pre-merge is an active concern. Initial state is not. Pre-merge has much more to do with real I/O and live changes. Initial state is just your first-frame data. The former needs input (the data to BE merged that is to be munged) whereas the latter is a provider of data for just the initial db.

I rarely use pre-merge. It’s a contributed feature that has some nice aspects, but I personally prefer to put that logic in a UISM or mutation. But, if you don’t have a logic system around your components and are just using load, then pre-merge is kinda nice.

I’m using pre-merge pretty heavily to add updates to time-series data. Say, I’m making two remote calls for overlapping data, I’m doing the logic to ensure that I overwrite updated data points without clobbering the existing data when it’s merged, ending up with a larger map that contains all keys needed in the UI. This all occurs inside a single pre-merge function. TX data looks something like this. [{:t-1 #inst 1 :key-a 10 :key-b 23} ; ... {:t-100 #inst 100 :key-a 34 :key-b 12}] [{:t-20 #inst 20 :key-a 55 :key-x true} ; ... {:t-60 #inst 60 :key-a 11 :key-x false}] Is this the correct use of pre-merge? I thought I was pretty smart, but… maybe I’m cutting steak with a fork here. Thoughts?

seems good. I wasn’t trying to say it isn’t useful

:url of fulcro-http-remote should set it, not append it. You sure you’re sending what you think you’re sending?

If you look at the implementation, it does NOT combine the url with anything at all internally.

Well that's weird. Earlier I was seeing http://localhost:4000/localhost:3000 in chrome's networking records, but I don't know how because it is working as you describe now (setting the url). Sorry about that, I'm just getting into looking up docs and source with emacs... lots to learn. Thank you.