The problem this solves
Hand an AI a feature request and it starts deciding things immediately: the database, the component library, the folder layout. By the time anyone reads the result, the question of what the feature should do has been answered by accident, inside the code.
The fix is ordering. Agree on what and why first, in words a non-engineer can review, and only then decide how.
How it actually works
MasterMind opens a numbered folder for the feature, such as specs/012-csv-export/, and writes spec.md:
- User stories in priority order. The first one alone is a usable product. Each has an independent test: how someone would see it working with nothing else built. This is what makes each story a slice you can ship, rather than a layer you have to wait on.
- Acceptance criteria with the trigger inside, such as “if the token expires, then re-authentication happens silently once.” A vague promise like “handles errors gracefully” has no trigger, so nobody can tell whether it happened.
- Requirements and success criteria with IDs (
FR-003,SC-001,US1/AC2). Every later task and every later finding points back to one of these, so “this is incomplete” becomes “requirement FR-003 is missing.” - Edge cases, what is out of scope, and the assumptions it made.
No technology appears in the spec. “Cache it in Redis” is replaced by the need it serves.
Gaps are handled on purpose. MasterMind fills most of them with a sensible default and lists it under
Assumptions, so you can see and overturn it. Only a gap that would change the product is marked as a
question, and there are never more than three. Those go to interview, which asks them one at a time
with a recommended answer.
Before handing the spec on, MasterMind checks it against a short quality list: no technology named, every requirement testable, every success criterion measurable, every story independently testable, words matching the project’s glossary.
When it fires
“Write the spec for team invitations.” “Start a new feature: recurring invoices.” “Turn this idea into requirements before we build it.”
🧠 MasterMind ▸ writing down what we're building, before how
└ specify · stories → requirements → success criteria → quality check
It also fires for any feature large enough to span sessions or people, or that touches money, authentication, data migration or a public contract.
When it does not fire
- A small, clear change. That goes straight to
build. - A fuzzy ask nobody has pinned down yet. Questioning comes first, in
interview; the spec is written once there is something to write.
What you get
A spec a product owner can review in ten minutes and an engineer can build from, with every requirement traceable through the plan, the tasks and the final check of the code.