title: Angular subscription to GraphQL mutation from Appsync Client
body: <p>I'm working on a chat app in Angular using GraphQL with Appsync in AWS. The workflow at the moment when creating a new chat is that a new chat is mocked up and sent to the server, on the server side a chat_id is generated for this chat which i need to retrieve and send it to my local store.</p>
  
  <p>My idea is that i should be able to subscribe to the mutate function, or the observable query that i create when doing the mutation. However, i receive the error "observable.subscribe is not a function" when trying to subscribe. And its the same if i try to subscribe to the entire function (the client.mutate function).</p>
  
  <p>This is my current code which is causing the issue:</p>
  
  <pre><code>this.appsync
        .hc()
        .then(client =&gt; {
          const observable: ObservableQuery = client.mutate({
            mutation: createChatRoom,
            variables: {
              input: {
                user_id: user.id,
                text: text,
              }
            },
            fetchPolicy: "no-cache"
          })
          observable.subscribe(data =&gt; console.log(data));
        })
  </code></pre>
  
  <p>I can also console log the observable and see that the values are stored in the __zone_symbol_value variable on the observable object. But i cannot retrieve these values, or subscribe to the observable.</p>
  
  <p>Any ideas or hints of how to go forward with this?</p>