Guide / Reviewed October 6, 2026

How to install and use Codex skills

Start with one repeated task, add a skill that fits it, and check the result. Here is a practical path from discovery to your first useful run.

What is a Codex skill?

A skill packages instructions for a particular workflow. Its folder contains a SKILL.md file and may include scripts or reference material. Codex can select a relevant skill from your request, or you can ask for it explicitly. OpenAI explains how skills work.

Pick a task you already understand: reviewing a pull request, looking up a library API, or checking a document. You will be able to tell whether the skill gives you a useful result. For occasional work, a clear prompt may be enough.

1. Choose and inspect one skill

Browse the Codex skills directory and open a card for its source and install options. Read the creator's instructions, required tools, and supported environment. A familiar repository name is not a substitute for checking the individual skill.

Write down your expected output before installing: a list of findings with file references, a working example, or a finished artifact. Prefer a focused workflow that explains how to verify that output. Our task-based selection guide gives you a few starting points.

2. Install through the documented path

OpenAI's curated catalog supports the built-in skill installer. For example, send this prompt in Codex to request its PDF skill:

$skill-installer pdf

The installer also accepts a skill's GitHub folder URL. Use the specific folder listed by its creator. A whole repository can contain several different skills; do not assume that a repository URL identifies just one. Follow any setup steps for its dependencies. Official catalog and installer examples.

Directory buttons labeled “Send to agent” copy instructions for you to paste; they do not install anything by themselves. Check the agent's installation result before moving on.

3. Run a small, inspectable task

Ask Codex to use the installed skill with a concrete input and a clear finish condition. For a PDF you can open and inspect, try:

Use the PDF skill to review this one-page document. Check the rendered layout and report clipped text, unreadable labels, or missing content. Give me findings before changing it.

Compare the findings with the actual document. A successful installation is only the first check; a useful run should follow the requested workflow and produce evidence you can examine. Keep a short example of a good result for the next time you use the skill.

If the skill does not appear or run

Check that installation finished and the skill has a valid SKILL.md file.
Restart Codex if the newly installed skill is not visible.
Ask for the skill by name and check whether a required tool or account is missing.
Read its current source if an install instruction differs from an older listing.

A skill being usable in Codex does not establish that it runs in your dot. Look for documented compatibility and the access it needs. For packaged tools and connections, browse Codex plugins alongside the skills directory.