Centrifugo provides HTTP and GRPC APIs for publishing messages into channels. Publish server API is very straighforward to use - it's a simple request with a channel and data to be delivered to active WebSocket connections subscribed to a channel.
Sometimes though Centrifugo users want to avoid synchronous calls to Centrifugo API delegating this work to asynchronous tasks. Many companies have convenient infrastructure for messaging processing tasks - like Kafka, Nats Jetstream, Redis, RabbitMQ, etc. Some using transactional outbox pattern to reliably deliver events upon database changes and have a ready infrastructure to push such events to some queue. From which want to re-publish events to Centrifugo.
In this post we get familiar with a tool called Benthos and show how it may simplify integrating your asynchronous message flow with Centrifugo. And we discuss some non-obvious pitfalls of asynchronous publishing approach in regards to real-time applications.