Codex CLI, OpenAI's command-line coding agent, supports SKILL.md skills through its .codex/skills/ directory. The same skills that work in Claude Code and OpenClaw work here. This guide covers the best ones to install first.

Quick Answer: The top 5 best Codex CLI skills for 2026 are code review, testing and QA, DevOps and deployment, documentation, and frontend development. These skills help Codex CLI understand specific project requirements and best practices.

How skills work in Codex CLI

Codex CLI reads skills from two locations:

• Personal: ~/.codex/skills/ — available in all your projects
• Project-level: .codex/skills/ — shared with your team via git

Each skill is a folder containing a SKILL.md file. Codex CLI loads them at startup and uses the description field to match skills to your prompts.

Because Codex CLI uses the open SKILL.md standard, you're not locked into one agent. Every skill listed below works in Claude Code, OpenClaw, Cursor, and Gemini CLI without modification.

Code review

A code review skill is the single highest-impact addition for most developers. It gives Codex CLI specific rules about what to check: security vulnerabilities, performance issues, error handling gaps, and your team's style conventions.

Without a review skill, Codex gives generic feedback. With one, it checks for the specific issues your codebase cares about — missing error boundaries in React, unvalidated API inputs, hardcoded credentials, or whatever your team has learned the hard way.

Browse code review skills on Agensi.

Testing and QA

Test generation skills teach Codex CLI your team's testing patterns. Which framework you use, how you name test files, what assertion style you prefer, and how thorough the edge case coverage should be.

The best testing skills auto-detect your test framework from package.json and match the style of your existing tests. The result is tests that slot into your suite without cleanup.

Browse testing and QA skills on Agensi.

DevOps and deployment

DevOps skills cover Docker configuration, CI/CD pipeline setup, infrastructure-as-code, and deployment automation. If you're writing Dockerfiles, GitHub Actions workflows, or Terraform configs, a DevOps skill keeps Codex aligned with best practices — multi-stage builds, pinned versions, non-root users, caching strategies.

Browse DevOps skills on Agensi.

Documentation

Documentation skills set standards for README files, API docs, code comments, and changelogs. They keep Codex CLI consistent about what sections to include, how to format them, and what level of detail to target.

Browse documentation skills on Agensi.

Frontend development

Frontend skills define your component conventions: file structure, styling approach, accessibility requirements, and state management patterns. Particularly useful for React, Vue, and Svelte projects where there are many valid ways to structure code and you want consistency.

Browse frontend skills on Agensi.

How to install skills in Codex CLI

Download a skill from Agensi and unzip

unzip code-reviewer.zip -d ~/.codex/skills/

Or clone from GitHub

git clone https://github.com/user/skill-name.git ~/.codex/skills/skill-name

Verify

ls ~/.codex/skills/skill-name/SKILL.md ```

Start a new Codex CLI session after adding skills. They load at startup.

Codex CLI vs Claude Code vs OpenClaw

All three agents support the same SKILL.md format. The main differences:

	Codex CLI	Claude Code	OpenClaw
Skills path	~/.codex/skills/	~/.claude/skills/	~/.openclaw/skills/
Underlying model	GPT-4.1	Claude	Claude
Project skills	.codex/skills/	.claude/skills/	.openclaw/skills/
Skill format	SKILL.md	SKILL.md	SKILL.md

The skills themselves are identical files. You can symlink a single skills folder across all three:

One set of skills, every agent. That's the point of the open SKILL.md standard.

For a detailed comparison of how skill formats differ across agents, see Claude Code Skills vs Cursor Rules vs Codex Skills.

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Browse cross-compatible skills for Codex CLI, Claude Code, and 20+ agents on Agensi.