What is platform-design-skills?

Platform Design Skills is a reference collection of over 450 design rules for building apps and websites across Apple and Android platforms. It covers Apple's official design guidelines (called the Human Interface Guidelines) for six Apple platforms, iPhone, iPad, Mac, Apple Watch, Apple Vision Pro, and Apple TV, plus Google's Material Design 3 guidelines for Android, and WCAG 2.2 web accessibility standards. Each platform's rules are distilled from the official documentation into structured files that AI coding assistants can use automatically. The practical purpose is to give AI agents accurate, up-to-date design guidance when you're asking them to review your app code or generate new UI. For example, you can ask an AI to "review this SwiftUI view for iOS compliance" or "check this Android screen against Material Design" and the skill files provide the reference rules the AI uses to evaluate and respond. The collection is installed with a single command using the npx skills tool. Each platform section includes individual rule files with examples and quick-reference metadata. Sources include Apple's 2025 HIG, Google's Material Design 3 documentation, the WCAG 2.2 accessibility specification, and supporting academic human-computer interaction research.