An ASP.NET Core template with dedicated authentication server using IdentityServer4, ASP.NET Core Identity Users and Entity Framework Core.
After initializing a project with this template, Web APIs, MVC applications and SPAs can be added to the root project or can be included as a client object in the src/AuthenticationServer/Config.cs file and they can all consume the dedicated authentication server.
See details in IS4 documentation here.
IS4 Repository: https://github.com/IdentityServer/IdentityServer4.