Facebook webhook, how to get conversation id from mid id

Question

Hello everyone i'm building a chat bot, i'm having a problem that is, when a user sends a message to my app, i don't get the conversation id like "t_31231231231231", instead I get "mid", I don't know how to get the conversation from "mid", i tried to find the document but maybe I haven't found it yet. :(

{
  "object": "page",
  "entry": [
    {
      "id": "553014938133297",
      "time": 1567149324484,
      "messaging": [
        {
          "sender": {
            "id": "2112675102192095"
          },
          "recipient": {
            "id": "553014938133297"
          },
          "timestamp": 1567149323879,
          "message": {
            "mid": "n89QDNpjbh7UUZjDj7mkfk-Mqd_vry00MlXChtxjo-ZLokFwJAtZ6udnPZibQjzAZpuqsN64UVjTly5cTCEKTQ",
            "text": "dasddsad",
            "nlp": {
              "entities": {},
              "detected_locales": [
                {
                  "locale": "vi_VN",
                  "confidence": 0.8299
                }
              ]
            }
          }
        }
      ]
    }
  ]
}

Answer 1

This might not be the ideal solution, but can serve as an improvisation. Since, you have the message_id you can fetch message to determine who the participants are, then you can match them with the participants in the conversations.participants.
What I did was to fetch all the conversations with their participants field. i.e

curl -i -X GET \
 "https://graph.facebook.com/v8.0/me/conversations?fields=participants&access_token=your-access-token-goes-here"

Which returns

{"data"=>
  [{"participants"=>
     {"data"=>
       [{"name"=>"Masroor Hussain",
         "email"=>"[email protected]",
         "id"=>"4275685679217538"},
        {"name"=>"Testpage",
         "email"=>"[email protected]",
         "id"=>"115083020351552"}]},
    "id"=>"t_781422919067688"}],
 "paging"=>
  {"cursors"=>
    {"before"=>
      "QVFIUlRKd1RBYmtvVXlicm95QUNZAbjVKUW5LbU5lYzhQM24ycmY1aTBXM1NTbnRSLURhc2xnSlBnOWE3OTJ4ZAy1KbS1LLVhUUEdqYmM0MmVzZAXZAZAX2xRdzJCbXpJSEowMmxzUHc0NlBXQ0FTVEdRSEZAZASmI2SGxsNlNOdC1XOWNSZADl0",
     "after"=>
      "QVFIUkdEUjNPek5jbE9RNUhzZAXpJTm9hWERvQVdGYVV5cHlfcDl6cEJyZAG5NaGpjR1NkUHI4R0JDd1VkWEU0RUh2ZADFOQUVzN0RwQ2tyYmpXcThEV0hjUDM2QXAxbFRLWDVzUGoyNmFjbkcyUzl3X0Myc1AtanRYUndjMDBSdVZAJZAnI0"
    }
  }
}

In the participants.data one participant is the page and the other is page_scoped_user. You can parse the response to match your participants and get the conversation id e.g here the conversation id would be "t_781422919067688"