What is game-porting-toolkit?

The Game Porting Toolkit is an official Apple repository of resources for developers who want to bring existing games and game engines to Apple platforms like macOS and iOS. It does not contain a standalone application to run, instead it provides skills, code samples, and a C++ library that assist developers doing this kind of porting work. The main new addition in this repository is a set of agent skills: structured knowledge files that can be loaded into AI coding assistants like Claude Code, Codex CLI, and Gemini CLI. These skills come in two types. Expert skills supply the AI with technical knowledge about Apple-specific graphics topics such as Metal 4, MetalFX, shader compilation, and platform debugging tools. Workflow skills guide the AI through a structured, multi-session porting process with defined stages: discovery, goal planning, execution, validation, and handoff. State from each session is saved to a local folder so that a porting project can be paused and resumed across multiple working sessions without losing context. The workflow is organized around goals and milestones. A goal is a broad target that spans multiple sessions, such as getting the simplest part of a game to render on screen. Each goal is broken into milestones, which are session-sized units of work. Within each milestone, the workflow walks through four phases with user checkpoints: preparing by studying the code, writing the code, verifying it works at runtime using GPU capture and validation tools, and committing and documenting the results. The repository also includes metal-cpp, a library that lets game code written in C++ call Metal directly without going through Objective-C. A tutorial sample walks through porting a game from other platforms to both macOS and iOS, covering topics like rendering, input, audio, physics, and cloud saves. Requirements include an Apple silicon Mac, macOS 27, Xcode 27, and Game Porting Toolkit 4. Apple is not accepting pull requests on this repository.