MassTransit: The Enterprise Service Bus for .NET

Don’t implement `RabbitMQ.Client` directly. It’s complex and error-prone. **MassTransit** abstracts the message broker (RabbitMQ, Azure Service Bus, SQS), providing a unified API for consumers, sagas, and fault tolerance.

Defining a Consumer

public class OrderConsumer : IConsumer<SubmitOrder>
{
    public async Task Consume(ConsumeContext<SubmitOrder> context)
    {
        var order = context.Message;
        // Process logic...
        await context.Publish(new OrderAccepted { Id = order.Id });
    }
}

Configuration

services.AddMassTransit(x =>
{
    x.AddConsumer<OrderConsumer>();
    
    x.UsingRabbitMq((ctx, cfg) =>
    {
        cfg.Host("localhost", "/", h => { ... });
        cfg.ReceiveEndpoint("order-queue", e =>
        {
            e.ConfigureConsumer<OrderConsumer>(ctx);
        });
    });
});

Key Takeaways

• MassTransit handles **Connection Recovery** and **Retry Policies** out of the box.
• Use **Sagas** for long-running stateful workflows.