@ mention user & channel in Teams using MS Graph API

There are ways to @mention a user while posting a conversation in Teams channel using flow action but as far as I know its not possible as of now to @mention a Teams channel using Flow actions. In this post, I will show you how to @mention a channel & user using a POST call to a MS Graph beta endpoint. To construct the endpoint URL you will need to know the TeamID & ChannelID, to get the information go to Teams > click the three dots > click Get link to channel > Copy the URL

Now decode the copied url, I’ve used Meyerweb Decoder. Your url will look something like below

End Point URL: https://graph.microsoft.com/beta/teams/groupIDorTeamID/channels/Channel ID/messages

Method: POST

Request Body:

{
 "importance": "high",
  "subject": "@Mention in Teams channel post!",
  "body": 
  {
    "content": "Hello <at id ='0'>Channel Name</at>, Test message on the channel with at mention.",
    "contentType": "html"
  },
  "mentions": [
    {
      "id": 0,
      "mentionText": "Channel Name",
      "mentioned": {
                        "conversation": {
                            "id": "ChannelID",
                            "displayName": "Channel Name",
                            "conversationIdentityType@odata.type": "#Microsoft.Teams.GraphSvc.conversationIdentityType",
                            "conversationIdentityType": "channel"
                        }
      }
    }
  ]
}

I’ve used Graph explorer to test the endpoint, if you have not signed in do sign in

Once you run the query on the explorer, you will see the Post in Channel with at mention as shown below

To @mention a user using Graph API, the endpoint is same as before but the request body has some changes as shown below

Request Body:

{
  "body": {
    "contentType": "html",
    "content": "Hello World User Display Name"
  },
  "mentions": [
    {
      "id": 0,
      "mentionText": "User Display Name",
      "mentioned": {
        "user": {
          "displayName": "User Display Name",
          "id": "UserID",
          "userIdentityType": "aadUser"
        }
      }
    }
  ]
}

To get your UserID, you can use the endpoint https://graph.microsoft.com/v1.0/me/

Reference: https://docs.microsoft.com/en-us/graph/api/channel-post-messages?view=graph-rest-beta&tabs=http

Summary: The endpoint which has been used in this post are beta endpoints. Graph API can be easily called using Power Automate, if you need some example on using a Graph API refer this post. Hope you find this post useful & informational. Let me know if there is any comments or feedback below.