Power Automate: Retrieve teamId and channelId from Teams Trigger

In an effort to reduce the number of edits a user would have to make when importing a Power Automate Flow which responds automatically to a new Teams message, I wanted to retrieve the Team ID and the Channel ID to use later in the Flow.

There were a number of available solutions (e.g. Solved: Re: Get Teams name and Teams Channel - Power Platform Community) however they all seemed to use a complex expression to get the required information.

Looking at the raw information provided by the trigger (add the trigger to a Flow, run it, then examine the run history to retrieve the raw data) showed that it should be possible to retrieve the information required without using a complex expression. Here’s the information in the trigger header and body:

{
     "headers": {
         "Transfer-Encoding": "chunked",
         "Vary": "Accept-Encoding",
         "Strict-Transport-Security": "max-age=31536000",
         "request-id": "25417c44-XXXX-XXXX-XXXX-1795a8963e18",
         "client-request-id": "25417c44-XXXX-XXXX-XXXX-1795a8963e18",
         "x-ms-ags-diagnostic": "{\"ServerInfo\":{\"DataCenter\":\"UK South\",\"Slice\":\"E\",\"Ring\":\"3\",\"ScaleUnit\":\"003\",\"RoleInstance\":\"LO2PEPF00000033\"}}",
         "Preference-Applied": "odata.track-changes",
         "OData-Version": "4.0",
         "Timing-Allow-Origin": "*",
         "x-ms-apihub-cached-response": "true",
         "retry-after": "180",
         "Date": "Tue, 03 Aug 2021 19:19:38 GMT",
         "Location": "https://uk-001.azure-apim.net/apim/teams/…/trigger/beta/teams/channels//messages?%24top=50&triggerState=$deltatoken~…",
         "Content-Type": "application/json",
         "Content-Length": "1439"
     },
     "body": {
         "@odata.type": "#microsoft.graph.chatMessage",
         "etag": "…",
         "messageType": "message",
         "createdDateTime": "2021-08-03T19:15:19.411Z",
         "lastModifiedDateTime": "2021-08-03T19:15:19.411Z",
         "importance": "normal",
         "locale": "en-us",
         "webUrl": https://teams.microsoft.com/l/message/1628018119411?groupId=&tenantId=&createdTime=1628018119411&parentMessageId=162XXXX11XXXX,
         "id": "…",
         "from": {
             "user": {
                 "id": "…”,
                 "displayName": "Andy Dawson",
                 "userIdentityType": "aadUser"
             }
         },
         "body": {
             "contentType": "text",
             "content": "This is another test, this time to see if the variable I need is directly readable..."
         },
         "channelIdentity": {
             "teamId": "",
             "channelId": ""
         },
         "attachments": [],
         "mentions": [],
         "reactions": []
     }
}

From this, the expressions to retrieve the TeamID and ChannelID are respectively:

• triggerBody()?['channelIdentity/teamId']
• triggerBody()?['channelIdentity/channelId']