Hi!
Since the introduction of AuthManager in
2016, there are two officially
supported authentication methods for bots:
action=login with a normal
password has been deprecated for a decade, and
action=clientlogin
API was never supported for non-interactive login.
Still, in the past, these methods worked most of the time -
often enough that many bots kept using them.
This is going to change very soon as we are introducing
more interactive challenges during login to improve account
security. If your bot still uses one of the non-supported
methods, please change it now. Usually this only requires
generating a bot password via
Special:BotPasswords and giving
the bot that instead of your normal password.
For the change that prompted this email, see
T395205. There will probably be
more such changes in the future, and they won't be announced
separately.
Thanks for your understanding, and for your help in
evolving the Wikimedia developer ecosystem.