Documentation
Configuration / CakeAuthenticator.logged_in_key
This enables you to specify the session key to look for when authenticating the user with Cake PHP. This option defaults to "isloggedin"
$moxieManagerConfig['CakeAuthenticator.logged_in_key'] = "MyLoggedInKey";
You can then use this code to authenticate the user:
// Login the user and override the filesystem.rootpath setting
CakeSession::write('MyLoggedInKey', "true");
CakeSession::write('moxiemanager.filesystem.rootpath', "/var/www/myroot");