codex-plan-review

codex-plan-review is a skill for Claude Code from jasonm4130/claude-skills. It costs 166 tokens per session (2,690 once invoked), scanned C, original, MIT.

A review skill that sends a finalized plan, specification, design document, architecture decision record, or code change for an adversarial review by another coding model.

In plain words
What is it for?
Use it after a plan or similar artifact is finalized to receive a read-only review focused on possible problems.
Why use it?
It helps uncover missing requirements, weak assumptions, and overlooked risks before implementation or approval.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: names the AskUserQuestion tool; mentions Codex.

Part of the codex-review plugin — 1 skill shipped together

Good fit Use it after a plan or similar artifact is finalized to receive a read-only review focused on possible problems.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jasonm4130/claude-skills/codex-plan-review
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.

Any agent
npx skills add jasonm4130/claude-skills --skill codex-plan-review
Clone the repo
git clone --depth 1 https://github.com/jasonm4130/claude-skills

Made for: Claude Code.

Or install codex-review, the plugin that ships this one along with the rest of its 1 skill.

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 codex-plan-review

README.md
[![agentmods](https://agentmods.dev/badge/skills/jasonm4130/claude-skills/codex-plan-review/github.svg)](https://agentmods.dev/skills/jasonm4130/claude-skills/codex-plan-review)
Your own site
<a href="https://agentmods.dev/skills/jasonm4130/claude-skills/codex-plan-review"><img src="https://agentmods.dev/badge/skills/jasonm4130/claude-skills/codex-plan-review/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.

agentmods 80×15 button for codex-plan-review

Your own site · 80×15
<a href="https://agentmods.dev/skills/jasonm4130/claude-skills/codex-plan-review"><img src="https://agentmods.dev/badge/skills/jasonm4130/claude-skills/codex-plan-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 166 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,690 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00166 $0.02690
Opus 5 $0.00083 $0.01345
Sonnet 5 $0.00033 $0.00538
Haiku 4.5 $0.00017 $0.00269

Measured 5d ago against content hash ef9d7bf01270, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade C, and why

codex-plan-review scanned grade C with 1 finding 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/codex-review.mjs, scripts/codex-review.test.mjs), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Cloud metadata endpointhighServer-side request forgery

One request to 169.254.169.254 can return temporary IAM credentials.

> | 2 | the deep-dive integrity branch — *after* 3 plan rounds + an audit | a host guard that let a fabricated finding aim the verifier's `WebFetch` at `169.254.169.254`; `startsWith`-only placeholder matching; unvalidat
plugins/codex-review/skills/codex-plan-review/SKILL.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codex Plan Review

Send a finalized plan/spec/design/ADR to OpenAI Codex (Terra, high effort, read-only sandbox) for adversarial review. The script handles mechanics; you handle judgment. Script path (resolve via this skill's base directory): scripts/codex-review.mjs, run with node.

The one non-negotiable prompt rule: the reviewer must never see your self-assessment. The script builds prompts from the file path only — never paste plan content, your confidence, or "tests pass" claims into any codex invocation. (Research: implementer framing degrades Codex review thoroughness 3–4×.)

Flow

  1. Announce: "Running Codex plan review (Terra, high effort) — round 1." If codex is missing or not logged in (codex login status), say so, skip, and continue without blocking the plan.
  2. Preflight: the artifact must be a file. Write conversation-only plans to their canonical path first (docs/superpowers/specs/…, the repo's own plans directory, or scratchpad for throwaways).
  3. Round 1: node <skill-dir>/scripts/codex-review.mjs review <file> --auto (use --force only when the user explicitly asked for a re-run). If it refuses with "chain already exists", tell the user this artifact version was already reviewed and stop unless they ask to force.
  4. On REVISE: walk findings one at a time. For accepted findings, amend the plan file. Dismissals require a stated reason in your reply — never silent. Then verify fixes: … review <file> --resume <sessionId> --chain <chainId>. Max 3 review rounds total — the script now refuses a 4th before spending any paid call. Plans do reach APPROVED: 12 of 63 review chains in the first 20 days, 9 of them at round 3 (first on 2026-07-16). If still REVISE after folding round-3 findings in, proceed to the audit anyway (see step 5) rather than stopping — the audit is most valuable exactly here, after three rounds of findings have been folded in. Only skip it if the user stops before folding the findings in; then log the note as cap-revise.
  5. Run the final audit — after either an APPROVED round or a round-3 REVISE whose findings have been folded in: … audit <file> --chain <chainId> (fresh Codex session, holistic scope; the script refuses a second audit on the same chain before spending any paid call). AUDIT: PASS → done. AUDIT: CONCERNS → surface findings verbatim and block: the plan is not review-complete until the user dispositions each concern. Never re-run the audit; if the user amends in response, the outcome class is audit-concerns-user-approved (user-approved, audit-unverified); if the user dismisses the concerns with reasons instead, it is audit-concerns-dismissed.

Read the full file on GitHub · 104 lines

Files

What ships with it

2 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. 5d ago Changed · -21 tokens per session ef9d7bf01270
  2. 10d ago First seen · 104 lines · 187 tokens per session scan C 44a90ef7de8c

Subscribe to this mod's changes

codex-plan-review is a skill published in the GitHub repository jasonm4130/claude-skills (5 stars, last pushed 4d ago), licensed MIT. It adds 166 tokens to every session and 2,690 once invoked, about $0.0008 per session on Opus 5. A static security scan graded it C with 1 finding (cloud metadata endpoint). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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