Function batch_search 

pub async fn batch_search(
    __arg0: State<Arc<AppState>>,
    agent: Option<Extension<AuthenticatedAgent>>,
    deadline: Option<Extension<Deadline>>,
    __arg3: Json<Value>,
) -> Result<Json<Value>, ApiError>

Hybrid search across several databases in one call, the query embedded once. Body: databases (names), query and/or embedding, k, context (also return each database’s heads up context), max_items (context size), agent_id, user_id. Every database must be readable by the token, or the whole request is refused. A database that does not exist is reported under errors without stopping the others.