vcad

name	vcad
description	Create 3D CAD models using vcad MCP tools. Use when the user asks to create 3D parts, mechanical components, plates with holes, brackets, or any parametric geometry. Supports primitives (cube, cylinder, sphere, cone), boolean operations, transforms, patterns, and export to STL/GLB.

vcad - Parametric CAD for AI Agents

Create 3D CAD models programmatically using the vcad MCP tools.

Available Tools

create_cad_document

Build geometry from structured primitives and operations.

export_cad

Export to STL (3D printing) or GLB (visualization).

inspect_cad

Get volume, surface area, bounding box, and triangle count.

Primitive Origins

Understanding where primitives are positioned is critical for correct placement:

Primitive	Origin	Extent
Cube	Corner at (0,0,0)	Extends to (size.x, size.y, size.z)
Cylinder	Base center at (0,0,0)	Height along +Z
Sphere	Center at (0,0,0)	Radius in all directions
Cone	Base center at (0,0,0)	Height along +Z

Positioning Operations

The at parameter accepts three formats:

1. Absolute: {x: 25, y: 15, z: 0} - exact coordinates in mm
2. Named: "center", "top-center", "bottom-center" - relative to base primitive
3. Percentage: {x: "50%", y: "50%"} - percentage of base primitive bounds

Common Patterns

Plate with Centered Hole

{
  "parts": [{
    "name": "plate",
    "primitive": {"type": "cube", "size": {"x": 50, "y": 50, "z": 5}},
    "operations": [
      {"type": "hole", "diameter": 6, "at": "center"}
    ]
  }]
}

Plate with Corner Holes

{
  "parts": [{
    "name": "mounting_plate",
    "primitive": {"type": "cube", "size": {"x": 100, "y": 60, "z": 5}},
    "operations": [
      {"type": "hole", "diameter": 4, "at": {"x": 10, "y": 10}},
      {"type": "hole", "diameter": 4, "at": {"x": 90, "y": 10}},
      {"type": "hole", "diameter": 4, "at": {"x": 10, "y": 50}},
      {"type": "hole", "diameter": 4, "at": {"x": 90, "y": 50}}
    ]
  }]
}

Cylinder with Blind Hole

{
  "parts": [{
    "name": "bushing",
    "primitive": {"type": "cylinder", "radius": 15, "height": 20},
    "operations": [
      {"type": "hole", "diameter": 10, "depth": 15, "at": "center"}
    ]
  }]
}

L-Bracket

{
  "parts": [{
    "name": "bracket",
    "primitive": {"type": "cube", "size": {"x": 40, "y": 40, "z": 5}},
    "operations": [
      {"type": "union", "primitive": {"type": "cube", "size": {"x": 5, "y": 40, "z": 30}}, "at": {"x": 0, "y": 0, "z": 5}},
      {"type": "hole", "diameter": 5, "at": {"x": 20, "y": 20}},
      {"type": "difference", "primitive": {"type": "cylinder", "radius": 2.5, "height": 40}, "at": {"x": 2.5, "y": 20, "z": 20}}
    ]
  }]
}

Linear Pattern of Holes

{
  "parts": [{
    "name": "rail",
    "primitive": {"type": "cube", "size": {"x": 200, "y": 20, "z": 10}},
    "operations": [
      {
        "type": "difference",
        "primitive": {"type": "cylinder", "radius": 3, "height": 15},
        "at": {"x": 20, "y": 10, "z": -2}
      },
      {
        "type": "linear_pattern",
        "direction": {"x": 1, "y": 0, "z": 0},
        "count": 5,
        "spacing": 40
      }
    ]
  }]
}

Circular Pattern

{
  "parts": [{
    "name": "flange",
    "primitive": {"type": "cylinder", "radius": 40, "height": 10},
    "operations": [
      {"type": "hole", "diameter": 20, "at": "center"},
      {
        "type": "difference",
        "primitive": {"type": "cylinder", "radius": 4, "height": 15},
        "at": {"x": 30, "y": 0, "z": -2}
      },
      {
        "type": "circular_pattern",
        "axis_origin": {"x": 0, "y": 0, "z": 0},
        "axis_dir": {"x": 0, "y": 0, "z": 1},
        "count": 6,
        "angle_deg": 360
      }
    ]
  }]
}

Workflow

1. Create: Use create_cad_document to build geometry
2. Inspect: Use inspect_cad to verify dimensions and volume
3. Export: Use export_cad to save as .stl or .glb

Tips

• Holes default to through-holes; specify depth for blind holes
• Use percentage positioning for parametric designs that scale
• Cube origin is at corner - add half-size to center operations
• Cylinder/cone origins are at base center - no X/Y offset needed for centered holes
• Always extend cutting cylinders past the part (the hole operation does this automatically)

Setup

Recommended: Install the vcad Claude Code plugin for zero-config setup (includes MCP server, skills, and slash commands):

claude plugin add vcad

Manual setup: Add the vcad MCP server to your Claude Code config:

{
  "mcpServers": {
    "vcad": {
      "command": "npx",
      "args": ["-y", "@vcad/mcp"]
    }
  }
}

Or run from local checkout:

{
  "mcpServers": {
    "vcad": {
      "command": "node",
      "args": ["packages/mcp/dist/index.js"]
    }
  }
}