Specify Behavior

Produce docs/specs/<YYYY-MM-DD>-<feature>/requirements.md from the approved frame-change outcome. Requirements are the durable source of intent: they outlive this conversation, and every task, test, and commit will cite their IDs.

Two modes — pick by what you were handed

Tier-1 mini-spec — a fix plus a guard for an already-approved feature (from amend-feature or root-cause). Not a new requirements.md: append to the owning feature's requirements.md (or docs/specs/fixes.md if unowned) the fix requirement (one EARS criterion, Step 2's forms) and its SHALL CONTINUE TO guard (Step 3, for the behavior the fix must not break).

Self-review just those two criteria: the ambiguity and testability scans, plus the code-claim check (Step 5) only when a criterion asserts how the system currently works — a guard usually does. Present both for approval, keep the feature's Status, and exit to test-first. Skip Steps 1 and 4 and the whole-file review — those are for a new feature, not a two-line mini-spec.

New feature — tier 2, or anything nothing has spec'd yet. Start from templates/requirements.md, resolving pack seeds in order, first path that exists: templates/ beside this SKILL.md, else ${CLAUDE_PLUGIN_ROOT}/templates when set, else ../../../templates relative to this SKILL.md. Every heading in that template is a REQUIRED slot: fill it, or write None — never drop one. Then run the full sequence below, one todo per step.

Step 1: Register the feature code

Pick a short unique prefix (2–12 chars, A–Z0–9, starts with a letter — e.g. SHELL, SYNC2). The catalog is shared: docs/specs/INDEX.md is the Domain router; feature cards live in docs/specs/catalog/<domain>.md. Add a card row to the owning shard BEFORE writing requirements (ensure a router row exists for that domain). Never put Code rows on INDEX itself; never reuse a retired code. Flat INDEX → stop and name /map-features Domain boundary migrate.

Bind the roadmap item. WHERE docs/roadmap/INDEX.md exists, read roadmap-bind.md beside this file and follow it exactly — the shard row's Roadmap item column is the only plan↔spec join. WHERE there is no roadmap, or the work was never a roadmap item, write —.

Promote ephemera. IF a .skills/_pending-<slug>/ directory was used for this work, move it to .skills/<CODE>/ (mv when CODE dir absent) so subsequent writes use the Feature root — see templates/skills-ephemera-paths.md. Done when: the code has a Draft card in the owning shard, and its Roadmap item cell holds a ROAD-N or —, and that ROAD is not already bound to another CODE.

Step 2: Write stories and EARS criteria

One ## N. <title> section per user story, each with acceptance criteria as EARS statements carrying hierarchical IDs **CODE-N.M** — N is the story number (same N as the ## N heading). That identity is load-bearing: later skills derive review units from it.

Each behavioral story carries a **Story:** line: As a <actor>, I want <capability>, so that <benefit>. That line must name one demoable act a person can do or prove-claim once the story lands — not a technical layer ("the storage layer is rewritten").

EARS forms:

• WHEN <event> THE SYSTEM SHALL <behavior> — event-driven
• WHILE <state> THE SYSTEM SHALL <behavior> — state-driven
• IF <unwanted condition> THEN THE SYSTEM SHALL <behavior> — error handling
• WHERE <feature enabled> THE SYSTEM SHALL <behavior> — optional features
• THE SYSTEM SHALL <behavior> — always-true invariants

One observable behavior per criterion. If a sentence needs "and", it is usually two criteria. There is no criteria-count cap — size is visible later from task file paths at plan/execute preflight, not from counting EARS lines. Done when: every story has ≥1 criterion, every criterion has exactly one WHEN/WHILE/IF/WHERE/ubiquitous form, and each **Story:** names one demoable act.

Step 2b: Non-functional requirements (quality attributes)

Behavioral criteria (Step 2) say what the system does; non-functional requirements (NFRs) say how well it must do it — and unstated quality attributes are where features quietly fail. After the behavioral criteria, fill the template's NFR section (pre-printed in templates/requirements.md):

## <N>. Quality attributes
**Section-kind:** nfr

SECTION-KIND IRON LAW
- NFR section MUST carry **Section-kind:** nfr (pre-printed in the template —
  do not delete it).
- absent = story  (unmarked section is a behavioral review unit)
- Fail visible: unmarked NFR → extra unit in preflight.
- Fail silent (forbidden): marking a real story nfr → boundary disappears.

Walk the four quality attributes:

• Performance — latency, throughput, resource ceilings.
• Security — authn/authz, data protection, the trust boundaries crossed.
• Reliability — availability, error budget, recovery, durability.
• Accessibility — conformance target (e.g. WCAG 2.1 AA), keyboard/SR support.

System docs for NFR grounding (thin consult)

WHEN an attribute is material for this feature (not already headed for None), read nfr-grounding.md beside this file and follow it exactly — which system doc to consult per attribute, the hard constraints that outrank it, and the write rules after consult. Do not invent a TB/THR/CMP/SLO (or product metric) ID without a bold definition in an Approved doc.

An attribute that does not apply is not silently dropped: record it as None with a short reason (e.g. "Accessibility: None — headless CLI") so the skip is a visible decision, not an oversight. None is for non-material attributes, not a shortcut past consult when the attribute is material.

The category is additive, never a new gate: a feature with no quality-attribute concerns records None across the four, and nothing else about the file or either authoring mode changes. In tier-1 mode, capture an NFR only when the fix itself is a quality-attribute change — the category adds no NFR obligation to a behavioral mini-spec.

Done when: the NFR section carries **Section-kind:** nfr; each of the four quality attributes is either an IDed NFR criterion or explicitly None with reason; and for every material attribute the consult outcome is recorded (Approved doc used, or Absent/non-authoritative no-op) before the line is written.

Step 3: Guard existing behavior

List every file the change touches, then work that list. A file with no existing behavior at risk gets an explicit no behavior to guard line and nothing more; for every existing behavior in the rest, add a guard — **CODE-N.M** (guard) WHEN <condition> THE SYSTEM SHALL CONTINUE TO <existing behavior>. Guards are what stop an agent from breaking load-bearing behavior nobody mentioned. For a tier-1 bugfix this step plus one fix requirement IS the spec, appended to the destination named under Two modes. Done when: every file the change touches is listed; every existing behavior found in those files has its own guard requirement; and every file with none carries the explicit no behavior to guard line. An empty guard set with no list behind it does not count.

Step 4: Out of Scope

List what this feature deliberately does NOT do. This section is the defense against scope creep during implementation and review.

Step 5: Self-review, then the approval gate

Self-review before showing the user:

• Ambiguity scan: could any criterion be read two different ways? Pick one reading and write it in.
• Testability scan: can each criterion be verified by an automated test or a concrete manual check? Rewrite any that can't.
• Placeholder scan: no bare "TBD", "etc.", "handle errors appropriately". WHEN the clarify-decisions close package listed Owned unknowns, paste them into Open Questions as topic — owner — date — forbid-guess (cấm đoán). A bare TBD without those three fields blocks Status: Approved — do not delete Open Questions by sweeping unknowns under the rug.
• Code-claim check (independent): if any criterion asserts how the system currently works, read self-review-conditional.md beside this file and follow it exactly — dispatch a review subagent to prove-claim it against the real code before the gate; a false premise here poisons design, plan, and code.
• Close-package ingest: when a clarify-decisions close package exists, read self-review-conditional.md beside this file and follow it exactly — do not let it excuse marking an NFR None when the close package already locked it.

Story-quality gate (consumer of demoable act). List every non-NFR ## N with its **Story:** line and have the user confirm each names one demoable act; split/rewrite and re-present any that fail. Only once all are confirmed, and the user has approved the file, may you set Status: Approved. Never silent-approve — "looks fine" without the per-story yes is not confirmation.

Then present the FILE to the user for review and STOP — do not proceed to design on the strength of conversational agreement; the written requirements are what get approved. Done when: the user has approved the written file and confirmed each behavioral story is one demoable act.

ID immutability

Once Approved, IDs never change meaning or get renumbered. Retire one by striking it through (~~**CODE-1.2**~~ superseded by CODE-1.4) — audit-trace treats struck IDs as undefined, so citing tests/tasks surface immediately.

Exit

REQUIRED SUB-SKILL: use design-solution (tier 2) or hand tier-1 fixes straight to test-first with the new IDs.