("HTTPListener").Stop();
            sp.GetStoredObject("HTTPListener").Close();
            sp.DeleteStoredObject("HTTPListener")
        } 
		catch {}
    }
	
	// Create time thread which waits for a request
    sp.CreateTimer("HTTPListenerTimer", 0, -1, "CreateHTTPListener('http://rob-sager:8081/');");
}

{ 
  "Title": "Title Text",
  "Message": "Your message here"
}

{ "Status": "OK" }