CAD-Query MCP Server

A Model Context Protocol (MCP) server that provides CAD generation and verification tools for Claude Code. This server enables conversational 3D modeling by exposing CAD-Query functionality through MCP tools.

Features

• verify_cad_query - Validates CAD-Query generated models against criteria
• generate_cad_query - (Stub implementation) Generates CAD-Query Python scripts from descriptions
• CAD-Query Integration - Full CAD-Query support for parametric 3D modeling
• STL/STEP Export - Direct export to 3D printing and CAD formats
• Visual Feedback - SVG generation for model inspection

Installation

# Install dependencies
uv sync

# For development with CAD verification capabilities
uv sync --extra cad

# Test the server
uv run python tests/test_server.py

# Run with MCP Inspector (interactive testing)
uv run mcp dev server.py

Claude Desktop Configuration

Add this to your Claude Desktop configuration file:

macOS

Location: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows

Location: %APPDATA%/Claude/claude_desktop_config.json

Configuration

{
  "mcpServers": {
    "cadquery-server": {
      "command": "python",
      "args": ["/path/to/cadquery-mcp-server/server.py"],
      "env": {}
    }
  }
}

MCP Tools

verify_cad_query

Validates a CAD-Query generated model against specified criteria.

Parameters:

• file_path (string): Path to the CAD-Query Python file
• verification_criteria (string): Description of what to verify

Example:

{
  "file_path": "models/coffee_mug.py",
  "verification_criteria": "coffee mug with handle, 10cm height, 8cm diameter"
}

Returns:

{
  "status": "PASS" | "FAIL",
  "message": "Description of result",
  "file_path": "Path to verified file",
  "criteria": "Verification criteria used",
  "details": "Additional verification details"
}

generate_cad_query (Stub Implementation)

Generates CAD-Query Python scripts from natural language descriptions.

NOTE: Currently returns a stub response indicating the feature is not yet implemented.

Parameters:

• description (string): Natural language description of the desired 3D model
• parameters (string, optional): Specific dimensions or constraints

Example:

{
  "description": "Create a coffee mug with a handle, 10cm tall and 8cm diameter",
  "parameters": "height=100mm, diameter=80mm, handle_width=15mm"
}

Returns:

{
  "status": "NOT_IMPLEMENTED",
  "message": "CAD code generation is not yet implemented",
  "description": "Input description",
  "parameters": "Input parameters",
  "details": "Additional information"
}

CAD-Query Script Requirements

All CAD-Query scripts must end with show_object(result):

import cadquery as cq
result = cq.Workplane("XY").box(10, 10, 10)
show_object(result)  # Required for processing

Development

Testing

# Test server functionality
uv run python tests/test_server.py

# Interactive testing with MCP Inspector
uv run mcp dev server.py

# Run evaluations
uv run python evaluations/evaluate_verify.py

Extending the Server

The current verify_cad_query implementation is a basic validator. You can enhance it to:

• Parse and validate CAD-Query syntax
• Execute model generation and catch errors
• Analyze resulting geometry dimensions
• Check for specific features and constraints
• Generate detailed validation reports

Dev tools

# formatting
uvx rff format

# running the MCP server
npx @modelcontextprotocol/inspector \
  uv \
  --directory $(pwd) \
  run \
  server.py