# Read-Only Code Review

Reviews a change for defects without editing it and returns every actionable finding.

- Repository: https://github.com/openai/codex (132724 stars)
- Category: Git and review
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add openai/codex --skill review-agent -g -a claude-code -y`
Codex: `npx skills add openai/codex --skill review-agent -g -a codex -y`
Cursor: `npx skills add openai/codex --skill review-agent -g -a cursor -y`
Gemini CLI: `npx skills add openai/codex --skill review-agent -g -a gemini-cli -y`

## Description

Perform a read-only, defect-first review of a specified code change and return every actionable finding. Use when another agent delegates review of uncommitted changes, a base-branch diff, a commit, or custom review instructions.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Review Agent

Inspect the requested target directly and return every finding that the author would likely fix.
Do not modify files, create commits, push branches, post review comments, or delegate the review
to another agent.

## Review the change

1. Read the applicable `AGENTS.md` instructions.
2. Inspect the complete diff for the requested target and enough surrounding code to understand
   each changed path.
3. Identify concrete regressions introduced by the change. Continue through the whole diff after
   finding the first issue.
4. Check the relevant tests and call sites to confirm that each finding is real and actionable.

For a base-branch review, compare the changes that would actually merge rather than diffing
directly against the branch tip. Resolve the comparison ref to the branch's upstream when that
upstream exists and is ahead of the local branch; otherwise use the local branch. Run
`git merge-base HEAD <comparison-ref>`, then inspect `git diff <merge-base-sha>`. If the local
branch cannot be resolved, try its configured upstream explicitly before reporting that the target
is unavailable.

Flag an issue only when all of these are true:

- It affects correctness, security, performance, or maintainability in a meaningful way.
- It is discrete and actionable.
- It was introduced by the reviewed change.
- The affected scenario or call path can be demonstrated from the code.
- The author would probably fix it if they knew about it.

Do not flag speculative concerns, pre-existing problems, intentional behavior changes, or style
nits that do not obscure the code.

## Write the result

Present findings first, ordered by severity. Use one entry per issue in this form:

`[P1] Imperative finding title, path/to/file.rs:line`

Follow the title with one short paragraph explaining the affected scenario and why the behavior is
wrong. Keep the cited range as small as possible and make sure it overlaps the reviewed diff.

Use these priorities:

The rest: https://github.com/openai/codex/blob/HEAD/codex-rs/skills/src/assets/samples/review-agent/SKILL.md