WatchOS 4.3.1 Beta 1 has been out almost two weeks now and 9to5mac has discovered a line of code which hints at potential third-party integration with Apple’s NanoTimeKit.

NanoTimeKit is responsible for a number of assets traditionally left inaccessible to developers, however in the new beta it has a developer tools server for watch face customization that currently appears designed to communicate with Xcode and a log message that reads, “This is where the 3rd party face config bundle generation would happen.”

The server is currently inactive, which means third parties are unable to tap into the framework, but that might change in a future version of watchOS.