JSON-RPC

JSON-RPC is a remote procedure call protocol encoded in JSON. It is similar to the XML-RPC protocol, defining only a few data types and commands. JSON-RPC allows for notifications (data sent to the server that does not require a response) and for multiple calls to be sent to the server which may be answered asynchronously.

stdioを使ったプロセス間通信でやり取りするケースが多い。

Haskellなら、System.Processを使ってゴニョれば良さそう。