CAD/BIM Automation

Inspect formats/versions, available tools/APIs, source-vs-issued status, units, coordinates/origin, levels/grids, layers/categories, naming, and revisions.

Choose the least destructive method: read/report → export to new file → supported API/script → original edit only with explicit permission. For proprietary formats, produce an application-native workflow rather than pretending an unsupported direct edit occurred.

Batch protocol: inventory → dry run → sample → validate → full run → post-change audit.

Verify counts, units, geometry bounds, naming, missing objects/categories, export integrity, and deltas. Never alter surveyed coordinates, structural geometry, life-safety elements, or issued information outside explicit scope and review.

Opt-in local Blender prototype (separately installed skill): if a trusted Blender executable is available and the user requests a NEW conceptual 3D scene, discover the installed architectural-drawing-generation skill first. Its own scripts/blender_native.py (worker and validator included) is the portable entry point; run doctor, then build SPEC.json NEW_OUT from that skill directory. Do not assume the standalone cad-bim-automation skill contains Blender code or repo docs. In a Gridline checkout, scripts/blender_native.py is merely a convenience launcher; docs/BLENDER_NATIVE_BRIDGE.md documents its limits. If the drawing skill is absent, report a missing dependency rather than inventing a path. This bridge creates editable conceptual mesh geometry and .glb with native readback; it cannot edit live models, install MCPs, reconstruct images, establish IFC/AutoCAD compliance or approve drawings. Ask for missing reference measurements and report unsupported details.

Optional signed source workflow: the drawing skill also supplies component_state.py for typed component/level/wall/opening/room proposals, exact Ed25519 owner approvals, immutable revisions, indexed impacts, stale conflicts, revalidated disjoint merges and approved restore. Keep owner keys outside the agent and never self-sign as a real owner. archimesh_components.py build --state-db DB --owner-key-sha256 PIN requires the signed current source and new output only; component_ifc.py additionally requires the state database, requirements and trusted source/owner pins. These source/file operations do not authorize live Revit/AutoCAD writes, replace native transactions/rollback, establish a complete external drawing dependency graph or close the general #15 gate. Read the drawing skill's actual commands/limits; do not assume this standalone automation skill contains its scripts.