How do you implement a RabbitMQ topic exchange for routing messages to multiple queues based on routing keys in NestJS?

Q: How do you implement a RabbitMQ topic exchange for routing messages to multiple queues based on routing keys in NestJS?

// npm i @golevelup/nestjs-rabbitmq @Module({ imports: [ RabbitMQModule.forRoot({ exchanges: [ { name: 'orders.topic', type: 'topic' }, ], uri: 'amqp://localhost', }), ], }) export class AppModule {} // Consumer — binds to routing key pattern @Injectable() export class OrderConsumer { @RabbitSubscribe({ exchange: 'orders.topic', routingKey: 'orders.*.created', // * matches one word queue: 'eu-orders-queue', }) handleOrderCreated(msg: OrderCreatedEvent): void { console.log('Order created:', msg); } @RabbitSubscribe({ exchange: 'orders.topic', routingKey: 'orders.#', // # matches zero or more words queue: 'audit-queue', }) auditAll(msg: unknown): void {} } // Publisher @Injectable() export class OrderPublisher { constructor(private amqpConnection: AmqpConnection) {} publish(order: Order, region: string): void { this.amqpConnection.publish( 'orders.topic', `orders.${region}.created`, order, ); } } * (asterisk) — matches exactly one word in the routing key. # (hash) — matches zero or more words; orders.# matches everything under orders. Topic exchanges are the most flexible pattern — prefer them over direct or fanout for complex routing. @golevelup/nestjs-rabbitmq provides a more complete AMQP integration than the built-in NestJS transport. Fanout exchanges broadcast to all bound queues regardless of routing key — use for broadcasting events.

Difficulty: 6/10

Topic exchange, Routing keys, NestJS microservices

The built-in NestJS RabbitMQ transport does not expose exchange configuration directly. Use @golevelup/nestjs-rabbitmq for advanced exchange patterns. Define exchanges in RabbitMQModule.forRoot(), bind handlers to routing key patterns with @RabbitSubscribe(), and publish with AmqpConnection.publish().

Topic exchange with @golevelup/nestjs-rabbitmq

Topic exchange routing key rules:

1
- (asterisk) — matches exactly one word in the routing key.
2

How do you implement a RabbitMQ topic exchange for routing messages to multiple queues based on routing keys in NestJS?

Difficulty: 6/10

Topic exchange, Routing keys, NestJS microservices

The built-in NestJS RabbitMQ transport does not expose exchange configuration directly. Use @golevelup/nestjs-rabbitmq for advanced exchange patterns. Define exchanges in RabbitMQModule.forRoot(), bind handlers to routing key patterns with @RabbitSubscribe(), and publish with AmqpConnection.publish().

Topic exchange with @golevelup/nestjs-rabbitmq

Topic exchange routing key rules:

1
- (asterisk) — matches exactly one word in the routing key.
2

How do you implement a RabbitMQ topic exchange for routing messages to multiple queues based on routing keys in NestJS?

How do you implement a RabbitMQ topic exchange for routing messages to multiple queues based on routing keys in NestJS?

(hash) — matches zero or more words; orders.# matches everything under orders.

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