Phase Contract

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 — including which grammar a phase is written in.

When to use

• The lane's plan step — lint every phase before emission.
• 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 /. Sole authorized exception: the templates' literal closing title Hardening & PR (docs/features/_TEMPLATE/SPEC.md, docs/fix/_TEMPLATE/SPEC.md) is kept verbatim — its & is a normalization separator, not a deliverable joiner, and its title-deliverable normalizes to hardening-pr. Any other &-joined title still FAILs.
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. ≥ 1 task, ≤ 8 tasks — every phase carries at least one checkbox task; a phase with zero tasks is BLOCKED (fail-closed). Final hardening/close-out phase: 1–10, 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).

The executed-phase exemption (boxes 3 and 7 only). A fully-ticked phase is historical: those two boxes are positional — box 3's budget and box 7's gh pr placement both key off the plan's last phase — and a replan appends its work after an executed hardening (the lane's replan append), which would otherwise retro-block work that already passed this gate when it was emitted. The exemption is scoped to those two boxes: boxes 1, 2, 4, 5, 6 and 8 stay armed for an executed phase, and for an unemitted phase every box stays armed, so pre-ticking a phase to dodge a check is a defect, never a pass.

The two grammars (fix #272)

One contract, two shapes. scripts/phase-lint.mjs mechanizes exactly this split and never carries a second copy of the semantics:

Precedence is fail-closed and one-way: if a document carries any plan-style phase heading, the plan grammar governs it; only when it carries none does the unit-doc grammar apply; a document with no phase in either answers BLOCKED: no-phases. A P<n> bullet outside ## Tasks (a progress-log line, for instance) is prose, never a phase.

Mapping the eight boxes to a bullet phase

A bullet has no separate title line and declares no layer, so two boxes have no input and are skipped (not "passed"); the rest run unchanged over the bullet's joined text:

The Relevant files: sub-section is metadata

A nested - Relevant files: <path, path…> line under a bullet declares that phase's read set (the lane's plan step writes it from its own discovery). It is never a task: it does not count toward box 3, never feeds a box-2 target and is scanned by no rule. Every entry must be a path or a glob; an empty list, an empty entry or a token that is neither fails the phase closed under its own relevant-files: finding id — a malformed read set is reported, never dropped. Never-authority (same rule as every selector): a file that is not listed is never out of scope — an executor may always add one, logging it in the unit doc's Progress log.

Result — fixed PASS/BLOCKED output

Phase-lint: PASS (8/8)

A unit-doc bullet phase reports the boxes it actually runs:

P<n> Phase-lint: PASS (6/6) · fingerprint P<n>:unit-doc:<n-tasks>:<title-deliverable>

or, on the first failing box:

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

A malformed Relevant files: sub-section reports under its own id:

P<n> relevant-files: <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. A unit-doc bullet phase has no layer, so its slot is the literal unit-doc (P<n>:unit-doc:<n-tasks>:<title-deliverable>, title = the bullet text up to its first :, with the (validator: …) span removed); both grammars hash the same way, so a re-lint of either is comparable with its own earlier run.

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.