;; server
(defvar *server* (jsonrpc:make-server))
(jsonrpc:expose *server* "sum" (lambda (args) (reduce #'+ args)))

(jsonrpc:server-listen *server* :port 50879 :mode :tcp)

;; client
(defvar *client* (jsonrpc:make-client))
(jsonrpc:client-connect *client* :url "http://127.0.0.1:50879" :mode :tcp)
(jsonrpc:call *client* "sum" '(10 20))
;=> 30

;; Calling with :timeout option
(jsonrpc:call *client* "sum" '(10 20) :timeout 1.0)
;=> 30