Error "Empty speech response"

Question

I tried to connect DialogFlow and Actions on Google, so I created some intents, connected the services, added explicit and implicit invocations etc, but when I try the bot in the simulator https://console.actions.google.com/project/[projectId]/simulator/ it always gives me the error:

"Failed to parse Dialogflow response into AppResponse, exception thrown with message: Empty speech response"

even tough inputType was "KEYBOARD".

What I tried so far:

• I did set "Response from this tab will be sent to the Google Assistant integration" in Dialog Flow (do you have to set it for every single intent?), but I don't see any extra setting for speech.
• I disabled the second language, first I had also intents in German
• I also turned off the Fullfillment Webhook (implemented in API v1 and then also v2) with no change
• I only found this user with the same problem https://productforums.google.com/forum/#!topic/dialogflow/xYjKlz31yW0;context-place=topicsearchin/dialogflow/Empty$20speech$20response but no resolution.
• the fulfillment checkbox is checked at the intents
• The bot works fine when I use it through "Try it now" on the very right in Dialog Flow or in the Web Demo https://bot.dialogflow.com/994dda8b-4849-4a8a-ab24-c0cd03b5f420

Unfortunately the docs don't say anything about this error. Any ideas?

Here a screenshot of the error on the Actions integration:

This is the full debug output:

{
  "agentToAssistantDebug": {
    "agentToAssistantJson": {
      "message": "Failed to parse Dialogflow response into AppResponse, exception thrown with message: Empty speech response",
      "apiResponse": {
        "id": "c12e1389-e887-49d4-b399-a332188ca946",
        "timestamp": "2018-01-27T03:55:30.931Z",
        "lang": "en-us",
        "result": {},
        "status": {
          "code": 200,
          "errorType": "success"
        },
        "sessionId": "1517025330705"
      }
    }
  },
  "assistantToAgentDebug": {
    "assistantToAgentJson": {
      "user": {
        "userId": "USER_ID",
        "locale": "en-US",
        "lastSeen": "2018-01-27T03:55:03Z"
      },
      "conversation": {
        "conversationId": "1517025330705",
        "type": "NEW"
      },
      "inputs": [
        {
          "intent": "actions.intent.MAIN",
          "rawInputs": [
            {
              "inputType": "KEYBOARD",
              "query": "Talk to Mica, the Hipster Cat Bot"
            }
          ]
        }
      ],
      "surface": {
        "capabilities": [
          {
            "name": "actions.capability.MEDIA_RESPONSE_AUDIO"
          },
          {
            "name": "actions.capability.WEB_BROWSER"
          },
          {
            "name": "actions.capability.AUDIO_OUTPUT"
          },
          {
            "name": "actions.capability.SCREEN_OUTPUT"
          }
        ]
      },
      "isInSandbox": true,
      "availableSurfaces": [
        {
          "capabilities": [
            {
              "name": "actions.capability.AUDIO_OUTPUT"
            },
            {
              "name": "actions.capability.SCREEN_OUTPUT"
            }
          ]
        }
      ]
    },
    "curlCommand": "curl -v 'https://api.api.ai/api/integrations/google?token=TOKEN' -H 'Content-Type: application/json;charset=UTF-8' -H 'Google-Actions-API-Version: 2' -H 'Authorization: AUTH_TOKEN'  -A 'Mozilla/5.0 (compatible; Google-Cloud-Functions/2.1; +http://www.google.com/bot.html)' -X POST -d '{\"user\":{\"userId\":\"USER_ID\",\"locale\":\"en-US\",\"lastSeen\":\"2018-01-27T03:55:03Z\"},\"conversation\":{\"conversationId\":\"1517025330705\",\"type\":\"NEW\"},\"inputs\":[{\"intent\":\"actions.intent.MAIN\",\"rawInputs\":[{\"inputType\":\"KEYBOARD\",\"query\":\"Talk to Mica, the Hipster Cat Bot\"}]}],\"surface\":{\"capabilities\":[{\"name\":\"actions.capability.MEDIA_RESPONSE_AUDIO\"},{\"name\":\"actions.capability.WEB_BROWSER\"},{\"name\":\"actions.capability.AUDIO_OUTPUT\"},{\"name\":\"actions.capability.SCREEN_OUTPUT\"}]},\"isInSandbox\":true,\"availableSurfaces\":[{\"capabilities\":[{\"name\":\"actions.capability.AUDIO_OUTPUT\"},{\"name\":\"actions.capability.SCREEN_OUTPUT\"}]}]}'"
  },
  "sharedDebugInfo": [
    {
      "name": "ResponseValidation",
      "subDebugEntry": [
        {
          "debugInfo": "API Version 2: Failed to parse JSON response string with 'INVALID_ARGUMENT' error: \": Cannot find field.\".",
          "name": "UnparseableJsonResponse"
        }
      ]
    }
  ]
}

Also "debugInfo" sounds like an internal problem:

"API Version 2: Failed to parse JSON response string with 'INVALID_ARGUMENT' error: \": Cannot find field.\"."

Here a screenshot of the welcome intent:

ps. It took me AGES to figure out, what

"Query pattern is missing for custom intent"

means - so I just document it here: In Dialog Flow - Intent - "User says" you have to DOUBLE CLICK on a word in the text input field when you want to set it as query parameter - which seems to be required for Actions on Google.

Answer 1

This happened to me. If this happens for an Intent you just added in the Dialogflow console and you are using Webhook fulfillment for the action, check the intent's fulfillment settings and ensure that the Webhook fulfillment slider is on. Evidently new intents don't automatically get webhook fulfillment: you have to opt each one in piecemeal (or at least, that was my experience).