AI Tool Changes: What's Shutting Down and When

Two older OpenAI API models retire

An earlier GPT-4o snapshot and GPT-4.1 nano leave the developer API under a notice issued in April.

Affects: software that calls OpenAI automatically — chatbots, automations, custom tools. Not the ChatGPT app.  Do: ask whoever built it whether these specific versions are in use.

OpenAI models stop working inside Cursor

Following Cursor's acquisition, OpenAI is ending the arrangement that supplies its models to the coding tool.

Affects: development teams using Cursor.  Do: nothing, unless you employ developers — then ask them if it changes their setup.

Gemini Gems become “skills”

Google begins converting personal-account Gems automatically, carrying over names, instructions and uploaded files. Business and enterprise accounts convert later.

Affects: anyone who built custom Gems in Gemini.  Do: two catches — converted skills arrive switched off and need activating, and skills require the Keep Activity setting turned on. Check that before the 17th if you disabled it.

OpenAI's Agent Builder shuts down

The visual tool for building agents, deprecated back in June, stops working entirely.

Affects: anyone who built a workflow in it.  Do: copy the logic out now if you haven't. Whatever you built needs rebuilding somewhere else.

Custom GPTs retire

Custom GPTs stop running and leave the GPT directory. Plugins are the replacement. Some business workspaces with an approved extension run to February 2027.

Affects: anyone who built or relies on a custom GPT.  Do: open each one and copy the instructions into a document you own. Conversations, custom actions and sharing settings don't transfer.

Full breakdown →

Four OpenAI models leave the API

GPT-4o, GPT-4o mini, GPT-4.1 and GPT-4.1 mini are removed from the developer API, along with anything custom-trained on them. GPT-6 Luna is the named replacement.

Affects: website chatbots, AI steps in Zapier or Make, custom-built tools, anything an agency or developer set up. Not the ChatGPT app.  Do: the notice goes to whoever holds the API key, which usually isn't you. Ask directly.

Full breakdown, plus the email to send →

Custom GPT extension deadline ends

The last date for business workspaces that were granted an extension past the December retirement.

Affects: larger organizations with an approved deferral.  Do: confirm with your administrator whether you actually have one. Most don't.

Business and enterprise Gems removed

Google has said business and enterprise Gems won't be removed before this date. No firm cutoff published yet.

Affects: Google Workspace accounts using Gems.  Do: nothing urgent. Worth knowing it's coming.

Aug 26, 2026 — OpenAI's Assistants API shut down, replaced by the Responses API.

Feb 13, 2026 — GPT-4o removed from the ChatGPT model picker. Separate from the API retirement above.

Rolling, no notice — vendors sometimes swap models underneath you with no announcement. Grok automatically moved everyone off its previous voice model in October. There's no list for these, which is rather the point.