NX MCP Server

MCP (Model Context Protocol) server for Siemens NX (UG). Enables AI agents to programmatically control NX's GUI for CAD operations.

Features

• 47 MCP tools covering core CAD operations
• File operations: create, open, save, close, export, import
• Sketching: lines, arcs, rectangles, constraints
• Modeling: extrude, revolve, sweep, blend, chamfer, hole, pattern, boolean, mirror
• Assembly: add components, mate, list, reposition
• Drawing: create sheets, add views, dimensions, export PDF
• Measurement: distance, angle, volume
• Utility: view control, undo, screenshot, journal recording
• Feature tree: list features, inspect parameters, bounding box

Prerequisites

• Siemens NX 2300+ (2023+)
• Python 3.10+
• NX Open Python API (bundled with NX)

Installation

pip install -e .

Configuration

Claude Code

Add to .claude/settings.local.json:

{
  "mcpServers": {
    "nx-mcp": {
      "command": "python",
      "args": ["-m", "nx_mcp.server"],
      "env": {
        "UGII_BASE_DIR": "C:\\Program Files\\Siemens\\NX2300"
      }
    }
  }
}

Generic MCP Client

Start the server via stdio:

python -m nx_mcp.server

Usage

1. Start Siemens NX
2. Ensure your MCP client has the server configured
3. Ask your AI agent to perform NX operations

Example prompts:

• "Create a new part called bracket.prt"
• "Draw a 50x30 rectangle on the XY plane and extrude it 20mm"
• "Add a 3mm fillet to all edges"
• "Export the current part as STEP"

Testing

pip install -e ".[dev]"
pytest tests/ -v

Tests run with mocked NX Open — no NX installation required.

Architecture

AI Agent <-> MCP Protocol (stdio) <-> MCP Server (Python) <-> NX Open API <-> NX Application

Project Structure

src/nx_mcp/
  server.py          # MCP server entry point
  nx_session.py      # NX session wrapper (singleton)
  response.py        # ToolResult / ToolError response types
  tools/
    registry.py      # @mcp_tool decorator and ToolRegistry
    file_ops.py      # File operations (8 tools)
    sketch.py        # Sketch tools (7 tools)
    modeling.py      # Modeling features (11 tools)
    feature_tree.py  # Feature queries (3 tools)
    assembly.py      # Assembly tools (4 tools)
    drawing.py       # Drawing tools (5 tools)
    measure.py       # Measurement tools (3 tools)
    utility.py       # View, undo, screenshot, journal (7 tools)
  utils/
    geometry.py      # Point3d, Vector3d, object resolution helpers
    selection.py     # ScCollector creation helpers
tests/
  test_tools/        # Per-module test suites (120 tests, all mocked)

License

MIT