How to post messages on a channel

Roman 0

I have a multi-tenant Microsoft Teams tab app. I want it to post messages on a selected channel from my server.

I successfully receive the token using this endpoint:

https://login.microsoftonline.com/{TENANT_ID}/oauth2/v2.0/token

Then, I use the token to post a message using this endpoint:
https://graph.microsoft.com/v1.0/teams/{TEAM_ID}/channels/{CHANNEL_ID}/messages

However, in the response, I encounter the error:
"message": "Missing role permissions on the request. API requires one of 'Teamwork.Migrate.All'. Roles on the request 'Group.Selected'."

I have added many permissions, including 'Teamwork.Migrate.All', but it doesn't resolve the issue."

Screenshot 2024-05-08 at 3.48.05 PM

Does this API even work? I've been struggling with it for 3 days already.

1 answer

Yakun Huang-MSFT 7,745 Reputation points Microsoft Vendor

2024-05-09T05:41:57.0166667+00:00

Hi @Roman

After my testing, it works fine, and the issue you're having may be that you don't get the token back after granting permission, or the value of the scope is wrong, below I share my testing process for your reference.

The first is to grant app application permissions.

The next step is to get the token and pay attention to the value of the scope.

After successfully obtaining the token, you can parse the token in the jwt.ms, this is my parsing result.

However, for sending messages, you need to use delegated permissions, as application permissions are only used to import messages.

Please use delegated permissions (ChannelMessage.Send), get a token through the Auth code flow, and send an email. Or it's easier to use Graph explorer.

For more information, please refer to this link:

https://learn.microsoft.com/en-us/graph/api/channel-post-messages?view=graph-rest-1.0&tabs=http

Hope this helps.

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Roman 0 Reputation points

2024-05-09T18:23:47.72+00:00

I did the same. It doesn't work.
But now I have a question about the tenant_id. What is the app multi-tenant? Will the "Teamwork.Migrate.All" permission work if my app is registered by tenant "A" and installed by tenant "B"?

Roman 0 Reputation points

2024-05-09T20:18:20.44+00:00

Please use delegated permissions (ChannelMessage.Send), get a token through the Auth code flow, and send an email.

I like using the "ChannelMessage.Send" instead of "Teamwork.Migrate.All". But in my case I have a script on my server which is going to send messages. It can't open browsers. Why do you suggest the Auth code flow and not the "client credentials flow"?

Roman 0 Reputation points

2024-05-09T20:44:28.41+00:00

When I send a message from Graph Explorer using "CHannelMessage.send" the message is sent from a person, not the app. How can I send messages FROM THE APP?

Yakun Huang-MSFT 7,745 Reputation points Microsoft Vendor

2024-05-10T08:34:56.4+00:00

Hi @Roman

A multi-tenant app is an app that can be used by users from any tenant, so if the app has been granted the "Teamwork.Migrate.All" permission, tenant "B" can also use that permission.

For more information on the de-edging of single-tenant and multi-tenant applications, please see this link:

https://learn.microsoft.com/en-us/entra/identity-platform/single-and-multi-tenant-apps

And according to the Graph API, the app permissions are only for migrations and can't send messages in channels, so I recommend that you use delegated permissions (on behalf of logged-in users).

You can refer to a similar question:

https://learn.microsoft.com/en-us/answers/questions/1168205/i-cant-send-message-in-chat-with-microsoft-graph-a

Finally, sending messages through the App, which is currently not supported by the Graph API, is recommended to use delegated permissions to send messages on behalf of users.

Roman 0 Reputation points

2024-05-10T13:06:10.3366667+00:00

How do other apps do that? I have an app installed and it sends messages to the General channel from itself

Yakun Huang-MSFT 7,745 Reputation points Microsoft Vendor

2024-05-13T06:35:12.7733333+00:00

Hi @Roman

There are many sources of sending messages, and I can't determine which way you use this one, but what is certain is that the app that uses application permissions only supports the import function, which I mentioned earlier.

Use the link to see what the message sources are:

https://learn.microsoft.com/en-us/graph/teams-messaging-overview#from

Finally, this is a document on using bots to send messages proactively, but note that this is not the same as using application permissions.

Please check this link for more information:

https://learn.microsoft.com/en-us/microsoftteams/platform/graph-api/proactive-bots-and-messages/graph-proactive-bots-and-messages?context=graph%2Fcontext&tabs=dotnet

Roman 0 Reputation points

2024-05-13T22:50:10.4133333+00:00

I understand that I can't send messages with application permissions.
What is the flow of posting messages to a channel using delegated permissions where the post author is the app? The links above are not helpful.

Yakun Huang-MSFT 7,745 Reputation points Microsoft Vendor

2024-05-14T07:43:30.1166667+00:00

Hi @Roman

When using delegated permissions, you need to use auth code flow.

First, you need to grant the app delegation permissions ChannelMessage.Send.

Then sent a request in the browser for the user to log in and get the code.

https://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorize? client_id=<clientId> &response_type=code &redirect_uri=<redirect URL> &response_mode=query &scope=offline_access ChannelMessage.Send &state=12345

Then use the obtained code to send a request to get the token.

Finally, tokens can be used to send messages in channel.

Detailed information about auth code flow:

https://learn.microsoft.com/en-us/entra/identity-platform/v2-oauth2-auth-code-flow

More information about send message in channel:

https://learn.microsoft.com/en-us/graph/api/channel-post-messages?view=graph-rest-1.0&tabs=http

Roman 0 Reputation points

2024-05-14T22:48:54.8866667+00:00

In your example, the post author will be a user who authorized permissions. However, you don't explain how to post a message where the author is the app.

If you don't know the answer or don't understand the problem, please redirect me to a technical person who can understand what I asked.

Yakun Huang-MSFT 7,745 Reputation points Microsoft Vendor

2024-05-15T02:45:58.8633333+00:00

According to the Graph API, you can't send information if the author is an application, because the API doesn't provide this interface, and you can only send messages in a channel if the user is logged in, so I've been telling you that you need to use delegated permissions, because delegated permissions require users to log in and send messages on behalf of a user.

Roman 0 Reputation points

2024-05-15T12:50:55.7533333+00:00

Other apps send messages somehow. Is there somebody who can explain how to send messages???
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