Choose an Event Adapter

Every Connectum EventBus uses the same EventAdapter contract. Choose a broker from workload and operational requirements, then keep broker-specific tuning in that adapter's generated API reference.

Broker Selection Matrix

Adapter	Persistence	Consumer coordination	Ordering scope	Best starting fit
Memory	No	None	Publish call	Unit tests and local prototypes
NATS JetStream	Yes	Durable consumers	Subject	Lightweight, low-latency service events
Kafka / Redpanda	Yes	Native consumer groups	Partition	High-throughput streams and retained logs
Redis Streams / Valkey	Configurable by Redis	Consumer groups	Stream	Teams already operating Redis-compatible infrastructure
AMQP / RabbitMQ / LavinMQ	Durable queues/exchanges when configured	Competing consumers	Queue	Routing topologies and external AMQP contracts

All production adapters implement at-least-once delivery semantics. Handlers must be idempotent and acknowledge only after their side effects are complete. Broker configuration determines actual durability and retention.

Memory

MemoryAdapter() ships with @connectum/events. It has no external dependency, persistence, or consumer groups and is intended for tests and local development.

import { MemoryAdapter } from '@connectum/events';

const adapter = MemoryAdapter();

NATS JetStream

Choose NATS for durable subjects, wildcard routing, and a compact operational footprint.

import { NatsAdapter } from '@connectum/events-nats';

const adapter = NatsAdapter({ servers: 'nats://localhost:4222' });

• Module hub
• NatsAdapterOptions

Kafka or Redpanda

Choose Kafka-compatible infrastructure for partitioned ordering, retained logs, and high-throughput stream processing.

import { KafkaAdapter } from '@connectum/events-kafka';

const adapter = KafkaAdapter({
  brokers: ['localhost:9092'],
  clientId: 'orders-service',
});

• Module hub
• KafkaAdapterOptions
• Redpanda example

Redis Streams or Valkey

Choose Redis Streams when the team already operates Redis-compatible infrastructure and needs stream consumer groups without a separate broker stack.

import { RedisAdapter } from '@connectum/events-redis';

const adapter = RedisAdapter({ url: 'redis://localhost:6379' });

• Module hub
• RedisAdapterOptions

AMQP or RabbitMQ

Choose AMQP for exchange/queue topology, competing consumers, or integration with an externally governed AMQP contract.

import { AmqpAdapter } from '@connectum/events-amqp';

const adapter = AmqpAdapter({
  url: 'amqp://localhost:5672',
  exchange: 'events',
  exchangeType: 'topic',
});

• Module hub
• AmqpAdapterOptions
• AMQP example

Automatic Client Identification

When an adapter-specific client or connection name is not supplied, the EventBus derives a service identifier from registered proto service names and the host. An explicit adapter option always wins. Use explicit names when broker ACLs, dashboards, or support procedures depend on stable identifiers.

Custom Adapters

Implement the generated EventAdapter contract when a broker is not covered. Keep serialization, connection lifecycle, subscription cancellation, acknowledgement behavior, and error semantics explicit.

Next Steps

• Publish and Subscribe
• Event Middleware
• @connectum/events