Replies and Topics

message.reply_to_message is not enough for production reply logic.

Valid reply semantics

In forum-enabled chats, replying to the topic starter is often not a meaningful reply target for command logic.

A practical rule:

• if there is no reply_to_message, it is not a reply
• outside forum topics, any reply is valid
• inside forum topics, ignore replies where reply_to_message.message_id == message.message_thread_id

Use scripts/topic_aware_reply_helpers.py.

Thread id normalization

message_thread_id needs normalization because Telegram uses it in several different ways:

• real forum topics
• private-message topics
• linked discussion groups for channel comments
• pseudo-thread ids in non-forum chats when replying to a bot

Useful rules:

• in forum chats, only return message_thread_id for real topic messages
• in linked discussion groups, keep message_thread_id only when it represents a real discussion thread
• ignore pseudo-thread ids created by bot replies in plain chats
• when needed, prefer the current message thread and fallback to the replied message thread

Reply filters

For routers, keep reusable reply filter expressions rather than repeating raw F.reply_to_message checks everywhere.

Two useful variants:

• IS_REPLY: true only for meaningful replies
• FILTER_REPLY_OR_NONE: allow no reply or a topic-root reply, but exclude arbitrary reply-to-user cases