Move a Custom GPT to a skill before custom GPTs retire on Dec 11, 2026
by PaperChaseWebb
Inventory your GPTs, export everything, migrate, rewrite the instructions as a SKILL.md that triggers at the right time, replace custom actions and test against the answers your GPT gives today.
- Price
- $14
- Difficulty
- Beginner
- Setup
- 20 min
- Format
- .md file
move-a-custom-gpt-to-a-skill.md · 11 KB · instant download after checkout
Want this built for you instead? We can build it for you.
What you end up with
Each GPT you rely on becomes a tested skill with a precise description, its reference files and a plan for any custom action, before the retirement date.
What you get
- One .md playbook with the dates and what transfers, sourced from OpenAI's help center (checked Oct 15, 2026)
- Inventory worksheet and an export checklist to run before anything becomes read-only
- SKILL.md template and rewrite rules for old GPT instructions
- Actions to apps or MCP decision table
- Test set template, user notice template and five prompts
Who it is for
People who built Custom GPTs for themselves, a team or clients and need them working as skills before Dec 11, 2026, especially GPTs that use knowledge files or custom actions.
Works with
Solid chips: the agent is named in this listing's own tools list. Dashed chip: Plain Markdown, so it also pastes into other agents such as Grok Bot, Hermes, OpenClaw or Muse. We list those as compatible by format only, not as tested.
Tools needed
Cost to run: No extra cost for the playbook. Plugin and app access depends on your ChatGPT plan.
Time to result: About one hour per simple GPT
How it works
Inventory
List every GPT, where it was created, who uses it and whether it has custom actions. Decide move, merge or let go.
Expected: A short move list ordered by risk.
Export
Save instructions, knowledge files, starters, action schemas and 5 to 10 real prompts with today's answers.
Expected: A folder per GPT you can rebuild from.
Publish and migrate
Publish final edits, then use Migrate to plugin from My GPTs when it is available for your account.
Expected: A private plugin with the GPT's instructions as a skill.
Rewrite the skill
Tighten the description, add a do-not-use line, move long facts into reference files and keep one worked example.
Expected: A SKILL.md that triggers on the right requests only.
Replace actions
Use the decision table: app connector, vendor MCP server, custom MCP server or a manual step.
Expected: Each action's operations covered or listed as dropped.
Test and tell users
Compare old and new answers on the saved prompts and one hard case, then send the notice.
Expected: Passes recorded, users switched before the date.
Sample prompt from the pack
Below are the instructions from my Custom GPT [name]: [paste instructions.md]. Rewrite them as a SKILL.md with a header (name, description) and these sections: When to use, Inputs to collect, Steps, Output format, Rules, Example. - Write the description so it triggers on: [list request types], and not on: [list nearby requests]. - Move long reference material out and tell me which file each part should go into. - Keep every rule that prevents a real mistake. Delete persona and filler. - List anything in the original you removed and why, so I can check.
The description decides when a skill runs. Test it with requests that should and should not trigger it.
Free preview of the file
# Move a Custom GPT to a skill before custom GPTs retire on Dec 11, 2026 PaperChase agent use case pack (playbook), version 1.0. For creators of Custom GPTs moving to ChatGPT plugins and skills, with notes on reusing the same skill in other agents that read SKILL.md. Time: about one hour per simple GPT, longer for GPTs with custom actions. ## The dates (checked Oct 15, 2026) OpenAI's help center says custom GPTs are scheduled to retire on Dec 11, 2026, and that creators can migrate a GPT to a plugin, where its instructions become a skill. Affected Enterprise workspaces with an approved deferral have until Feb 11, 2027. For Enterprise workspaces, creation of new custom GPTs is planned to end on Oct 26, 2026. OpenAI notes dates can change, so follow the notice in your own account. Source: OpenAI Help Center, "Custom GPT retirement and migration FAQ", https://help.openai.com/en/articles/20001519-custom-gpt-retirement-and-migration-faq ## What carries over and what does not According to that FAQ: | Part of your GPT | In the migration | |---|---| | Instructions | Become a skill in the new plugin | | Knowledge files | Copied into the plugin's reference files | | Connected apps | Added to the plugin as apps | | Custom actions | Do not transfer. Rebuild with an available app or a custom MCP server | | Selected model | Does not carry over | | Sharing settings and users | Do not carry over. The plugin starts private | | Drafts and unpublished edits | Do not transfer. Migration uses the latest published version | | The original GPT | Becomes read-only after migration, usable until retirement | ## Why a straight migration is not enough GPT instructions were written to be read on every message by one model. A skill is picked up when its description matches the request and may run alongside other skills and apps. Instructions that worked as a GPT can be ignored, triggered at the wrong time or clash with other skills unless you rewrite them a little. ## The plan 1. Inventory your GPTs and decide which to move 2. Export everything before you touch anything 3. Publish final edits, then migrate 4. Rewrite the instructions as a clear skill 5. Replace custom actions 6. Test against saved prompts and one hard case 7. Tell your users and reuse the skill elsewhere ## Contents 1. Inventory worksheet 2. Export checklist 3. Migration steps 4. SKILL.md template and rewrite rules 5. Actions to apps or MCP decision table 6. Test set template 7. User notice template 8. Prompts for each stage
Worth knowing
- Dates and migration details come from OpenAI's help center as of Oct 15, 2026. OpenAI says they can change; your account notice takes priority.
- Not affiliated with or endorsed by OpenAI.
- Custom actions do not transfer. Rebuilding them can need technical setup and, in workspaces, admin permissions.
Questions
Where does the Dec 11, 2026 date come from?
OpenAI's help center article Custom GPT retirement and migration FAQ, checked on Oct 15, 2026. It also gives Feb 11, 2027 for Enterprise workspaces with an approved deferral. The playbook links the source.
Can I reuse the skill outside ChatGPT?
Often, yes. The SKILL.md format is supported by several agents, including Claude Code and Codex. Folder locations and limits differ, so check each tool's docs.
Details
Version 1.0 · Updated Oct 15, 2026 · Markdown version of this page
License: Personal and commercial use by the buyer. No resale, redistribution or republishing as a competing pack. See Downloads in the terms. Download terms
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