How to listen to remote Commerce events

This will be a quick tips for people who want to listen to external Commerce events. I have a perculiar situation where I via the Service API import my products, but the service API isn't hosted on the same site/server as my site, but on a separate one instead. This means that I can't listen to local events like I would normally and will have to listen to remote events. But is there such events for Commerce? I know that Episerver sends remote events for cache invalidations, so maybe they send events for Commerce event too.

To listen to local Commerce events you can create your own implementation of CatalogEventListenerBase and one of the out of the box implementation of this abstract class is the CatalogEventBroadcaster. This class will take the local event and send out remote events that we can listen to! So to solve my problem I implemented the following in a IConfigurableModule.

	[ModuleDependency(typeof(ServiceContainerInitialization))]
	public class CatalogEventListener : IConfigurableModule
	{
		public void Initialize(EpiserverCommerce.Framework.Initialization.InitializationEngine context)
		{
			Event ev = Event.Get(CatalogEventBroadcaster.CommerceProductUpdated);
			ev.Raised += Ev_Raised;
		}

		private void Ev_Raised(object sender, EpiserverCommerce.Events.EventNotificationEventArgs e)
		{
			if (!(e.Param is Byte[])) return;
			var eventArgs = DeSerialize(e.Param as Byte[]);
			// Care only about catalog entry events
			var catalogEvents = eventArgs as CatalogContentUpdateEventArgs;
			if (catalogEvents == null || !catalogEvents.CatalogEntryIds.Any()) return;

			switch (catalogEvents.EventType)
			{
				case Mediachase.Commerce.Catalog.Events.CatalogEventBroadcaster.CatalogEntryUpdatedEventType:
					catalogEvents.CatalogEntryIds.ForEach(entryId => UpdateIndex(entryId));
					break;
				default:
					break;
			}
		}

		private static EventArgs DeSerialize(byte[] buffer)
		{
			var formatter = new BinaryFormatter();
			using (var stream = new MemoryStream(buffer))
			{
				return formatter.Deserialize(stream) as EventArgs;
			}
		}		
	}

Big thanks to Quan Mai for helping me find the right class!