IDEA: Centralized userId

Hi all- I’ve been working on a number of Addins, and I try to keep them “configuration lite”, but a frequent need is to know the current logged in user. See for example my Visits library, which doesn’t no Auth of its own but would like to record any logged in users with the traffic record. Currently I handle this by checking $_SESSION[‘user_id’], and supplying a config file so folks can provide their location. But working on anew library with the same issue has me wondering:would it be useful to have CI store the userid after login, accessible as a core service or config?