browser-screenshots

name	browser-screenshots
description	Capture and persist browser screenshots or GIFs for visual review of a web UI. Use when verifying a UI change visually, reviewing a page's design or layout, recording a multi-step interaction (dropdown, hover, form flow), toggling dark mode for a comparison shot, or when a screenshot needs to be written to disk rather than only shown inline.

Browser screenshots

Ask for a target directory at the start of any visual review session if one has not been specified.

Picking a capture method

Try in this order. Each fallback exists because the one above it fails in a specific, known way.

1. gif_creator for any multi-step interaction. One GIF per feature is clearer than several stills, and it actually writes a file to disk and returns the path. It only works on the agent's managed tab group — in a regular browser session it fails with "not in managed tab group".
2. computer / zoom for a single still that only needs to be seen inline. save_to_disk: true does not write a file despite the name; it only embeds the image in the conversation. When the target is a <canvas>, javascript_tool can read it out (canvas.toDataURL()) for the Write tool; anything else that needs a disk file goes to method 3.
3. mss stills driven from Bash, when gif_creator is unavailable or the shot must land on disk. Full procedure in mss-capture.md.

Dark mode

Check how the app themes before toggling. The class toggle below covers Tailwind-style .dark setups; apps keyed off prefers-color-scheme or a data-theme attribute need window.matchMedia emulation or the attribute set instead.

document.documentElement.classList.add('dark')     // or .remove('dark')

Methods that do not work

Do not spend turns rediscovering these.

• screencapture -x in Bash — the shell process lacks screen recording permission
• html2canvas — fails on the modern CSS color() function, which many design systems use
• tell application "Google Chrome" to activate on its own — picks the wrong window when several are open; use the URL-matching loop in mss-capture.md