Window Controller

macOS Window Controller

Find, activate, and screenshot macOS windows across Spaces. Supports filtering by application name, window title (regex), process path, and command line arguments.

Quick Start

# List ALL windows
/window-controller list

# Find windows by app name (partial match)
/window-controller find "GoLand"

# Find windows by title pattern (regex)
/window-controller find --title "research.*"

# Activate window (switches to its Space)
/window-controller activate "GoLand"

# Take screenshot of window (saves to artifacts by default)
/window-controller screenshot "GoLand"

# Get window info as JSON (for automation)
/window-controller find "GoLand" --json

Filtering Options

By Application Name

# Partial match on kCGWindowOwnerName
/window-controller --find "GoLand"
/window-controller --find "Chrome"

By Window Title (Regex)

# Match window title with regex
/window-controller --find --title "monokai-islands"
/window-controller --find --title ".*\.py$"
/window-controller --find "GoLand" --title "research"

By Process Path

# Filter by executable path
/window-controller --find "GoLand" --path-contains "Applications"
/window-controller --find "GoLand" --path-excludes "~/Applications/"

By Command Line Arguments

# Filter by process command line
/window-controller find "Main" --args-contains "idea.plugin.in.sandbox.mode"

By PID

# Find window by specific process ID
/window-controller find --pid 12345

JetBrains Sandbox IDEs

JetBrains sandbox IDEs (launched via ./gradlew runIde) have a key difference:

Sandbox IDEs appear as "Main" (Java process name), NOT "GoLand" or "IntelliJ IDEA"!

# Find sandbox IDE (reliable method)
/window-controller find "Main" --args-contains "idea.plugin.in.sandbox.mode"

# Find by Gradle cache path
/window-controller find "Main" --path-contains ".gradle/caches"

# Find by project name in title
/window-controller find "Main" --title "my-project"

How It Works

Window Detection

Uses CGWindowListCopyWindowInfo with kCGWindowListOptionAll to list ALL windows including:

• Off-screen windows
• Windows on other Spaces
• Hidden/minimized windows

Process Information

Uses psutil to get detailed process information:

• Executable path (exe())
• Command line arguments (cmdline())

Space Detection

Parses the macOS Spaces configuration plist to map windows to Space indexes and identify which Space is currently active:

~/Library/Preferences/com.apple.spaces.plist

Window Activation

Uses AppleScript to activate applications:

osascript -e 'tell application "GoLand" to activate'

macOS automatically switches to the Space containing the activated window (when enabled in System Settings).

Artifact Output Path

CRITICAL: NEVER use --output unless the user EXPLICITLY states the artifact MUST be at a specific location. This should be EXTREMELY rare. Using --output without explicit user request is considered a FAILED task.

Screenshots are automatically saved to claude-code/artifacts/window-controller/ with timestamped filenames (e.g., 251216120000-screenshot_GoLand.png). The artifact path is always returned in the JSON output - use that path for subsequent operations.

Screenshot Capture

# Take screenshot - path is returned in output
/window-controller screenshot "GoLand" --json
# Returns: {"screenshot": "/path/to/artifacts/.../251216120000-screenshot_GoLand.png", ...}

# Screenshot without activating first
/window-controller screenshot "GoLand" --no-activate

# Control settle time (default 1000ms)
/window-controller screenshot "GoLand" --settle-ms 2000

Capture Backends

Two capture backends are available for screenshots:

ScreenCaptureKit (macOS 12.3+):

• Captures windows on ANY Space without switching
• Works with occluded (covered) windows
• No window activation required
• Cannot capture minimized windows
• Requires Screen Recording permission

The screenshot command automatically uses ScreenCaptureKit when available (macOS 12.3+) and falls back to Quartz on older systems. Use --no-activate with ScreenCaptureKit to capture windows on other Spaces without switching.

JSON Output

For automation and scripting, use --json with find:

/window-controller find "GoLand" --json

Output:

{
  "app_name": "GoLand",
  "window_title": "research – models.py",
  "window_id": 190027,
  "pid": 57878,
  "exe_path": "/Users/.../Applications/GoLand.app/Contents/MacOS/goland",
  "cmdline": ["goland", "."],
  "layer": 0,
  "on_screen": null,
  "bounds": {"x": 0, "y": 39, "width": 2056, "height": 1290},
  "space_index": 3
}

Permissions Required

Screen Recording (required for window names on macOS 10.15+)

System Settings → Privacy & Security → Screen Recording → Add Terminal/Python

Accessibility (required for AppleScript activation)

System Settings → Privacy & Security → Accessibility → Add Terminal/Python

Testing

Verify the skill works by running:

# Should list all windows with titles
/window-controller list

# Should show info for a running app
/window-controller find "Finder"

# If you have an app in full-screen, this should switch and return:
/window-controller activate "GoLand"

Expected list output:

App                  Title                                    Space  PID
--------------------------------------------------------------------------------
GoLand               research – window_controller.py          3      57878
Ghostty              ~ - fish                                 2      12345
Finder               Documents                                1      456

Troubleshooting

"No windows found"

1. Check if app is running: ps aux | grep -i goland
2. Grant Screen Recording permission
3. Try without filters first: --find "GoLand"

Window names are empty

Grant Screen Recording permission to the terminal/Python process.

Activation doesn't switch Spaces

Enable "When switching to an application, switch to a Space with open windows" in System Settings → Desktop & Dock → Mission Control.

Can't find sandbox IDE

1. Ensure ./gradlew runIde is running
2. Sandbox IDEs appear as "Main", not "GoLand"!
3. Use: --find "Main" --args-contains "idea.plugin.in.sandbox.mode"
4. List all windows: --list | grep -i main

Technical References

• ScreenCaptureKit - Apple's modern capture API (macOS 12.3+)
• CGWindowListCopyWindowInfo
• CGWindowListCreateImage - Legacy screenshot API (deprecated macOS 15)
• Identifying Spaces in Mac OS X
• psutil Documentation
• PyObjC Quartz Framework