SDD

SDD — Spec-Driven Development for Claude Code

A self-contained Claude Code plugin that carries a feature from a one-line idea to
reviewed, verified, shipped code through 23 atomic, stack-agnostic skills and a
TDD implementation engine — with a living decomposition roadmap above the per-feature flow and a
design pipeline (design-system · ux-flows · screens) for UI features.

Every skill is Socratic (it walks decisions with you, it doesn't dump a wall of output),
gated (a stage hard-refuses when its prerequisite artifact is missing), and stack-agnostic
(no language, tracker, or test tool is hard-coded — the skills detect what your repo uses).
The Q&A skills are depth-tunable (easy / medium / hard) and run on any Claude plan or
model tier — no skill requires a specific one; judgment agents default to opus and degrade
gracefully when it's unavailable (see Levers).

The flow

There are three kinds of skill. Most of your time is the backbone — a straight line you
walk in order. A few are utilities you call whenever you need them. Two close the loop
after the code is written.

Install

Claude Code — native plugin:

After updating to a new release: re-run /plugin install sdd@sdd, then /reload-plugins.

Codex CLI — cd into your project first (installs into .agents/skills/ + .codex/agents/
of the current directory; --global for ~, --prefix DIR for an arbitrary directory):

Restart codex and type $sdd-specify. Alternative: codex plugin marketplace add genkovich/sdd,
then inside codex /plugins → the sdd tab → Install plugin — registers the
unprefixed names ($specify) instead of the script's $sdd-specify. Pick one path, not
both — running both shows every skill twice. Undo: install.sh codex --uninstall (script) or
/plugins → uninstall (marketplace). Windows: run the installer from…