How to Rebuild a Custom GPT as a Krater Persona in 5 Minutes
Custom GPTs stop working December 11. Copy your instructions into a Krater Persona and keep your model choice, apps and schedule.
What carries over, what changes
| Custom GPT | Krater Persona |
|---|---|
| Custom instructions | The Persona's own instructions, pasted verbatim |
| Conversation starters | First message you send, or saved prompts |
| One model family (OpenAI) | Any of 500+ models; Smart Auto Router picks per message, or pin your favorite |
| Knowledge uploads (frozen files) | Keep files and connected apps (living documents, always current |
| Actions via APIs | Connected apps via OAuth: Notion, Gmail, Google Docs, Slack and more, no code |
| Text + images | Text, images, video, voice and music in the same chat |
| Manual use only | Schedulable with Tasks: runs on a timer, results waiting for you |
Rebuild yours in five minutes
Step 1: Copy your GPT's instructions
In ChatGPT, open your GPT and edit it. Copy the full instruction text from the Configure tab. This is the only part that is truly yours and it does not export automatically. If you use GPTs other people made, write down what they actually did in one sentence (most are a paragraph of instructions you can rewrite better yourself).
Step 2: Create the Persona
Open Krater Personas, click "Create your own", paste the instructions in, name it, done. If your old GPT had a particular tone or workflow quirks, keep them. The instructions field works exactly like the one you are used to.
Step 3: Give it your knowledge
Instead of frozen uploads, drop the same documents into Keep or connect the app that owns them. A Notion-based GPT becomes a Persona with Notion connected: one OAuth click in /additions and it reads the current pages, not a frozen snapshot.
Step 4: Pick a model (or let the router pick)
This is the upgrade. A GPT only ever ran on OpenAI's models. A Persona runs on the Smart Auto Router across 500+ models, or pin GPT-5.6 for analysis, Claude for careful writing, Gemini for multimodal work. Test your five most common prompts and keep whichever wins.
Step 5: Optional: put it on a schedule
GPTs waited for you. A Persona can also work on a timer with Tasks: your weekly-report GPT becomes a Persona that delivers the report every Monday morning without being asked.
Bonus: rebuild it better than it was
Most GPTs were built with the GPT Builder's auto-generated instructions: a wall of pleasantries that quietly fought the model. Rebuilding is a chance to write the spec the GPT should have had. A sharper Persona instruction set looks like this:
Role: what it is, in one line.
Voice: how it talks (direct, warm, terse).
Always: the behaviors it must do every time (explain edits, cite sources).
Never: what to refuse (no fluff, no unpinned speculation).
Output: the format you want back (markdown table, 3 options, one-liner).
Tools: which connected apps it may use and when.Paste that into the Persona and you will get a stricter assistant than the original GPT, because the instructions are doing the work instead of the builder's boilerplate.
Two Persona tricks GPTs never had: @-mention it anywhere. Pull the Persona into any chat mid-conversation instead of starting a dedicated thread, and stack multiple Personas in one conversation (your Copy Editor persona edits what your Researcher persona drafted). And it works on files mid-chat, not just at setup: drop a document into the conversation and the Persona reads it with its full instruction set active.
A real example
A typical custom GPT: "You are an experienced B2B copy editor. You edit for clarity, cut filler, keep the author's voice, and explain every change you make. British English. Flag any claim that needs a source."
As a Persona: same text pasted in, named "Copy Editor", running on Claude for the editing pass. Now it can also rewrite the accompanying LinkedIn post, generate the header image, and check a connected Google Doc, in one conversation, for $20/month flat with 1,500 credits.
What you lose, honestly
Two things do not carry over. Public GPT Store distribution: if you published a GPT for others, there is no store to migrate it to (Personas are yours or your team's). And conversation history: old chats stay behind, so export anything you need before December.
For everything else, a Persona is the same job done better: your instructions, your tools, any model, on a schedule if you want it.
FAQ
Can I import a custom GPT automatically? There is no official cross-platform importer anywhere. The instructions are the GPT. Copy-paste is a five-minute job, and it is the only migration that preserves exactly what you wrote.
Does a Persona cost extra? No. Personas are part of every Krater plan. Pro is $20/month with 1,500 credits across 500+ models.
Can my team share a Persona? Yes. Personas work inside shared Krater team workspaces, like workspace GPTs did.
What if my GPT is already gone? The instructions may still be recoverable in some states. See why your custom GPT disappeared and what to do.
What about GPTs with API actions? If your GPT called custom APIs, the closest equivalent is connecting the app's official integration on Krater (Notion, Gmail, Slack, Docs and more). Custom API calls are the one case where OpenAI's plugins may genuinely be the better destination.
Retirement dates from OpenAI's FAQ, checked 1 October 2026. For the full picture see Custom GPTs are retiring December 11: your migration options.