OkGraphql okGraphql = new OkGraphql.Builder()
                .okClient(okHttpClient)
                .baseUrl("http://192.168.1.16:8888/graphql")
                .converter(new GsonConverter(new Gson()))
                .build();

okGraphql
        .query("{" +
                "  hero {" +
                "    name" +
                "  }" +
                "}"
        )
        .enqueue(responseString -> {
            //play with your responseString
        }, error -> {
            //display the error
        });

class Character {
     String name;
}
   
class StarWarsResponse {
   Character hero;  
}

okGraphql
        .query("{" +
                "  hero {" +
                "    name" +
                "  }" +
                "}"
        )
        
        .cast(StarWarsResponse.class) //will automatically cast the data json to

        .enqueue(response -> {
            //play with your StarWarsResponse
        }, error -> {
            //display the error
        });

okGraphql
         .query(
                 "Hero($episode: Episode, $withFriends: Boolean!) {" +
                         "  hero(episode: $episode) {" +
                         "    name" +
                         "    friends @include(if: $withFriends) {" +
                         "      name" +
                         "    }" +
                         "  }"
         )

         .variable("episode", "JEDI")
         .variable("withFriends", false)

         .cast(StarWarsResponse.class) //will automatically cast the data json to
         
         .toSingle()
         .observeOn(AndroidSchedulers.mainThread())
         .subscribe(
                 data -> textView.setText(data.toString()),
                 throwable -> textView.setText(throwable.getLocalizedMessage())
         );

okGraphql

      .query(newField()
              .field(newField("human").argument("id: \"1000\"")
                      .field("name")
                      .field("height")
              )
      )
      
      ...

 okGraphql
          .mutation("CreateReviewForEpisode($ep: Episode!, $review: ReviewInput!) {" +
                  "  createReview(episode: $ep, review: $review) {" +
                  "    stars" +
                  "    commentary" +
                  "  }" +
                  "}")
          .variable("ep", "JEDI")
          .variable("review", "{ \"stars\": 5, \"commentary\": \"This is a great movie!\"")
          .enqueue(responseString -> {
              text1.setText(responseString);
          }, error -> {
              text1.setText(error.getLocalizedMessage());
          });

okGraphql

                .body("{" +
                        "  leftComparison: hero(episode: EMPIRE) {" +
                        "    ...comparisonFields" +
                        "  }" +
                        "  rightComparison: hero(episode: JEDI) {" +
                        "    ...comparisonFields" +
                        "  }" +
                        "}"
                )

                .fragment("comparisonFields on Character {" +
                        "  name" +
                        "  appearsIn" +
                        "  friends {" +
                        "    name" +
                        "  }" +
                        "}")

                .enqueue(responseString -> {
                    query_hero_enqueue.setText(responseString);
                }, error -> {
                    query_hero_enqueue.setText(error.getLocalizedMessage());
                });