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 '' 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 } }