You’re thinking of retrieval augmented generation (RAG) with a vector database. Its something that’s being actively developed. I haven’t had time to dig much into it, especially currently. But the terms themselves should give you a starting point.

Edit: a quick google gives what could be a promising starting point https://huggingface.co/learn/cookbook/rag_llamaindex_librarian

https://www.science.org/content/blog-post/things-i-won-t-work-dioxygen-difluoride

Probably related to this, very fun column to read.