/phase-contract

name: phase-contract
user-invocable: false
version: 1.0.0
author: "Gabriel Trabanco <gtrabanco@users.noreply.github.com>"
license: MIT
metadata:
  internal: true
description: >
  Internal contract: the single owner of the eight phase-lint rules, the fixed
  PASS/BLOCKED result, and the normalized phase fingerprint. Consumed by
  plan-feature-scaffold, plan-fix, and execute-phase. Not a menu entry.

Phase Contract (internal)

The one authoritative owner of phase shape for this workflow. Planners lint every phase they emit against the eight rules below; `execute-phase` re-checks the same rules before any edit. Nothing else may define what a valid phase is.

When to use

• `plan-feature-scaffold` — lint every phase of a feature plan before emission.
• `plan-fix` — lint every phase of a fix SPEC before commit.
• `execute-phase` — phase-lint pre-flight guard before editing a phase.
• Templates store the contract version + fingerprint + lint result, never the

eight rules (they point here).

The eight phase-lint rules

Every implementation phase must pass all 8 boxes before it is emitted (planner skills) or executed (`execute-phase` pre-flight). Fail-closed: any unticked box blocks emission/execution until the phase is re-cut or split.

1. **Title names ONE deliverable** — FAIL if it joins nouns with `+`, `,`, `&`, `and`/`y`, or `/`. 2. **One declared layer** — each phase declares exactly one of the fixed enum `schema/db | domain | api | ui | config/infra | docs | hardening | close-out`; FAIL if any task's target file belongs to another. Tests for the phase's own layer belong to the phase; a test-only phase declares `hardening`. 3. **≤ 8 tasks** (close-out phase: ≤ 10, only the literal close-out chain). 4. **One checkbox = one deliverable** — FAIL if a task contains a `→` chain of implementation steps, enumerates > 3 cases/scenarios, or creates > 1 file of distinct concerns. 5. **Zero decision words** — FAIL on `Decide`, `choose`, `OR` between alternatives, `If … then <change scope>`. 6. **No conditional scope mutation** — a task may not move work between phases at runtime. 7. **No external/manual gates inside implementation phases** — human/out-of-repo verifications live in the hardening/close-out phase, marked `manual`. 8. **Machine-checkable done-when** — every phase ends with one verifiable invariant (a command + expected outcome).

Result — fixed PASS/BLOCKED output

Phase-lint: PASS (8/8)

or, on the first failing box:

Phase-lint: BLOCKED — box <n>: <one-line reason>

A BLOCKED phase is re-cut or split; it is never emitted, committed, or executed as-is (no `--force` bypass exists for a non-atomic phase — that decision belongs to the user).

Normalized phase fingerprint

Each phase's fingerprint is a deterministic string over the phase's shape: `P<n>:<layer>:<n-tasks>:<title-deliverable>`. It binds the lint result to the exact phase version a plan committed to — templates and plans record `Phase-lint: PASS (8/8) · fingerprint <fingerprint>` so later re-lints and `execute-phase` can confirm nothing in the phase shape drifted since planning.

Guardrails

• Sole owner of the eight rules — planners and executor point here, never carry

their own copy.

• Never relax a rule to let a phase pass; re-cut the phase instead.
• Docs only — no code, no branch.