I couldn't find answers about using both frameworks working together.
We are planning to build an identity provider service (like Google Account) which is used to authenticate a user and provide OpenId Connection protocol to a Rely Party app. We have existing projects built in ServiceStack which work all fine. However, ServiceStack seems not to be compatible with IdentityServer4 in regards to authenticating a user. ServiceStack has its own authentication mechanism and IdentityServer4 relies on Asp.NET Identity Model. If I sign in via ASP.NET Identity Model, ServiceStack APIs may not recognize the user has signed in. And vice versa.
Is there any suggestion about this is a dead end or some solution that may make them work together?