Window arrange

Skill MichaelAdamGroberman/mac-mcp/skills/window-arrange

Use when the user wants to manipulate window layout — focus an app, tile windows side-by-side, send a window to a specific space, maximize, or restore a previous arrangement. Encodes the right tool sequence (list → match → move/resize) and the macOS-specific gotchas around AX windows vs CGWindowID.From its SKILL.md

Install

npx -y skills add MichaelAdamGroberman/mac-mcp --skill window-arrange

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

2 stars2 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

SKILL.md

2.7 KB, as published. Nobody here has run it

Window arrangement with mac-mcp

Window IDs are CGWindowIDs from list_windows. The Accessibility API uses its own AX handles, but mac-mcp's move_window / resize_window / focus_window accept CGWindowIDs directly and translate internally.

Common patterns

"Focus app X" / "switch to app X"

focus_app bundle_id=<X>     # preferred — exact
# or
focus_app name=<X>          # fallback — localized name

If the app isn't running, focus_app will launch it (when bundle_id is provided). It returns launched:true so you can tell the user.

"Tile two windows side by side"

list_windows                                 # find the two ids
# Get screen size from screenshot_screen.width/height of display 0 OR
# from the existing window bounds + extrapolation.
move_window window_id=<A> x=0 y=0
resize_window window_id=<A> width=<W/2> height=<H>
move_window window_id=<B> x=<W/2> y=0
resize_window window_id=<B> width=<W/2> height=<H>

Caveat: macOS menu bar takes ~30 px at the top, dock takes 80 px at the bottom (when visible). For "true" usable area, query a specific display via screenshot_screen and use that width/height as bounds.

"Maximize this window" / "make it fullscreen"

mac-mcp does not yet have a fullscreen_window tool (real fullscreen creates a new Space). For "maximize without fullscreen":

move_window window_id=<id> x=0 y=0
resize_window window_id=<id> width=<display_width> height=<display_height>

"Switch to space N"

set_space index=<N>

This synthesises Ctrl+N (the system shortcut for "Switch to Desktop N"). It only works if the user has those shortcuts enabled in System Settings → Keyboard → Keyboard Shortcuts → Mission Control. If the user reports nothing happened, that's likely why.

Gotchas

Multiple windows of the same app: list_windows returns one entry per window with the same owner. Match by title to disambiguate, not by pid.
Hidden windows: pass on_screen_only=false to list_windows to include minimized/hidden ones.
Floating panels: high layer values (>= 25) are usually system overlays (notifications, menu bar). Filter them out unless the user asks about them specifically.
Permission: move_window / resize_window / focus_window require Accessibility. If they error with tcc_accessibility_denied, invoke the mac-mcp-tcc-grant skill.