I would like to work on it.

Sure, if you have any idea feel free to propose a pull request

I don't know if this would work, but would it make sense to just use regex?

Filters.command("start", "/") and in the background it creates the compiled regex:

f"{prefix}{command}(@{username)?" which would return /start(@samplebot)? and trigger on both with and without the @samplebot at the end.

@ColinTheShark The issue is how to get the bot username to be used inside the filter, automatically.

While we have the message instance available in the filter's callback, we can do message._client.get_me().username, or call get_me() somewhere in the client and store the username somewhere and then do message._client.username in the filter. Both solutions are ugly because they make use of non-public attributes (_client).

Maybe we can just match (?i).+@\w+bot?

Using such a generic Regex would possibly catch updates meant for other clients 🤔

If my bot were ColinSharkBot, /hi@AhoyBot would also be caught by my bot and unintentionally react to it.

(Commenting here parallel to the discussion in the chat to have it in the Issues, too)

Would it make sense to always call get_me() on Client.start() and make that info available? I guess there are more scenarios where that would be useful...