Agentic 3D Models

Parametric CAD models designed and generated by agents using Python and build123d. All dimensions are millimetres.

Quick start

Install uv, then:

uv sync
uv run modelgen generate mounting_plate --output-dir outputs/mounting_plate
uv run modelgen validate outputs/mounting_plate/mounting_plate.stl
uv run modelgen generate t_joint --output-dir outputs/t_joint
uv run modelgen validate outputs/t_joint/t_joint.stl
orca-slicer --info outputs/t_joint/t_joint.stl
uv run pytest

The generated STL is suitable for slicing. The STEP file is retained for CAD editing. Generated files are ignored by Git; the Python source is authoritative.

Agent workflow

1. Convert the request into explicit dimensions, tolerances, material, and print orientation.
2. Add or modify a model module under models/ with a build_model() function.
3. Add geometry assertions under tests/.
4. Generate and validate STL/STEP artifacts.
5. Inspect the STL in a slicer before manufacturing.

Models should be solid, deterministic, watertight, and designed with realistic clearances and minimum feature sizes for the target printer.

The OrcaSlicer --info check is part of the artifact workflow: it confirms the STL is a single manifold object before it is sent to a slicer or printer.

FreeCAD & MCP Integration (Nix)

This repository includes a flake.nix providing FreeCAD and freecad-mcp.

Running FreeCAD and MCP Server

1. Enter the Nix dev shell (automatically installs and links the FreeCADMCP addon):

   nix develop
   

2. Launch FreeCAD with MCP Addon:

   freecad
   # Or run directly via Nix:
   nix run .#freecad
   

   In FreeCAD, switch to the "MCP Addon" workbench and start the RPC server (or enable "Auto-Start Server" in FreeCAD MCP menu).

3. Run the MCP server:

   nix run .#freecad-mcp
   # Or inside `nix develop`:
   freecad-mcp
   

MCP Client Configuration

To allow MCP clients (such as Antigravity, Claude Desktop, etc.) to control FreeCAD:

{
  "mcpServers": {
    "freecad": {
      "command": "nix",
      "args": ["run", "/home/daniel/Repositories/3dprint#freecad-mcp"]
    }
  }
}