A desktop for computer-use agents

How do you open a sandbox's desktop?

Run sbx desktop with the sandbox's id, or click Open desktop on the sandbox in the dashboard. Per Sandboxer's desktop docs, the stream runs over VNC (noVNC over plain HTTPS), so it works through any firewall that allows HTTPS.

sbx desktop <sandbox-id>
sbx browser <sandbox-id>   # just Chrome, without the desktop around it

The first open takes a few seconds while the desktop starts. A stopped sandbox has no desktop until you resume it.

How does an agent use the desktop?

Sandboxer's integrated agents get computer tools (screenshot, move, click, type and scroll) that act on the same screen you see. Your own agents can drive it too, with xdotool, Playwright against the headed Chrome, or any VNC client.

That makes the desktop useful for testing a checkout flow, filling in a form, or debugging an Electron app, with a person able to watch or take over.

Who can see the screen?

A desktop URL carries a secret token, and anyone with the URL can see and control the screen. Each URL works for ten minutes. A browser that opens it in time stays signed in for that session, up to 8 hours. To show the desktop inside your own product, put it in an <iframe> on a page you authenticate yourself.

Can you record what the agent did?

Yes. Run ffmpeg in the background against display :1, stop it when the agent is done, and copy the video out with sbx scp. The desktop docs show the exact commands.

The screen is 1920×1080, which is also the largest size. Desktop sessions usually survive a stop and resume, because the sandbox's memory is restored.

Can you change the desktop's look or size?

Yes. Put a PNG at ~/.config/sandboxer/wallpaper.png on the sandbox and the desktop shows it within a couple of seconds; delete the file to go back to the default. To make the screen smaller than 1920×1080, add the mode with xrandr --newmode and --addmode first, then switch to it. Copy and paste between your computer and the sandbox with the clipboard panel in the noVNC sidebar.