Strix Sandbox MCP Server

Sandboxed security testing tools for Claude Code via MCP (Model Context Protocol).

Overview

This MCP server provides 35 tools for security testing in isolated Docker containers:

• Browser Automation - Playwright-powered web interaction (12 tools)
• HTTP Proxy - mitmproxy-based traffic interception (7 tools)
• Terminal Execution - tmux-based command execution (2 tools)
• Python Execution - IPython-based code execution (2 tools)
• Findings Tracking - SQLite-backed vulnerability documentation (5 tools)
• File Operations - Workspace file management (3 tools)
• Sandbox Management - Container lifecycle control (3 tools)

Quick Start

1. Build the Docker Image

cd strix-sandbox-mcp
docker compose build

2. Start the Container

docker compose up -d

3. Configure Claude Code

Add the MCP server to your Claude Code configuration:

claude mcp add strix-sandbox -- python -m strix_sandbox.server

Or add to your MCP settings file:

{
  "mcpServers": {
    "strix-sandbox": {
      "command": "python",
      "args": ["-m", "strix_sandbox.server"]
    }
  }
}

Tools Reference

Sandbox Management

Tool	Description
sandbox_create	Create an isolated sandbox environment
sandbox_destroy	Destroy a sandbox and cleanup resources
sandbox_status	Get status and resource usage of a sandbox

Browser Tools

Tool	Description
browser_launch	Launch a Chromium browser
browser_goto	Navigate to a URL
browser_click	Click at coordinates
browser_type	Type text into focused element
browser_scroll	Scroll page up/down
browser_screenshot	Take a screenshot
browser_execute_js	Execute JavaScript
browser_new_tab	Open a new tab
browser_switch_tab	Switch to a different tab
browser_close_tab	Close a tab
browser_get_source	Get page HTML source
browser_close	Close the browser

Proxy Tools (mitmproxy)

Tool	Description
proxy_start	Start/restart the proxy
proxy_list_requests	List captured HTTP requests
proxy_view_request	View request/response details
proxy_send_request	Send an HTTP request
proxy_repeat_request	Replay a captured request with modifications
proxy_set_scope	Configure interception scope
proxy_get_sitemap	Get discovered sitemap

Terminal Tools

Tool	Description
terminal_execute	Execute a shell command
terminal_send_input	Send input to running process

Python Tools

Tool	Description
python_execute	Execute Python code
python_session	Manage Python sessions

Findings Tools

Tool	Description
finding_create	Record a security finding
finding_list	List recorded findings
finding_update	Update an existing finding
finding_delete	Delete a finding
finding_export	Export findings as report

File Tools

Tool	Description
file_read	Read a file from workspace
file_write	Write content to a file
file_search	Search files using ripgrep

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Claude Code (Client)                      │
└─────────────────────────────────────────────────────────────┘
                              │
                              │ MCP Protocol (stdio)
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                 strix-sandbox MCP Server                     │
│                    (Python + FastMCP)                        │
│                                                             │
│  src/strix_sandbox/                                         │
│  ├── server.py          # MCP tool definitions              │
│  ├── tools/             # Tool implementations              │
│  └── runtime/           # Docker container management       │
└─────────────────────────────────────────────────────────────┘
                              │
                              │ HTTP (port 9999)
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                   Docker Container (Sandbox)                 │
│                                                             │
│  ┌───────────┐ ┌───────────┐ ┌───────────┐ ┌───────────┐  │
│  │ Playwright│ │   tmux    │ │  IPython  │ │ mitmproxy │  │
│  │ (Browser) │ │ (Terminal)│ │ (Python)  │ │  (Proxy)  │  │
│  └───────────┘ └───────────┘ └───────────┘ └───────────┘  │
│                                                             │
│  container/                                                 │
│  ├── tool_server.py    # FastAPI tool execution server      │
│  ├── browser_instance.py                                    │
│  ├── terminal_session.py                                    │
│  └── python_instance.py                                     │
└─────────────────────────────────────────────────────────────┘

Development

Prerequisites

• Python 3.12+
• Docker
• Poetry (optional, for local development)

Local Setup

# Install dependencies
pip install -e ".[dev]"

# Run the MCP server locally
python -m strix_sandbox.server

# Run tests
pytest tests/

Building Docker Image

# Build image
docker build -t strix/sandbox-mcp:latest ./container

# Run container
docker run -d --name strix-sandbox \
    -p 9999:9999 -p 8080:8080 \
    -e TOOL_SERVER_TOKEN=your-token \
    --cap-add SYS_ADMIN \
    strix/sandbox-mcp:latest

Security Considerations

• The sandbox container runs with SYS_ADMIN capability (required for Playwright)
• All tool execution is isolated within Docker containers
• Authentication is required for the tool server (token-based)
• File operations are restricted to the /workspace directory
• Only use for authorized security testing

License

MIT License - See LICENSE for details.

Related Projects

• strix-security - Claude Code Skills for security testing
• Model Context Protocol