>The fact that there isn't even a client for the world's most popular search database is indicative of the ecosystem as a whole.
It indicates that you haven't written one? That's a rather strange attitude, for sure it doesn't have a wrapper for any rest api, what it has is all needed tools for write it, that's what really matters. The tool in repo above does not even use a library, only generated bindings. It's much easier to write a client to a rest api in OCaml than in Go due to derivers [1], atdgen [2] and the power of the language. Take a look at graphql bindings as an example [3] [4].