diff --git a/Base/XBaseHub.cs b/Base/XBaseHub.cs
index b15aac2..1375fd7 100644
--- a/Base/XBaseHub.cs
+++ b/Base/XBaseHub.cs
@@ -14,7 +14,7 @@ namespace xPushService.Base {
     /// <summary>
     /// a base class for implementing Hubs ...
     /// </summary>
-    public abstract class XBaseHub : Hub {
+    public abstract class XBaseHub : Hub, IXBaseHub {
         //
         #region Props ...
         protected readonly IXPushGroupStore groupStore;
diff --git a/Interfaces/IXBaseHub.cs b/Interfaces/IXBaseHub.cs
new file mode 100644
index 0000000..af941bb
--- /dev/null
+++ b/Interfaces/IXBaseHub.cs
@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using xPushService.Models;
+
+namespace xPushService.Interfaces
+{
+    public interface IXBaseHub
+    {
+        Task OnConnectedAsync();
+        Task OnDisconnectedAsync(Exception exception);
+        Task NotifyNewConnection(string connectionId);
+        Task UpdateLastSeen();
+        Task PushMessageAsync(XPushMessage message);
+        Task AuthorizedMessageAsync(XPushMessage message);
+        Task PushMessageToAll(XPushMessage message);
+        Task PushMessageToConnection(
+            string connectionId,
+            XPushMessage message
+        );
+        Task PushMessageToConnections(
+            IEnumerable<string> connectionIds,
+            XPushMessage message
+        );
+    }
+}
\ No newline at end of file