Question about cross platform library

Hello!
I have task. I need develop cross platform SDK for working by HTTP.
Example:

send request by http
< return filled Class response

But, i wanna integrate this SDK to already written native apps (objc and java projects).

How i can do it?

like that on go lang

There are many options to achieve this. Retrofit is a popular library, already proven to work with MOE:

http://square.github.io/retrofit/

hm, i mean:
Write in MOE and “compile” like framework for iOS / macOS