I like the SPORE (Specification to a POrtable Rest Environment) approach better. You create a description file in JSON and each native language client can use that file to access the HTTP API. https://github.com/SPORE/specifications

SPORE already has clients for Clojure, Javascript, Lua, NodeJS, Perl, Python, and Ruby. I have used SPORE in a few projects and I was not disappointed. Another approach to solving the cross language library problem.