Save the Setup in a Project
Keep the brief and the file together in a project, and the next run starts from both instead of from a blank box.
A project is a space whose instructions and files apply to every chat inside it. Write the brief in once, drop in a past document you were happy with, and the next contract is a single attachment away.
Tool | Where the brief goes | Where the files go |
|---|---|---|
Claude | Set project instructions | Project knowledge |
ChatGPT | Project settings, under the ••• menu | Project files |
Claude's free plan allows five projects. ChatGPT takes five files per project on Free, twenty-five on Go and Plus, forty on Pro.
If you already keep a prompt like this in a custom GPT, move it. Custom GPTs stop working on 11 December 2026, and OpenAI converts them from My GPTs with Migrate to plugin. Personal accounts can no longer create new ones, and workspaces are planned to stop on 26 October 2026. Both dates are OpenAI's and can move, so follow the notice in your own account.
You were about to build a custom GPT to hold this brief. What is the better move today?
Put the brief in a project, which both tools support today
Build the custom GPT and migrate it before the retirement date
Keep the brief in a note and paste it in each time
A project does the same job for one person, on free plans in both tools, and nothing about it stops working in December. Building the GPT first means doing the work twice, and copying the brief in by hand is the step people stop doing in week two.