title: How to push Google Cloud Platform Pub/Sub message to C# desktop application
body: <p>I am trying to create C# desktop application that can receive Google Cloud Platform Pub/Sub message. I can't get it to work with Push approach(<a href="https://cloud.google.com/pubsub/docs/subscriber#push_pull" rel="nofollow noreferrer">https://cloud.google.com/pubsub/docs/subscriber#push_pull</a>). What I understand from documentation - when message is published Pub/Sub pushes HTTP request to the subscriber to an endpoint. Then endpoint sends back HTTP success status code.
  This is how I create my Subscriber:</p>
  
  <pre><code>        TopicName topicName = new TopicName("test-project-123", "myTopicName");
          SubscriberServiceApiClient subscriberService = await SubscriberServiceApiClient.CreateAsync();
          SubscriptionName subscriptionName = new SubscriptionName("test-project-123", "mySubscriberName");
          subscriberService.CreateSubscription(subscriptionName, topicName, pushConfig: null, ackDeadlineSeconds: 60);
  </code></pre>
  
  <p>Here, I assume, pushConfig is where I would specify endpoint to which Pub/Sub should send request to which my program in return should send success status code. What I don't understand is how my desktop application will know that request is pushed to this endpoint and how exactly does it have to respond to it? I believe the answer should be simple, but web development is a totally new thing for me so this solution is something I find very difficult to figure out. Any ideas or code samples would be highly appreciated</p>