name: smith-cad description: Build, inspect, dimension, and validate CAD models with the Smith Elixir library and native OCEx geometry. Use for Smith scripts, assemblies, or Livebook modeling; supports numerical inspection without vision.

Smith CAD

Use the project's installed Smith version. For 0.2, read the inspection guide and API index when selecting operations. In a checkout or dependency, the same guide is guides/inspection.md.

Keep modeling in ordinary Elixir functions and immutable recipes. A standalone .exs is enough; use Livebook when the user wants an interactive walkthrough. Preserve existing notebook edits and its chosen dependency setup.

Build → evaluate → inspect → check → revise:

• Evaluate expensive stages once. Smith.from_result/1 branches from a native snapshot without rebuilding its source; rerun upstream stages after edits.
• Name relevant snapshots in Smith.Inspection.run/2. Inspect topology through Smith.Inspection.topology/3 with bounded pages and geometric selectors.
• Measure actual geometry with Smith.Measure. Circle-center anchors expose feature spacing; extents expose overall dimensions. Ambiguous selections are errors. Face and edge indices apply only to their recorded revision.
• Express requirements as bounds, topology counts, containment, clearance, or measurement checks. Read report.status: {:ok, report} alone does not mean checks passed. Keep failed requirements separate from kernel errors and unresolved design data.
• Use Smith.Inspection.write/3 for JSON and revision-linked PNG observations. Text-only agents should read the JSON. Vision-capable agents can also inspect the referenced images. Never claim to have inspected an image you did not read.
• Use sections and Smith.Inspection.compare/2 to investigate internal geometry and added/removed material. Compare shapes when equal volume is insufficient.
• For drawings, use Smith.Drawing.dimension/3 with a Smith.Measure from the same source revision. Do not label a feature with its input parameter and call that a measured dimension. Dimensions are annotations, not driving constraints.
• Finish printable deliverables with Smith.export/3 and its mesh/STEP checks. Follow the project's viewer/reload conventions when they exist.

Coordinates are millimeters; modeling angles are degrees. Report tolerances in the check's units: containment can use mm, mm², or mm³. Clearance has separate linear and interference-volume tolerances. Numerical precision, manufacturing allowances, print compensation, and uncertain drawing dimensions are distinct.

Keep assumptions visible. A valid solid is not proof of intended shape or real hardware fit. Do not weaken a failing check merely to make a report pass. An empty or failed section is not evidence of absence of material. Native geometry and inspection errors remain actionable evidence for the next edit.