title: API.AI does not connect to my back-end
body: <p>I'm writing an agent using API.AI I'm observing that my back-end is not called everytime. I can see that in my access logs. Any idea what can cause the issue?</p>
  
  <p>Here is the response of the console:</p>
  
  <pre><code>{
    "id": "c1902c75-1550-43f6-9cc8-b0461f1dfac7",
    "timestamp": "2016-12-22T19:58:13.49Z",
    "result": {
      "source": "agent",
      "resolvedQuery": "echo test",
      "action": "",
      "actionIncomplete": false,
      "parameters": {
        "myInput": "test"
      },
      "contexts": [],
      "metadata": {
        "intentId": "062b4383-06a0-40fe-bbeb-9189db49aeb8",
        "webhookUsed": false,
        "webhookForSlotFillingUsed": "false",
        "intentName": "Response"
      },
      "fulfillment": {
        "speech": "",
        "messages": [
          {
            "type": 0,
            "speech": ""
          }
        ]
      },
      "score": 0.75
    },
    "status": {
      "code": 200,
      "errorType": "success"
    },
    "sessionId": "70be8f65-81f0-40be-a271-84a2d4960224"
  }
  </code></pre>
  
  <p>I see there no error which explains why my backend is not called.</p>
  
  <p>Here is a screenshot of my intent:</p>
  
  <p><a href="https://i.stack.imgur.com/2evfP.png"><img src="https://i.stack.imgur.com/2evfP.png" alt="my intent with webhook"></a></p>