python-telegram-bot/python-telegram-bot · warning · RuntimeError

Cannot set name for filters.{self.__class__.__name__}

Error message

Cannot set name for filters.{self.__class__.__name__}

What it means

Filters like `filters.Chat` and `filters.User` generate their `name` from their current chat_ids/usernames. Since the name is derived state, assigning `.name` on these filter instances raises RuntimeError.

Source

Thrown at src/telegram/ext/filters.py:815

        chat_or_user = self._get_chat_or_user(message)
        if chat_or_user:
            if self.chat_ids:
                return chat_or_user.id in self.chat_ids
            if self.usernames:
                return bool(chat_or_user.username and chat_or_user.username in self.usernames)
            return self.allow_empty
        return False

    @property
    def name(self) -> str:
        return (
            f"filters.{self.__class__.__name__}("
            f"{', '.join(str(s) for s in (self.usernames or self.chat_ids))})"
        )

    @name.setter
    def name(self, _: str) -> NoReturn:
        raise RuntimeError(f"Cannot set name for filters.{self.__class__.__name__}")


class Chat(_ChatUserBaseFilter):
    """Filters messages to allow only those which are from a specified chat ID or username.

    Examples:
        ``MessageHandler(filters.Chat(-1234), callback_method)``

    Warning:
        :attr:`chat_ids` will give a *copy* of the saved chat ids as :class:`frozenset`. This
        is to ensure thread safety. To add/remove a chat, you should use :meth:`add_chat_ids`, and
        :meth:`remove_chat_ids`. Only update the entire set by ``filter.chat_ids = new_set``,
        if you are entirely sure that it is not causing race conditions, as this will complete
        replace the current set of allowed chats.

    Args:
        chat_id(:obj:`int` | Collection[:obj:`int`], optional):
            Which chat ID(s) to allow through.

View on GitHub (pinned to d3b69d2e9f)

Solutions

1. Remove the `.name` assignment for built-in Chat/User filters; the name auto-reflects its configured IDs/usernames.
2. For a custom label, subclass the filter and override the `name` property instead of assigning it.

Example fix

# before
f = filters.Chat(chat_id=123)
f.name = "my-chat"  # RuntimeError

# after
f = filters.Chat(chat_id=123)  # name auto: filters.Chat(123)

# do not assign .name to Chat/User filters; subclass instead
class MyChat(filters.Chat):
    @property
    def name(self):
        return 'my-chat'

try:
    f.name = 'x'
except RuntimeError as e:
    if 'Cannot set name' in str(e):
        pass

When it happens

Trigger: Executing `filters.Chat(chat_id=1).name = "x"` — any assignment to `.name` on `_ChatUserBaseFilter` subclasses (Chat, User, ForwardedFrom, and similar).

Common situations: Applying the custom-filter naming convention (`self.name = ...`) to built-in filters, or generic code that labels every filter object it receives.

Related errors

• Cannot set name for combined filters.
• Can't set {self._chat_id_name} in conjunction with (already
• Can't set {self._username_name} in conjunction with (already
• The `year` argument is required if the `year` attribute was
• Base URL string contains unsupported insertion: {key}

AI-assisted analysis of python-telegram-bot/python-telegram-bot@d3b69d2e9f (2026-08-28). Data as JSON: /api/errors/c374ad11e106db8f. Report an issue: GitHub.