Handle inconsistent API response with Retrofit

You will have to write custom deserializer or register a type adapter as explained in this -

https://sites.google.com/site/gson/gson-user-guide#TOC-Custom-Serialization-and-Deserialization

Try to do by using TypeAdapterFactory. Sample of that class as shown below.

public class ItemTypeAdapterFactory implements TypeAdapterFactory {    @Override    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {        final TypeAdapter<T> delegate = gson.getDelegateAdapter(this, type);        final TypeAdapter<JsonElement> elementAdapter = gson.getAdapter(JsonElement.class);        return new TypeAdapter<T>() {            public void write(JsonWriter out, T value) throws IOException {                delegate.write(out, value);            }            public T read(JsonReader in) throws IOException {                JsonElement jsonElement = elementAdapter.read(in);                if (jsonElement.isJsonObject()) {                    JsonObject jsonObject = jsonElement.getAsJsonObject();                    if (jsonObject.has("data") && jsonObject.get("data").isJsonObject()) {                        jsonElement = jsonObject.get("data");                    }                }                return delegate.fromJsonTree(jsonElement);            }        }.nullSafe();    }}

And this Gson into RestAdapter

final Gson gson = new GsonBuilder().registerTypeAdapterFactory(new ItemTypeAdapterFactory()).create();final Client client = new OkClient(new OkHttpClient());final RestAdapter restAdapter = new RestAdapter.Builder().setClient(client).setLogLevel(RestAdapter.LogLevel.FULL).setConverter(new GsonConverter(gson)).setEndpoint(context.getString(R.string.base_url)).build();