FreeCAD MCP Server is an integration layer that enables AI assistants to control FreeCAD directly through natural language for 3D parametric modeling and CAD design tasks. It creates a bridge between Claude Desktop and the open-source FreeCAD application, allowing you to generate mechanical parts, assemblies, and 3D models via conversational commands. Key features include: - Natural language control of FreeCAD from Claude Desktop for hands-free CAD modeling - Parametric 3D design capabilities including mechanical parts like flanges, toy car models, and custom assemblies - 2D drawing conversion to create 3D solid models from sketches and technical drawings - Real-time RPC communication between the AI assistant and the FreeCAD instance - Auto-start server option for seamless workflow integration - Cross-platform support for Windows, macOS, and Linux FreeCAD installations

[](https://mseep.ai/app/neka-nat-freecad-mcp)

FreeCAD MCP

This repository is a FreeCAD MCP that allows you to control FreeCAD from Claude Desktop.

Demo

Design a flange

Design a toy car

Design a part from 2D drawing

#### Input 2D drawing

#### Demo

This is the conversation history. https://claude.ai/share/7b48fd60-68ba-46fb-bb21-2fbb17399b48

Install addon

FreeCAD Addon directory is

Please put addon/FreeCADMCP directory to the addon directory.

git clone https://github.com/neka-nat/freecad-mcp.git
cd freecad-mcp
cp -r addon/FreeCADMCP ~/.FreeCAD/Mod/

When you install addon, you need to restart FreeCAD. You can select "MCP Addon" from Workbench list and use it.

And you can start RPC server by "Start RPC Server" command in "FreeCAD MCP" toolbar.

Auto-Start RPC Server

By default, the RPC server must be started manually each time FreeCAD opens. To start it automatically:

1. Open the FreeCAD MCP menu (switch to the MCP Addon workbench first) 2. Check Auto-Start Server

The setting is saved to freecad_mcp_settings.json and persists across sessions. On the next FreeCAD launch, the RPC server will start automatically once the application finishes loading.

You can disable it at any time by unchecking Auto-Start Server in the same menu.

Setting up Claude Desktop

Pre-installation of the uvx is required.

And you need to edit Claude Desktop config file, claude_desktop_config.json.

For user.

{
  "mcpServers": {
    "freecad": {
      "command": "uvx",
      "args": [
        "freecad-mcp"
      ]
    }
  }
}

If you want to save token, you can set only_text_feedback to true and use only text feedback.

{
  "mcpServers": {
    "freecad": {
      "command": "uvx",
      "args": [
        "freecad-mcp",
        "--only-text-feedback"
      ]
    }
  }
}

For developer. First, you need clone this repository.

git clone https://github.com/neka-nat/freecad-mcp.git

{
  "mcpServers": {
    "freecad": {
      "command": "uv",
      "args": [
        "--directory",
        "/path/to/freecad-mcp/",
        "run",
        "freecad-mcp"
      ]
    }
  }
}

Remote Connections

By default the RPC server does not accept remote connections and listens on localhost. To control FreeCAD from another machine on your network:

1. Enable remote connections in FreeCAD

In the FreeCAD MCP toolbar:

1. Check Remote Connections — the RPC server will bind to 0.0.0.0 (all interfaces) on the next restart. For security reasons, it only accepts connections from the IP addresses or CIDR subnets specified in the Allowed IPs field. By default this is 127.0.0.1. 2. Click Configure Allowed IPs and enter a comma-separated list of IP addresses or CIDR subnets that are allowed to connect, e.g.:

   192.168.1.100, 10.0.0.0/24
   

127.0.0.1 is always the default. Invalid entries are rejected with an error dialog. Restart the RPC server after changing these settings.

2. Point the MCP server at the remote host

Pass the --host flag with the IP address or hostname of the machine running FreeCAD:

{
  "mcpServers": {
    "freecad": {
      "command": "uvx",
      "args": [
        "freecad-mcp",
        "--host", "192.168.1.100"
      ]
    }
  }
}

The --host value is validated on startup — it must be a valid IPv4/IPv6 address or hostname.

Tools

Contributors

Made with contrib.rocks.