Migrate a Custom GPT to a Skill
Updated 2026-10-18. Facts below come from OpenAI's own help pages, linked at the end. Dates are OpenAI's planned dates and can change, so check the notice for your account.
The Short Version
- OpenAI is replacing custom GPTs with plugins. A plugin is a package that can contain skills, apps, or both.
- When you use OpenAI's Migrate to plugin button, your GPT's instructions become a skill inside a new private plugin, and its knowledge files are copied in as reference files.
- Custom actions, the selected model, drafts and sharing settings do not carry over.
- After you migrate, the original GPT becomes read-only. It keeps working until the retirement date.
Step 1: Get Ready
- List the GPTs you rely on, and whether you created them. Only the creator, or a workspace admin, can migrate a GPT.
- Publish any draft you want to keep. Migration uses the latest published version. Publishing does not mean sharing publicly.
- Save a few prompts you use often, plus one hard case, and the answers you liked. You will use them to compare the replacement.
- Write down what your GPT uses: instructions, knowledge files, custom actions, and connected apps.
Step 2: Migrate With OpenAI's Button
When migration is available for your account, go to My GPTs, find the GPT under Created by me, and choose Migrate to plugin. OpenAI says migration may reach different accounts at different times, so you may not see the button yet. If you do not see it, you must be the creator or a workspace admin, the GPT must be published, and plugins must be enabled for you.
The new plugin starts private. It is not installed for anyone and nobody else can use it until you share it.
What Transfers and What Does Not
| Your GPT Has | In the Plugin |
|---|---|
| Instructions | Become a skill in the plugin. Review the wording. |
| Knowledge files | Copied into the plugin as reference files. Test that they are used the way you expect. |
| Connected apps | Added to the plugin as apps. |
| Custom actions | Do not transfer. Rebuild them with a supported app or a custom MCP server. |
| Selected model | Does not carry over. Enterprise defaults apply in Enterprise workspaces. |
| Drafts and unpublished edits | Do not transfer. |
| Sharing settings | Not copied. Share the replacement again. |
| Conversation starters and past chats | May not copy over. Save useful prompts yourself. |
Step 3: Test
Try the plugin on your saved prompts and the hard case. Check that the right skill is chosen, that it follows your format, that it uses your reference files, and that the tools it needs are available. Test both picking the plugin yourself and asking in plain words, because automatic skill selection depends on the request. If a needed capability is missing, keep using the original until you have a tested replacement.
Step 4: Share and Switch
Share the plugin with the people who used your GPT, ask one of them to install and try it, and tell your team what changed. Make future edits in the plugin, not the old GPT. Your existing conversations with custom GPTs stay accessible after retirement. OpenAI says you can still migrate a GPT after retirement, even though the GPT itself will no longer run.
Using Your GPT's Instructions as a Portable Skill
This section is Swarmnest's own guidance, not OpenAI's.
A skill is a folder with a SKILL.md file: a short header with a name and a description, then your instructions in Markdown. If you want your GPT's behavior to work outside ChatGPT, you can copy your instructions into a SKILL.md by hand and put your knowledge files in a references/ folder next to it. The same folder works in tools that read the open format, such as Codex, Claude, Cursor and Gemini CLI, though each tool installs it in its own way. See any listing's "Install in 30 Seconds" box. Tips:
- Write the
descriptionas "what it does and when to use it". Agents read only that line first to decide whether to load the skill. - Keep instructions short and move long material into reference files.
- Replace each custom action with an MCP server or a script. Browse MCP servers in our directory. Scripts make a skill software, so we label them "Includes Scripts".
- Do not paste secrets or API keys into a skill.
Skills That Help You Write Skills
Skill Creator (Anthropic)
Skill Creator is a skill for creating, installing or managing agent skills and plugins, published by Anthropic in the skills repository. It ships with code the agent may run.
Skill Creator (OpenAI)
Skill Creator is a skill for creating, installing or managing agent skills and plugins, published by OpenAI in the skills repository. It ships with code the agent may run.
Plugin Creator
Plugin Creator is a skill for creating, installing or managing agent skills and plugins, published by OpenAI in the skills repository. It ships with code the agent may run.
If You Use Someone Else's GPT
You cannot migrate it. Check the GPT's notice and ask its creator, or a workspace admin, to migrate it and share the replacement with you.
Sources (Checked Oct 18, 2026)
- OpenAI Help Center: Custom GPT retirement and migration FAQ, for dates, what transfers and who can migrate.
- ChatGPT Learn: Moving your custom GPT workflows to plugins, for the steps and the comparison with plugins.
- OpenAI Help Center: Creating and editing GPTs, which notes that personal ChatGPT plans (Free, Go, Plus, Pro) can no longer create or publish new GPTs.
Not Verified
- Exact migration availability per account. OpenAI's own pages give different target dates (Sep 17 and Sep 22, 2026) and say it varies by account.
- Whether the Oct 26, 2026 creation cutoff applies the same way to every plan. OpenAI's FAQ lists it for affected Enterprise workspaces and says other plans are expected to follow the same timeline.
- Gemini Gems have their own timeline. A guide for that is planned.
Not affiliated with OpenAI. This guide is general information, not legal or business advice.