review-code

review-code is a skill for Claude Code, Codex from Phelan164/codex-howto. It costs 57 tokens per session (462 once invoked), scanned A, original, MIT.

A read-only review of code changes for defects, regressions, security risks, data-integrity problems, concurrency hazards, and missing meaningful tests. It examines the diff and follows changed behavior through its callers, storage, side effects, and tests.

In plain words
What is it for?
Use it to review pull requests, branches, commits, patches, or working-tree changes and report findings with their location, impact, evidence, and likely fix direction.
Why use it?
It helps identify problems that may not be visible from the changed lines alone, while filtering out speculation and style preferences.

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/phelan164/codex-howto/review-code
Any agent
npx skills add Phelan164/codex-howto --skill review-code
Clone the repo
git clone --depth 1 https://github.com/Phelan164/codex-howto

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for review-code

README.md
[![agentmods](https://agentmods.dev/badge/skills/phelan164/codex-howto/review-code.svg)](https://agentmods.dev/skills/phelan164/codex-howto/review-code)
Your own site
<a href="https://agentmods.dev/skills/phelan164/codex-howto/review-code"><img src="https://agentmods.dev/badge/skills/phelan164/codex-howto/review-code.svg" alt="Measured on agentmods" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 462 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 $0.00057 $0.00462
Opus 5 $0.00028 $0.00231
Sonnet 5 $0.00011 $0.00092
Haiku 4.5 $0.00006 $0.00046

Measured 3d ago against content hash 55c15fab4eb0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

review-code 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 3d 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/review-code/SKILL.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Review Code

Workflow

  1. Establish the review target and comparison base.
  2. Inspect the diff, then trace changed behavior through callers, contracts, persistence, side effects, and tests.
  3. Inspect the target, isolation, fixtures, and side effects before running a narrow check that materially confirms a suspected issue.
  4. Rank findings by impact and confidence; remove duplicates and speculation.
  5. Return findings first, followed by open questions and a short summary.

Use correctness as the default lens. For large, risky, or requirement-heavy changes, add the standards and specification lenses in references/review-lenses.md. Keep each finding tied to its source; documented rules and acceptance criteria outrank personal preference.

Finding standard

Each finding must include:

  • severity;
  • precise file and line or symbol;
  • the failing scenario or invariant;
  • user or system impact;
  • evidence or a reproduction path;
  • a concise fix direction when clear.

Do not report style preferences, theoretical risks without a reachable path, or issues outside the change unless the diff materially exposes them.

Review boundaries

  • Review in read-only mode by default.
  • Do not run production-integrated, shared-environment, or destructive tests without explicit authorization and verified isolation.
  • Do not modify, comment, approve, or request changes on a remote PR unless asked.
  • Do not equate passing tests with correctness.
  • Do not treat generated code or lockfile churn as a defect without understanding its source.
  • Respect repository-specific compatibility and risk rules.
  • State when a claim was not reproduced.

Checklist

Read references/review-checklist.md when the change touches APIs, data, authorization, concurrency, infrastructure, or tests.

Output

If there are no actionable findings, say so directly and name residual unverified areas. Keep the summary shorter than the findings.

Read the full file on GitHub · 55 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 55 lines · 57 tokens per session scan A 55c15fab4eb0

Subscribe to this mod's changes

review-code is a skill published in the GitHub repository Phelan164/codex-howto (3 stars, last pushed 5d ago), licensed MIT. It adds 57 tokens to every session and 462 once invoked, about $0.0003 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 2026-08-31.