I can get details about my dashboard and nav files from :
| rest /services/data/ui/view
| rest /services/data/ui/nav
However when I just use | rest /services/data/ui I see an endpoint called panels. I would assume this is for prebuilt panels but | rest /services/data/ui/panels yields no results even though I have prebuilt panels under .../data/ui. Is the endpoint supported in 6.2?
This endpoint is supported (I just hit it on my own instance). Perhaps you are running into a permission issue. Does the user you are running | rest /services/data/ui with have permissions to the panels?
Also a quick test - what happens when you browse to the endpoint directly? -