Adapter.cs

public class CustomAdapter : DefaultEventAdapter
    {
        protected override byte[] ToBytes(object @event, JObject metadata, out string type, out bool isJson)
        {
            
            var bytes = base.ToBytes(@event, metadata, out type, out isJson);
        
            //Add some additional metadata:
            metadata["additionalProp"] = true;

            //set the type yourself
            switch (@event)
            {
                case CommittedEvent<UserAccountAggregate, UserAccountId, UserAccountCreatedEvent> s:
                    type = "UserAccountAggregate.UserAccountCreatedEvent.0";
                    break;
                
                case CommittedEvent<UserAccountAggregate, UserAccountId, UserAccountNameChangedEvent> s:
                    type = "UserAccountAggregate.UserAccountNameChangedEvent.0";
                    break;
            }

            
            
            return bytes;

        }
        protected override object ToEvent(byte[] bytes, JObject metadata)
        {
            //Use the metadata to determine if you need to do something additional to the data
            //Do something additional with bytes before handing it off to be deserialized.
            return base.ToEvent(bytes, metadata);
        }         
    }