---
name: closed-loop
description: >
  Run one task through the V-model verification loop: CP-2 plan → CP-3 build →
  CP-3v component verify → CP-4 integration verify (full lane) → CP-5 acceptance.
  The worker never grades its own homework; evidence rows trace back to AC-n.
  Opt-in: invoke with /closed-loop or by asking for the closed loop, proper
  verification, or an evidence trail. Ordinary work does not run this.
---

# Closed-loop execute (V-model right arm)

Mechanical verification pipeline. Every verify step emits **evidence rows** tied to acceptance criterion IDs (`AC-n`).

## When to use

The harness is opt-in. Run it when:

- Invoked as `/closed-loop <task>` or `/closed-loop <spec-path>`.
- The user asks for the closed loop, proper verification, or an evidence trail.
- `verification_harness: on` in `00-inbox/MY-PROFILE.md` and this is a build task.
- Another skill that declares a `normal`+ lane reaches its verify step.

Do **not** run it on a request that did not ask for it. Notes, briefs, research, drafts, and ordinary edits are not harness runs, and a checkpoint ledger on those is pure overhead.

## Phase 0 — Lane + run folder

```bash
bash .claude/lib/lane-classify.sh explain "<task>"
bash .claude/lib/checkpoint.sh init 04-projects/harness/runs/<YYYY-MM-DD-HHmm>
```

| Lane | Checkpoints |
|---|---|
| `tiny` | CP-3 → CP-5 (if mutating) |
| `normal` | CP-1 → CP-2 → CP-3 → CP-3v → CP-5 |
| `full` | + CP-4 + claim-verifier + CP-6 |
| `bug` | root-cause ledger (CP-0) before CP-3 |

Record: `checkpoint.sh record <run-dir> CP-0 PASS|SKIP "<lane>"`

## Phase 1 — CP-1 Spec (acceptance criteria)

If spec exists, use its `## Acceptance criteria` + traceability matrix. Else write:

`04-projects/harness/runs/<id>/criteria.md` using `references/spec-template.md` (criteria + matrix sections only).

Each criterion: **falsifiable** + `AC-n` ID + verify method.

Record: `checkpoint.sh record <run-dir> CP-1 PASS "N criteria"`

## Phase 2 — CP-2 Plan

Map tasks → AC IDs in `evidence/CP-2-plan.md`. Update matrix status to `pending`.

Record: `checkpoint.sh record <run-dir> CP-2 PASS`

## Phase 3 — CP-3 Build

Worker implements. Returns deliverable path only.

## Phase 4 — CP-3v Component verify

```
retry=0
loop:
  spawn task-verifier (fresh context, read-only)
  merge EVIDENCE rows into evidence/ledger.md
  if PASS → break
  if FAIL:escalate → record CP-3v FAIL, escalate
  if FAIL:fixable && retry < 2 → fix-agent → retry++
  else → escalate
```

Copy verifier EVIDENCE rows into `evidence/CP-3v-component.md`.

Record: `checkpoint.sh record <run-dir> CP-3v PASS|FAIL`

## Phase 5 — CP-4 Integration verify (`full` or multi-task)

Spawn `integration-verifier` (read-only). Append rows to ledger.

Skip for single-task `normal`.

Record: `checkpoint.sh record <run-dir> CP-4 PASS|SKIP`

## Phase 6 — CP-5 Acceptance (post-condition)

For each mutation, observe artifact (curl, screenshot, re-fetch). Emit:

`EVIDENCE AC-n | CP-5 | PASS | <observation> | <artifact>`

**UI/UX flow changes:** the post-condition is *visual*. Screenshot every meaningful state with whatever browser tooling the environment has, then read the image and confirm no overflow, misalignment, clipping, wrong color, or broken responsive layout before PASS. The Observation must describe what you saw; the artifact is the screenshot/GIF in `evidence/`. Fix any visual defect and re-capture. See CLAUDE.md → Visual Verification.

Write `evidence/CP-5-acceptance.md`. **Traceability closure**: every AC in matrix has ≥1 PASS row in ledger.

Record: `checkpoint.sh record <run-dir> CP-5 PASS|FAIL`

## Phase 7 — Record + handoff

- Append to `.claude/logs/loop-ledger.tsv`
- Update spec traceability matrix statuses to `verified`
- **`full` lane / big task:** generate an HTML rollup from `references/report-template.html` → `04-projects/harness/runs/<id>/report.html`, filled from `criteria.md` + `evidence/ledger.md` (criteria, AC traceability, verifier verdicts, post-condition observations). Self-contained; `SendUserFile` it or publish as an Artifact. Skip for `normal`/`tiny`.
- Suggest `/retro <run-dir>` for CP-7

## Integration

| Skill | Lane | CP-4 |
|---|---|---|
| `ultragoal` | `full` per phase (never downgraded) | integration-verifier + north-star acceptance |
| `team-brief` | full | claim-verifier |
| `comprehensive-analysis`, `auto-research` | full | claim-verifier on cited claims |
| `content-factory` | normal | skip |
| `review-cockpit` | normal | skip; CP-6 is the user's approval per card |

## Escalation template

```
ESCALATED — <task>
Lane: <lane> | Last CP: <CP-n>
Evidence bundle: 04-projects/harness/runs/<id>/evidence/
Open AC IDs: <list without PASS rows>
Decision needed: <one question>
```