Co-authored by Claudia Zentner 

Starting with IBM Cloud Pak for Business Automation 23.0.2, you can expose and trigger workflow automations as Kafka-based automation services. Workflow Designer allows you to easily enable your workflow automations for message-event-driven, loosely coupled interactions. 

To expose a Kafka-based automation service, you create a Kafka service in Workflow Designer and publish it to the automation service catalog in Business Automation Studio. To trigger such an automation service from another workflow automation, you discover and invoke it like any other automation service. 

The following example illustrates a Loan Approval workflow automation with a Loan Approval process that is exposed as a Kafka-based automation service. This automation service is then triggered from another automation named Loan Request automation. 

Creating a Kafka service 

Before you can expose a Kafka-based automation service, you create a Kafka service in Workflow Designer. For how to do that, see the Triggering workflow automations using Kafka message events blog. 

Exposing a Kafka service as an automation service 

To expose the Loan Approval Kafka service to Business Automation Studio as an automation service, you publish version 1 of the Loan Approval automation that contains the Kafka service. 
 

After you published the automation version, the Kafka-based automation service appears in the automation service catalog. 

You have successfully exposed a Kafka service as an automation service and can now proceed with triggering the automation service from another automation. 

Triggering Kafka automation services 

To trigger your Kafka-based automation service from the Loan Request workflow automation, you add an automation service to it. For doing that, select the Loan Approval automation service, and then select its submit operation. 

The Loan Approval automation service is now added to your Loan Request automation. Note the interaction style of this automation service is asynchronous and one-way. This is because the automation service is Kafka-based and thus allows for a fire-and-forget interaction. 

To invoke this automation service, you can now use it as the implementation of the Submit Loan Approval service task in your service flow. 

Click Run to execute this service flow in Workflow Designer. This starts the service flow, including the Submit Loan Approval activity. The activity triggers the Kafka-based automation service from the Loan Approval automation. The service task completes right away without waiting for a result because it is an asynchronous, one-way automation service. 

For more information about how to enable loosely coupled, message event-driven interactions exposing Kafka automation services and triggering Kafka automation services, see Creating a Kafka service, Providing workflow automation services, and Calling an automation service from a workflow automation in the documentation of IBM Cloud Pak for Business Automation 24.0.1 or later.