Launch daemons, launch agents, and startup items are helper executables that macOS starts on behalf of the user that extend the capabilities of apps or provide additional capabilities to users. For example, a LaunchDaemon can provide persistent background service for an app, a LaunchAgent can provide auxiliary UI capabilities like menu bar extras, and a Login Item can provide the ability to auto-mount remote directories or launch applications when the user logs in.
A new structure in the app bundle simplifies the installation of these login items and associated property lists. This new structure allows you to keep helper app resources inside the app’s bundle, which reduces the need for specialized installation scripts or permission to write files into system directories. The SMAppService object is used to control helper executables that live inside an app's main bundle. It can also be used to register and control LoginItems, LaunchAgents, and LaunchDaemons as helper executables for an app and it works with any type of app regardless of how it was installed. Managing these items with mobile device management (MDM) server allows organizations to keep login and background items enabled so users cannot disable them.
