Spec-Driven Development as a single Agent Skill. Drop it in, type naturally, ship features that don't embarrass you in two weeks.
specdd turns vague, top-of-mind feature requests into production-grade specs before code is written — without a CLI, without four config files, without ceremony you don't need. One skill, any modern AI coding agent: Claude (Code, Desktop, Web), Codex, Copilot, Cursor, Windsurf, Gemini CLI, anything else that reads SKILL.md or AGENTS.md-style instructions.
You: "build me a settings page where users can change their email"
specdd:
→ triages the scope (Feature)
→ asks the 2-3 questions you didn't think to address (verification email?
active sessions? what's the success state?)
→ produces a tech-free spec + a 2-minute technical plan
→ only after you say "ship it" → writes code
→ runs the production-grade checklist before declaring done
No npx, no uv tool install, no specify init. Just a folder.
Two patterns broke the same way:
Vibe-coding — describe a feature in one line, get code that compiles and looks right but misses the empty state, the error state, the keyboard handling, the "what happens when the user double-clicks the button" — discovered in production.
Heavy spec frameworks like github/spec-kit — fix the rigor problem but introduce a CLI, four mandatory artifacts, and ceremony that's overkill for solo and one-off work.
specdd splits the difference. Spec-driven development that scales down to a 15-minute task and scales up to a multi-day project — same workflow, different ceremony.
- One opinionated workflow — triage → interview → spec → plan → (tasks) → build & verify
- Question-asking by default — interviews you for the gaps your one-liner left, instead of guessing
- Tech-free specs — what & why for the user, separated from how for the agent
- Production-grade checklist before "done" — empty/error/loading states, a11y, keyboard, mobile, observability
- UX defaults baked in — five-states rule, confirmation patterns, optimistic updates, accessible focus management
- Scales to scope — Quick (5-line inline mini-spec), Feature (spec + plan inline), Project (spec + plan + tasks as files)
- Surface-agnostic — same skill in Claude Code, Claude.ai, Codex CLI, Cursor, Copilot, Windsurf
/plugin marketplace add unboundinnov/specdd
/plugin install specdd@specddThat's it. The skill activates automatically when you ask for any feature work.
git clone --depth=1 https://github.com/unboundinnov/specdd /tmp/specdd-src
cp -r /tmp/specdd-src/plugins/specdd/skills/specdd ~/.claude/skills/
rm -rf /tmp/specdd-srcOr scope to a single project: copy into .claude/skills/ inside the project instead.
- Download
specdd.zipfrom Releases (or zipplugins/specdd/skills/specdd/). - Claude.ai → Settings → Capabilities → Skills → Upload skill.
- Upload the zip.
mkdir -p ~/.codex/skills
git clone --depth=1 https://github.com/unboundinnov/specdd /tmp/specdd-src
cp -r /tmp/specdd-src/plugins/specdd/skills/specdd ~/.codex/skills/
rm -rf /tmp/specdd-srcThese agents don't natively load SKILL.md yet. Copy the content of SKILL.md into the agent's instructions file:
- Cursor:
.cursor/rules/specdd.mdc(or legacy.cursorrules) - GitHub Copilot:
.github/copilot-instructions.md - Windsurf:
.windsurfrules - Aider:
CONVENTIONS.mdreferenced from.aider.conf.yml
Reference files in references/ can be copied alongside or inlined.
| Phase | What happens |
|---|---|
| 1. Triage | Skip / Quick / Feature / Project — surfaced so you can correct it. |
| 2. Interview | 2–5 right questions for your request type, tappable where possible. Doesn't ask what it can infer. |
| 3. Spec | Tech-free: who / what / why / states / edge cases / out-of-scope / non-functional. You sign off. |
| 4. Plan | Tech approach: stack, files, decisions with rationale, alternatives, risks. <2 minutes to read. |
| 5. Tasks | (Project scope only) Ordered, verifiable units with explicit done-signals. |
| 6. Build & verify | Implement against spec; deviations require a spec update. Production checklist before "done". |
SKILL.md is the entry point; templates, checklists, and examples are in references/.
| specdd | github/spec-kit | |
|---|---|---|
| Install | Copy a folder, or one /plugin install |
uv tool install, specify init, CLI per-project |
| Surface | Any agent that reads SKILL.md / instructions |
30+ agents via Specify CLI |
| Ceremony | Scales: 5 lines for a small change, 3 files for a project | Mandatory: constitution.md, spec.md, plan.md, tasks.md |
| Slash commands | None — conversational | /speckit.specify, /speckit.plan, /speckit.tasks, /speckit.implement |
| UX defaults | Baked in (5-states rule, a11y, confirmation patterns, motion) | Project-defined in constitution.md |
| Best for | Solo, indie, one-off features, mid-size teams | Larger teams, established projects, formal SDD adoption |
What specdd inherits from SDD literature (and spec-kit): the spec → plan → tasks workflow shape, the spec.md / plan.md / tasks.md filenames, the "tech-free spec" framing. These are general SDD concepts (Spec Driven Development pre-dates spec-kit), and keeping the filenames means specs migrate cleanly if you ever adopt spec-kit later.
What's specdd's own: the triage step (scale to scope), the interview phase with tappable options, the build & verify phase with the production-grade checklist, UX-first opinionation with the five-states rule, the common-sense gates. No CLI, no slash commands, no constitution.
See references/examples/:
example-quick-feature.md— Quick scope (~15 min of work)example-feature-spec.md— Feature scope (~3 hours of work)example-project.md— Project scope (multi-day)
Issues and PRs welcome. Particularly interested in:
- Request-type interview playbooks (the more specific, the better)
- Surface-specific install instructions for new agents
- Worked examples from real projects
Open an issue first for substantial changes; keep PRs focused; match the existing tone.
MIT. See LICENSE.
Inspired by, and respectfully different from, github/spec-kit, BMAD, and Kiro. Built on the Agent Skills format by Anthropic.
If specdd helps you ship better, a ⭐ helps people find it.