First, check your plan

OpenAI's help centre (checked 11 October 2026) lists skill uploads for Business, Enterprise, Healthcare and Edu. An admin has to allow skills, and skill uploading is a separate switch.

Personal plans (Free, Go, Plus and Pro) can't upload a skill in chat. OpenAI says standalone skills work in the ChatGPT desktop app and in Codex, and skills that come inside plugins work in chat on every plan. Personal plans also can't create new custom GPTs, and all custom GPTs retire on 11 December 2026.

On a workspace plan: upload the skill

  1. Download the skill: on its Trilly page, press Add to my AI and choose ChatGPT.
  2. Open Plugins in ChatGPT's sidebar, then the Skills tab.
  3. Choose Create, then Upload from your computer, and pick the .zip.
  4. Wait for ChatGPT's check. It scans every upload. If it says Needs Review or Blocked, your workspace rules are holding it back. Ask your admin.
  5. Ask as normal, or type @ and the skill's name.

Full ChatGPT guide with admin tips.

On a personal plan: the desktop app or Codex

The skill's Add to my AI page offers a ChatGPT and Codex plugin for the ChatGPT desktop app and Codex. You add it once with OpenAI's Codex command-line tool, restart the desktop app, then choose it in the Plugins Directory. The ChatGPT guide has the steps. If you already use Codex, you can also put the skill folder straight into ~/.agents/skills: see the Codex guide.

Or paste a Project version

Some skills come with a Project version, if the skill's maker made one.

  1. Choose the Project version on the skill's Add to my AI page.
  2. Create a Project in ChatGPT, open its menu, then Project settings.
  3. Paste it into the project's instructions.
  4. Upload any extra files the page lists.
  5. Chat inside the project whenever you need the skill.

A pasted copy is a snapshot. It won't update when the maker improves the skill, and Trilly can't count your use in the skill's public numbers. Any scripts in the skill won't run either.

What about custom GPTs?

Don't start one. OpenAI is retiring custom GPTs on 11 December 2026 (FedRAMP workspaces, and Enterprise workspaces with an approved deferral, have until 11 February 2027) and moves their instructions into skills. More in AI skills vs prompts vs custom GPTs.

ChatGPT can connect to apps built on MCP, the open standard the Trilly connector uses. On Business, Enterprise and Edu, custom apps that can take actions are a beta feature, and an admin may need to allow them. On Pro, developer mode only allows read and fetch actions, so adding skills through a link won't work there. See Link your AI.

Find something to add: skills that work with ChatGPT.