Linux client written in C. Can be build with the added Makefile for linux.
Depends on libcurl (+ssl) https://curl.haxx.se and json-c https://github.com/json-c/json-c

Gentoo:
https://packages.gentoo.org/packages/net-misc/curl
https://packages.gentoo.org/packages/dev-libs/json-c

Fedora:
https://packages.fedoraproject.org/pkgs/json-c/json-c-devel/
https://packages.fedoraproject.org/pkgs/curl/libcurl-devel/

Debian:
https://packages.debian.org/search?keywords=libcurl4-openssl-dev
https://packages.debian.org/search?keywords=json-c