Computer Use Skill

Full desktop GUI control for headless Linux servers. Creates a virtual display (Xvfb + XFCE) so you can run and control desktop applications on VPS/cloud instances without a physical monitor.

Environment

• Display: :99
• Resolution: 1024x768 (XGA, Anthropic recommended)
• Desktop: XFCE4

Quick Start

export DISPLAY=:99

# Take screenshot
./scripts/screenshot.sh

# Click at coordinates
./scripts/click.sh 512 384 left

# Type text
./scripts/type_text.sh "Hello world"

# Press key combo
./scripts/key.sh "ctrl+s"

# Scroll down
./scripts/scroll.sh down 5

Actions Reference

Action	Script	Arguments	Description
screenshot	screenshot.sh	—	Capture screen → base64 PNG
cursor_position	cursor_position.sh	—	Get current mouse X,Y
mouse_move	mouse_move.sh	x y	Move mouse to coordinates
left_click	click.sh	x y left	Left click at coordinates
right_click	click.sh	x y right	Right click
middle_click	click.sh	x y middle	Middle click
double_click	click.sh	x y double	Double click
triple_click	click.sh	x y triple	Triple click (select line)
left_click_drag	drag.sh	x1 y1 x2 y2	Drag from start to end
left_mouse_down	mouse_down.sh	—	Press mouse button
left_mouse_up	mouse_up.sh	—	Release mouse button
type	type_text.sh	"text"	Type text (50 char chunks, 12ms delay)
key	key.sh	"combo"	Press key (Return, ctrl+c, alt+F4)
hold_key	hold_key.sh	"key" secs	Hold key for duration
scroll	scroll.sh	dir amt [x y]	Scroll up/down/left/right
wait	wait.sh	seconds	Wait then screenshot
zoom	zoom.sh	x1 y1 x2 y2	Cropped region screenshot

Workflow Pattern

1. Screenshot — Always start by seeing the screen
2. Analyze — Identify UI elements and coordinates
3. Act — Click, type, scroll
4. Screenshot — Verify result
5. Repeat

Tips

• Screen is 1024x768, origin (0,0) at top-left
• Click to focus before typing in text fields
• Use ctrl+End to jump to page bottom in browsers
• Most actions auto-screenshot after 2 sec delay
• Long text is chunked (50 chars) with 12ms keystroke delay

System Services

# Services auto-start on boot
sudo systemctl status virtual-desktop   # Xvfb on :99
sudo systemctl status xfce-desktop      # XFCE session

# Manual restart if needed
sudo systemctl restart virtual-desktop xfce-desktop

Opening Applications

export DISPLAY=:99
chromium-browser --no-sandbox &    # Web browser
xfce4-terminal &                   # Terminal
thunar &                           # File manager

Requirements

System packages (install once):

sudo apt install -y xvfb xfce4 xfce4-terminal xdotool scrot imagemagick dbus-x11 chromium-browser