Projects, custom GPTs and sharing

20 minutes. For everyone. Save your instructions once. Share one version with the team.

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In Lesson 3, Dana typed "I'm the office manager at a heating and cooling company" at the start of her request. That's fine once. By the tenth time, it's a waste. And when three people each type their own version, the company ends up with three different tones, three sets of facts and three sets of mistakes.

ChatGPT has two ways to save instructions and share them: projects and custom GPTs. This lesson recommends projects for new work, and explains why: OpenAI has announced that custom GPTs are being retired.

Projects: the shared folder for a kind of work

OpenAI describes a project as a place that keeps related chats, files and instructions together, so ChatGPT works from the same context each time. A shared project goes further: everyone in it works from the same instructions and the same files.

At Comfort Zone Heating & Cooling, our fictional HVAC company, Dana made one project called Customer Messages. It holds:

Instructions: who the company is, the tone to use, what never goes in a message, and "plain text only."
Files: the current price sheet, service area list and maintenance plan terms.

Now both dispatchers start every customer draft inside that project. Same voice. Same facts. When a price changes, Dana replaces one file and everyone gets the new number.

Step 1: Create a project (3 minutes)

Select New project in the sidebar.
Give it a name, and pick an icon and color.

Name it after the work, not the person: "Customer Messages," "Job Write-Ups," "Hiring," "Monthly Reports."

Step 2: Add instructions (5 minutes)

Select the more options menu (•••) in the project, then select Project settings, and add your instructions. OpenAI notes that project instructions apply only inside that project, and they override each person's own custom instructions there.

Here's a starting point. Swap in your own details:

> You help the office team at Comfort Zone Heating & Cooling, a heating and cooling company, write messages to homeowners. > > - Write in plain, friendly language. Short sentences. No jargon. > - Use only the facts in our files or in the request. If a fact is missing, write [CHECK: what's missing] instead of guessing. > - Never promise an arrival time, a price for unseen work, a refund or a discount. Write "HAND OFF" and stop if the message is about any of those, or about damage, safety or a complaint. > - Plain text only, ready to paste into an email or text. No tables, buttons or charts. > - Keep emails under 120 words and texts under 40.

The line about plain text matters more now that GPT-6 can answer with interactive elements (Lesson 3).

Step 3: Add files (2 minutes)

Upload the reference files the work needs: PDFs, spreadsheets, documents or pasted text. OpenAI says Business projects support up to 40 files.

Only add files you'd be comfortable with anyone in the project reading. A price sheet, yes. A spreadsheet of customer phone numbers, no.

Step 4: Share it (5 minutes)

Select Share to open the sharing pane. In a Business workspace, OpenAI says you can:

Invite people or groups in your workspace, giving each one chat access or edit access.
Share a workspace link, which lets anyone in your workspace join. People who join that way get chat access, and you can raise it to edit afterward.

What the two access levels mean, per OpenAI:

Chat access: use the project's chats, files and instructions. Can't invite others.
Edit access: also update instructions, add or remove files, and invite others.

A few facts worth knowing before you share:

A workspace project can have up to 100 collaborators.
Shared projects use project-only memory. They don't use anyone's personal memories or custom instructions from outside the project.
In a shared project, deleting a file removes it for everyone.
The project owner can remove people and delete the project. Deleting a project can't be undone, and it removes the project's chats and files for everyone.
Workspace owners can control project sharing and decide which roles can create or share projects, in workspace settings.

Keep edit access small. At Comfort Zone, Dana has edit access to Customer Messages. The dispatchers have chat access. One person owns the facts.

Custom GPTs: use the ones you have, plan for the change

A custom GPT is a saved assistant with its own name, instructions, knowledge files and tools. In Business, members can create them, and share them with specific people, with anyone in the workspace who has the link, or with the whole workspace. Permission levels are Can chat, Can view settings and Can edit.

Here's the important news. OpenAI has announced it is retiring custom GPTs across ChatGPT plans and recommends moving them to plugins, which can bundle reusable instructions with connected apps. On its help pages, as of October 10, 2026:

Custom GPTs are scheduled to retire on December 11, 2026. OpenAI says to follow the notice for your own account or workspace, because timing can differ.
Existing GPTs keep working until the retirement date. Your old conversations with them stay accessible afterward.
When migration is available, the GPT's creator goes to My GPTs and selects Migrate to plugin. The migration uses the GPT's latest published version, so drafts don't transfer.
After migration, the original GPT becomes read-only.
Sharing doesn't carry over. The new plugin starts private. You'll need to share it again.
Custom actions don't transfer. If a GPT connects to another system through an action, plan extra time.

What to do about it (5 minutes)

Don't build new team setups as GPTs. Use a shared project instead. It does the same core job (instructions plus files, shared with the team).
List the GPTs your team uses. On the Workspace Setup Checklist, write each one's name, who created it, and who uses it.
For each one, decide: move it into a shared project now, or wait for migration to plugins. Either way, put a date on it well before December 11.
Save your test prompts. OpenAI's own advice is to save a few familiar prompts so you can compare the replacement's results. Your Prompt Retest Log from Lesson 3 is exactly that.

Sharing a single chat

Sometimes you just want to show a coworker one good conversation. Select Share on the chat to make a link. In Business, only people in your workspace can open it (Lesson 2). If you share a chat from a project, the person sees only that chat, not the rest of the project.

Do this now

Create one shared project for the work your team repeats most.
Add instructions, including the plain-text line, and the reference files.
Share it: chat access for most people, edit access for one or two.
List your team's custom GPTs and pick a plan and date for each.

Check it worked

One shared project exists, with instructions and current files.
At least two people other than you have used it for a real task.
Only one or two people have edit access.
Every custom GPT your team relies on is listed, with a plan and a date before December 11, 2026.

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Next: bring your documents and tools into ChatGPT, carefully.

→ Lesson 5: Files, connected apps and plugins

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