Description

In Telegram threaded mode, natural chat replies (non-tool responses) are being sent with empty message bodies, causing:

telegram sendMessage failed: (400: Bad Request: message text is empty)
telegram final reply failed: GrammyError: message text is empty

Environment

• OpenClaw version: 2026.2.1
• Channel: Telegram
• Mode: Threaded sessions (thread-per-topic)

Steps to Reproduce

1. Enable Telegram with threaded mode
2. Start a conversation in a thread
3. Have the agent respond naturally (not via message tool)
4. Response fails with empty text error

Expected Behavior

Agent's natural replies should be captured and sent correctly to threads.

Actual Behavior

The reply text is empty by the time it reaches the Telegram API, causing a 400 error.

Workaround

Using the message tool explicitly with replyTo works correctly. Only natural chat responses fail.

Logs

2026-02-02T14:22:33.845Z error gateway/channels/telegram telegram sendMessage failed: Call to 'sendMessage' failed! (400: Bad Request: message text is empty)
2026-02-02T14:26:04.909Z error gateway/channels/telegram telegram sendMessage failed: Call to 'sendMessage' failed! (400: Bad Request: message text is empty)