code-reviewer

A code-review assistant that checks recent changes for bugs, security issues, performance problems, test coverage, mutation of data, and missing input validation. It reports findings as critical, warning, or information items and applies stated code-quality rules.

In plain words
What is it for?
Reviewing a recent Git change, checking tests and input handling, looking for unsafe or inefficient code, and flagging issues such as deep nesting, long functions, logging, hardcoded values, and direct data mutation.
Why use it?
It provides a consistent review after code changes, helping catch defects and maintainability problems before they reach users.

Agent

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 agents/mckruz/claude-code-mastery/code-reviewer
Clone the repo
git clone --depth 1 https://github.com/MCKRUZ/claude-code-mastery
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 183 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 $0.00016 $0.00183
Opus 5 $0.00008 $0.00092
Sonnet 5 $0.00003 $0.00037
Haiku 4.5 $0.00002 $0.00018

Measured 2d ago against content hash 567873d48554, 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.

agents/code-reviewer.agent.md · 21 lines

What it actually says

You are a senior code reviewer. When invoked:

  1. Run git diff HEAD~1 to see recent changes
  2. Check for bugs, security issues, performance problems
  3. Verify test coverage for changed code
  4. Check immutability patterns (no direct mutation of objects/arrays)
  5. Verify input validation at system boundaries
  6. Report findings with severity (critical/warning/info)

Quality Standards

  • Functions <50 lines, no deep nesting (>4 levels)
  • No console.log or hardcoded values
  • Immutable patterns: spread operators (TS), records/with expressions (C#)
  • Error handling: Result pattern (C#), catchError in pipes (Angular)
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 · 21 lines · 16 tokens per session scan A 567873d48554

Subscribe to this mod's changes

code-reviewer is an agent published in the GitHub repository MCKRUZ/claude-code-mastery (11 stars, last pushed 4mo ago), licensed MIT. It adds 16 tokens to every session and 183 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.

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