OpenSCAD MCP Server

MCP Version FastMCP Test Status License

A production-ready Model Context Protocol (MCP) server that provides OpenSCAD 3D rendering capabilities to AI assistants and LLM applications. Built with FastMCP for robust, scalable performance.

🎯 Zero-Installation Execution

Run directly from GitHub without any setup:

uv run --with git+https://github.com/quellant/openscad-mcp.git openscad-mcp

Perfect for MCP clients, CI/CD pipelines, and instant deployment scenarios!

Related MCP server: OpenSCAD MCP Server

🚀 Quick Start

Zero-Installation Execution with `uv`

No installation required! Run directly from GitHub:

# Run via script entry point (recommended) uv run --with git+https://github.com/quellant/openscad-mcp.git openscad-mcp # Or run as Python module uv run --with git+https://github.com/quellant/openscad-mcp.git python -m openscad_mcp

Traditional Installation (Optional)

# Clone and run locally git clone https://github.com/quellant/openscad-mcp.git cd openscad-mcp uv run openscad-mcp

Configure with Claude Desktop

Add to your Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

Option 1: Direct from GitHub (Recommended)

{ "mcpServers": { "openscad": { "command": "uv", "args": ["run", "--with", "git+https://github.com/quellant/openscad-mcp.git", "openscad-mcp"], "env": { "OPENSCAD_PATH": "/usr/bin/openscad" } } } }

Option 2: Local Installation

{ "mcpServers": { "openscad": { "command": "uv", "args": ["run", "openscad-mcp"], "cwd": "/path/to/openscad-mcp", "env": { "OPENSCAD_PATH": "/usr/bin/openscad" } } } }

🔒 Security: --allowedTools Requirement

IMPORTANT: When using the OpenSCAD MCP server with Claude CLI or other MCP clients, you MUST explicitly grant permissions using the --allowedTools flag for security. This prevents unauthorized tool usage and ensures controlled access to server capabilities.

Required Permissions

The OpenSCAD MCP server requires explicit permission for each tool:

openscad-mcp:check_openscad - Permission to check OpenSCAD installation
openscad-mcp:render_single - Permission to render single views
openscad-mcp:render_perspectives - Permission to render multiple perspectives

Example Usage with Claude CLI

# Start the server with uv and grant permissions # (Create mcp-config.json with uv configuration first) # Grant permission for a single tool claude --config mcp-config.json \ --allowedTools openscad-mcp:check_openscad \ "Check if OpenSCAD is installed" # Grant permission for multiple tools claude --config mcp-config.json \ --allowedTools openscad-mcp:check_openscad,openscad-mcp:render_single \ "Render a cube with dimensions 30x30x30" # Grant full permissions for all OpenSCAD tools claude --config mcp-config.json \ --allowedTools openscad-mcp:check_openscad,openscad-mcp:render_single,openscad-mcp:render_perspectives \ "Create a gear model and show it from multiple angles"

Create

{ "mcpServers": { "openscad-mcp": { "command": "uv", "args": ["run", "--with", "git+https://github.com/quellant/openscad-mcp.git", "openscad-mcp"], "env": { "OPENSCAD_PATH": "/usr/bin/openscad" } } } }

Testing with Permissions

Use the provided test script to verify proper permission configuration:

# Run all permission tests ./test_claude_with_permissions.sh all # Test individual tools ./test_claude_with_permissions.sh check # Test check_openscad only ./test_claude_with_permissions.sh single # Test render_single only ./test_claude_with_permissions.sh perspectives # Test render_perspectives only # Launch interactive session with full permissions ./test_claude_with_permissions.sh interactive # Show usage examples ./test_claude_with_permissions.sh examples

✨ Features

🎯 Production-Ready: 100% test success rate with comprehensive integration testing
🔧 Single View Rendering: Render OpenSCAD models from any camera angle with full control
📐 Multiple Perspectives: Generate standard orthographic and isometric views automatically
🎬 Animation Support: Create turntable animations for 360° model visualization
⚡ Async Processing: Non-blocking renders using FastMCP framework for optimal performance
🖼️ Base64 Encoding: Images returned as base64-encoded PNGs for seamless integration
✅ Verified Compatibility: Fully compatible with FastMCP 2.11.3 and Pydantic 2.11.7

📋 Prerequisites

Python 3.10+ (required for FastMCP 2.11.3)
OpenSCAD (Download from openscad.org)
uv (Install from docs.astral.sh) - Only needed for zero-installation execution

No additional Python packages required when using

📦 Installation

Method 1: Zero-Installation with `uv` (Recommended)

No installation required! Just run directly:

# Run directly from GitHub - uv handles everything automatically uv run --with git+https://github.com/quellant/openscad-mcp.git openscad-mcp # All dependencies (FastMCP 2.11.3, Pydantic 2.11.7, etc.) are resolved and installed automatically

Method 2: Local Development with `uv`

# Clone for local development git clone https://github.com/quellant/openscad-mcp.git cd openscad-mcp # Run with uv (installs dependencies automatically) uv run openscad-mcp # Or run as module uv run python -m openscad_mcp

Method 3: Traditional pip Installation

# Only if you can't use uv git clone https://github.com/quellant/openscad-mcp.git cd openscad-mcp pip install -e . python -m openscad_mcp

⚙️ Configuration

Environment Variables

Create a .env file in the project root:

# OpenSCAD Configuration OPENSCAD_PATH=/usr/bin/openscad # Path to OpenSCAD executable OPENSCAD_TIMEOUT=30 # Timeout for rendering operations (seconds) # Server Configuration MCP_SERVER_NAME=openscad-mcp MCP_SERVER_VERSION=1.0.0 MCP_SERVER_TRANSPORT=stdio # Transport: stdio, sse, or http # Rendering Configuration MCP_RENDER_MAX_CONCURRENT=4 # Max concurrent renders MCP_RENDER_DEFAULT_WIDTH=800 # Default image width MCP_RENDER_DEFAULT_HEIGHT=600 # Default image height

Configuration File (Optional)

Create config.yaml for advanced configuration:

server: name: "OpenSCAD MCP Server" version: "1.0.0" transport: stdio openscad: timeout: 30 default_color_scheme: "Cornfield" rendering: max_concurrent: 4 default_width: 800 default_height: 600

🛠️ Available MCP Tools

1. `render_single`

Render a single view of an OpenSCAD model with complete camera control.

Parameters:

Parameter	Type	Required	Description
`scad_content`	string	No*	OpenSCAD code to render
`scad_file`	string	No*	Path to .scad file
`camera_position`	[x,y,z]	No	Camera position (default: [30,30,30])
`camera_target`	[x,y,z]	No	Look-at point (default: [0,0,0])
`camera_up`	[x,y,z]	No	Up vector (default: [0,0,1])
`image_size`	[w,h]	No	Image dimensions in pixels
`color_scheme`	string	No	OpenSCAD color scheme
`variables`	dict	No	Variables to pass to OpenSCAD
`auto_center`	bool	No	Auto-center the model

*Either scad_content or scad_file must be provided

Example Request:

{ "tool": "render_single", "arguments": { "scad_content": "cube([10, 10, 10]);", "camera_position": [30, 30, 30], "image_size": [800, 600], "color_scheme": "Cornfield" } }

Example Response:

{ "success": true, "image": "data:image/png;base64,iVBORw0KGgo...", "metadata": { "width": 800, "height": 600, "render_time": 1.23 } }

2. `render_perspectives`

Generate multiple standard views of a model (front, back, left, right, top, bottom, isometric).

Parameters:

Parameter	Type	Required	Description
`scad_content`	string	No*	OpenSCAD code to render
`scad_file`	string	No*	Path to .scad file
`distance`	float	No	Camera distance from origin
`image_size`	[w,h]	No	Image dimensions for each view
`variables`	dict	No	Variables to pass to OpenSCAD
`views`	list	No	Specific views to render

Example Request:

{ "tool": "render_perspectives", "arguments": { "scad_file": "model.scad", "views": ["front", "isometric", "top"], "distance": 200, "image_size": [400, 400] } }

3. `check_openscad`

Verify OpenSCAD installation and get version information.

Parameters:

Parameter	Type	Required	Description
`include_paths`	bool	No	Include searched paths in response

Example Request:

{ "tool": "check_openscad", "arguments": { "include_paths": true } }

📚 MCP Resources

`resource://server/info`

Get server configuration and capabilities.

Returns:

Server version and status
OpenSCAD version and path
Rendering capabilities
Active operations count
Configuration details

🏗️ Architecture

The server implements a clean architecture pattern:

┌─────────────────────────────────────┐ │ MCP Client (Claude) │ └─────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────┐ │ FastMCP Server (Presentation) │ │ - MCP Protocol Handler │ │ - Tool Decorators │ └─────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────┐ │ Application Layer (Business) │ │ - Rendering Logic │ │ - Parameter Validation │ └─────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────┐ │ Infrastructure Layer (External) │ │ - OpenSCAD CLI │ │ - File I/O Operations │ └─────────────────────────────────────┘

🧪 Testing

The server has achieved 100% test success rate across all integration tests:

# Run comprehensive test suite python comprehensive_test.py # Run MCP tools integration test python test_mcp_tools.py # Run server startup test python test_server_startup.py

See Test Report for detailed results.

🔧 Development

Project Structure

openscad-mcp-server/ ├── src/ │ └── openscad_mcp/ │ ├── __init__.py # Package initialization │ ├── __main__.py # Entry point │ ├── server.py # FastMCP server implementation │ ├── types.py # Pydantic models & types │ └── utils/ │ └── config.py # Configuration management ├── tests/ # Test suite ├── pyproject.toml # Project configuration ├── README.md # This file ├── CHANGELOG.md # Version history ├── API.md # Detailed API documentation └── .env.example # Environment template

Extending the Server

To add new rendering capabilities:

Define parameter types in types.py:

class CustomRenderParams(BaseModel): # Your parameters here pass

Add tool function in server.py:

@mcp.tool async def custom_render(params: CustomRenderParams) -> RenderResult: """Your custom rendering logic""" # Implementation pass

Update documentation in API.md

🐛 Troubleshooting

OpenSCAD Not Found

# Check OpenSCAD installation which openscad # Set environment variable export OPENSCAD_PATH=/path/to/openscad # Or add to .env file OPENSCAD_PATH=/usr/local/bin/openscad

Permission Errors

# Ensure execute permissions chmod +x /path/to/openscad

Rendering Timeouts

Increase timeout in configuration:

export OPENSCAD_TIMEOUT=60 # 60 seconds

FastMCP Compatibility Issues

Ensure correct versions:

pip install fastmcp==2.11.3 pydantic==2.11.7

📈 Performance

Single view rendering: ~1-3 seconds (complexity dependent)
Multiple perspectives: ~5-10 seconds for 8 views
Base64 encoding: < 0.1s overhead
Memory footprint: ~50 MB base + 10-20 MB per render
Concurrent renders: Up to 4 (configurable)

🚦 Production Status

✅ Ready for Production

All tests passing (100% success rate)
FastMCP 2.11.3 compatibility verified
Comprehensive error handling
Async operation support
Resource management implemented
Documentation complete

📝 License

MIT License - See LICENSE file for details

🤝 Contributing

Contributions are welcome! Please:

Fork the repository
Create a feature branch (git checkout -b feature/amazing-feature)
Commit your changes (git commit -m 'Add amazing feature')
Push to the branch (git push origin feature/amazing-feature)
Open a Pull Request

📮 Support

Issues: GitHub Issues
Documentation: Full API Documentation
Test Report: Integration Test Results

🙏 Acknowledgments

FastMCP - The excellent MCP framework
OpenSCAD - The programmable CAD software
Model Context Protocol - The MCP specification

Version: 1.0.0 | Status: Production Ready | Last Updated: 2025-08-25

OpenSCAD MCP Server

🎯 Zero-Installation Execution

🚀 Quick Start

Zero-Installation Execution with uv

Traditional Installation (Optional)

Configure with Claude Desktop

Option 1: Direct from GitHub (Recommended)

Option 2: Local Installation

🔒 Security: --allowedTools Requirement

Required Permissions

Example Usage with Claude CLI

Testing with Permissions

✨ Features

📋 Prerequisites

📦 Installation

Method 1: Zero-Installation with uv (Recommended)

Method 2: Local Development with uv

Method 3: Traditional pip Installation

⚙️ Configuration

Environment Variables

Configuration File (Optional)

🛠️ Available MCP Tools

1. render_single

2. render_perspectives

3. check_openscad

📚 MCP Resources

resource://server/info

🏗️ Architecture

🧪 Testing

🔧 Development

Project Structure

Extending the Server

🐛 Troubleshooting

OpenSCAD Not Found

Permission Errors

Rendering Timeouts

FastMCP Compatibility Issues

📈 Performance

🚦 Production Status

📝 License

🤝 Contributing

📮 Support

🙏 Acknowledgments

Resources

Tools

Appeared in Searches

New MCP Servers

Latest Blog Posts

MCP directory API

Zero-Installation Execution with `uv`

Method 1: Zero-Installation with `uv` (Recommended)

Method 2: Local Development with `uv`

1. `render_single`

2. `render_perspectives`

3. `check_openscad`

`resource://server/info`