How do I authenticate to a Custom Web Api from a SharePoint 2013/2016 single page app? I've seen a couple examples of using session which i really don't want to use, I'm thinking maybe a custom security token service or would it be better to add the web api as a provider hosted app (high trust) since this is on premises?
I found a solution finally, this one actually makes sense: http://blog.baslijten.com/getting-sharepoint-2013-apps-and-webapi-to-work/