Initial commit carried over from private repo. This is V2.

code/MessengerApi.Db/Repositories/UserRepository.cs

@@ -0,0 +1,18 @@
+using MessengerApi.Db.Contracts.Repositories;
+using MessengerApi.Db.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace MessengerApi.Db.Repositories
+{
+    public class UserRepository : Repository<User>, IUserRepository
+    {
+        public UserRepository(DbSet<User> db) : base(db)
+        {
+        }
+
+        public User SingleByApiKeyAndEnabled(Guid id, bool enabled)
+        {
+            return this.db.Single(x => x.ApiKey == id && x.IsEnabled == enabled);
+        }
+    }
+}