AI Tools Field Guide

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Beginner — Use AI tools at work

GPTs, plugins and what replaces them

Lesson 12 of 16≈5 min

A custom GPT is ChatGPT with your instructions and files saved inside it. OpenAI has said it will retire GPTs and move them into plugins, which bundle the same instructions (now called skills) with connections to other apps. If you rely on a GPT, keep its instructions and files somewhere you control and plan the move now.

What a GPT is

OpenAI's own line on the GPTs page says it best: "custom versions of ChatGPT that combine instructions, extra knowledge, and any combination of skills". You write the instructions once, attach reference files, and anyone you share it with opens it like a chat. The worked example on GPTs, agents and skills builds one in ten minutes.

The GPTs page in ChatGPT: Discover custom versions of ChatGPT that combine instructions, extra knowledge, and any combination of skills; a Search GPTs box; category tabs from Top Picks to Education; and three Featured GPTs from outside companies.
The GPTs page is also the GPT store: a search box, category tabs, and Featured GPTs published by outside companies. A GPT from the store is someone else's instructions; read what it asks to connect to before you use it.

Screenshot by the author, 25 September 2026.

Plugins: the new home for helpers

The top of the ChatGPT sidebar: New chat, Scheduled, Library, Plugins and Explore.
The ChatGPT sidebar in September 2026: New chat, Scheduled, Library, Plugins and Explore.

Screenshot by the author, 25 September 2026.

ChatGPT's Plugins page, with a Skills tab beside it and an Add button: Connect plugins to let ChatGPT work across your tools, a search box, a row of installed plugin icons, Public and Personal tabs, and a Popular list including Gmail, Google Drive, Outlook Email, GitHub and Health.
The Plugins page: "Connect plugins to let ChatGPT work across your tools." Plugins and Skills tabs at the top, the ones you installed in a row, Public and Personal tabs, and a Popular list with Gmail, Google Drive, Outlook Email and GitHub.

Screenshot by the author, 25 September 2026.

A plugin is a package. It can hold skills (saved instructions, the part a GPT used to be), apps (a connection to Gmail, Drive, GitHub and so on) and reference files. Public and Personal tabs separate published plugins from your own. Installed plugins also appear in the plus menu under the chat box, next to the built-in tools.

The plus menu under ChatGPT's chat box: Add photos and files, Add library files, Work in a project, Create image, Web search, Sketch, Deep research, Gmail, Template Creator (create reusable templates saved as personal skills) and Presentations.
The plus menu with plugins installed. Gmail reads and manages mail; Template Creator makes "reusable templates saved as personal skills"; Presentations creates and edits slides.

Screenshot by the author, 25 September 2026.

What OpenAI says about the change

OpenAI's help center (Custom GPT retirement and migration FAQ, read 25 September 2026) sets out the plan:

Part of your GPT After migration to a plugin
Instructions Become a skill inside the plugin
Connected apps Added to the plugin as apps
Knowledge files Copied into the plugin as reference files
Custom actions (calls to outside APIs) Do not carry over; rebuild them
The model you chose Does not carry over
Conversation starters and past chats May not copy

For business workspaces OpenAI's dates are 25 September 2026 for the end of new GPT creation and 11 December 2026 for GPTs to stop running. Other plans get their dates through notices inside ChatGPT. After a GPT is migrated it turns read-only, and OpenAI warns that the plugin may answer a little differently.

What to do about it

  1. Open each GPT you rely on and copy its instructions into a document you keep
  2. Download or locate its knowledge files
  3. Run the migration when ChatGPT offers it, or build a plugin with the same skill and files
  4. Test the plugin on three prompts you know the right answer to
  5. Tell the people who used the GPT where the new one lives

Do not start a new GPT today. Put a new helper in a project if it is for you, or in a plugin skill if others need it.

The same idea in the other tools

Tool Name for a saved helper Where it lives
ChatGPT Plugin skill (was a custom GPT) Plugins, then Skills
Gemini Gem, or an agent on a work account Gems (Google)
Grok Skill The plus menu, then Skills; see automations for running one on a timer
Claude Skill Loaded when a task calls for it (Anthropic)

The four parts do not change from tool to tool: instructions, files, a model and the tools it may use. Keep your instructions in a plain document and you can rebuild the helper anywhere in ten minutes.

Vendor facts checked ; re-verify before relying on them.