verification-loop

A set of checks to run after a significant code change or before creating a pull request, a proposed change for review. It uses the project's own build, type-checking, linting, and test commands, then reports failures and skipped checks.

In plain words
What is it for?
Use it after implementing a feature, refactoring code, or preparing a pull request to verify the project is in a workable state.
Why use it?
It catches build errors, type problems, lint issues, and failing tests before changes are shared or merged. It also makes the remaining risks clear when a check cannot be run.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/cloudnative-co/claude-code-starter-kit/verification-loop
Any agent
npx skills add cloudnative-co/claude-code-starter-kit --skill verification-loop
Clone the repo
git clone --depth 1 https://github.com/cloudnative-co/claude-code-starter-kit

Made for: Claude Code, Codex.

Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 688 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00019 $0.00688
Opus 5 $0.00010 $0.00344
Sonnet 5 $0.00004 $0.00138
Haiku 4.5 $0.00002 $0.00069

Measured 2d ago against content hash 18009036f966, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

verification-loop scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/verification-loop/SKILL.md · 92 lines

How it starts

The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Pick the right command for each phase from the project's own configuration (package.json scripts, Makefile, CI workflow, etc.). The commands below are examples, not prescriptions. Summarize long output instead of pasting it verbatim.

Phase 1: Build Verification

Check that the project builds. Examples: npm run build, cargo check, go build ./..., shellcheck -S warning *.sh.

If the build fails, STOP and fix before continuing.

Phase 2: Type Check

Run the project's type checker if it has one. Examples: npx tsc --noEmit (TypeScript), pyright . or mypy . (Python).

Report all type errors. Fix critical ones before continuing.

Phase 3: Lint Check

Run the project's linter. Examples: npm run lint, ruff check ., shellcheck.

Phase 4: Test Suite

Run the project's test suite, with coverage if available. Examples: npm test -- --coverage, pytest --cov, bash tests/run-unit-tests.sh.

Report:

  • Total tests: X
  • Passed: X
  • Failed: X
  • Coverage: X% (against the project's target)

Phase 5: Security Scan

Check for leaked secrets in the changes:

  • If a dedicated scanner is available (gitleaks, trufflehog), use it.
  • Otherwise, follow the bundled security-review skill.
  • At minimum, review the added lines of git diff for credentials, tokens, and keys. Do not report PASS based on a repository-wide grep.

Also check for leftover debug output (e.g., console.log, print) in the changed files.

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:

Read the full file on GitHub · 92 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 92 lines · 19 tokens per session scan A 18009036f966

Subscribe to this mod's changes

verification-loop is a skill published in the GitHub repository cloudnative-co/claude-code-starter-kit (147 stars, last pushed 8d ago), licensed MIT. It adds 19 tokens to every session and 688 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens