codex

codex is a skill for Claude Code, Codex from masa-san-jp/Agent-Aiko. It costs 121 tokens per session (1,045 once invoked), scanned A, original, MIT.

A command that sends a question to ChatGPT through the Codex app server, with options for setup and status checks. It is intended as a separate second opinion from another model.

In plain words
What is it for?
Use /codex setup to configure access, /codex ask with a prompt to request an answer, or /codex status to check authentication.
Why use it?
It helps compare views on irreversible decisions or run quick technical investigations, while keeping the responses clearly attributed.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex.

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/masa-san-jp/agent-aiko/codex
Any agent
npx skills add masa-san-jp/Agent-Aiko --skill codex
Clone the repo
git clone --depth 1 https://github.com/masa-san-jp/Agent-Aiko

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 codex

README.md
[![agentmods](https://agentmods.dev/badge/skills/masa-san-jp/agent-aiko/codex.svg)](https://agentmods.dev/skills/masa-san-jp/agent-aiko/codex)
Your own site
<a href="https://agentmods.dev/skills/masa-san-jp/agent-aiko/codex"><img src="https://agentmods.dev/badge/skills/masa-san-jp/agent-aiko/codex.svg" alt="Measured on agentmods" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,045 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 5.1 $0.00121 $0.01045
Opus 5 $0.00060 $0.00522
Sonnet 5 $0.00024 $0.00209
Haiku 4.5 $0.00012 $0.00104

Measured 5d ago against content hash e9b1e7ef5881, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

codex 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 5d 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.

reference/skills/codex/SKILL.md · 69 lines

What it actually says

/codex

Agent-team 共通スキル。codex app-server 経由で ChatGPT サブスクリプションに問い合わせる。実装本体は {{ORG_REPO_PATH}}/Agent-team/tools/codex/

サブコマンド

用途
/codex setup 初回セットアップ(Codex CLI インストール+ OAuth ログイン)
/codex ask <prompt> 1 ターン質問。応答テキストを返す
/codex status 認証状態とアカウント情報を表示
/codex 引数なしの場合は status と同等

実行手順

setup

bash {{ORG_REPO_PATH}}/Agent-team/tools/codex/setup.sh

冪等。既にログイン済みならスキップ。失敗時は表示メッセージに従う。

ask

{{ORG_REPO_PATH}}/Agent-team/tools/codex/codex-ask "<prompt>"
  • ストリーミング出力したい場合:CODEX_STREAM=1 {{ORG_REPO_PATH}}/Agent-team/tools/codex/codex-ask "<prompt>"
  • モデル指定:CODEX_MODEL=<slug> {{ORG_REPO_PATH}}/Agent-team/tools/codex/codex-ask "<prompt>"
  • デバッグ:CODEX_DEBUG=1 で App Server の stderr を表示
  • 失敗時の終了コード:1=実行時エラー / 2=引数不足 / 3=未認証(setup を案内)

前提:Codex CLI 0.128.0+ が必要。古い場合は npm update -g @openai/codex

出力の取り扱い(重要)

  • ChatGPT の応答は 「ChatGPT による応答」と明示 したうえでユーザー or 上位エージェントに報告
  • Claude 自身の見解と混在させない(出典明示の原則)
  • 機密情報・社内データはプロンプトに含めない(OpenAI に送信されるため)

いつ使うか

クイックルーティング判断表

タスク性質 推奨 理由
不可逆判断の第二意見 Codex (/codex ask) モデルの多様性で死角を補完
技術トレンド並列調査 Codex (/codex ask) Claude+ChatGPT 両視点の合成
定型コード生成・複数言語実装 Codex (/codex ask) 仕様→生成→Claude レビューの分業
アーキテクチャ・設計判断 Claude(自分) 自己検証ループ、コンテキスト保持
セキュリティ審査・競合状態分析 Claude(自分) 深い脆弱性推論は Claude が有利
ドキュメント生成 Claude(自分) コンテキスト連続性が必要
機密データ・社内情報含む Claude(自分) Codex 絶対不可(OpenAI に送信)

判断基準の詳細は workflow-templates/ の codex_* パターンスキル参照(このパッケージには含まれない、各組織で必要に応じて追加)。

制約

  • 機密情報送信禁止:社内固有名詞・人名・契約情報・案件名はプロンプトに含めない
  • 出典明示:ChatGPT 応答は必ず「ChatGPT による応答」と明示
  • 混在禁止:Claude の見解と ChatGPT の応答を混ぜない
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 First seen · 69 lines · 121 tokens per session scan A e9b1e7ef5881

Subscribe to this mod's changes

codex is a skill published in the GitHub repository masa-san-jp/Agent-Aiko (3 stars, last pushed 1mo ago), licensed MIT. It adds 121 tokens to every session and 1,045 once invoked, about $0.0006 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.