Where does Codex store skills?

Personal skills live in `$HOME/.agents/skills/` and repository-scoped skills in `.agents/skills/` inside the project. Each skill is a folder containing a `SKILL.md`.

Is a Codex SKILL.md the same as Claude's?

Yes — both use the open Agent Skills SKILL.md format, so a well-written skill is largely portable. The main difference is the install location (.agents/skills for Codex, ~/.claude/skills for Claude).

How do I invoke a Codex skill?

Codex triggers matching skills automatically from the description. You can also call one explicitly with `$skill-name`, or list installed skills with `/skills`.

What's the difference between SKILL.md and AGENTS.md?

AGENTS.md is always-on, repo-wide guidance; a SKILL.md skill is task-specific and loaded only when relevant. Use AGENTS.md for project conventions and skills for repeatable workflows.

Do I need to write code for a Codex skill?

No — a skill is markdown with a short frontmatter. Scripts are optional. You can also generate one with the free Skill Builder.

Codex Skills: How to Create an OpenAI Codex SKILL.md

OpenAI Codex Skills let you package a repeatable workflow as a SKILL.md so Codex runs it the same way every time. This guide covers the format, where Codex looks for skills, the four ways to create one, and a free generator.

What are OpenAI Codex Skills?

Codex Skills are reusable workflow bundles that extend OpenAI Codex with task-specific know-how. Each skill is a folder with a SKILL.md file — frontmatter plus instructions — so Codex performs a recurring task (a release checklist, a migration, a review) the same way every time, and invokes it automatically when it recognizes the task.

Codex Skills use the same open Agent Skills SKILL.md format as Claude. If you're new to the idea, read what agent skills are first.

Codex Skills vs AGENTS.md, plugins, and Claude Skills

SKILL.md (skill) — on-demand, task-specific instructions Codex loads when relevant.
AGENTS.md — repo-wide, always-on guidance for how Codex should behave in that project. A skill is scoped and loaded only when needed.
Plugin — packages skills and tooling for distribution.
Claude Skills — the same open standard; a well-written SKILL.md is largely portable between Codex and Claude.

Anatomy of a Codex SKILL.md

The frontmatter needs two fields:

name — lowercase, kebab-case, matching the folder.
description — what the skill does and when it should trigger (this is how Codex decides to use it).

The markdown body holds the imperative instructions. Keep it under ~500 lines and prefer instructions over scripts unless you need deterministic behavior.

Four ways to create a Codex skill

1. Built-in $skill-creator — Codex scaffolds a skill by asking what it does and when it should trigger. 2. Record & Replay — demonstrate a workflow once; Codex drafts a reusable skill from the steps. 3. Manual — create the folder and write SKILL.md yourself (below). 4. Skill Builder — generate a clean SKILL.md with ProfessorGPT's free wizard, no config needed.

Step by step: writing your first Codex SKILL.md

Follow the steps below to create and enable a skill.

Where Codex skills live and how to invoke them

Codex discovers personal skills in $HOME/.agents/skills/ and repository skills in .agents/skills/ inside a project. Add a folder + SKILL.md:

mkdir -p ~/.agents/skills/release-notes
# add ~/.agents/skills/release-notes/SKILL.md

Codex picks up changes after a restart and invokes a skill automatically when a task matches. You can also reference one explicitly with $skill-name or list installed skills with /skills.

A complete Codex SKILL.md you can copy

---
name: release-notes
description: Drafts release notes from merged pull requests since the last tag. Use when the user asks to write a changelog or release notes.
---

# Release Notes

1. List merged PRs since the latest git tag.
2. Group them into Features, Fixes, and Chores.
3. Write one concise bullet per change, user-facing language.
4. Output valid Markdown ready to paste into a GitHub release.

Build a Codex skill without the setup

Skip the boilerplate: the Skill Builder produces a standard SKILL.md that works in Codex, Claude, and Gemini CLI, or browse ready-made skills.