Services let people access functionality in one app from within another app. An app that provides services advertises the operations it can perform on particular types of data. The system then intelligently exposes these services in the app menu and in contextual menus that appear when Control-clicking text, files, and other kinds of data. For example, a service for creating a Mail message is available when you have selected text.

Give each service a short, focused title that describes exactly what it does. Strive to create a unique service title. If there are two or more services with identical names, the app name is automatically displayed after each service to distinguish them. When naming a service, use title-style capitalization and avoid definite and indefinite articles. Examples of good examples are Look Up in Dictionary and Make New Sticky Note.

Avoid providing an “Open in My App” service. People can use the Open With menu item in the Finder to open a selected file in a particular app.

Assign a keyboard shortcut to a service if it’s something people will use regularly. Don’t use standard keyboard shortcuts that the system and standard menu items already define. Note that if the keyboard shortcut you choose conflicts with a keyboard shortcut used by the current app, the app’s shortcut is always used.

Use a share extension instead of a service to share user content with other apps and social services. See Share Extensions.

Consider providing Automator actions. If your app includes Automator actions, users can use those actions to create their own custom services. See Automator Actions.

For developer guidance, see Services Implementation Guide.