Can't install app in private channel

[jerbob92]

Describe the bug
I have updated my app to manifest version 1.25, and added the "supportsChannelFeatures": "tier1".
I have also removed the supportedChannelTypes to get through the validation.

When trying to add the app to a private channel, it does allow it, but nothing seems to happen, it just opens the channel with a new message that tags the bot. The bot never gets anything to indicate it was installed, and it also doesn't receive any messages.

To Reproduce

1. Create an app on manifest 1.25 that allows installing in private channels
2. Install the app to the tenant
3. Install the app in the team
4. Try to add the app to the private channel
5. See that nothing happens.

Expected behavior
The bot should get a message that it was added to a channel and should receive messages from the channel.

Screenshots

VS Code Extension Information (please complete the following information):

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Additional context

[m365-agent-toolkit-assistant]

👋 Hi @jerbob92,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 2 business days

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

This issue is a known limitation during the rollout of manifest v1.25 and "supportsChannelFeatures": "tier1" for private channels. Currently:

• Toolkit and server-side validation block publishing with manifest v1.25.
• Even after updating the manifest, bots do not reliably receive "installed" events or channel messages in private channels.

Workaround:
No effective workaround exists until Microsoft completes the upstream API and toolkit updates required for private channel support with manifest v1.25. For now, bots may not function as expected in private channels, and app installation is inconsistent.

Recommended Action:

• Monitor this GitHub issue for fixes and updates.
• Ensure you are using the latest Microsoft 365 Agents Toolkit and Teams client version.
• If critical, revert to public channels for bot interactions or consider removing "supportsChannelFeatures" temporarily.

Apologies for the inconvenience—this is an active platform bug, not a code issue.

✨We'd love your feedback! Please take a moment to fill out our survey.

---

Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!

[jerbob92]

I have found out that Microsoft has paused rollout of apps in private channels:

It's a it odd because the documentation makes it looks like it's fully supported already: https://learn.microsoft.com/en-us/microsoftteams/platform/build-apps-for-shared-private-channels?tabs=tabs%2Cexternal-users%2Csharedchannel

[tecton]

Hi @jerbob92, the private channel is probably not rolled out yet. Shared channel is generally available but private channel is public developer preview.

[jerbob92]

@tecton Actually also doesn't work in developer preview. But it's probably caused by pausing the rollout of private channel support:

Updated March 17, 2026: We have paused rollout of this feature at this time and will provide updates via this post when we are ready to proceed. We apologize for any inconvenience.

[shlomisas]

@jerbob92 any updates here or we can say that Teams not support Bots in private channels?

In our case - after installing/adding the bot to a private channel, the user redirects to the channel with the bot tagge, then, when sending this message (with our bot tagged) we're able to get it in our backend and reply back to the user.

But! when just sending a regular message without tagging the bot - we never gets it.

We also have issue that trying to tag the bot ourselves by typing @ doesn't show our bot in the list, the only way to do it is copy/paste the original tag from the default message i described above and submit it.

The whole private channels support feel to buggy 😢

[jerbob92]

@shlomisas I was not able to get it to work at all, none of the messages arrived in the bot. I even tried upgrading the app to developer preview schema, but did not make any difference. I tried asking here and there but did not really get any answer besides that the rollout was paused.

Its odd that the released is delayed by this much time and no updates are given or an explanation of the delay. A lot of people within our organization are waiting for this feature.

There is also very buggy validation in the Teams Admin portal and Team Dev portal where it blocks the validation when both supportsChannelFeatures and supportedChannelTypes are set. The validation fails but the interfaces don't tell you why, you have to look at the developer tools to figure it out.

[shlomisas]

@jerbob92 i had the same at the beginning but then added:

"manifestVersion": "1.25",
"supportsChannelFeatures": "tier1"

To the manifest and it started to work but with this weird behavior:

1. Public channels - works well even without mention my app
2. Shared channels - works only when mention my app and i can do it by type @ and see my app loaded in the suggestions list
3. Private channels - works only when mention the app but when typing @ the list is empty and my app isn't there (the only way to make it work is to copy the app tag from another place (e.g. Shared Channel) and paste it in the channel)

I also check @linear official app and the behavior is the same

It's a shame that in today's era of having agentic AI apps that need to be triggered from Teams / Slack (which works amazing BTW and is super flexiable) the basic functionality doesn't work and we cannot provide good service to our customers. 😭