Zato is a Python-based middleware and backend platform designed for integrating and building server-side systems. The platform belongs to a broader family of solutions that, depending on one’s background, will be known under the name of an integration layer, integration platform, service-oriented platform, enterprise service bus, API server, message bus, message queue, message broker, orchestration engine or similar.

One of the additions in the upcoming Zato 3.2 release of is an extension to its publish/subscribe mechanism that lets services publish messages directly to other services. Let’s check how to use it and how it compares to other means of invoking one’s API services. How does it work? In your Zato service, you can publish a message to any other services as below. Simply point self.pubsub.publish to the target service by the latter’s name and it will receive your message.

This article introduces features built into Zato that let one take advantage of publish/subscribe topics and message queues in communication between Zato services, API clients and backend systems.

Zato publish/subscribe message queues and topics offer several ways to gain insight into the inner workings of all the components taking part in message delivery and this article presents an overview of the mechanisms available.