Problem

When a user replies in a Teams channel thread, the bot's response creates a new top-level post instead of staying in the same thread. This breaks threaded conversations for project-based workflows.

Environment

• Clawdbot version: 2026.1.24-3
• Channel: msteams
• Conversation type: Channel (not DM or group chat)

Steps to Reproduce

1. Bot posts a message to a Teams channel (e.g., a project update)
2. User replies to that message (creating a thread)
3. Bot responds
4. Expected: Bot's reply appears in the same thread
5. Actual: Bot's reply creates a new top-level channel post

Technical Investigation

We investigated the msteams extension code and tried several patches:

Attempt 1: Setting replyToId on the activity

\\ ypescript
// In buildActivity()
if (replyToId) {
activity.replyToId = replyToId;
}
\
Result: No effect - reply still goes to channel root

Attempt 2: Using continueConversation with thread context

\\ ypescript
// Preserve raw conversation ID with ;messageid= suffix
const baseRef = buildConversationReference(params.conversationRef, { preserveThreadContext: true });
const threadRef = { ...baseRef, activityId: threadReplyToId };
await params.adapter.continueConversation(params.appId, threadRef, async (ctx) => {
await ctx.sendActivity(activity);
});
\
Result: No effect

Attempt 3: Including conversation object in activity

\\ ypescript
if (replyToId && conversationRef.rawConversationId) {
activity.conversation = {
id: conversationRef.rawConversationId, // Includes ;messageid=<thread_root>
conversationType: conversationRef.conversation?.conversationType,
};
}
\
Result: No effect

Root Cause Analysis

The issue appears to be in how the Bot Framework SDK handles Teams channel threading:

1. normalizeMSTeamsConversationId strips the ;messageid=\ suffix from conversation IDs, losing thread context
2. The
   eplyStyle: 'thread'\ config option doesn't seem to affect channel message threading
3. Bot Framework's \sendActivity\ doesn't automatically thread based on the incoming message context for channels

Relevant Files

• \extensions/msteams/src/messenger.ts\ - sendMSTeamsMessages, buildActivity
• \extensions/msteams/src/inbound.ts\ - normalizeMSTeamsConversationId
• \extensions/msteams/src/policy.ts\ - resolveMSTeamsReplyPolicy
• \extensions/msteams/src/monitor-handler/message-handler.ts\ - conversationRef building

Suggested Fix

For Teams channels, replying in a thread requires:

1. Storing the thread root message ID from incoming \�ctivity.replyToId\
2. Using the Bot Framework REST API directly: \POST /v3/conversations/{conversationId}/activities/{replyToActivityId}\
3. Or using Graph API: \POST /teams/{teamId}/channels/{channelId}/messages/{messageId}/replies\

Workaround

Currently using Graph API directly for thread replies as a workaround.

Config

\\yaml
channels:
msteams:
teams:
'59b87350-910c-496a-ab9f-c7aff8438e55':
replyStyle: 'thread'
requireMention: false
channels:
'*':
replyStyle: 'thread'
\\

This config has no effect on channel threading behavior.