Codex is a coding agent from OpenAI that runs locally in a computer terminal and helps users work with code. It is used by developers from the command line, with related integrations available for code editors and the desktop experience; the catalogue’s add-ons extend its workflows.
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.
npx skills add openai/codex --skill review-agentgit clone --depth 1 https://github.com/openai/codexWrote 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.
[](https://agentmods.dev/skills/openai/codex/review-agent)<a href="https://agentmods.dev/skills/openai/codex/review-agent"><img src="https://agentmods.dev/badge/skills/openai/codex/review-agent/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/openai/codex/review-agent"><img src="https://agentmods.dev/badge/skills/openai/codex/review-agent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.00552 |
| Opus 5.5 | $0.00019 | $0.00221 |
| Sonnet 5.5 | $0.00010 | $0.00110 |
| Haiku 4.5 | $0.00005 | $0.00055 |
Grade A, and why
review-agent 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 1mo 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.
Copies of this mod
8 near-identical copies found in the catalogue:
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
- review-agent — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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
- Read the applicable
AGENTS.mdinstructions. - Inspect the complete diff for the requested target and enough surrounding code to understand each changed path.
- Identify concrete regressions introduced by the change. Continue through the whole diff after finding the first issue.
- 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:
P0: universal release blocker or critical failure.P1: urgent defect that should be fixed next.P2: ordinary defect that should be fixed.P3: low-impact issue that is still worth fixing.
What ships with it
1 file 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.
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.
- 1mo ago First seen · 58 lines · 48 tokens per session scan A 07079efd0dc7
review-agent is a skill published in the GitHub repository openai/codex (129,540 stars, last pushed today), licensed Apache-2.0. It adds 48 tokens to every session and 552 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other skills, from other repositories
autoreview
Structured code review through the shared OpenClaw agent-skills installation.
omh-code-review
This is an OMH code-review workflow skill, projected for Agent Skills hosts (Claude Code, Codex, Cursor, opencode, OpenClaw, pi).
revdiff-plan
Review the last Codex assistant message (plan, analysis, or proposal) with inline annotations in a TUI overlay. Extracts the most recent response from Codex rollout files and opens it in revdiff for review and annotation. Activates on "revdiff-plan", "review plan with revdiff", "annotate plan", "review last response"…
asplos-writing-style
Use when drafting or revising ASPLOS prose — engineering the first two pages that rapid review actually reads, stating the cross-layer insight as one quotable sentence, structuring per-layer mechanism sections, writing bounded claims, and fitting everything into 11 self-contained pages that include figures and…
explore-unknowns
Guide the user through a quadrant walk that maps the unknowns of a task — open by listing the known knowns, then work through known unknowns, unknown knowns, and unknown unknowns one stage at a time, ending with a complete four-quadrant map in the user's hands. Use when a request is ambiguous or underspecified, the…
re0-merge
Review and land an external contribution the way this suite does: gate it against the thesis, land it with the author's credit intact, complete a new skill rather than merging it raw, then approve, credit, and explain before closing. Use when reviewing a pull request, as any collaborator or maintainer, not only the…