ClaudSkills / Engineering / engineering-misc

Codex Agent

Q: What is a Claude Code skill and how does the Codex Agent skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Codex Agent is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Engineering · Sub-category: engineering-misc · Last updated: 2026-05-21

type:review

MANDATORY for code review - must use Codex CLI for all code reviews, then apply fixes based on Codex feedback. Also use for cross-verification, debugging, and getting alternative implementations.

From the source SKILL.md

This skill enables Claude Code to collaborate with OpenAI's Codex CLI agent.

What this skill does

Codex Agent is a community-contributed Claude Code skill in the engineering-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/codex-agent/ and loads when your prompt matches the skill's trigger.

Who uses this skill

The Codex Agent Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 76,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/codex-agent
curl -L https://claudskills.com/skills/codex-agent/SKILL.md \
  -o ~/.claude/skills/codex-agent/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/codex-agent/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/codex-agent/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\codex-agent\SKILL.md on Windows. See the full install guide for step-by-step instructions.

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Codex Agent Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/codex-agent/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Codex Agent skill do?

MANDATORY for code review - must use Codex CLI for all code reviews, then apply fixes based on Codex feedback. Also use for cross-verification, debugging, and getting alternative implementations.

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Codex Agent skill?

Use Codex Agent when your Claude Code task falls under the Engineering category — specifically in the engineering misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Codex Agent" or describe the task and let Claude pick). Browse related skills at /category/engineering/.

What is a Claude Code skill and how does the Codex Agent skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Codex Agent is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/majiayu000/claude-arsenal/blob/HEAD/skills/codex-agent/SKILL.md
Author: majiayu000

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

majiayu000. (2026). Codex Agent [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/codex-agent/

BibTeX

@misc{codex-agent-2026,
  author    = {majiayu000},
  title     = {Codex Agent [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/codex-agent/}
}

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Badge

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Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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