LibraryLaunchDaemons

Library/LaunchDaemons refers to the directory in macOS and other Darwin-based systems that stores property list files used by launchd to configure system-wide background services. Each plist in this directory defines a daemon, which is a background process that can start at system boot or on demand and typically runs with elevated privileges as root.

A plist in this directory describes how the daemon should be started and managed. Common keys include Label (a unique name), ProgramArguments or Program (the executable and its arguments), RunAtLoad (start when the plist is loaded), and KeepAlive (whether the process should be kept running or respawned after exit). Other keys such as StartInterval, UserName, StandardOutPath, and StandardErrorPath control scheduling, execution context, and logging. When launchd processes these plists at startup, the defined daemons become active background services.

There is a clear distinction between LaunchDaemons and LaunchAgents. Daemons in /Library/LaunchDaemons run as root and do not require a user session, making them suitable for system-wide services. Launch Agents, in contrast, run per user and reside in user-specific or /Library/LaunchAgents directories. The files in /Library/LaunchDaemons must be owned by root:wheel and typically have secure permissions to prevent unauthorized modifications.

Security considerations are important, as improperly configured or malicious plist files can grant elevated privileges or persistence. Administrators manage these daemons with tools such as launchctl to load, unload, start, or stop them. Custom daemons placed here are commonly used for background maintenance tasks or long-running services required by the system or applications.