syl2042/screenshot

Screenshot Capture

Follow these save-location rules every time:

1. If the user specifies a path, save there.
2. If the user asks for a screenshot without a path, save to the OS default screenshot location.
3. If Codex needs a screenshot for its own inspection, save to the temp directory.

Tool priority

• Prefer tool-specific screenshot capabilities when available (for example: a Figma MCP/skill for Figma files, or Playwright/agent-browser tools for browsers and Electron apps).
• Use this skill when explicitly asked, for whole-system desktop captures, or when a tool-specific capture cannot get what you need.
• Otherwise, treat this skill as the default for desktop apps without a better-integrated capture tool.

macOS permission preflight (reduce repeated prompts)

On macOS, run the preflight helper once before window/app capture. It checks Screen Recording permission, explains why it is needed, and requests it in one place.

The helpers route Swift's module cache to $TMPDIR/codex-swift-module-cache to avoid extra sandbox module-cache prompts.

bash <path-to-skill>/scripts/ensure_macos_permissions.sh

To avoid multiple sandbox approval prompts, combine preflight + capture in one command when possible:

bash <path-to-skill>/scripts/ensure_macos_permissions.sh && \
python3 <path-to-skill>/scripts/take_screenshot.py --app "Codex"

For Codex inspection runs, keep the output in temp:

bash <path-to-skill>/scripts/ensure_macos_permissions.sh && \
python3 <path-to-skill>/scripts/take_screenshot.py --app "<App>" --mode temp

Use the bundled scripts to avoid re-deriving OS-specific commands.

macOS and Linux (Python helper)

Run the helper from the repo root:

python3 <path-to-skill>/scripts/take_screenshot.py

Common patterns:

• Default location (user asked for "a screenshot"):

python3 <path-to-skill>/scripts/take_screenshot.py

• Temp location (Codex visual check):

python3 <path-to-skill>/scripts/take_screenshot.py --mode temp

• Explicit location (user provided a path or filename):

python3 <path-to-skill>/scripts/take_screenshot.py --path output/screen.png

• App/window capture by app name (macOS only; substring match is OK; captures all matching windows):

python3 <path-to-skill>/scripts/take_screenshot.py --app "Codex"

• Specific window title within an app (macOS only):

python3 <path-to-skill>/scripts/take_screenshot.py --app "Codex" --window-name "Settings"

• List matching window ids before capturing (macOS only):

python3 <path-to-skill>/scripts/take_screenshot.py --list-windows --app "Codex"

• Pixel region (x,y,w,h):

python3 <path-to-skill>/scripts/take_screenshot.py --mode temp --region 100,200,800,600

• Focused/active window (captures only the frontmost window; use --app to capture all windows):

python3 <path-to-skill>/scripts/take_screenshot.py --mode temp --active-window

• Specific window id (use --list-windows on macOS to discover ids):

python3 <path-to-skill>/scripts/take_screenshot.py --window-id 12345

The script prints one path per capture. When multiple windows or displays match, it prints multiple paths (one per line) and adds suffixes like -w<windowId> or -d<display>. View each path sequentially with the image viewer tool, and only manipulate images if needed or requested.

Workflow examples

• "Take a look at <App> and tell me what you see": capture to temp, then view each printed path in order.

bash <path-to-skill>/scripts/ensure_macos_permissions.sh && \
python3 <path-to-skill>/scripts/take_screenshot.py --app "<App>" --mode temp

• "The design from Figma is not matching what is implemented": use a Figma MCP/skill to capture the design first, then capture the running app with this skill (typically to temp) and compare the raw screenshots before any manipulation.

Multi-display behavior

• On macOS, full-screen captures save one file per display when multiple monitors are connected.
• On Linux and Windows, full-screen captures use the virtual desktop (all monitors in one image); use --region to isolate a single display when needed.

Linux prerequisites and selection logic

The helper automatically selects the first available tool:

1. scrot
2. gnome-screenshot
3. ImageMagick import

If none are available, ask the user to install one of them and retry.

Coordinate regions require scrot or ImageMagick import.

--app, --window-name, and --list-windows are macOS-only. On Linux, use --active-window or provide --window-id when available.

Windows (PowerShell helper)

Run the PowerShell helper:

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1

Common patterns:

• Default location:

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1

• Temp location (Codex visual check):

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1 -Mode temp

• Explicit path:

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1 -Path "C:\Temp\screen.png"

• Pixel region (x,y,w,h):

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1 -Mode temp -Region 100,200,800,600

• Active window (ask the user to focus it first):

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1 -Mode temp -ActiveWindow

• Specific window handle (only when provided):

powershell -ExecutionPolicy Bypass -File <path-to-skill>/scripts/take_screenshot.ps1 -WindowHandle 123456

Direct OS commands (fallbacks)

Use these when you cannot run the helpers.

macOS

• Full screen to a specific path:

screencapture -x output/screen.png

• Pixel region:

screencapture -x -R100,200,800,600 output/region.png

• Specific window id:

screencapture -x -l12345 output/window.png

• Interactive selection or window pick:

screencapture -x -i output/interactive.png

Linux

• Full screen:

scrot output/screen.png

gnome-screenshot -f output/screen.png

import -window root output/screen.png

• Pixel region:

scrot -a 100,200,800,600 output/region.png

import -window root -crop 800x600+100+200 output/region.png

• Active window:

scrot -u output/window.png

gnome-screenshot -w -f output/window.png

Error handling

• On macOS, run bash <path-to-skill>/scripts/ensure_macos_permissions.sh first to request Screen Recording in one place.
• If you see "screen capture checks are blocked in the sandbox", "could not create image from display", or Swift ModuleCache permission errors in a sandboxed run, rerun the command with escalated permissions.
• If macOS app/window capture returns no matches, run --list-windows --app "AppName" and retry with --window-id, and make sure the app is visible on screen.
• If Linux region/window capture fails, check tool availability with command -v scrot, command -v gnome-screenshot, and command -v import.
• If saving to the OS default location fails with permission errors in a sandbox, rerun the command with escalated permissions.
• Always report the saved file path in the response.