It will work with any JSON but It'll work faster if you write the JSON out a bit at a time.

Consider if you are writing data from a db: you can either collect all the rows together then write them out, or you can write them out one at a time as you get them. If you write one at a time you are in a sense streaming even if you're not using a streaming protocol.

On a slow network reading any http is like a stream because you can use the first bit to arrive without waiting for the rest. The faster the network the less the benefit but it shouldn't end up worse.