Here is suggestion to use KEKS codec with a simple client-server
Remote Procedure Call interface. It is very similar to
=> https://www.jsonrpc.org/ JSON-RPC
=> https://github.com/msgpack-rpc/msgpack-rpc MessagePack-RPC

Call, reply and notify message headers ([schema/tcl] format):

<<    [schemas/rpc.tcl]

It is advisable to use UUIDv7 for call/notify's id.
Reply's id must be the same as in corresponding call.
Empty error string means no error occurred.

Notification differs only by its type and no reply expectation.
