WatchKit.fx is the framework that provides the classes for building the UI for Apps, Glances and Notifications on watchOS. Its UI classes start with a WKInterface* prefix.

All types from WatchKit.fx are exposed in the WatchKit Namespace.

See the Your First watchOS App with Fire tutorial for getting started with Apple Watch development.

Working with watchOS requires Elements 8.2 or later and is currently supported only in Fire.

Some recommended topics in Apple's excellent documentation are:

See Also