some changes

Femto.Common/Integration/Event.cs

@@ -0,0 +1,6 @@
+namespace Femto.Common.Integration;
+
+public abstract record Event : IEvent
+{
+    public Guid EventId { get; } = Guid.CreateVersion7();
+}

Femto.Common/Integration/IEvent.cs

@@ -2,7 +2,7 @@ using MediatR;
 
 namespace Femto.Common.Integration;
 
-public interface IIntegrationEvent : INotification
+public interface IEvent : INotification
 {
     public Guid EventId { get; }
 }

Femto.Common/Integration/IEventBus.cs

@@ -0,0 +1,13 @@
+namespace Femto.Common.Integration;
+
+public interface IEventBus : IEventPublisher
+{
+    public delegate Task Subscriber(IEvent evt, CancellationToken cancellationToken);
+    void Subscribe(Subscriber subscriber);
+    
+}
+
+public interface IEventPublisher
+{
+    Task Publish<T>(T evt) where T : IEvent;
+}

Femto.Common/Integration/IEventHandler.cs

@@ -0,0 +1,24 @@
+namespace Femto.Common.Integration;
+
+public interface IEventHandler
+{
+    Task Handle(IEvent evt, CancellationToken cancellationToken = default);
+}
+
+public abstract class EventHandler<T> : IEventHandler
+    where T : IEvent
+{
+    protected abstract Task Handle(T evt, CancellationToken cancellationToken);
+
+    public async Task Handle(IEvent evt, CancellationToken cancellationToken = default)
+    {
+        if (evt is not T typedEvt)
+        {
+            throw new InvalidOperationException(
+                $"Event {evt.GetType()} is not of type {typeof(T)}"
+            );
+        }
+
+        await Handle(typedEvt, cancellationToken);
+    }
+}

Femto.Common/Integration/IIntegrationEventBus.cs

@@ -1,6 +0,0 @@
-namespace Femto.Common.Integration;
-
-public interface IIntegrationEventBus
-{
-    void Subscribe<T>() where T : IIntegrationEvent;
-}