Retrofit ships with support for OkHttp's RequestBody and ResponseBody types but the library is content-format agnostic. The child modules contained herein are additional converters for other popular formats.

To use, supply an instance of your desired converter when building your Retrofit instance.

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.example.com")
    .addConverterFactory(GsonConverterFactory.create())
    .build();