If you’re an IBM Integration Bus or App Connect Enterprise developer, you can create complex integration solutions by developing message flows in the Integration Toolkit and packaging them into BAR files.
A BAR file is a compressed file to which you add deployable resources in IBM Integration Bus or App Connect Enterprise. When you develop an integration solution in Integration Bus or App Connect Enterprise, you package your message flows and all the resources that those message flows use in a BAR file, then deploy the BAR file to an integration server. That server can be on premises or in IBM® App Connect. You can run your Integration Bus or App Connect Enterprise solutions in App Connect, without the need to acquire and maintain an IT infrastructure. When you upload a BAR file to App Connect, an integration server is created to run the contents of the BAR file. You can configure basic authentication and secure connectivity between your cloud-based and on-premises resources (see Running enterprise integration solutions in App Connect on IBM Cloud).