Feature Spec Generator

Fill in the form — get a ready-to-use spec. Copy or download the Markdown.

One or two sentences describing what this feature achieves.

What is explicitly out of scope?

Given / When / Then format. At least one criterion required.

Nulls, duplicates, concurrency, permissions — anything tricky.

Before you export

  • Make the goal observable enough that QA can verify it without guessing.
  • Include at least one non-goal so implementation does not expand silently.
  • Cover one happy path, one failure path, and one edge case in acceptance criteria.
spec.md

What this tool actually produces

Review-ready Markdown

The generator output is meant to be pasted into a ticket, pull request, or design review. It should name the owner, decision, evidence, and follow-up work before implementation starts.

# Feature Spec: Retry failed invoice payment

Owner: Billing platform
Non-goal: no new payment provider

Acceptance Evidence:
- duplicate click creates one payment_attempt
- provider timeout leaves invoice in retryable state
- support UI shows pending provider confirmation

After export

Treat the generated feature spec as a starting artifact. Replace example values, attach evidence, assign reviewers, and remove sections your team will not maintain.

  • Keep the output next to the implementation work.
  • Map every acceptance item to test or review evidence.
  • Do not paste secrets, customer data, or private incident details.

What is a Feature Spec?

A feature spec is a short, structured document that defines what a feature does, how you know it works (acceptance criteria), and what could go wrong (edge cases) — all before writing any code. It aligns product, engineering, and QA around a shared source of truth.

Writing specs before coding reduces rework, catches misunderstandings early, and makes AI-assisted development more reliable. Instead of vague requirements, your team gets testable, reviewable contracts.

Learn more: What is Spec-First Development? or browse our Feature Spec Template.

How to use this generator well

Start with the decision, not the UI

Name the product behavior the team is committing to. "Contact deduplication" is stronger than "add a dedupe button" because it leaves room to discuss data rules, automation, permissions, and recovery.

Write non-goals before implementation starts

Non-goals protect focus. They tell reviewers what not to request in the first build and give engineers a clear reason to reject scope creep without turning every discussion into a debate.

Turn each criterion into evidence

For every Given/When/Then row, decide how it will be proven: unit test, integration test, contract test, manual QA note, log check, or rollout metric. A criterion without evidence is just intent.

Use edge cases to expose hidden work

Null input, duplicates, permissions, concurrency, time zones, retry behavior, limits, and rollback are where many "small" features become risky. Listing them early makes tradeoffs visible.

What a reviewer should be able to answer

Scope

What exactly changes for the user, API, data model, or workflow? What does not change in this iteration?

Correctness

What examples prove the behavior works? Which failure paths are intentional, and which should block release?

Release safety

Can the change be rolled out gradually, observed in production, and rolled back without data loss or customer confusion?

Weak vs strong feature goal

Weak

Improve the account settings page and make it easier for users to update preferences.

This sounds reasonable, but it does not say which preferences, what "easier" means, which users are included, or how QA should verify success.

Strong

Allow workspace admins to update notification defaults for new members. Existing members keep their current settings. Changes are audit logged and visible in the admin activity feed.

This goal names the actor, state boundary, behavior, and verification evidence.

Using the generated spec with AI coding tools

Prompt with boundaries

Paste the spec and tell the assistant to implement only the listed goals, avoid non-goals, and produce tests for each acceptance criterion. This keeps the assistant from expanding scope quietly.

Review against evidence

Ask for a checklist that maps each code change to a criterion, edge case, or deliverable. If a change cannot be mapped, either remove it or update the spec and re-review.

When a lighter note is enough

Pure copy edits

A typo fix, label correction, or static text update usually needs a small change note, not a full feature spec.

Throwaway exploration

Use a short experiment brief when the goal is learning, not shipping. Turn it into a spec once the behavior is ready to commit.

No user-visible behavior

Internal refactors can use technical design notes instead, unless they affect data, rollout safety, performance, or API contracts.

What a finished feature spec should prove

The team agrees on the first shippable slice

A good feature spec names what ships now, what waits, which roles are affected, which states change, and how the team knows the slice is complete. It should reduce scope debate during code review.

Tests can be derived directly

QA should be able to turn acceptance criteria into test cases without interviewing the author. If the test still depends on a private explanation, the spec is not ready for implementation.

How to use the export in review

Run the scope check first

Before reviewing implementation details, ask whether the goal, non-goals, and first shippable slice are explicit. If the scope is still negotiable, the team should resolve that before debating technical design.

Turn every criterion into evidence

Each acceptance criterion should map to a test, screenshot, log line, query, or manual verification step. The generated spec is strongest when reviewers can point to the exact evidence that proves the change is complete.

Feature spec FAQ

How long should a feature spec be?

Long enough to remove ambiguity, short enough for a reviewer to finish in one sitting. For most feature work, one or two pages of precise bullets beats a long narrative that hides the decisions.

When should I use the template instead?

Use the Feature Spec Template when you want to write manually in a document. Use this generator when you want a guided form, live preview, draft restore, and quick Markdown export.

How this tool was designed and reviewed

Built from spec review failures

The form emphasizes goals, non-goals, acceptance criteria, edge cases, outputs, dependencies, and review questions because those are the gaps that most often turn into rework during implementation.

Reviewed for implementation readiness

Generated output is checked by whether a reviewer can identify the first shippable slice, required evidence, excluded work, and AI coding boundaries without needing a follow-up meeting.