Desktop Control via CUA Server

This skill allows OpenClaw to control the desktop using the CUA computer server API.

⚠️ Security Notice

This skill requires installing and running a third-party server (cua-computer-sdk) that has full control over your desktop.

Before using this skill:

• The server can simulate keyboard, mouse, and take screenshots
• Only run on systems where you trust all users and processes
• The server runs with your user privileges (no sudo/admin required)
• By default, only accessible from localhost (safe for local use)

Prerequisites

• Python 3.12+ installed on your system
• CUA computer server running on port 8000 (see installation below)
• Access to localhost:8000 only (network exposure not recommended)

Installation

Recommended: Temporary Session (Safest)

Run the server only when needed, in a terminal you can monitor:

# Install the Computer SDK (official CUA package)
pip install cua-computer-sdk

# Verify package (optional but recommended)
pip show cua-computer-sdk  # Check publisher and version

# Run temporarily (Ctrl+C to stop)
cua-server start --port 8000 --bind 127.0.0.1

# In another terminal, verify it's running locally only
curl http://localhost:8000/status
netstat -an | grep 8000  # Should show 127.0.0.1:8000

This is the safest approach - the server only runs when you explicitly start it and stops when you close the terminal.

Alternative: Install from Source

For transparency, you can review and run from source:

# Clone and review the code first
git clone https://github.com/trycua/cua-computer-server
cd cua-computer-server

# Review the code before running
ls -la
cat requirements.txt  # Check dependencies

# Install and run
pip install -r requirements.txt
python -m cua_server --port 8000 --bind 127.0.0.1

Running the Server

Option 1: Manual Start (Recommended)

# Start in foreground - you can see what it's doing
cua-server start --port 8000

# Stop with Ctrl+C when done

Option 2: Background Process (Temporary)

# Run in background for current session only
cua-server start --port 8000 &

# Note the process ID
echo "Server PID: $!"

# Stop when done
kill <PID>

Note: This skill does NOT require persistent/system service installation. Running the server temporarily when needed is the recommended approach.

Scope & Limitations

This skill:

• ✅ Controls YOUR desktop when the server is running
• ✅ Runs with YOUR user privileges (no admin/sudo needed)
• ✅ Only accessible from localhost by default

Security Best Practices

1. Run Temporarily: Start the server only when needed, stop when done
2. Localhost Only: Keep default binding to 127.0.0.1
3. No Network Exposure: Avoid --bind 0.0.0.0 unless absolutely necessary
4. Monitor Activity: Run in foreground to see what commands are executed
5. Limited Scope: The server can only do what your user account can do

Quick Test

After starting the server, verify it works:

# Simple health check
curl http://localhost:8000/status
# Should return: {"status": "ok"}

# Take a screenshot (safe test)
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "screenshot"}' \
  -o screenshot.json

# If successful, you'll get a JSON response with base64 image data

Troubleshooting

Port Already in Use:

# Check what's using port 8000
lsof -i :8000              # macOS/Linux
netstat -ano | findstr :8000  # Windows

# Solution: Use a different port
cua-server start --port 8001

Permission Denied (Linux):

# You may need to add your user to the input group for keyboard/mouse control
sudo usermod -a -G input $USER
# Log out and back in for changes to take effect

Display Not Found (Linux):

# Check your display variable
echo $DISPLAY

# Set it explicitly
DISPLAY=:0 cua-server start --port 8000

Server Not Responding:

# Check if the process is running
ps aux | grep cua-server       # Linux/macOS
tasklist | findstr cua-server  # Windows

# Try running in foreground to see errors
cua-server start --port 8000 --debug

Available Commands

Take Screenshot

Capture the current screen:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "screenshot"}' \
  | jq -r '.result.base64' \
  | base64 -d > screenshot.png

Click at Coordinates

Click at specific x,y coordinates:

# Click at center of 1280x720 screen
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "left_click", "params": {"x": 640, "y": 360}}'

Right Click

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "right_click", "params": {"x": 640, "y": 360}}'

Double Click

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "double_click", "params": {"x": 640, "y": 360}}'

Type Text

Type text at the current cursor position:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "type_text", "params": {"text": "Hello, World!"}}'

Press Hotkey

Press a key combination:

# Ctrl+C
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "hotkey", "params": {"keys": ["ctrl", "c"]}}'

# Ctrl+Alt+T (open terminal)
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "hotkey", "params": {"keys": ["ctrl", "alt", "t"]}}'

Press Single Key

Press a single key:

# Press Enter
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "press_key", "params": {"key": "enter"}}'

# Press Escape
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "press_key", "params": {"key": "escape"}}'

Move Cursor

Move cursor to specific position:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "move_cursor", "params": {"x": 100, "y": 200}}'

Scroll

Scroll up or down:

# Scroll down 3 units
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "scroll_direction", "params": {"direction": "down", "amount": 3}}'

# Scroll up 5 units
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "scroll_direction", "params": {"direction": "up", "amount": 5}}'

Launch Application

Launch an application by name:

# Launch Firefox
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "launch", "params": {"app": "firefox"}}'

# Launch Terminal
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "launch", "params": {"app": "xfce4-terminal"}}'

Open File or URL

Open a file or URL with default application:

# Open URL
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "open", "params": {"path": "https://example.com"}}'

# Open file
curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "open", "params": {"path": "/home/cua/document.txt"}}'

Get Window Information

Get current window ID:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "get_current_window_id"}'

Window Control

Maximize window:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "maximize_window", "params": {"window_id": "0x1234567"}}'

Minimize window:

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "minimize_window", "params": {"window_id": "0x1234567"}}'

Demo Workflows

Browser Navigation Demo

Open Firefox and navigate to a website:

# Take initial screenshot
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "screenshot"}' -o initial.json

# Launch Firefox
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "launch", "params": {"app": "firefox"}}'
sleep 3

# Focus address bar (Ctrl+L)
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "hotkey", "params": {"keys": ["ctrl", "l"]}}'
sleep 1

# Type URL
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "https://example.com"}}'

# Press Enter
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "press_key", "params": {"key": "enter"}}'
sleep 5

# Take final screenshot
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "screenshot"}' -o final.json

Text Editor Demo

Open text editor and type content:

# Open terminal
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "hotkey", "params": {"keys": ["ctrl", "alt", "t"]}}'
sleep 2

# Type command to open text editor
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "mousepad"}}'
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "press_key", "params": {"key": "enter"}}'
sleep 2

# Type some text
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "Hello from OpenClaw!\nThis is automated desktop control."}}'

# Save file (Ctrl+S)
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "hotkey", "params": {"keys": ["ctrl", "s"]}}'
sleep 1

# Type filename
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "openclaw-demo.txt"}}'
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "press_key", "params": {"key": "enter"}}'

Form Filling Demo

Fill out a web form:

# Assuming browser is open with form visible

# Click on first input field (adjust coordinates)
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "left_click", "params": {"x": 400, "y": 300}}'

# Type name
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "John Doe"}}'

# Tab to next field
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "press_key", "params": {"key": "tab"}}'

# Type email
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "john@example.com"}}'

# Tab to next field
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "press_key", "params": {"key": "tab"}}'

# Type message
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "type_text", "params": {"text": "This form was filled automatically by OpenClaw!"}}'

# Submit form (click submit button)
curl -X POST http://localhost:8000/cmd -H "Content-Type: application/json" -d '{"command": "left_click", "params": {"x": 400, "y": 500}}'

Helper Functions

Check Server Status

curl http://localhost:8000/status

List All Available Commands

curl http://localhost:8000/commands | jq

Get Screen Size

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "get_screen_size"}'

Get Cursor Position

curl -X POST http://localhost:8000/cmd \
  -H "Content-Type: application/json" \
  -d '{"command": "get_cursor_position"}'

Environment Variables

• CUA_SERVER_URL: Base URL for CUA server (default: http://localhost:8000)

Tips

1. Wait Between Commands: Add sleep between commands to allow UI to update
2. Check Coordinates: Screen is 1280x720, center is at (640, 360)
3. Screenshot for Debugging: Take screenshots before and after actions to verify
4. Use Variables: Store coordinates and text in variables for reusability

Example OpenClaw Usage

Once this skill is loaded, you can use it in OpenClaw conversations:

User: "Take a screenshot and open Firefox"
OpenClaw: *executes the screenshot and launch firefox commands*

User: "Type 'Hello World' in the current window"
OpenClaw: *executes the type_text command*

User: "Click at the center of the screen"
OpenClaw: *executes click command at 640,360*

Troubleshooting

1. Connection Refused: Make sure CUA server is running on port 8000
2. No Response: Check if you're in the container or have SSH tunnel set up
3. Commands Not Working: Verify with curl http://localhost:8000/status
4. Wrong Coordinates: Remember screen is 1280x720, adjust coordinates accordingly