To make it fast, I foresee some sort of client which serves as one to house the AI search bot. It's connected to all the relays and the AI injests the data across all of nostr. It then categorizes this data and caches it. Sort of like keeping shorthand notes. Then when the AI search service is queried by a client, it can run through its cached notes and recall for the query how to retrieve said data (noteID or whatever). It would only ever need to retrieve data from the relays once to learn it and store the relevant details since it only needs to point you to the note (instead of constant polling like current clients do now to retrieve the actual note).