commandExeption.cs

public class Module : NancyModule
{
    public Module(IMediator mediator)
    {
        Put["/customers/{CustomerId:Guid}/changepricinglevel/{MessageId:Guid}", true] = async (parameters, token) =>
        {
            var cmd = this.Bind<Command>();
            var envelope = new Envelope<Command>((Guid)parameters.MessageId, cmd);

            try
            {   
                await mediator.SendAsync(envelope);
                return HttpStatusCode.NoContent;
            }
            catch (Exception ex)
            {
                ex.ToExceptionless()
                    // Set the reference id of the event so we can search for it later (reference:id).
                    // This will automatically be populated if you call ExceptionlessClient.Default.Configuration.UseReferenceIds();
                    .SetReferenceId(((Guid)parameters.MessageId).ToString("N"))
                    // Add the envelope command object
                    .AddObject(envelope, "ChangePricingLevel")
                    // Set the customerId
                    .SetProperty("CustomerId", parameters.CustomerID)
                    // Add an Command tag.
                    .AddTags("Command")
                    // Mark critical.
                    .MarkAsCritical()
                    // Submit the event.
                    .Submit();

                return HttpStatusCode.InternalServerError;
            }
        };
    }
}