Ca Feature Agent Skill

/ca-feature — spec-driven feature

The single permitted entry to implementation work. No feature code is written before a spec is approved and tdd Phase 1 clears. A one-line idea is not a spec — brainstorming makes it one.

Orientation: if .codearbiter/code-map.md is present, read it first — a coarse concern→path→role map that orients task authoring. Absent is fine; it is read-on-demand, populated by context-creation or commit-gate heal.

Resume — an interrupted pipeline is re-entered, never restarted

Before triage, scan <project-root>/.codearbiter/specs/ and plans/ for an existing slug

matching $ARGUMENTS (invoked bare, list every resumable pipeline and ask which). A crash,

compaction, or closed session mid-pipeline loses nothing — the spec, the plan, and each task's

status cell are on disk. On a match, confirm the resume with the user in one line

("resume <slug> at <point>?") and re-enter at the furthest checkpoint reached:

• Plan exists with non-ACCEPTED tasks → executing-plans (its Phase 1 batches only the

remaining tasks).

• Plan exists, every task ACCEPTED → commit-gate (the work is done and verified; it was the

commit that never happened).

• Spec approved, no plan → writing-plans.
• Spec exists but never approved → brainstorming, at its approval gate — not from scratch.

Re-running brainstorming against an already-approved spec is the failure mode this section exists

to prevent: it discards approved decisions and re-asks answered questions. Only an explicit user

request ("start over") restarts an existing slug — and that is logged to triage.log like any

classification.

Step 0 — change-class triage (logged)

Before routing, classify the request. The small lane applies only when ALL of these hold —

judged against $ARGUMENTS and a quick look at the code, never assumed:

• the change touches ≤ 2 implementation files (plus their tests);
• no §4 reference-map scope-touch: auth/crypto/secrets, dependencies, migrations/schema, telemetry,

public API surface, domain vocabulary;

• no new dependency, endpoint, command, or configuration surface;
• the behavior change is expressible as 1–3 concrete, individually testable acceptance criteria.

Small lane: state the mini-spec inline (the 1–3 criteria) and STOP for the user's one-reply

confirmation. On confirmation, append one line to <project-root>/.codearbiter/triage.log

(append-only, >>):

[ISO-8601 timestamp] | BY: <git user.email> | LANE: small | SCOPE: <one-line> | BASIS: <criteria met>

Then route directly to tdd — the confirmed criteria are its Phase 1 obligations; Phases 2–6 run

unchanged — and exit through the full commit-gate and finishing-a-development-branch exactly as

the full lane does. The lane trims ceremony, never gates.

Any criterion violated, or uncertain → full lane (below). Uncertainty is full-lane; the triage

never guesses.

Flow — full lane

Route through the pipeline in order; each step gates the next:

• brainstorming — refine $ARGUMENTS into a concrete spec by Socratic questioning: challenge

vague language, surface hidden complexity, force trade-offs. Writes the spec to

<project-root>/.codearbiter/specs/<slug>.md. **Hard gate: no plan and no code until the

user approves the spec.** Genuinely-unresolved unknowns become [CONFIRM-NN] in

open-questions.md, never guesses.

• writing-plans — decompose the approved spec into small tasks, each with an exact path and a

verification that maps to a tdd obligation (it does not replace one). Writes

<project-root>/.codearbiter/plans/<slug>.md with bijective criterion↔task coverage.

• executing-plans — coordinates the plan in small batches with human checkpoints. Each batch is

delegated to subagent-driven-development (fresh author agent per task, spec-compliance review,

quality review, fresh verification). The user acknowledges between batches; nothing advances until

they do.

• commit-gate — the only path to a commit; nine gates, including behavioral proof.
• finishing-a-development-branch — terminal step: open-PR / merge-via-PR / discard. Every

change lands through a PR; never a direct write to the default branch.

The autonomous counterpart (/ca-sprint) runs the same spec→plan but passes the full plan to

subagent-driven-development directly, without per-batch checkpoints. That path is its own entry,

not /feature.

Scope routing

Scope determines which author agent subagent-driven-development dispatches per task:

backend-author, frontend-author, or infra-author — per the mapping in tech-stack.md. A

multi-area feature runs the appropriate agent per task; the full suite must be green before

transitioning between scope areas.

When NOT to use

• A known defect with a reproduction → /fix.
• A behavior-preserving restructure → /refactor.
• A question or quick discussion → /btw.
• Persisting work already written → /commit.

Hard gate

MUST NOT write feature code before a spec is approved AND tdd Phase 1 clears — the brainstormed

spec in the full lane, the user-confirmed mini-spec in the small lane. MUST NOT take the small lane

unless every Step 0 criterion holds, and MUST log the classification to

.codearbiter/triage.log before tdd begins. MUST NOT skip writing-plans in the full lane.

MUST NOT resolve a [CONFIRM-NN] in the spec by guessing — surface it.

MUST NOT restart an interrupted pipeline whose artifacts exist on disk — resume at the furthest

checkpoint per the Resume ladder, unless the user explicitly asks to start over.