Trying to figure out what sql query maddy does to change user passwords, but first, i’m looking for the subcommand that actually does that… on the source code

it uses the queries you define for add/del/set/keys. which corrispond to something like INSERT INTO <table> (key, value) VALUES ($key, $value), DELETE ..., or UPDATE ...

the commands are issued by using the maddycli but not the running maddy daemon.

see https://maddy.email/reference/table/sql_query/

the best way to locate in source is anything that implements the MutableTable interface… https://github.com/foxcpp/maddy/blob/master/framework/module/table.go#L38