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Memory & Knowledge

How to use custom GPTs for client knowledge (and plan for their retirement)

3 min read

What still works with a custom GPT per client in October 2026, how to keep its knowledge clean, and how to get ready for OpenAI's move to Plugins.

Short answer: OpenAI plans to retire custom GPTs and recommends moving workflows to Plugins. Retirement is planned for December 11, 2026 for affected Enterprise workspaces, and new GPT creation is no longer available on personal plans. If you have client GPTs today, keep their knowledge files current, export what you would need to rebuild them, and plan the move.

Facts below come from OpenAI's help article Creating and editing GPTs, read October 9, 2026. Check it for updates; OpenAI says other plans are expected to follow the same timeline.

Who can still build one

  • Business, Enterprise and Edu workspaces can create, edit and publish GPTs when workspace settings allow.
  • Free, Go, Plus and Pro accounts cannot create or publish new GPTs. Existing GPTs remain usable until retirement.

Step 1: Inventory your client GPTs

List every GPT you use for a client, with its owner, its instructions and its knowledge files. Copy the instructions into a document now. That copy is what you will move into whatever replaces the GPT.

Step 2: Clean up the knowledge files

A GPT can hold up to 20 files of up to 512 MB each. OpenAI says knowledge works best for reference material, such as documentation, guides and handbooks. That is document retrieval, the RAG side of the picture; decisions that change belong in memory (see agentic memory vs RAG). For client work, that means:

  • Keep: brand guide, product sheet, approved messaging, style rules.
  • Remove: old plans and drafts that contradict current decisions.
  • Add a dated "Current decisions" file and replace it when things change.

Step 3: Tighten the instructions

Open the GPT in the editor and review the instructions. Useful lines for a client GPT:

Use the knowledge files as the source of truth for Ridgeline Outfitters.
If "Current decisions" disagrees with another file, it wins.
Never mention other clients or bring in facts not in these files.

Step 4: Plan the move

OpenAI recommends Plugins, which bring reusable instructions and connected apps together, and says a migration flow is planned. Before your retirement date:

  1. Keep the exported instructions and files in one folder per client.
  2. Watch for retirement notices for your workspace.
  3. Decide where each client's knowledge will live next, and test it with one client first.

Sources

Checked October 9, 2026.

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