An application programmer writes a client program, adding calls to Client-Library functions to set up control structures, connect to servers, send commands, process results, and clean up. A Client-Library program is compiled, linked, and run in the same way as any other C program under CICS or IMS TM.
An application program can act as both client and server.
Such a program, called a mixed-mode program, contains both Client-Library
calls to send requests and Gateway-Library calls to accept and process
requests. For more information, as well as an example of a mixed-mode
program, see the Mainframe Connect Server Option Programmer’s
Reference for COBOL.