Simulated Desktop (Preview)

When you set provider="simulated" in your task config, you can preview it in a lightweight HTML/CSS desktop environment without Docker. This renders OS-themed window chrome, taskbars, and desktop styling around your GUI.

Available Themes

Usage

Set provider: "simulated" and choose a theme:

import cua_bench as cb

@cb.tasks_config(split="train")
def load():
    return [
        cb.Task(
            description='Click the Submit button',
            computer={
                "provider": "simulated",  # Enables simulated desktop
                "setup_config": {
                    "os_type": "win11",  # win11 or macos
                    "width": 1920,
                    "height": 1080,
                }
            }
        )
    ]

Then preview:

cb interact tasks/my_task --variant-id 0

Multiple Theme Variants

Generate tasks across different desktop themes:

@cb.tasks_config(split="train")
def load():
    themes = ["win11", "macos"]

    return [
        cb.Task(
            description=f'Complete the form',
            computer={
                "provider": "simulated",
                "setup_config": {
                    "os_type": theme,
                    "width": 1280,
                    "height": 800,
                }
            }
        )
        for theme in themes
    ]

Limitations

Simulated desktop runs in a browser, so it has some restrictions:

• No shell actions: Can't execute bash commands or scripts
• No native apps: Can't install or run real applications
• HTML/CSS only: Only works with custom GUIs created via launch_window() or install_app()

For tasks requiring shell access or native applications, use Docker or QEMU environments instead.

Why Use Simulated Desktop?

• No Docker: Runs directly in browser with Playwright
• Fast: Instant startup, no VM boot time
• Visual Diversity: Train agents on different OS appearances
• Deterministic: Same theme always renders identically
• Lightweight: Run thousands in parallel

Use simulated desktop for quick iteration and agent development. Switch to Docker/QEMU when you need real OS environments.