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  3. Write Product Spec skill
warpdotdev · 29K installs

Write Product Spec skill
Runs by itself, feature needs a spec.

Behavior written as testable invariants.

Install the Write Product Spec skill and make it a habit: follow https://gethabit.dev/skills/warpdotdev/write-product-spec.md

  1. 1Copy
  2. 2Paste into Claude Code, Codex or Cursor
  3. 3It runs by itself

29K installs628 starsMIT licenceSource on GitHub ↗

Write Product Spec

by warpdotdev · 29K installs

The skill

The write product spec skill writes PRODUCT.md for a significant feature: a short summary and an exhaustive Behavior section of numbered, testable invariants from the user's view.

Only when you ask.

The habit

Behavior written as testable invariants.

↻ Runs by itselffeature needs a spec

How the habit works.
You don't have to.

Three questionsWhen does it start? How does it check its work? What does it remember?

01

It starts by itself

feature needs a spec. Runs in Claude Code routine or GitHub Actions.

  • ↻ feature needs a spec
  • issues.labeled == spec, or a Linear ticket for a significant feature

02

It checks its work

your answers + section check. If a check fails, it tells you.

  • ✓specs/<id>/PRODUCT.md exists
  • ✓Summary and Behavior sections are present
  • ✓Behavior is a numbered list
  • ✓no Validation, Success criteria or Testing section

03

It remembers

product spec. The next run reads it first: the existing PRODUCT.md and DECISIONS.md if present.

specs/<id>/PRODUCT.md

One run, step by step.
Then it stops.

Stop ruleOne feature spec per run.

  1. 01

    Pick the id

    Use a Linear ticket, a gh- issue id or a kebab-case feature name you give.

  2. 02

    Gather context

    Ask with ask_user_question for users, key behaviors and edge cases that are missing.

  3. 03

    Ask for Figma

    For UI features, ask if a mock exists and record the link or Figma: none provided.

  4. 04

    Write Behavior

    Write numbered invariants for states, inputs, errors, edge cases and focus.

  5. 05

    Keep framing thin

    Add Problem, Goals or Open questions only when they add something.

  6. 06

    Hand off

    Once PRODUCT.md is agreed, invoke write-tech-spec for TECH.md.

What it may do.
Nothing more.

Safe by defaultIt writes only in its own folder and asks you before anything goes out.

Is it for you?
Use it when it fits.

Quick checkRead both lists. If the left one sounds like you, the Write Product Spec skill helps.

Use it when

  • ✓ You need a PRD before building
  • ✓ Feature behavior is ambiguous
  • ✓ Agents will implement from the spec

Skip it when

  • – The change is a trivial fix
  • – You need an implementation plan, not behavior

Questions

Write Product Spec skill, answered.

Does it include implementation details?

No. It describes what the consumer of the surface sees and relies on, not internal types or data flow.

Does it create tickets?

Only when you ask, using the Linear MCP tools or the gh CLI.

How do I install the Write Product Spec skill?

Copy the prompt at the top into your agent. It installs the skill from warpdotdev/common-skills and sets up the habit. Or run npx skills add warpdotdev/common-skills --skill write-product-spec.

Is the Write Product Spec skill free?

Yes. It is published under MIT. Habit is free too.

Write Product Spec. Now as a habit.

Install the Write Product Spec skill and make it a habit: follow https://gethabit.dev/skills/warpdotdev/write-product-spec.md

  • Free
  • No account
  • Undo in one line

All warpdotdev skills →More planning skills →

Works in

  • Claude Code
  • Codex
  • Cursor
  • ChatGPT
  • Claude app

Made by warpdotdev, published under MIT. Habit links to the original and never changes it. Is this your skill?

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