Before this package was adopted by a new author, I believe it was a good option for dealing with JSONRPC APIs. As it stands now, people writing Perl client software for JSONRPC are not as well served as they used to be. The module has deprecated JSON::RPC::Client, renamed that to JSON::RPC::Legacy::Client and pegged it to JSONRPC v1. I would guess that more people write client code than set up servers, so this is an odd direction to go. Such is life, however.
I recently needed to write some code to communicate with a production service that offers a JSONRPC v2 interface. Looking around, the best option I could find was LWP::UserAgent + JSON::RPC2. Based on prior experience with JSON::RPC I had not expected to roll my own client, and I was not particularly happy about it. I have not rated this package since I did not use it, and just leaving this as a comment.