simplecadapi

name	simplecadapi
description	Thin SimpleCAD SDK reference skill focused on the public API surface, core types, and current modeling workflows.
license	AGPL-3.0
compatibility	Documentation/reference bundle for current SimpleCADAPI surfaces.
metadata	{"project":"simplecadapi","version":"2.0.1b1","package-name":"simplecadapi","package-version":"2.0.1b1"}

SimpleCAD SDK Skill

Philosophy

• This is a thin SDK reference skill: docs only.
• SDK source code is not bundled in this skill.

Working From Repo Root

• Tool calls run from the repo root.
• Use one explicit skill root: ./skills/simplecadapi/ or ./workspace/skills/simplecadapi/.
• Main doc paths:
  • <skill_root>/SKILL.md
  • <skill_root>/references/docs/api/README.md
  • <skill_root>/references/docs/api/<api_name>.md
  • <skill_root>/references/docs/stdlib/README.md
  • <skill_root>/references/docs/stdlib/<stdlib_api_name>.md
  • <skill_root>/references/docs/core/<type_name>.md
  • <skill_root>/references/SDK_OVERVIEW.md
  • <skill_root>/references/SDK_SURFACES.md
  • <skill_root>/references/MODELING_WORKFLOWS.md

MUST Requirements

1. Read SKILL.md, references/docs/api/README.md, and references/docs/stdlib/README.md before choosing APIs.
2. Read the exact API Markdown page for every API you use.
3. Read the needed core/ or exact api/ docs when an API needs Edge, Face, Wire, Solid, GraphSession, Sketch, or expression types.
4. Prefer the standard parts library for standard parts before hand-modeling with core geometry APIs.
5. Follow the documented API signatures exactly.
6. When calling any SimpleCAD public API or standard-library function, use keyword arguments for every documented parameter; do not use positional arguments.
7. Use the graph/model JSON workflow for replayable tasks: GraphSession, export_session_json, export_model_json, import_model_json, and replay_model_json.
8. Use geometry APIs for integrated parts: profiles, features, booleans, transforms, tagging, QL inspection, serialization, and exports.
9. Use tags consistently through apply_tag(shape=..., tag=...) and list_tags(shape=...); do not call shape member tag mutators.
10. Build and validate incrementally. Each step MUST include a small grounding print, and grounding MUST use QL where possible.
11. For inspection/debugging, query geometry with QL and print only the queried facts you need; do not print whole solids or full model objects.
12. Boolean operations return a single Solid.
13. Use union_rsolid(...) for boolean union.
14. For automated example/test harnesses, prefer the repo-local examples in examples/ and avoid scratch scripts in sandbox/.
15. If union cannot produce exactly one merged solid, it fails explicitly; do not silently pick one piece.
16. If a single merged solid is required and union fails, slightly adjust part placement so intended bodies overlap/embed, then recompute.
17. If a task depends on model replay or interchange, prefer export_model_json() output over hand-written payloads.

Standard Parts Library

• SimpleCAD includes a standard library for parameterized mechanical parts.
• When the user needs a standard part and does not require complex custom geometry changes, use a standard-library function first.
• Current package-level standard-library surfaces include scad.std.gear for involute gears, internal ring gears, racks, and cycloidal discs, plus scad.std.bearing for ball bearing assemblies.
• Read references/docs/stdlib/README.md to discover standard-library functions.
• Read references/docs/stdlib/<function_name>.md before calling a standard-library function.
• Standard-library functions return normal SimpleCAD shapes or product assemblies that can be transformed, tagged, assembled, exported, and used with graph/model JSON workflows.

Boolean result discipline

• union_rsolid(...), cut_rsolid(...), and intersect_rsolid(...) accept mixed inputs: standalone Solid, lists of Solid, and nested sequences.
• They return a single Solid.
• union_rsolid(...) already applies the package's default glue mode and a conservative internal tolerance.
• If a union cannot produce exactly one merged solid, it fails explicitly instead of returning multiple pieces.
• If a single merged solid is required but union fails, slightly move the parts so they overlap instead of merely touching, then recompute the union.

Modeling Mental Model

• Start with intent: identify the part, its reference axes, critical profiles, and the features that produce the final solid.
• Build from lower-dimensional geometry to higher-dimensional geometry: Vertex / Edge / Wire / Face profiles first, then Solid features such as extrude, revolve, loft, and sweep.
• Keep modeling operations functional. Create new values from public functions such as make_circle_rface(...), extrude_rsolid(...), cut_rsolid(...), and fillet_rsolid(...).
• Use keyword arguments for all SimpleCAD function calls, for example make_box_rsolid(width=10.0, height=20.0, depth=3.0) instead of positional arguments.
• Use GraphSession when the model should be replayable, inspectable, exported as model JSON, or translated to another CAD system.
• Treat model JSON as the interchange boundary. Prefer export_model_json(session=...) and replay_model_json(json_str=...) over hand-authored operation payloads.
• Use QL for precise grounding. Query faces, edges, centers, normals, areas, lengths, curve types, and tags; print only the facts needed to validate the current step.
• Use get_edges(index), get_faces(index), get_wires(index), or get_vertices(index) when an indexed topology pick is intentional; these picks are preserved as geo select nodes in replayable graph workflows.
• Use tags for semantic intent and selection anchors, such as role.mounting_surface, anchor.datum.primary, face.top, or group.fasteners.
• Keep numeric and geometric facts in metadata or graph payloads, not in tags.
• When a QL-selected face or edge is used by a later feature, expect the graph/model workflow to preserve that selection as a stable geo select node.
• For FreeCAD translation, prefer canonical model JSON generated from a GraphSession; selected profiles and detail-feature selections should come from the graph rather than ad hoc object lookup.

Tagging Mental Model

• Public tag attachment is apply_tag(shape=..., tag=...).
• Public tag inspection is list_tags(shape=...), which returns a stable sorted list.
• Tags are normalized lowercase dot-separated semantic tokens, for example role.mounting_surface, anchor.datum.primary, group.fasteners, face.top, or solid.boolean.cut.
• Do not encode numeric dimensions or descriptive geometry payloads in tags; store them in metadata such as shape.get_metadata("geo") or shape.set_metadata(...).
• apply_tag(...) does not expose propagation controls. The SDK propagates role/anchor/group-style semantic tags downward and keeps topology-specific tags such as face.*, edge.*, wire.*, vertex.*, and solid.* local.
• Primitives, face auto-tagging, features, booleans, transforms, and tracking may add normalized topology/operation tags automatically.
• Prefer QL tag predicates (ql.tag("role.*"), ql.select(...).where(...)) for inspection and grounding.

SDK Focus

• This skill is intended to describe the public CAD Python SDK surface.
• Prefer the generated API, stdlib, and core docs over environment/bootstrap instructions.
• API docs include an Import Surface section that distinguishes top-level exports, submodule APIs, and translator backend APIs under simplecadapi.translator.<backend>.
• Stdlib docs include an Import Surface section that identifies the package-level simplecadapi.std.gear module export.
• Use references/SDK_OVERVIEW.md for the package-level map.
• Use references/SDK_SURFACES.md for the main public surfaces.
• Use references/MODELING_WORKFLOWS.md for graph/model-oriented patterns.

Example SDK usage

import simplecadapi as scad
from simplecadapi import GraphSession, export_model_json, make_box_rsolid

Typical replayable usage in a Python script:

import simplecadapi as scad
from simplecadapi import GraphSession, export_model_json, replay_model_json

with GraphSession() as session:
    shape = scad.make_box_rsolid(width=10.0, height=20.0, depth=30.0)

model_json = export_model_json(session=session)
rebuilt = replay_model_json(json_str=model_json)
print(len(rebuilt))

Use the graph/model JSON workflow when the task needs reproducibility, interchange, or replayable outputs.

References

• references/SDK_OVERVIEW.md
• references/SDK_SURFACES.md
• references/MODELING_WORKFLOWS.md
• references/SDK_PACKAGE_SUMMARY.md
• references/docs/api/
• references/docs/stdlib/
• references/docs/core/