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Hands-on AI Playbook

Skills on OpenAI

ChatGPT and Codex support Agent Skills natively, using the same open SKILL.md format as Claude and other platforms. Since July 2026 the ChatGPT app (Mac, Windows, Linux) has three modes — Chat, Work, and Codex — and ChatGPT and Codex share one plugin directory, so a plugin installed once works in all of them.

Before you start: in ChatGPT, click Plugins in the left sidebar. If you see Add marketplace, you can install plugins (any paid plan — Plus, Pro, Business, Enterprise). If you see a Skills tab with a Create button, you can upload skills (any paid plan except Free and Go; on Enterprise and Edu an admin turns Skills on). On Free or Go, use the Codex folder path below.

Install a plugin (paid plans)

Section titled “Install a plugin (paid plans)”

Plugins → Add marketplace, paste the marketplace address (for the Hands-on AI plugin: jamesgray-ai/handsonai-plugins), then Install the plugin. Plugin skills work in Chat and Work on the web, desktop, and mobile, and in Codex. In Work, type @ and the skill name to use one; in Codex, type $ and the name.

Business, Enterprise, and Edu admins can add a marketplace for the whole workspace: Admin → Plugins → Add → Import marketplace (it syncs daily).

→ Plugins (official OpenAI docs)

Upload a skill (paid plans)

Section titled “Upload a skill (paid plans)”

Plugins → Skills → Create → Upload from your computer, then choose the skill’s .zip (don’t unzip it). Uploaded skills are available in the ChatGPT app and in Codex.

→ Skills in ChatGPT (official OpenAI docs)

Codex — folders on disk (every plan, including Free)

Section titled “Codex — folders on disk (every plan, including Free)”

Codex reads skill folders from disk, in this order: .agents/skills/ in your current folder and up to the repository root, then ~/.agents/skills/ in your home folder (the usual place — it works in every project), then /etc/codex/skills. Unzip the skill and move its folder there; then type $ in Codex to pick it, or /skills to list what’s loaded. This works in the Codex CLI, the Codex tab in the ChatGPT app, and the IDE extension.

From the CLI, the plugin also installs with codex plugin marketplace add jamesgray-ai/handsonai-plugins then codex plugin add handsonai@handsonai.

→ Build skills — Codex (official OpenAI docs)

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