In OpenAI Pro ($20/mo) one can start a project with a set of files. Various chats can be had about this project topic with the files providing additional information. I've discovered the projects are isolated. They'll use memory configurable in settings but they don't use chat history outside the project. This can give ChatGPT chats in projects a different tone.

My question is this: Is this fine tuning with those project documents or RAG and what's the difference?

Thanks for the clarification. OpenAI projects in ChatGPT are meant for end users to get personalized help using their own documents, inside the ChatGPT UI.

Promptrepo is for developers and product teams to build new AI-powered features in their product. It’s about creating custom models that run behind the scenes in apps, not just improving a personal chat experience.

So while OpenAI projects use RAG for better chats, Promptrepo helps teams build and deploy fine-tuned APIs that serve structured outputs like JSON, labels, or extracted fields to build your own AI powered product.