Is there a way either through the front end or using the python API to view all layers that have stored credentials?
I am migrating to a new server using windows auth so need to be able to find and update all of them
It would seem that when you simply add a link to another org's service, looking at the item's URL shows something like:
https://services6.arcgis.com/Do88DoK2xjTUCXd1/arcgis/rest/services/OSM_Landuse_NA/FeatureServer
But when it is stored with credentials, you get this:
https://maps.co.kendall.il.us/portal/sharing/servers/<server-itemID>/rest/services/<service-name>/FeatureServer
If you use the ArcGIS Python API, you could easily search through your content to find these items with a bit of regular expressions. and a quick loop.
There may be a way to browse those proxy "servers" directly, but I haven't done it. If I happen to look into it further, I'll update my post here.