That is a nice sequence diagram[1]; I like how each endpoint param values are written out and the color distinctions. What tool did you use to create it?
[1] https://storage.ghost.io/c/b8/53/b853e3d4-3186-409d-9c7f-7da...
[1] https://storage.ghost.io/c/b8/53/b853e3d4-3186-409d-9c7f-7da...
Disclaimer: I cut it off after a few minutes because I got impatient. It could have gotten closer if I waited longer.