ForgeCAD Design Spec

by ForgeCAD

ForgeCAD Design Spec is a Writing skill for Claude Code, published by ForgeCAD in forgecad-public-kit.

923 stars103 forkson ForgeCAD/forgecad-public-kitAdded 2026/08/22Repository updated 2026/06/15

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agent-skillscad-as-codecad-examplesforgecadissue-trackerjavascript-cadparametric-cadtypescript-cad

Install in seconds

Install ForgeCAD Design Spec

Copy ForgeCAD Design Spec into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/ForgeCAD/forgecad-public-kit/tree/mainline/skills/forgecad-design-spec ~/.claude/skills/forgecad-design-spec

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/ForgeCAD/forgecad-public-kit.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: skills/forgecad-design-spec/SKILL.md in ForgeCAD/forgecad-public-kit
Installs to: ~/.claude/skills/forgecad-design-spec
Collection: One of 10 skills cataloged from this repository
Category: Writing — 1012 skills

What ForgeCAD Design Spec does

ForgeCAD Design Spec creates a design brief, HLD, or LLD before coding by working through use, assembly, interfaces, decisions, and verification. It is used to turn a vague physical product request into a reviewable markdown spec with clear assumptions and validation points.

ForgeCAD Design Spec is cataloged under Writing on DirSkills. ForgeCAD Design Spec comes from a repository tagged agent-skills, cad-as-code, cad-examples, forgecad and issue-tracker.

Documentation

README

Excerpt

Design Spec

The design document — a git-committed, diff-reviewed markdown file — is the source of truth. Not the code, not the chat, not your head. You iterate it by commit-and-review, and the git diff is the review artifact.

Validate the design by mentally operating the thing, step by step. Walk it as someone assembles, uses, or moves it. The step with no answer — "how does the servo get inside the housing?" — is the real design gap. A spec that reads complete on the page can still hide a hole that only surfaces when you try to put it together in your head. State each gap falsifiably: not "tolerances might be tight" but "the 12mm arm cantilevers under gripping load, may flex >0.5mm."

This is the opening of the README. Read the full README on GitHub.

Frequently asked about ForgeCAD Design Spec

What else does ForgeCAD publish alongside ForgeCAD Design Spec?
ForgeCAD Design Spec is one of 10 skills that DirSkills catalogs from ForgeCAD/forgecad-public-kit, the repository it ships in. Its siblings there include ForgeCAD, ForgeCAD Build Model and ForgeCAD Image Prompt. Each one is a separate skill with its own page in this directory, installs the same way ForgeCAD Design Spec does, and is maintained by ForgeCAD in that same repository. The rest of the collection is listed on the ForgeCAD/forgecad-public-kit page.
How does ForgeCAD Design Spec compare to other Writing skills?
ForgeCAD Design Spec ranks #508 by stars among the 1012 Writing skills in this catalog. The most-starred ones next to it are Article Writing, Social Media Content Calendar and Knowledge Comic Creator. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of ForgeCAD Design Spec against them. Open each page to compare what they document and how they install.