Some proprietary protocols are easier to implement than open ones. The other day I wrote against one API server that just accepts messages in json format over an ssl socket. It was maybe 3 or 4 lines of python? (Not counting setting up the connection) and probably wouldn’t have been bad in C. For the shell you could use OpenSSL s_connect and something to generate json (awk or echo would probably be enough since it was all flat dictionaries of strings.)

> There were small errors in their documentation of how things actually worked.

that sucks, but I’ve run into that with people speaking “http” and not just special protocols.