Google Actions帐户关联流程后，智能家居应用返回错误

Question

I am developing a Google Smart Home App, and I used my developing account to link to the Smart Home App.

And Everything is ok before token exchange. I found that Google Assitant showed "something went wrong,try again." It seems that the account linking was failed. I checked the official document, but I could not find the point that where is wrong.

The following as the token exchange api return:

{
 "token_type":"bearer",
  "access_token":"5699ebed735aa4c58836ad5ccd025e2c",
  "refresh_token":"8e8119ab5fbec7e3c5b5df3a162b4a3e",
  "expires_in":3600
}

The following as actions.json:

{
 "actions": [{
   "name": "actions.devices",
    "deviceControl": {
    },
   "fulfillment": {
     "conversationName": "automation"
   }
 }],
 "conversations": {
   "automation" :
   {
     "name": "automation",
     "url": "https://xxxxxx"
   }
 }
}

BTW, I tried many times, and My server never received the "action.devices.SYNC".

Answer 1

As soon as I added the fulfillment api version it started to work.

 "conversations": {
   "automation" :
   {
     "name": "automation",
     "url": "https://xxxxxx",
     "fulfillmentApiVersion": 2
   }
 }