OAS Extensions

When to use

Use this skill any time the task involves attaching domain-specific data outside the Core/Layout vocabulary: industrial machinery, materials, MEP systems, site context, or vendor metadata (Autodesk/Revit families, APS URNs). If the data fits a Core entity directly (e.g. a Furniture placement), keep it in Core — don't reach for an extension.

Key types

• Extension envelope — top-level extensions dictionary keyed by extension name
• Machinery — industrial equipment with multi-axis rotation and CAD geometry source
• Material — material definitions referenced by id from Core/Layout entities
• Site — site context (boundaries, orientation, surroundings)
• AutodeskMetadata — Revit family names, APS URNs, vendor-specific identifiers

Critical rules