Newtonsoft BSON Serializer

var endpointConfiguration = new EndpointConfiguration("Samples.Serialization.ExternalBson");
var serialization = endpointConfiguration.UseSerialization<NewtonsoftJsonSerializer>();
serialization.ContentTypeKey("application/bson");
serialization.ReaderCreator(stream => new BsonDataReader(stream));
serialization.WriterCreator(stream => new BsonDataWriter(stream));

public class MessageBodyWriter :
    IMutateIncomingTransportMessages
{
    static ILog log = LogManager.GetLogger<IMutateIncomingTransportMessages>();

    public Task MutateIncoming(MutateIncomingTransportMessageContext context)
    {
        var bodyAsString = Encoding.UTF8
            .GetString(context.Body.ToArray());
        log.Info("Serialized Message Body:");
        log.Info(bodyAsString);
        return Task.CompletedTask;
    }
}

endpointConfiguration.RegisterMessageMutator(new MessageBodyWriter());

var message = new CreateOrder
{
    OrderId = 9,
    Date = DateTime.Now,
    CustomerId = 12,
    OrderItems = new List<OrderItem>
    {
        new OrderItem
        {
            ItemId = 6,
            Quantity = 2
        },
        new OrderItem
        {
            ItemId = 5,
            Quantity = 4
        },
    }
};
await endpointInstance.SendLocal(message)
    .ConfigureAwait(false);