01
It starts by itself
new feature request. Runs in Claude Code routine or GitHub Actions.
- ↻ new feature request
issues.opened with a feature request, or you start a feature in a session
Addy Osmani · 62K installsAnthropic · Claude Code · Learning JavaScript Design PatternsSpec-Driven Development skill
Runs by itself, when you start a new feature.
Less rework and fewer wrong builds.
Install the Spec-Driven Development skill and make it a habit: follow https://gethabit.dev/skills/addyosmani/spec-driven-development.md
- 1Copy
- 2Paste into Claude Code, Codex or Cursor
- 3It runs by itself
62K installs109K starsMIT licenceSource on GitHub ↗
Spec-Driven Development
by Addy Osmani · 62K installs
The skill
Makes your agent write a plan you approve before it writes any code.
Only when you ask.
Less rework
Less rework and fewer wrong builds. Every feature starts from a plan you approved.
↻ Runs by itselfwhen you start a new feature
How the habit works.
You don't have to.
When does it start? How does it check its work? What does it remember?
One run, step by step.
Then it stops.
Stops after one phase per run; the next phase starts only after you approve.
- 01
Scope check
If the request bundles several separately testable capabilities, propose a capability map with module ids and build order for your review.
- 02
State assumptions
List what the agent assumes and ask you clarifying questions until the requirements are concrete.
- 03
Write the spec
Cover the six core areas, success criteria and open questions, save it, and stop for your approval.
- 04
Plan
After approval, follow planning-and-task-breakdown and save the plan to tasks/plan.md.
- 05
Tasks
Record small tasks with acceptance criteria and a verify step in tasks/todo.md, then wait for your review.
- 06
Implement
Build tasks one by one with incremental-implementation, test-driven-development and context-engineering.
- 07
Keep it alive
Update and commit the spec when decisions or scope change.
What it may do.
Nothing more.
It writes only in its own folder and asks you before anything goes out.
- Writes only inSPEC.md, SPEC-*.md, tasks/**, src/**
- Talks tono outside service
- Sendsnothing
- Your OKIt asks you before anything goes out.
Is it for you?
Use it when it fits.
Read both lists. If the left one sounds like you, the Spec-Driven Development skill helps.
Use it when
- ✓ You start a new project or feature
- ✓ Requirements are vague or incomplete
- ✓ The change touches many files or modules
Skip it when
- – It is a one-line fix or typo
- – The requirement is already clear and self-contained
Spec-Driven Development skill, answered.
Why does it stop after the spec?
The skill requires your approval before planning starts, in a later turn.
What if my project already uses OpenSpec?
The loop keeps that tool's format and does not create a second SPEC.md.
Does it fit small fixes?
No. One-line fixes and typos skip the spec.
How do I install the Spec-Driven Development skill?
Copy the prompt at the top into your agent. It installs the skill from addyosmani/agent-skills and sets up the habit. Or run npx skills add addyosmani/agent-skills --skill spec-driven-development.
Is the Spec-Driven Development skill free?
Yes. It is published under MIT. Habit is free too.
Spec-Driven Development. Now as a habit.
Install the Spec-Driven Development skill and make it a habit: follow https://gethabit.dev/skills/addyosmani/spec-driven-development.md
All Addy Osmani skills →More planning skills →
Works in
- Claude Code
- Codex
- Cursor
- ChatGPT
- Claude app
Made by Addy Osmani, published under MIT. Habit links to the original and never changes it. Is this your skill?