Problem

When a user sends a message inside a Feishu group topic thread, the bot's reply spawns a new topic instead of staying inside the existing thread. This affects all message types: final responses, tool progress messages, and streaming partial responses.

Root Cause

Three gaps in the Feishu adapter's topic threading logic:

1. Inbound normalization (feishu.py): When a message is a reply within a topic (non-root message), message.thread_id is empty — only message.root_id contains the topic ID. The code only read thread_id, missing the fallback to root_id.

2. Outbound send (_send_raw_message): Feishu uses two ID prefixes:

   • om_ → message ID (valid as reply_to for im.v1.message.reply)
   • omt_ → topic/thread ID (not valid as reply_to — triggers API error 99992354)

   When reply_to was empty and only thread_id (an omt_ ID) was available, the code fell through to im.v1.message.create which doesn't place messages inside topics.

3. Gateway runner (run.py): Metadata carried thread_id but not reply_to_message_id (the original user message ID), so downstream consumers (stream, progress, status callbacks) couldn't use im.v1.message.reply to stay inside topics.

Fix (3 changes)

gateway/platforms/feishu.py

• _normalize_inbound_message: Add root_id → thread_id fallback
• _send_raw_message:
  • om_ thread_id (message ID) → use as reply_to directly
  • omt_ thread_id (topic ID) → use reply_to_message_id from metadata as the reply target
  • Fallback: pass root_id to im.v1.message.create so new messages land inside the topic
• _build_create_message_body: Accept optional root_id parameter
• Added TOPIC_DEBUG / SEND_DEBUG logging for future troubleshooting

gateway/run.py

• Initial send: When source.thread_id starts with omt_, add reply_to_message_id = original event_message_id to metadata
• Progress messages: Same treatment — carry reply_to_message_id for Feishu topics
• Status callbacks: Same
• Stream consumer: Same

Testing

Verified in production (Feishu group chat with topics enabled). Four scenarios tested:

1. ✅ Reply from topic root message → stays in topic
2. ✅ Reply from non-root message inside topic → stays in topic
3. ✅ Tool progress messages → appear inside topic
4. ✅ Streaming partial responses → appear inside topic