Communication via RPC

How can I send and receive data via RPC? I haven’t found any RPC libraries for Elixir. Can I instead use an http library?

you have the erlang rpc library

For example:, module, fun, args)

More info:

$ erl -man rpc

Can I do that via an http client such as HttpPoison by providing all necessary headers and body?

No. This is a pure erlang/elixir solution which can do RPC between erlang/elixir nodes.

I guess I am not quite sure exactly what you are after? xml-rpc? soap?

I have an external command line application. Not Erlang/Elixir. And it has RPC interface. I’m able to call its RPC methods via curl Thus I should be able to do the same thing via any http client in Elixir?

Yes, any elixir/erlang HTTP client will work.
HttpPoison as you mentioned. You also have the built-in erlang httpc client if you want to avoid dependencies.