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ProductOperator Vault

Product Spec Writer Pack

Convert a rough product idea into a crisp implementation-ready spec.

Runtime
35-60 minutes
Difficulty
Intermediate
Format
Product planning pack

Example run

The artifact is the proof.

Tested 2026-07-12 · Claude (Fable 5)

Scenario: A two-person team running a $79/mo scheduling tool for 34 pottery studios turned the one-liner 'add a class waitlist' into a buildable spec.

Sample artifact

From the example run
1. Malformed email → 400 with field-level 'That email doesn't look right.' 4. 6th join from one IP in 60 seconds → 429 + 'Try again in a minute.' 9. Resend fails 3x over 15 min → offer marked send_failed, next student offered, payload logged for replay. 12. Payment completing after offer expiry (session opened before) → booking honored; if the seat was re-offered and double-claimed, second payment auto-refunded and owner emailed.

Before

One sentence — 'when someone cancels, the first waitlisted person gets the spot' — with the claim window, payment timing, double-cancellation race, and webhook-after-expiry behavior all left for the engineer to guess.

After

Five blocking questions answered up front, then a 9-section spec: a 28-cell edge-case matrix with zero blank cells, 16 trigger-to-result acceptance criteria mapped 1:1 to named tests, full route contracts, and two punted decisions parked in non-goals with owners. The fresh-eyes check caught one missed decision (owner cancels the whole class) before handoff.

Run it like this

  1. 01Fill the five inputs — idea, exact user, current workaround, outcome, constraints
  2. 02Paste the whole file into your AI tool and answer its blocking questions before it writes anything
  3. 03Make it fill every matrix cell and hit all six mandatory coverage items — no blanks, no banned words
  4. 04Walk the section-9 decision list; anything punted gets an owner, not 'TBD'
  5. 05Run the six-step quality check, then hand the spec to your agent unchanged

What you leave with

Useful output, not another chat.

01

Implementation-ready spec

02

Numbered, testable acceptance criteria

03

Edge-case matrix and mapped test plan

Contents

The working parts.

Best for Builders delegating features to engineers, agents, or future selves.

Master spec prompt
Acceptance criteria generator
Edge-case matrix
Route and component checklist
Test-plan block
Worked example

Useful for

Feature specsAgent handoffsMVP scoping