wtf is xcode-skills?

This repository packages and redistributes a set of Apple-authored agent skills that were exported from the Xcode 27 developer beta. The skills themselves were not created by this repository's author. Apple ships them inside its developer tooling, and this project simply makes them easier to install outside of Xcode, for use with AI coding assistants like Claude Code, Codex, and Grok CLI. The skills cover several areas of Apple platform development. There are skills for SwiftUI best practices and the new APIs introduced in SDK 27, a skill for modernizing older UIKit apps to handle multi-window setups, a skill for auditing security settings in Xcode build configurations, a guide for a C language safety extension, a tool for migrating older test suites to Swift Testing, and a skill for verifying how an app behaves on a device or simulator using screenshots and UI inspection. Installation is done through plugin commands in whichever coding agent you are using. For Claude Code you run two commands: one to register this repository as a plugin marketplace source and one to install the skills from it. Similar commands exist for Codex CLI, the Codex desktop app, and Grok CLI. There is also a manual option where you copy the skills folder directly into your project directory. The repository is a thin packaging layer. It contains marketplace manifests and distribution files, not original skill content. Anyone working on Apple platform apps who wants these skills available inside their AI coding assistant can install them from here without needing access to the full Xcode 27 beta toolchain.