REXX/CICS provides integrated client/server support to REXX execs by providing facilities to allow REXX execs to act as clients (which make requests to REXX/CICS servers) and by providing facilities to allow REXX execs to act as servers (with the ability to wait for and process requests from REXX/CICS clients).
REXX/CICS facilities are provided which allow REXX/CICS servers to wait on requests from clients (WAITREQ), and to retrieve (C2S) and set (S2C) the contents of client REXX variables.
Servers use Automatic Server Initiation (ASI) to start automatically when they receive their first request.