Sandbox MCP

General-purpose Python execution sandbox for MCP clients, with persistent execution, artifact capture, Manim rendering, guarded shell access, and lightweight web app workflows.

Sandbox MCP is designed to stay broadly useful across coding assistants and MCP directories. It can run Python, generate plots and files, render Manim animations, launch or export small Flask/Streamlit demos, and expose prompts/resources that help an LLM discover how to use the sandbox well.

🎬 Demo: Manim Animation in Action

See the Sandbox MCP server creating beautiful mathematical animations with Manim:

Alternative formats: MP4 Video | GIF Animation

Example: 3D mathematical animation generated automatically by the sandbox

Related MCP server: Lodestar MCP Server

🚀 Quick Start

# Clone the repository
git clone https://github.com/scooter-lacroix/sandbox-mcp.git
cd sandbox-mcp

# Install with uv (recommended)
uv venv && uv pip install -e .

# Run the MCP server
uv run sandbox-server-stdio

✨ Features

🔧 Enhanced Python Execution

• Code Validation: Automatic input validation and formatting

• Virtual Environment: Auto-detects and activates .venv

• Persistent Context: Variables persist across executions

• Enhanced Error Handling: Detailed diagnostics with colored output

• Interactive REPL: Real-time Python shell with tab completion

🎨 Intelligent Artifact Management

• Automatic Capture: Matplotlib plots and PIL images

• Categorization: Smart file type detection and organization

• Multiple Formats: JSON, CSV, and structured output

• Recursive Scanning: Deep directory traversal

• Smart Cleanup: Configurable cleanup by type or age

🎬 Manim Animation Support

• Pre-compiled Examples: One-click animation execution

• Quality Control: Multiple rendering presets

• Video Generation: Auto-saves MP4 animations

• Example Library: Built-in templates and tutorials

• Environment Verification: Automatic dependency checking

🌐 Web Application Hosting

• Flask & Streamlit: Launch web apps with auto port detection

• Process Management: Track and manage running servers

• URL Generation: Returns accessible endpoints

🔒 Security & Safety

• Command Filtering: Blocks dangerous shell commands (configurable)

• Guarded Execution: Code runs with resource limits and timeouts

• Timeout Control: Configurable execution limits (default 30s)

• Resource Monitoring: Memory and CPU usage tracking

• Multiple Isolation Levels: In-process, process pool, worktree, and container

• Note: This is a guarded execution environment, not a strongly isolated sandbox. For production use with untrusted code, consider running in a container or VM.

🛡️ Isolation Levels

Choose the right isolation level for your use case:

Process Pool Example:

from sandbox.sdk import LocalSandbox, SandboxConfig, IsolationLevel

config = SandboxConfig(
    isolation_level=IsolationLevel.PROCESS_POOL,
    max_workers=4,
    memory_limit_mb=256,
)

async with LocalSandbox.create(name="my-session", config=config) as sandbox:
    result = await sandbox.run("print('Isolated execution')")

See SECURITY.md for detailed threat model and isolation strategies.

🔌 MCP Integration

• Dual Transport: HTTP and stdio support

• LM Studio Ready: Drop-in AI model integration

• FastMCP Powered: Modern MCP implementation

• Discoverable Interface Surface: Tools, prompts, resources, skills, and interactive templates

📦 Installation

Prerequisites

• Python 3.11+

• uv (recommended) or pip

Method 1: Install from PyPI (Recommended)

Install the latest stable release from PyPI:

# Using uv (fastest)
uv pip install sandbox-mcp

# Or using pip
pip install sandbox-mcp

For immediate use with AI applications:

# Run directly with uvx
uvx sandbox-mcp

Method 2: Direct Git Installation

For the latest development version:

# Using uv
uvx git+https://github.com/scooter-lacroix/sandbox-mcp.git

# Or clone and install
git clone https://github.com/scooter-lacroix/sandbox-mcp.git
cd sandbox-mcp
uv venv
uv pip install -e .

Method 3: Development Installation

For contributing or customization:

Using uv (Recommended)

git clone https://github.com/scooter-lacroix/sandbox-mcp.git
cd sandbox-mcp
uv venv
uv pip install -e ".[dev]"

Using pip

git clone https://github.com/scooter-lacroix/sandbox-mcp.git
cd sandbox-mcp
python -m venv .venv
# On Linux/Mac:
source .venv/bin/activate
# On Windows:
# .venv\\Scripts\\activate
pip install -e ".[dev]"

Verify Installation

# Check version
sandbox-mcp --version

# Test HTTP server
sandbox-server --help

# Test stdio server
sandbox-mcp --help

🖥️ Usage

🖥️ Usage

Command Line Interface

# Start HTTP server (web integration)
sandbox-server

# Start stdio server (LM Studio integration)
sandbox-mcp

# Backward-compatible stdio alias
sandbox-server-stdio

MCP Integration

The Sandbox MCP server supports multiple integration methods:

Method 1: Direct Git Integration (Recommended)

For LM Studio, Claude Desktop, VS Code, and other MCP-compatible applications:

{
  "mcpServers": {
    "sandbox": {
      "command": "uvx",
      "args": ["git+https://github.com/scooter-lacroix/sandbox-mcp.git"],
      "env": {},
      "start_on_launch": true
    }
  }
}

Method 2: Local Installation

For locally installed versions:

{
  "mcpServers": {
    "sandbox": {
      "command": "sandbox-server-stdio",
      "args": [],
      "env": {},
      "start_on_launch": true
    }
  }
}

Method 3: HTTP Server Mode

For web-based integrations:

# Start HTTP server
python -m sandbox.mcp_sandbox_server --port 8765

Then configure your application:

{
  "mcpServers": {
    "sandbox": {
      "transport": "http",
      "url": "http://localhost:8765/mcp",
      "headers": {
        "Authorization": "Bearer your-token-here"
      }
    }
  }
}

Application-Specific Configurations

VS Code/Cursor/Windsurf (using MCP extension):

{
  "mcp.servers": {
    "sandbox": {
      "command": "sandbox-server-stdio",
      "args": [],
      "env": {},
      "transport": "stdio"
    }
  }
}

Jan AI:

{
  "mcp_servers": {
    "sandbox": {
      "command": "sandbox-server-stdio",
      "args": [],
      "env": {}
    }
  }
}

OpenHands:

{
  "mcp": {
    "servers": {
      "sandbox": {
        "command": "sandbox-server-stdio",
        "args": [],
        "env": {}
      }
    }
  }
}

Available MCP Tools

Sandbox MCP exposes a broader tool surface than the quick table below. For the machine-readable catalog used by marketplace-style listings, see docs/marketplace-profile.json.

Skills, Prompts, and Resources

• Skill: manim_storyboard_skill turns a concept into a storyboard, ready-to-render Manim code, and a suggested sandbox workflow.

• Interactive template: manim_scene_template creates a focused Manim scene from a concept, duration target, and quality preset.

• Interactive template: sandbox_example_template creates runnable artifact-focused examples for plots, images, tables, or generated files.

• Interactive template: sandbox_web_app_template creates small Flask or Streamlit demos ready for start_web_app or export_web_app.

• Resource: sandbox://server/overview exposes a succinct server summary and capability map.

• Resource: sandbox://catalog/interfaces exposes a machine-readable list of tools, prompts, resources, skills, and templates.

Hosted Deployment Notes

For local IDE assistants, use sandbox-server-stdio. For remote or directory-hosted use cases such as MCPHub-compatible listings, run the HTTP server behind TLS and authentication, then point clients at the Streamable HTTP endpoint:

python -m sandbox.mcp_sandbox_server

# Optional for hosted deployments
SANDBOX_MCP_HOST=0.0.0.0 SANDBOX_MCP_PORT=8765 python -m sandbox.mcp_sandbox_server

Deployment checklist:

• Put the HTTP transport behind a reverse proxy or ingress that terminates TLS.

• Add authentication before exposing the server outside a trusted network.

• Treat this as a guarded execution environment, not a hardened isolation boundary.

• Use export_web_app and build_docker_image when you want to turn sandbox-generated demos into deployable examples.

• Keep marketplace metadata in sync with docs/marketplace-profile.json and deployment notes in docs/marketplace.md.

💡 Examples

Enhanced SDK Usage

Local Python Execution

import asyncio
from sandbox import PythonSandbox

async def local_example():
    async with PythonSandbox.create_local(name="my-sandbox") as sandbox:
        # Execute Python code
        result = await sandbox.run("print('Hello from local sandbox!')")
        print(await result.output())
        
        # Execute code with artifacts
        plot_code = """
import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 10, 100)
y = np.sin(x)

plt.figure(figsize=(8, 6))
plt.plot(x, y)
plt.title('Sine Wave')
plt.show()  # Automatically captured as artifact
"""
        result = await sandbox.run(plot_code)
        print(f"Artifacts created: {result.artifacts}")
        
        # Execute shell commands
        cmd_result = await sandbox.command.run("ls", ["-la"])
        print(await cmd_result.output())

asyncio.run(local_example())

Remote Python Execution (with microsandbox)

import asyncio
from sandbox import PythonSandbox

async def remote_example():
    async with PythonSandbox.create_remote(
        server_url="http://127.0.0.1:5555",
        api_key="your-api-key",
        name="remote-sandbox"
    ) as sandbox:
        # Execute Python code in secure microVM
        result = await sandbox.run("print('Hello from microVM!')")
        print(await result.output())
        
        # Get sandbox metrics
        metrics = await sandbox.metrics.all()
        print(f"CPU usage: {metrics.get('cpu_usage', 0)}%")
        print(f"Memory usage: {metrics.get('memory_usage', 0)} MB")

asyncio.run(remote_example())

Node.js Execution

import asyncio
from sandbox import NodeSandbox

async def node_example():
    async with NodeSandbox.create(
        server_url="http://127.0.0.1:5555",
        api_key="your-api-key",
        name="node-sandbox"
    ) as sandbox:
        # Execute JavaScript code
        js_code = """
console.log('Hello from Node.js!');
const sum = [1, 2, 3, 4, 5].reduce((a, b) => a + b, 0);
console.log(`Sum: ${sum}`);
"""
        result = await sandbox.run(js_code)
        print(await result.output())

asyncio.run(node_example())

Builder Pattern Configuration

import asyncio
from sandbox import LocalSandbox, SandboxOptions

async def builder_example():
    config = (SandboxOptions.builder()
              .name("configured-sandbox")
              .memory(1024)
              .cpus(2.0)
              .timeout(300.0)
              .env("DEBUG", "true")
              .build())
    
    async with LocalSandbox.create(**config.__dict__) as sandbox:
        result = await sandbox.run("import os; print(os.environ.get('DEBUG'))")
        print(await result.output())  # Should print: true

asyncio.run(builder_example())

MCP Server Examples

Basic Python Execution

# Execute simple code
result = execute(code="print('Hello, World!')")

Matplotlib Artifact Generation

code = """
import matplotlib.pyplot as plt
import numpy as np

# Generate plot
x = np.linspace(0, 10, 100)
y = np.sin(x)

plt.figure(figsize=(8, 6))
plt.plot(x, y, 'b-', linewidth=2)
plt.title('Sine Wave')
plt.xlabel('x')
plt.ylabel('sin(x)')
plt.grid(True)
plt.show()  # Automatically captured as artifact
"""

result = execute(code)
# Returns JSON with base64-encoded PNG

Flask Web Application

flask_code = """
from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/')
def home():
    return '<h1>Sandbox Flask App</h1>'

@app.route('/api/status')
def status():
    return jsonify({"status": "running", "server": "sandbox"})
"""

result = start_web_app(flask_code, "flask")
# Returns URL where app is accessible

Shell Command Execution

# Install packages via shell
result = shell_execute("uv pip install matplotlib")

# Check environment
result = shell_execute("which python")

# List directory contents
result = shell_execute("ls -la")

# Custom working directory and timeout
result = shell_execute(
    "find . -name '*.py' | head -10", 
    working_directory="/path/to/search",
    timeout=60
)

Manim Animation Creation

# Simple circle animation
manim_code = """
from manim import *

class SimpleCircle(Scene):
    def construct(self):
        circle = Circle()
        circle.set_fill(PINK, opacity=0.5)
        self.play(Create(circle))
        self.wait(1)
"""

result = create_manim_animation(manim_code, quality="medium_quality")
# Returns JSON with video path and metadata

# Mathematical graph visualization
math_animation = """
from manim import *

class GraphPlot(Scene):
    def construct(self):
        axes = Axes(
            x_range=[-3, 3, 1],
            y_range=[-3, 3, 1],
            x_length=6,
            y_length=6
        )
        axes.add_coordinates()
        
        graph = axes.plot(lambda x: x**2, color=BLUE)
        graph_label = axes.get_graph_label(graph, label="f(x) = x^2")
        
        self.play(Create(axes))
        self.play(Create(graph))
        self.play(Write(graph_label))
        self.wait(1)
"""

result = create_manim_animation(math_animation, quality="high_quality")

# List all animations
animations = list_manim_animations()

# Get example code snippets
examples = get_manim_examples()

Error Handling

# Import error with detailed diagnostics
result = execute(code="import nonexistent_module")
# Returns structured error with sys.path info

# Security-blocked shell command
result = shell_execute("rm -rf /")
# Returns security error with blocked pattern info

🏗️ Architecture

Project Structure

sandbox-mcp/
├── src/
│   └── sandbox/                   # Main package
│       ├── __init__.py           # Package initialization
│       ├── mcp_sandbox_server.py # HTTP MCP server
│       ├── mcp_sandbox_server_stdio.py # stdio MCP server
│       ├── server/               # Server modules
│       │   ├── __init__.py
│       │   └── main.py
│       └── utils/                # Utility modules
│           ├── __init__.py
│           └── helpers.py
├── tests/
│   ├── test_integration.py       # Main test suite
│   └── test_simple_integration.py
├── pyproject.toml                # Package configuration
├── README.md                     # This file
├── .gitignore
└── uv.lock                       # Dependency lock file

Core Components

ExecutionContext

Manages the execution environment:

• Project Root Detection: Dynamic path resolution

• Virtual Environment: Auto-detection and activation

• sys.path Management: Intelligent path handling

• Artifact Management: Temporary directory lifecycle

• Global State: Persistent execution context

Monkey Patching System

Non-intrusive artifact capture:

• matplotlib.pyplot.show(): Intercepts and saves plots

• PIL.Image.show(): Captures image displays

• Conditional Patching: Only applies if libraries available

• Original Functionality: Preserved through wrapper functions

MCP Integration

FastMCP-powered server with:

• Dual Transport: HTTP and stdio protocols

• Tool Registry: 7 available MCP tools

• Streaming Support: Ready for real-time interaction

• Error Handling: Structured error responses

🔒 Security Model

Important: Sandbox MCP is designed for single-user development scenarios, not multi-tenant production use.

What It Provides

✅ Isolated execution contexts for LLM code generation ✅ Artifact management and capture ✅ Path traversal prevention ✅ Session isolation

What It Does NOT Provide

❌ Multi-tenant isolation ❌ Protection against malicious code ❌ Process-level security boundaries

For production use or multi-tenant scenarios, use RemoteSandbox with container isolation.

See SECURITY.md for complete threat model.

📚 Documentation

For comprehensive usage information, troubleshooting guides, and advanced features:

• FAQ and Limitations - Common issues and sandbox restrictions

• Enhanced Features Guide - Advanced capabilities and examples

• API Reference - Complete API documentation

🧪 Testing

Run the test suite to verify installation:

uv run pytest tests/ -v

Test categories include:

• Package import and sys.path tests

• Error handling and ImportError reporting

• Artifact capture (matplotlib/PIL)

• Web application launching

• Virtual environment detection

🤝 Contributing

1. Fork the repository

2. Create a feature branch

3. Run tests: uv run pytest

4. Submit a pull request

For development setup:

uv venv && uv pip install -e ".[dev]"

License

Apache License

Attribution

This project includes minor inspiration from:

• Microsandbox - Referenced for secure microVM isolation concepts

The majority of the functionality in this project is original implementation focused on MCP server integration and enhanced Python execution environments.

Changelog

v0.3.0 (Enhanced SDK Release)

• 🚀 Enhanced SDK: Complete integration with microsandbox functionality

• 🔄 Unified API: Single interface for both local and remote execution

• 🛡️ MicroVM Support: Secure remote execution via microsandbox server

• 🌐 Multi-Language: Python and Node.js execution environments

• 🏗️ Builder Pattern: Fluent configuration API with SandboxOptions

• 📊 Metrics & Monitoring: Real-time resource usage tracking

• ⚡ Async/Await: Modern Python async support throughout

• 🔒 Enhanced Security: Improved command filtering and validation

• 📦 Artifact Management: Comprehensive file artifact handling

• 🎯 Command Execution: Safe shell command execution with timeouts

• 🔧 Configuration: Flexible sandbox configuration options

• 📝 Documentation: Comprehensive examples and usage guides

v0.2.0

• Manim Integration: Complete mathematical animation support

• 4 New MCP Tools: create_manim_animation, list_manim_animations, cleanup_manim_animation, get_manim_examples

• Quality Control: Multiple animation quality presets

• Video Artifacts: Auto-saves MP4 animations to artifacts directory

• Example Library: Built-in Manim code examples

• Virtual Environment Manim: Uses venv-installed Manim executable

v0.1.0

• Initial enhanced package structure

• Dynamic project root detection

• Robust virtual environment integration

• Enhanced error handling with detailed tracebacks

• Artifact management with matplotlib/PIL support

• Web application launching (Flask/Streamlit)

• Comprehensive test suite

• MCP server integration (HTTP and stdio)

• CLI entry points

• LM Studio compatibility