Error "Empty speech response" - actions-on-google

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).

Answer 2

I experienced this situation too.
My problem was that I used a SimpleResponse in my fulfillment index.js without referencing to it. So the solution for me was to add SimpleResponse like this in index.js:
const {dialogflow, SimpleResponse} = require('actions-on-google');
So, always check if you aren't using any dependencies without including it in your js-file.
Probably not the most common cause of the problem, but it can be.

Answer 3

I got this when running through the codelabs tutorial (https://codelabs.developers.google.com/codelabs/actions-1/index.html#4) and didn't name my intent the same name as it is referenced in the webhook script:

Answer 4

I came across this error when trying to develop my own WebHook. I first verified that my code was called by looking into the Nginx log, after which I knew there was a problem in my JSON output because I based my output on outdated examples.
The (up-to-date) documentation for both V1 and V2 of the API can be found here:
https://dialogflow.com/docs/fulfillment/how-it-works
This example response for v2 of the dialogflow webhook API helped me to resolve this error:
{
"payload": {
"google": {
"expectUserResponse": true,
"richResponse": {
"items": [
{
"simpleResponse": {
"textToSpeech": "this is a simple response"
}
}
]
}
}
}
}
Source: https://github.com/dialogflow/fulfillment-webhook-json/blob/master/responses/v2/ActionsOnGoogle/RichResponses/SimpleResponse.json
You can find more examples in the official github repository linked above.

Answer 5

Another possibility is if you have a text response (even an empty one) like so:
Then you need to click the trash can next to the response to clear it out to use the webhook.

Answer 6

The Actions on Google support helped me fix this problem:
I needed to add a text as Default Response to the intent used for Explicit Invocation.