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Developing Telegram Bots for Groups ​

Group bots are powerful. They provide features in groups — the space where people talk to each other. There are a lot of details to consider though.

Joining groups ​

Users can add bots to groups, but bots cannot join groups on their own. The bot's developer can forbid adding to groups using BotFather settings.

In public groups (those with usernames), bots can only be added by administrators. Group admins can grant the bot permissions for deleting group members or performing other administrative actions.

A group may contain up to 20 bots.

python
@dp.my_chat_member(ChatMemberUpdatedFilter(IS_NOT_MEMBER >> IS_MEMBER))
async def handle_join(event: ChatMemberUpdated):
    await event.answer('Hello ' + event.chat.title)

Sending messages to group members ​

Group messages are visible to all members. A bot cannot send a message that only one person in the group will see. For example, when a bot greets new members, all existing members will also receive this greeting message.

To keep the chat clean, the bot can automatically delete auxiliary messages after a certain period. Here is an example of deleting greeting messages after 30 seconds (unless the program is interrupted):

python
@dp.chat_member(ChatMemberUpdatedFilter(IS_NOT_MEMBER >> IS_MEMBER))
async def handle_join(event: ChatMemberUpdated):
    user = event.new_chat_member.user
    answer = await event.answer('Welcome to the group, {user.first_name}')
    await asyncio.sleep(30)
    await answer.delete()

Note that if your bot needs to personally contact new group users, join requests may be useful to get PM permission — we will explore join requests later in the book.

Privacy mode and visible messages ​

Many bots are designed to react only to commands. For this reason, Telegram by default protects group privacy and doesn't notify bots about non-command messages.

If you want your bot to see all chat messages, you need to disable the privacy mode.

Privacy mode is a BotFather setting and it is activated by default. In this mode, the bot only gets updates about commands and other group messages that may address the bot. This includes:

  • Commands
  • Replies on bot messages, replies to replies and so on
  • Messages mentioning the bot
  • System messages

When the privacy mode is off, the bot can see all messages in groups except for ones from other bots.

Also, if a bot is a group admin, it sees all messages regardless of the privacy mode setting.

A bot that doesn't see some messages

Troubles turning off privacy mode?

After disabling the privacy mode, you need to remove the bot from the group and add it back for the changes to take effect.

Mobile and desktop Telegram apps indicate whether the privacy mode is on in group member lists:

Пример бота

Force reply

If a bot with privacy mode enabled asks a question in a group, the user's response must be a reply for the bot to see it.

To make replying easier, a bot can send a "force reply" message which automatically initiates the reply interface for the user.

However, I don't recommend using force reply. In my opinion, automatic replies only confuse users.

Admin rights ​

When a user promotes a bot to a group admin, they can select admin rights. There is a BotFather setting for specifying the admin rights suggested by default.

The right to remain anonymous, which allows users to send messages on behalf of the group, has no effect on bots.

Choosing rights

Messages on behalf of groups and channels ​

Not only users can send messages in groups. Your program should correctly handle messages sent by other entities:

  • Messages from a linked channel in a discussion group (API treats them as forwarded)
  • Messages from a group by anonymous group admins
  • Messages from public channels by premium users

Examples ​

Determining chat type (e.g. for storing in a database:)

python
@dp.message(F.chat.type == ChatType.GROUP | F.chat.type == ChatType.SUPERGROUP])
async def handle_group_message(message: Message):
    if message.sender_chat is None:
        print('Message from user')
    if message.sender_chat is not None and message.sender_chat.type == ChatType.SUPERGROUP:    
        print('Message from supergroup')
    elif message.sender_chat is not None and message.sender_chat.type == ChatType.CHANNEL:
        print('Message from channel')

Getting the sender's name:

python
name = message.from_user.first_name if message.from_user else message.sender_chat.title

Art Ivanov