RabbitMQBroker

RabbitMQBroker is the main entry point for publishing and consuming events.

---

Creating a broker

const broker = new RabbitMQBroker("payments_service");

The peer name is visible in RabbitMQ management tools.

---

Declaring topology

const pub = await broker
  .queue("payments_queue")
  .exchange("payments_exchange", {
    exchangeType: "topic",
  });

This:

• asserts the queue
• asserts the exchange
• binds them together
• returns a typed broker interface

---

Exchange options

{
  exchangeType?: "topic" | "direct" | "fanout";
  routingKey?: string;
  durable?: boolean;          // default: true
  publisherConfirms?: boolean // default: false
}

---

Publishing

await pub.produce(eventEnvelope);

Or using factories:

const api = pub.with({ orderCreated });
await api.orderCreated({ id: "o-1" });

---

Consuming

sub.handle("orderCreated", async (_id, ev) => {
  console.log(ev.data);
});

await sub.consume({
  prefetch: 50,
  concurrency: 10,
  onError: "dead-letter",
});

---

Consume options

type ConsumeOptions = {
  prefetch?: number;
  concurrency?: number;
  onError?: "ack" | "requeue" | "dead-letter";
};

---

Notes

• Reconnects are automatic
• Delivery is at-least-once
• Handlers should be idempotent

---

Summary

RabbitMQBroker owns connection, topology, publishing, and consuming. It exposes a small, explicit API aligned with RabbitMQ semantics.