Closed Loop Skill for Claude

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

• /execute <task> or /execute <spec-path>
• Any skill at normal+ lane after implementation
• Code changes, deploys, multi-step vault deliverables

Phase 0 — Lane + run folder

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 04-projects/harness/templates/SPEC-template.md (criteria + matrix 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*. Capture with browser-harness (evidence_shot per state; FlowRecorder→.save_gif() for a flow; pixel_diff against the intended/prior state), then read the image and confirm no overflow/misalignment/clipping/wrong-color/broken-responsive 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 04-projects/harness/templates/report.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 |

| dogfood-release | full | Playwright cross-verify |

| blog-publish | normal | skip |

| content-factory | normal | skip |

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>