Similar to the "login_as_master_name" variable that's set if present, a new variable will be set in all custom hook _pre.sh/_post.sh scripts, if it's available: login_key_name=keyname which will be the name of the key used to login, if the login was done using a "Login Key" Note, that custom hooks scripts can be called by things that do not use a login at all, such as restores, or things like that. So there is no guarantee that it will be set if any of those other methods are used... not to mention all normal logins not using a login key :)