The user exit programming interface (XPI)

The user exit programming interface (XPI) provides global user exit programs with access to CICS® services.

Overview of the XPI
The user exit programming interface (XPI) provides global user exit programs with access to some CICS services. It consists of a set of macro function calls that you can use in your user exit programs.
Making an XPI call
An XPI call has two sets of parameters: input parameters, including the XPI function call and the parameters passed to the call, and output parameters, by which CICS can return values to you, including response and reason codes that tell you whether the call was successful.
Release-sensitive XPI call
You can use a release-sensitive XPI call so that the XPI call can execute successfully on all currently supported CICS releases. To do this, replace the CALL XPI parameter with the RELSENSCALL XPI parameter, and assemble the program. You can use the release-sensitive XPI call alternative with all XPI commands.
Global user exit XPI examples, showing the use of storage
The following example illustrates the use of the XPI and storage in a global user exit program. It is not a complete program, but merely an example of entry and exit code for any global user exit program, and the use of the XPI function.
XPI syntax
The XPI functions use special syntax. The description of each function defines only the options that are specific to that call.

Parent topic: Customizing with user exit programs