Docker Sandbox Setup

Computer Use gives Claude control over your computer. For safety during development, we use Docker to create an isolated environment.

Why Docker?

Concern	Docker Solution
Accidental file deletion	Isolated filesystem
Unintended commands	Contained execution
Network access	Controlled networking
System changes	Disposable containers

Using Anthropic's Quickstart

Anthropic provides a ready-to-use Docker setup:

# Clone the quickstart repository
git clone https://github.com/anthropics/claude-quickstarts.git
cd claude-quickstarts/computer-use-demo

# Build the container
docker build -t computer-use-demo .

# Run with your API key
docker run -e ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY \
    -p 5900:5900 -p 8501:8501 -p 6080:6080 \
    computer-use-demo

Container Ports

Port	Service	Access
5900	VNC	View desktop via VNC client
6080	noVNC	View desktop in browser
8501	Streamlit	Demo web interface

Accessing the Desktop

Option 1: Browser (noVNC)

http://localhost:6080/vnc.html

Option 2: VNC Client

vnc://localhost:5900

Custom Dockerfile

For your own projects, start with this base:

FROM ubuntu:22.04

# Install desktop environment
RUN apt-get update && apt-get install -y \
    xvfb \
    x11vnc \
    fluxbox \
    firefox \
    python3 \
    python3-pip

# Set display
ENV DISPLAY=:99

# Install Anthropic SDK
RUN pip3 install anthropic

# Start virtual display
CMD Xvfb :99 -screen 0 1024x768x24 & \
    fluxbox & \
    x11vnc -display :99 -forever -shared

Resolution Configuration

Set screen resolution in Docker:

# 1024x768 - Fast, low cost
Xvfb :99 -screen 0 1024x768x24

# 1920x1080 - Full HD, more detail
Xvfb :99 -screen 0 1920x1080x24

Safety Note: Never run Computer Use agents with access to sensitive data, credentials, or production systems during development.

In the next lesson, we'll create your first Computer Use agent. :::