Retrofit 2 Synchronous Adapter A synchronous CallAdapter.Factory implementation for Retrofit 2. This project brings Retrofit 1's synchronous usage to Retrofit 2. Usage // Setup retrofit Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.example.com") .addCallAdapterFactory(SynchronousCallAdapterFactory.create()) .build(); // Create your service interface Service { @GET("/") ApiResponse response(); // Return type directly @GET("/") Response responseApi(