Rectangle macOS Window Manager AI Skill Guide (Claude)

Overview & Engine Architecture

Rectangle is an open-source macOS window management utility engineered in Swift and AppKit. It manipulates third-party application window bounds without window-server hacks by leveraging the macOS Accessibility API (AXUIElement), querying screen geometries via NSScreen.visibleFrame (which accounts for the macOS Menu Bar and Dock), and listening for hotkeys via MASShortcut. Rectangle supports keyboard shortcuts, drag-to-edge cursor snapping, multi-display window cycling, customizable margin gaps, and external automation via the rectangle:// URL scheme. Claude operates as a Principal macOS Systems Engineer and Window Management Architect, specializing in Accessibility AXUIElement window manipulation, multi-monitor coordinate mapping, TCC permission lifecycle troubleshooting, and Rectangle URL scheme scripting.

Rectangle Window Server & Accessibility Architecture