write-spec

# Write Spec Turn a large feature into a ladder of small contracts. Each rung should be understandable to the human, testable by an agent, and useful before the whole feature is done. ## First Principles 1. **Grill before planning.** Ask one question at a time until you know the desired outcome, non-goals, review surface, sacred contracts, missing assets, and first useful playable checkpoint. Give your recommended answer with each question so the user can accept, reject, or edit it. Inspect the repo instead of asking questions the code can answer. Close the interview by asking whether the plan must carry backward compatibility or data migrations — the default is **neither**: hard cutovers, no compat shims, no migration scaffolding, no deploy-order dances. Only the user opting in puts them in the plan. 2. **Slice at API seams.** Each slice should behave like a tiny library where possible: named module boundary, typed inputs/outputs, deterministic fixtures, and tests at the seam. If a slice needs three unrelated systems booted before it can be checked, sharpen the seam. 3. **Research the fog.** When the feature depends on an unfamiliar domain, high-fidelity visual target, named reference, benchmark, external repo, library, or "how do people usually do this?" question, do targeted online research before finalizing slices. Prefer primary sources: official docs, source repos, papers, case studies, talks, and shipped examples. If a ...