>>Nimitz+d7
I wouldn't be surprised if they essentially just add it to the prompt. ("You are ChatGPT... You are talking to a user that prefers cats over dogs and is afraid of spiders, prefers bullet points over long text...").
>>lxgr+C7
I think RAG approach with Vector DB is more likely. Just like when you add a file to your prompt / custom GPTs.
Adding the entire file (or memory in this case) would take up too much of the context. So just query the DB and if there's a match add it to the prompt after the conversation started.