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Agent Applications

An agent is a special type of application designed to help the user in an unobtrusive manner. Agents typically run in the background, providing information as needed to the user or to another application. Agents can display panels occasionally or come to the foreground to interact with the user if necessary. User interactions should always be brief and have a specific goal, such as setting preferences or requesting a piece of needed information.

An agent may be launched by the user but is more likely to be launched by the system or another application. As a result, agents do not show up in the Dock or the Force Quit window. Agents also do not have a menu bar for choosing commands. User manipulation of an agent typically occurs through dialogs or contextual menus in the agent user interface. For example, the iChat application uses an agent to communicate with the chat server and notify the user of incoming chat requests. The Dock is another agent program that is launched by the system for the benefit of the user.

The way to create an agent application is to create a bundled application and include the LSUIElement key in its Info.plist file. The LSUIElement key notifies the Dock that it should treat the application as an agent when double-clicked by the user. For more information on using this key, see Runtime Configuration Guidelines.

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