Unable to receive POST messages from Webhook (Follow Users)

[Lyganesh]

I have a project in .NET that uses HTTP Listener to get all the POST body sent to my IP.

public void StartListener()
{
using (var httpListener = new HttpListener())
{
httpListener.Prefixes.Add(@“http://192.168.1.8:6345/”);

  		try
  		{
  			httpListener.Start();
  		}
  		catch
  		{
  		}

  		while (httpListener.IsListening)
  		{
  			var context = httpListener.GetContext();
  			ProcessRequest(context);
  		}
  	}
  }

  private void ProcessRequest(HttpListenerContext context)
  {
  	// Get the data from the HTTP stream
  	var body = new StreamReader(context.Request.InputStream, context.Request.ContentEncoding).ReadToEnd();
  	Console.WriteLine(body);

  	byte[] b = Encoding.UTF8.GetBytes("ACK");
  	context.Response.StatusCode = 200;
  	context.Response.KeepAlive = false;
  	context.Response.ContentLength64 = b.Length;

  	var output = context.Response.OutputStream;
  	output.Write(b, 0, b.Length);
  	context.Response.Close();
  }

All my friends confirmed that they can send me a request with anything on the body and I will, in fact, see it on my console. However I tried subscribing to a Webhook using someone’s popular stream that I know would get a lot of follows (Shroud, for example).

https://api.twitch.tv/helix/webhooks/hub?hub.mode=subscribe&hub.topic=https://api.twitch.tv/helix/users/follows?to_id=37402112&hub.callback=http://MYPUBLICIP:6345&hub.lease_seconds=864000

For testing purposes I tried using other websites like requestb.in to see if they get the requests, and they do. However, I do not get any post messages back to my listener when subscribing to that webhook. So far it’s the only thing I can’t receive, if I do a simple request with anything on the body to “http://MYIP:6345”, I will receive it and see it in the console.

I am using Postman to make the requests. Any ideas what could be wrong?

[3ventic]

Do you see the challenge GET that you don’t seem to be handling?

[Syzuna]

Is that IP even reachable from the internet? bcs that looks like an internal IP adress to me which cant be used for callback POST requests

[Lyganesh]

I found the issue, turns out I did not respond to the challenge…