mcp-cad

MCP server for Autodesk Inventor. Give AI agents direct parametric control over your CAD models.

32 tools across 7 domains — connection, documents, sketches, 3D features, parameters, iProperties, and export. All through COM automation. No VBA, no macros.

Requirements

• Windows with Autodesk Inventor installed (any recent version)
• Python 3.10+
• OpenCode, Claude Desktop, or any MCP-compatible client

Quick start

git clone https://github.com/Andiveli/mcp-cad.git
cd mcp-cad
.\scripts\install.ps1

The installer creates a virtual environment, installs dependencies, runs the test suite, and auto-configures OpenCode. Open the folder in OpenCode and the server starts automatically.

Tools

Connection

Tool	Description
inventor_connect	Connect to a running Inventor instance or launch a new one
inventor_health	Check connection health and document state
inventor_disconnect	Release COM reference without closing Inventor

Documents

Tool	Description
doc_open	Open an existing Inventor document
doc_new_part	Create a new part document
doc_new_assembly	Create a new assembly document
doc_save	Save the active document
doc_save_as	Save to a new path
doc_close	Close the active document

Sketches

Tool	Description
sketch_create	Create a new sketch on XY, XZ, or YZ plane
sketch_line	Draw a line segment
sketch_circle	Draw a circle
sketch_arc	Draw an arc
sketch_rectangle	Draw a rectangle (2-corner)
sketch_dimension	Add a dimension constraint

3D Features

Tool	Description
extrude	Extrude a sketch profile (join/cut/intersect)
revolve	Revolve a profile around an axis
fillet	Apply fillet to edges
chamfer	Apply chamfer to edges

Parameters

Tool	Description
param_list	List model parameters (with optional filter)
param_get	Get a parameter value
param_set	Set a parameter value
param_set_expression	Set a parameter using an expression

iProperties

Tool	Description
iproperty_get	Get an iProperty
iproperty_set	Set an iProperty
iproperty_summary	Get all Summary iProperties
iproperty_custom_get	Get a custom property
iproperty_custom_set	Set (or create) a custom property

Export

Tool	Description
export_step	Export to STEP
export_stl	Export to STL
export_pdf	Export to PDF
export_dxf	Export sketch/flat pattern to DXF

Architecture

mcp_cad/
├── server.py              FastMCP instance + 32 tool registrations
├── errors.py              Exception hierarchy (InventorError → COM/permission/not-found)
├── inventor/
│   ├── client.py          COM connection lifecycle (connect, health, disconnect)
│   ├── document.py        Document operations
│   ├── sketch.py          2D sketch geometry
│   ├── feature.py         3D features
│   ├── parameter.py       Model parameters
│   ├── property.py        iProperties
│   └── export.py          STEP/STL/PDF/DXF export
└── tests/
    200 tests, COM-mocked, run on Linux

All managers receive the driver and access the COM object via driver.inventor — a property that always reflects the current connection state. No stale references.

Development

# Run tests (works on Linux)
python -m pytest tests/ -v

# Run with coverage (needs pytest-cov in venv)
python -m pytest tests/ --cov=mcp_cad --cov-report=term-missing

Tests mock the entire COM layer — no Inventor installation needed for development. 200 tests covering happy paths, error scenarios, disconnected guards, and edge cases.

Configuration

OpenCode (auto-configured by installer)

{
  "mcp": {
    "mcp-cad": {
      "type": "local",
      "command": [".venv\\Scripts\\python.exe", "-m", "mcp_cad"]
    }
  }
}

Claude Desktop (manual)

{
  "mcpServers": {
    "mcp-cad": {
      "command": "C:\\path\\to\\mcp-cad\\.venv\\Scripts\\python.exe",
      "args": ["-m", "mcp_cad"]
    }
  }
}

Limitations

• Windows-only (Inventor COM requires native Windows)
• stdio transport only (SSE/remote transport planned)
• No Docker support (COM cannot cross container boundaries)
• Assemblies, drawings, iLogic, and sheet metal not yet implemented