Unable to Send Messages to Teams Channels Using Graph API with Application Permissions

Question

When using the Graph API with Application Permissions, sending messages to Teams channels is resulting in the error below.
While Delegated Permissions work correctly for sending messages, is there another approach that allows sending messages to Teams channels using Application Permissions? Additionally, is it possible to send messages to Teams channels with the O365 Management API?

Answer 1

Hello ABHISHEK KUMAR,

Thank you for contacting Microsoft!

As the error message says, application permissions can only be used to import third-party platform messages, not to send messages. To send messages, you must use delegated permissions.

As per https://learn.microsoft.com/en-us/graph/api/chatmessage-post?view=graph-rest-1.0&tabs=http#permissions-for-channel

You can refer the below mentioned post for reference:

https://learn.microsoft.com/en-us/answers/questions/2118234/permissions-for-send-message-in-channel-api-result

Additionally, the O365 Management API doesn't support sending messages to Teams channels directly. However, as a workaround you can use Webhooks and connectors which might help you achieve this functionality.

Create a webhook in teams - Go to the channel where you want to send messages, click on "Connectors", and add an "incoming webhook".

Get the webhook URL - copy the URL provided by Teams.

Send a message using the webhook URL - Use an HTTP post request to send a JSON payload to the webhook URL.

Hope this helps.

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