wtf is xcode27-skills?

Xcode 27 Skills is a collection of instruction sets, called Agent Skills, for AI coding tools that help developers build iOS, macOS, and other Apple platform apps. The content was authored by Apple and exported from Xcode 27, this repository redistributes it for convenience but does not claim any rights to the underlying guidance. There are seven skills in the collection. One covers best practices for SwiftUI, the framework Apple uses for building modern app interfaces. Another covers what changed in SwiftUI for the 2027 OS releases. A third helps update older UIKit apps to support modern multi-window environments. A fourth updates test suites to use Swift Testing, a newer testing approach. The remaining three cover a C language extension for memory safety, an audit of security-related build settings in Xcode, and on-device verification of app behavior through screenshots and UI inspection. Installing the skills can be done in one of two ways. The first is a command-line tool called skills that detects which AI agent you are using and places the files where the agent expects them. The second is a manual copy: clone the repository, then copy the relevant skill directories into your agent's skills folder. Each skill is a self-contained directory with a single entry file plus optional reference documents and helper scripts. Once installed, the AI agent loads a skill automatically when your request matches that skill's description. In Claude Code, you can also invoke a skill directly by typing its name as a command.