In the recent release of IBM App Connect on IBM Cloud – Enterprise plan (beta), the callable flow function has been expanded so that IBM App Connect flows can call IBM Integration Bus flows. This opens up new exciting hybrid integration opportunities where the massive collection of IBM App Connect applications can be combined with the rich on-premises capability of IBM Integration Bus. Here are some examples of the powerful integrations that are now possible: Integrate events from cloud-based applications like Salesforce, Insightly, and Marketo with on-premises packaged applications like SAP. This allows the SAP system part of the integration to be run on-premises to remove the need to expose the SAP system directly to the internet. All communications with SAP are controlled by the callable flow running on premises. Also, by not directly integrating the cloud integration to the SAP system, it reduces the amount of network interactions required to one call from the cloud to the running callable flow. Integrate IBM App Connect flows into on-premises transports like IBM MQ, file systems (including managed file transfer), and databases without having to allow direct access from the cloud to these transports. Each transport can be accessed by constructing an IBM Integration Bus callable flow that allows access in a controlled manner. Allow the exchange of data from cloud-based formats using JSON or XML to proprietary message formats like EDIFact, COBOL structures, or CSV by using callable flows to convert between these formats using the rich message parsing technology available in IBM Integration Bus. To use callable flows in an IBM App Connect flow is simple: In the flow, add a new action. From the list of available applications, select Callable flow. Select Invoke as the action. The flow editor provides a list of all available deployed IBM Integration Bus callable flow applications and a list of their endpoints in the IBM App Connect system: Changing to advanced mode allows these fields to be directly typed rather than discovered. The action then allows direct mapping to the IBM Integration Bus LocalEnvironment and Message trees. Any data available in the IBM App Connect flow can be mapped directly to these structures: There is no need to copy any definitions from IBM Integration Bus to IBM App Connect or vice versa. As long as the callable flow is deployed and configured in App Connect, it can be discovered and then executed when the flow runs. Try this out for yourself using the tutorial: Create an event driven flow that integrates Salesforce leads with an on-premises sales system.