Problem

The Microsoft Agents SDK (which replaced Bot Framework) no longer populates activity.channelData.team.name or activity.channelData.channel.name. Only .id fields are provided:

{
  "teamId": "19:[email protected]",
  "teamName": null,
  "channelName": null,
  "teamObj": {"id": "19:[email protected]"},
  "channelObj": {"id": "19:[email protected]"}
}

At startup, the channel resolution maps user-friendly config keys (e.g. "Automation") to Graph API group IDs (e.g. fa101332-cf00-431b-...). But the Agents SDK sends the channel conversation thread ID (e.g. 19:[email protected]) as activity.channelData.team.id.

This ID mismatch causes the allowlist matcher to never find a team match, silently dropping all channel messages when groupPolicy: "allowlist" is set. DMs are unaffected.

Root Cause

1. Monitor startup resolves "Automation" → Graph group ID fa101332-... and re-keys teams: config
2. Incoming message has teamId = "19:[email protected]" (conversation thread ID)
3. buildChannelKeyCandidates(teamId, teamName) produces only the thread ID (teamName is null)
4. resolveChannelEntryMatchWithFallback tries to match thread ID against Graph group ID keys → no match
5. channelGate.allowed = false → message dropped

Fix

After resolving each channel during startup, also register the team config under the channel's conversation ID. This ensures the allowlist matcher can find the team config regardless of which ID format the SDK provides.

Change: extensions/msteams/src/monitor.ts — 9 lines added in the resolution loop
Test: extensions/msteams/src/policy.test.ts — New test case for null teamName/channelName with ID-based matching

Debugging Evidence

Captured from a live 2026.2.9 deployment:

msteams channels resolved: Automation/General→fa101332-cf00-.../19:[email protected]

Activity data (teamName/channelName both null):

{"teamId":"19:[email protected]","teamName":null,"channelName":null}

Log confirming the drop:

dropping group message (not in team/channel allowlist)

Workaround (for users on current release)

Set groupPolicy: "open" in msteams config. The teams: block with requireMention: true still gates when the bot responds.

Closes #9873

Greptile Overview

Greptile Summary

This PR updates the Microsoft Teams extension’s startup allowlist resolution to handle an ID mismatch introduced by the Microsoft Agents SDK. During channel resolution in extensions/msteams/src/monitor.ts, the resolved team config (keyed by the Graph group ID) is also aliased under the channel conversation thread ID when they differ, so inbound events that provide only activity.channelData.team.id as a thread ID can still match allowlisted teams/channels.

It also adds a regression test in extensions/msteams/src/policy.test.ts covering the Agents SDK case where teamName/channelName are absent and matching must succeed based on ID keys alone.

Confidence Score: 4/5

• This PR is likely safe to merge and narrowly addresses the reported ID mismatch in allowlist matching.
• Changes are small and localized to config resolution/aliasing, and the added test exercises the Agents SDK null-name scenario. I could not run tests in this environment (no node/pnpm available), so the score is slightly reduced due to lack of execution verification.
• extensions/msteams/src/monitor.ts

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