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

Choose the commands adaptively for the current project instead of running every example blindly. Use the stack-appropriate command from references/STACK-DETECTION.md when the repo does not match the default examples below.

Phase 1: Build Verification

# Python projects (uv)
uv build 2>&1 | tail -20
# OR
python -m build 2>&1 | tail -20

# Node.js projects
npm run build 2>&1 | tail -20
# OR
pnpm build 2>&1 | tail -20

If build fails, STOP and fix before continuing.

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

# Python projects
pytest --cov=src --cov-report=term-missing 2>&1 | tail -50

# Node.js projects
npm run test -- --coverage 2>&1 | tail -50

Report:

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

Phase 5: Security Scan

# Python: Check for secrets
grep -rn "sk-" --include="*.py" . 2>/dev/null | head -10
grep -rn "api_key" --include="*.py" . 2>/dev/null | head -10
pip-audit

# Node.js: 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 debug statements
grep -rn "print(" --include="*.py" src/ 2>/dev/null | head -10
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]

Overall:   [READY/NOT READY] for PR

Issues to Fix:
1. ...
2. ...

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 this skill

Integration with Hooks

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

Reference Files

Load only what is needed:

• references/STACK-DETECTION.md - how to choose the right verification command set for the current repo
• references/REPORT-TEMPLATE.md - report structure for final verification output
• examples/example-verification-report.md - example final report