cybrix.ai / gpt-migration
Custom GPTs retire December 11, 2026. Move yours to a plugin.
OpenAI is replacing custom GPTs with ChatGPT plugins: skill instructions plus a remote MCP server, with optional widgets that render inside the chat. GPT Actions don't carry over on their own. I've already rebuilt 23 of my own GPTs this way and can do the same for yours.
Leave time for testing and review.
A plugin has to be built, tested in ChatGPT and submitted before the cutoff. Starting early means your users never notice the switch.
From a GPT to a plugin.
A plugin is more work than a GPT, but it can do much more: real tools with typed inputs, visual results in the chat, and per-user accounts.
Custom GPT
- Instructions and uploaded knowledge files
- Actions described by an OpenAPI schema
- Images and files come back as links
- Listed in the GPT Store
- Works only inside ChatGPT, and only until December 11, 2026
ChatGPT plugin
- Skill instructions plus an MCP server you control
- Tools with typed parameters and safety annotations
- Widgets render charts, diagrams, previews and players inline
- OAuth sign-in when users need their own data
- Listed in the ChatGPT Plugins directory; the server also works with other MCP clients such as Claude
What I do.
The same process I used on my own catalog, from audit to a plugin that's ready for review.
Audit the GPT
Instructions, knowledge files, Actions, conversation starters, and what your users actually rely on.
Rebuild the tools
Actions become MCP tools with typed parameters, clear descriptions and safety hints. Your existing API can stay where it is.
Add a widget
Where a result is visual, it renders in the chat instead of as a link: charts, diagrams, slide previews, audio.
Sign-in if needed
OAuth 2.1 so each user's data stays theirs, only when the plugin needs accounts.
Make it review-ready
Checked with the same MCP inspector I use on my own plugins, with privacy policy and test prompts prepared.
Run side by side
The GPT keeps working until the cutoff while the plugin is tested, so nothing breaks for your users on the way.
I've moved my own catalog first.
Prompt-only GPTs gained real tools along the way: screenplay export to PDF and Final Draft, image cropping and icon sets, printable roast cards.
Have something to build? Let's talk.
Email is the quickest way to reach me. A few lines is plenty to start. I'll reply with questions or a suggested next step.
Useful to include
- What you want the AI or software to do, and for whom
- The systems it has to talk to (APIs, databases, SaaS tools)
- Where it should run: your cloud, your servers, or hosted
- Any deadline, such as the December 11 GPT cutoff