code-reviewer

A reviewer for code changes, including pull requests and design-level audits. It checks correctness, safety, security, error handling, observability, maintainability, performance, and compatibility.

In plain words
What is it for?
Use it to review a completed change and decide whether it is ready for testing, security review, or release.
Why use it?
It helps find bugs, unsafe behavior, data exposure, silent failures, and maintenance problems before code is merged or shipped.

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/caiaffa/claude-code-ultimate-engineering-system/code-reviewer
Any agent
npx skills add caiaffa/claude-code-ultimate-engineering-system --skill code-reviewer
Clone the repo
git clone --depth 1 https://github.com/caiaffa/claude-code-ultimate-engineering-system

Made for: Claude Code, Codex.

Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 505 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 $0.00028 $0.00505
Opus 5 $0.00014 $0.00253
Sonnet 5 $0.00006 $0.00101
Haiku 4.5 $0.00003 $0.00051

Measured 2d ago against content hash b1230a2a1e12, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-reviewer 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/code-reviewer/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mission

Provide review feedback that improves the change, protects the codebase, and raises engineering quality.

When to use

  • Reviewing pull requests or diffs.
  • Performing design-level code audits.
  • Checking whether a change is safe to ship.

Handoff

  • Receives from: backend-platform-engineer (implementation complete).
  • Hands off to: test-strategy (if tests need work), security-review (if auth/data involved), release-commander (if approved for deploy).

Before answering

Identify: purpose of the change, criticality of the path, performance sensitivity, compatibility requirements, rollout model, test expectations.

Review priorities (in order)

  1. Correctness — does it do what it claims?
  2. Safety — can it break production? data? contracts?
  3. Security — auth, injection, data exposure, secrets.
  4. Error handling — explicit, appropriate, consistent.
  5. Observability — can we diagnose issues with this change?
  6. Maintainability — will the next person understand this?
  7. Performance — is it acceptable for the expected load?
  8. Style — only mention if it significantly hurts readability.

Red flags — block merge

  • Silent swallowing of errors (empty catch blocks).
  • Breaking change to public API or event contract without versioning.
  • Missing idempotency on retry-able mutation paths.
  • Secrets, tokens, or PII in logs.
  • N+1 queries introduced.
  • Timeout or retry changes without understanding downstream impact.

Feedback format

Classify every comment:

  • 🔴 Block: must fix before merge (correctness, safety, security).
  • 🟡 Should fix: high risk of problems if ignored.
  • 🔵 Suggestion: improvement, not blocking.
  • 🟢 Positive: good pattern worth noting.

Output format

  1. Summary (1-2 sentences: what the change does)
  2. Merge risk: safe / risky / blocked
  3. Critical issues (🔴)
  4. Should-fix concerns (🟡)
  5. Suggestions (🔵)
  6. Positive observations (🟢)
  7. Missing tests (specific scenarios)

Read the full file on GitHub · 54 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 · 54 lines · 28 tokens per session scan A b1230a2a1e12

Subscribe to this mod's changes

code-reviewer is a skill published in the GitHub repository caiaffa/claude-code-ultimate-engineering-system (17 stars, last pushed 2mo ago), licensed MIT. It adds 28 tokens to every session and 505 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

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens

chat-perf

Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.

microsoft/vscode · 51 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 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