Verification loop

Verification Loop Skill

A comprehensive verification system for Claude Code sessions.

When to Use

Invoke this skill:

• After completing a feature or significant code change
• Before creating a PR
• When you want to ensure quality gates pass
• After refactoring

Verification Phases

Phase 1: Build Verification

# Check if project builds
npm run build 2>&1 | tail -20
# OR
pnpm build 2>&1 | tail -20

If build fails, STOP and fix — then re-verify from Phase 1 in a fresh instance. Continuing through the remaining phases yourself would make you the verifier of code you just wrote, which the Verdict Contract below forbids.

Phase 2: Type Check

# TypeScript projects
npx tsc --noEmit 2>&1 | head -30

# Python projects
pyright . 2>&1 | head -30

Report all type errors. Fix critical ones before continuing.

Phase 3: Lint Check

# JavaScript/TypeScript
npm run lint 2>&1 | head -30

# Python
ruff check . 2>&1 | head -30

Phase 4: Test Suite

# Run tests with coverage
npm run test -- --coverage 2>&1 | tail -50

# Check coverage threshold
# Target: 80% minimum

Report:

• Total tests: X
• Passed: X
• Failed: X
• Coverage: X%

Phase 5: Security Scan

# Check for secrets
grep -rn "sk-" --include="*.ts" --include="*.js" . 2>/dev/null | head -10
grep -rn "api_key" --include="*.ts" --include="*.js" . 2>/dev/null | head -10

# Check for console.log
grep -rn "console.log" --include="*.ts" --include="*.tsx" src/ 2>/dev/null | head -10

Phase 6: Diff Review

# Show what changed
git diff --stat
git diff HEAD~1 --name-only

Review each changed file for:

• Unintended changes
• Missing error handling
• Potential edge cases

Output Format

After running all phases, produce a verification report:

VERIFICATION REPORT
==================

Build:     [PASS/FAIL]
Types:     [PASS/FAIL] (X errors)
Lint:      [PASS/FAIL] (X warnings)
Tests:     [PASS/FAIL] (X/Y passed, Z% coverage)
Security:  [PASS/FAIL] (X issues)
Diff:      [X files changed]

Verdict:   PASS | PASS_WITH_NITS | FAIL

Findings:
| ID | Severity | Finding | Evidence (file:line / command output) |
|----|----------|---------|---------------------------------------|
| F1 | HIGH     | ...     | ...                                   |

Verdict Contract

The report ends with exactly one verdict. Free-prose closings ("looks ready", "should be fine") are banned — they leave room to bury defects. A fixed vocabulary makes the report honest and machine-checkable.

Verdict	Meaning	Action
PASS	All gates green, zero findings at any severity	Ship
PASS_WITH_NITS	Ship-safe: only LOW/MEDIUM findings, each recorded with a follow-up	Ship + log follow-ups
FAIL	Any gate red, or one or more CRITICAL/HIGH findings	Block → fix → re-verify

Every finding gets exactly one severity:

• CRITICAL — data loss, security hole, or the change misbehaves in real use if shipped
• HIGH — main-path defect or regression; users will hit it
• MEDIUM — edge-case or quality defect; unlikely to block real use
• LOW — nit: style, naming, doc wording

Rules:

• Severity is judged by impact evidence, not by how easy the fix is.
• FAIL → fix → re-verify is one cycle. A fix alone never upgrades the verdict — the re-verification must reproduce green.
• A run that aborts early (Phase 1 build failure) still emits a report: verdict FAIL with the failing gate as a CRITICAL finding. Stopping to fix is how you reach the next verdict, not a reason to skip issuing this one — an unreported run reads as "not run".
• The instance that wrote the change never issues its own verdict: verification runs in a fresh instance (see the model-orchestration skill's V&V separation).

Continuous Mode

For long sessions, run verification every 15 minutes or after major changes:

Set a mental checkpoint:
- After completing each function
- After finishing a component
- Before moving to next task

Run: /verify

Integration with Hooks

This skill complements PostToolUse hooks but provides deeper verification. Hooks catch issues immediately; this skill provides comprehensive review.