Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add NiJingzhe/SimpleCADAPI --skill skillgit clone --depth 1 https://github.com/NiJingzhe/SimpleCADAPIWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/nijingzhe/simplecadapi/skill)<a href="https://agentmods.dev/skills/nijingzhe/simplecadapi/skill"><img src="https://agentmods.dev/badge/skills/nijingzhe/simplecadapi/skill/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/nijingzhe/simplecadapi/skill"><img src="https://agentmods.dev/badge/skills/nijingzhe/simplecadapi/skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00071 | $0.02201 |
| Opus 5.5 | $0.00028 | $0.00880 |
| Sonnet 5.5 | $0.00014 | $0.00440 |
| Haiku 4.5 | $0.00007 | $0.00220 |
Grade A, and why
simplecadapi scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SimpleCAD SDK Skill
This file is the router: it owns load order, route selection, and execution discipline only. Each selected workflow owns its procedure. Classify the request, load exactly one workflow, follow its domain and discipline references, and read exact API pages for the APIs its steps use.
Mandatory load order
Paths are relative to this file's directory.
- Read this file.
- Select exactly one workflow from Task routing. If two rows plausibly match, ask one discriminator question that names the candidate outcomes; never pick silently between routes with different deliverables.
- Read the selected workflow in full. From selection on, it owns the procedure; do not load another workflow's procedure.
- Load each required domain/discipline file the workflow names before the step that uses it; optional ones only when their trigger fires.
- Before the first call of any API, read its exact page
(
references/docs/api/<name>.md,references/docs/stdlib/<name>.md,references/docs/core/<type>.md). A method absent from its page does not exist, however plausible it looks.
- You MUST NOT read the full API or stdlib index up front; the workflow names every page its steps need.
- Routing questions are decided here; after selection the workflow owns execution. You MUST always follow the global rules and execution discipline below.
- Questions about an existing STEP file that change nothing enter no
workflow; you MUST use
references/domains/step-inspection.mdfor them directly. - Creating, installing, updating, or removing a SimpleCADAPI addon (a
third-party skill+tooling package around
.scadpkg) enters no workflow; you MUST usereferences/domains/addon-development.mddirectly.
Task routing
Read exactly one workflow first, per the user's goal:
| User goal | Workflow |
|---|---|
| Model one physical part | references/workflows/single-part-modeling.md |
| Multi-part product or mechanism (custom parts, stdlib gears/bearings, connectors, constraints, package) | references/workflows/assembly-product-build.md |
| Rebuild an editable model from a STEP file | references/workflows/step-reconstruction.md |
| Export/translate a validated package | references/workflows/export-and-translation.md |
| Produce a GB engineering drawing (DXF) from validated geometry | references/workflows/engineering-drawing.md |
| Rebuild a 3D model from a vector-PDF engineering drawing | references/workflows/drawing-reconstruction.md |
What ships with it
60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/discipline/assembly-positioning.md 5.5 KB
- references/discipline/datums-and-coordinate-systems.md 2.9 KB
- references/discipline/failure-and-repair.md 7.2 KB
- references/discipline/feature-ordering.md 4.0 KB
- references/discipline/feature-tree-convention.md 7.6 KB
- references/discipline/geometric-validation.md 7.8 KB
- references/discipline/manufacturing-boundaries.md 4.4 KB
- references/discipline/mechanical-modeling.md 4.4 KB
- references/discipline/requirement-and-cad-brief.md 3.4 KB
- references/docs/api/add_arc_rsketch.md 389 B
- references/docs/api/add_belt_constraint_rassembly.md 537 B
- references/docs/api/add_bspline_rsketch.md 717 B
- references/docs/api/add_circle_rsketch.md 394 B
- references/docs/api/add_component_rassembly.md 419 B
- references/docs/api/add_connector_rpart.md 304 B
- references/docs/api/add_ellipse_rsketch.md 574 B
- references/docs/api/add_fixed_constraint_rassembly.md 430 B
- references/docs/api/add_gear_constraint_rassembly.md 522 B
- references/docs/api/add_line_rsketch.md 393 B
- references/docs/api/add_point_rsketch.md 337 B
- references/docs/api/add_prismatic_constraint_rassembly.md 527 B
- references/docs/api/add_rack_pinion_constraint_rassembly.md 517 B
- references/docs/api/add_revolute_constraint_rassembly.md 523 B
- references/docs/api/analyze_tolerance.md 878 B
- references/docs/api/and_.md 261 B
- references/docs/api/apply_tag_rselection.md 518 B
- references/docs/api/apply_tag.md 287 B
- references/docs/api/assemble.md 618 B
- references/docs/api/Assembly.md 477 B
- references/docs/api/AssemblyBuildResult.md 409 B
- references/docs/api/AssemblySolveReport.md 829 B
- references/docs/api/assess_dimension_rverdict.md 2.1 KB
- references/docs/api/assign_material_rpart.md 312 B
- references/docs/api/BRepComparison.md 947 B
- references/docs/api/BRepEntityError.md 345 B
- references/docs/api/BRepInspection.md 613 B
- references/docs/api/BRepModel.md 537 B
- references/docs/api/BSplineFitResult.md 659 B
- references/docs/api/build_section_annotation_rrecord.md 1.4 KB
- references/docs/api/CacheEntry.md 264 B
- references/docs/api/CacheLockTimeout.md 318 B
- references/docs/api/CacheMode.md 212 B
- references/docs/api/CachePolicy.md 461 B
- references/docs/api/CacheRecord.md 468 B
- references/docs/api/CacheReport.md 404 B
- references/docs/api/CacheStats.md 316 B
- references/docs/api/calibrate_drawing_scale_rcalibration.md 1.1 KB
- references/docs/api/canonical_frame.md 332 B
- references/docs/api/canonical_unit_for_dimension.md 405 B
- references/docs/api/capture.md 530 B
- references/docs/api/CaptureResult.md 406 B
- references/docs/api/CenterDecl.md 369 B
- references/docs/api/chamfer_rsolid.md 918 B
- references/docs/api/check_tolerance.md 655 B
- references/docs/api/classify_benchmark_result.md 2.0 KB
- references/docs/api/clear_step_model_cache_rnone.md 364 B
- references/docs/api/compare_boundary_distance_rdescriptor.md 654 B
- references/docs/api/compare_entities_rdescriptor.md 492 B
- references/docs/api/compare_global_properties_rdescriptor.md 471 B
- references/docs/api/compare_inspections_rinspectionsummarycomparison.md 528 B
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +1 lines · +6 tokens per session 4ba5f264fd99
- 1mo ago Changed · +7 lines 79f98150e057
- 1mo ago Changed 114370939261
- 1mo ago First seen · 187 lines · 65 tokens per session scan A 7737e6c3531c
simplecadapi is a skill published in the GitHub repository NiJingzhe/SimpleCADAPI (125 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 71 tokens to every session and 2,201 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-07.
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