FreeCAD

Create or modify 3D CAD models in FreeCAD using parametric JSON operations.

FreeCAD Skill

Description

Create or modify 3D CAD models in FreeCAD using parametric operations.

When to use

Use when user asks to:

• create objects (primitives like box, cylinder, sphere, cone, torus)
• modify geometry (scale, translate, rotate, fillets, cut, fuse, etc.)
• generate CAD files
• perform complex multi-step CAD operations

Input (JSON)

{ "operation": "create_primitive | boolean | transform | batch | export | inspect | modifier | array | profile", "parameters": { ... } }

Output (JSON return)

On success, the script prints a JSON payload to stdout containing the names, bounding boxes, and metadata of all active objects. This acts as your visual feedback interface.

Instructions

1. Convert user request into JSON. You may use batch to combine steps.
2. Call: python {baseDir}/scripts/cad_engine.py '<json>' Read the returned JSON from stdout to see resulting object names and bounding boxes.
3. Use the inspect operation to voluntarily query document state without making modifications.

Rules

• NEVER generate FreeCAD code yourself
• ONLY call the engine
• ALWAYS pass structured JSON
• For complex shapes, break down the request into basic primitives, transforms, and booleans using the batch operation.

Output

• model.FCStd
• model.step

Examples

Create a Primitive: { "operation": "create_primitive", "parameters": { "type": "box", "length": 100, "width": 100, "height": 50, "name": "MyBox", "position": [0, 0, 0] } }

Batch CSG (Cut a hole in a box): { "operation": "batch", "parameters": { "steps": [ { "operation": "create_primitive", "parameters": { "type": "box", "length": 50, "width": 50, "height": 10, "name": "BaseBox" } }, { "operation": "create_primitive", "parameters": { "type": "cylinder", "radius": 5, "height": 10, "name": "HoleCyl", "position": [25, 25, 0] } }, { "operation": "boolean", "parameters": { "type": "cut", "base": "BaseBox", "tool": "HoleCyl", "name": "ResultShape" } } ] } }

Scale: { "operation": "scale_object", "parameters": { "scale_factor": 0.8 } }