skill-codex

A plugin that connects Claude Code with OpenAI Codex through a shared tool interface. It lets one coding agent ask Codex to do work, review code, or give another opinion.

In plain words
What is it for?
Delegating bounded coding tasks, getting independent code reviews, and consulting Codex about technical decisions.
Why use it?
It provides a second coding perspective without requiring you to switch manually between tools or create a separate API key.

Plugin for Claude Code

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.

Claude Code
/plugin marketplace add Arystos/skill-codex
agentmods
npx agentmods add plugins/arystos/skill-codex/marketplace
Clone the repo
git clone --depth 1 https://github.com/Arystos/skill-codex

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

skill-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 2d 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.

.claude-plugin/marketplace.json · 27 lines

What it actually says

{
  "name": "skill-codex",
  "metadata": {
    "description": "Bridge Claude Code to the OpenAI Codex CLI for cross-model code review, task delegation, and second opinions — using your Codex subscription, no API key."
  },
  "owner": {
    "name": "Arystos",
    "url": "https://github.com/Arystos"
  },
  "plugins": [
    {
      "name": "skill-codex",
      "source": "./",
      "description": "Use OpenAI Codex from Claude Code for code review, task delegation, and second opinions via MCP — with your Codex subscription, no API key. Windows-native, live progress.",
      "version": "0.8.1",
      "author": {
        "name": "Arystos",
        "url": "https://github.com/Arystos"
      },
      "homepage": "https://github.com/Arystos/skill-codex",
      "license": "MIT",
      "keywords": ["codex", "code-review", "mcp", "developer-tools"],
      "category": "development"
    }
  ]
}
Files

What ships with it

2 files beside marketplace.json 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. 2d ago First seen · 27 lines scan A bcedab2faf7e

Subscribe to this mod's changes

skill-codex is a plugin published in the GitHub repository Arystos/skill-codex (5 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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.