Transports Overview

Transports handle message delivery between services.

Choosing a Transport

Transport	Best For	Features
RabbitMQ	General purpose	Topic routing, DLQ, clustering
Kafka	High throughput	Partitioning, replay, ordering
SQS	AWS native	FIFO queues, serverless
Azure Service Bus	Azure native	Sessions, scheduling
GCP Pub/Sub	GCP native	Global, serverless
Redis	Low latency	Streams, consumer groups
NATS	Cloud native	JetStream, lightweight
In-Memory	Testing	No external deps

Transport Interface

All transports implement:

interface Transport {
  start(): Promise<void>;
  stop(): Promise<void>;
  subscribe<T>(options: TransportSubscribeOptions, handler: Handler<T>): Promise<void>;
  publish<T>(message: T, options: TransportPublishOptions): Promise<void>;
}

Basic Usage

import { createBus } from '@saga-bus/core';
import { RabbitMqTransport } from '@saga-bus/transport-rabbitmq';

const transport = new RabbitMqTransport({
  url: 'amqp://localhost:5672',
});

const bus = createBus({
  transport,
  store,
  sagas: [{ definition: orderSaga }],
});

await bus.start();

Configuration Patterns

Environment-Based

function createTransport() {
  if (process.env.NODE_ENV === 'test') {
    return new InMemoryTransport();
  }
  return new RabbitMqTransport({
    url: process.env.RABBITMQ_URL!,
  });
}