@Override
  public Object decode(Response response, Type type)
      throws IOException, DecodeException, FeignException {
    final RequestTemplate template = response.request().requestTemplate();
    final MeteredBody body = response.body() == null ? null : new MeteredBody(response.body());

    response = response.toBuilder().body(body).build();

    final Object decoded;
    try (final Timer.Context classTimer =
        metricRegistry
            .timer(
                MetricRegistry.name(
                    metricName.metricName(template.methodMetadata(), template.feignTarget()),
                    "uri",
                    template.methodMetadata().template().path()),
                metricSuppliers.timers())
            .time()) {
      decoded = decoder.decode(response, type);
    }

    if (body != null) {
      metricRegistry
          .histogram(
              metricName.metricName(
                  template.methodMetadata(), template.feignTarget(), "response_size"),
              metricSuppliers.histograms())
          .update(body.count());
    }

    return decoded;
  }
Warp feign {@link Decoder} with metrics.
dropwizard-metrics4/src/main/java/feign/metrics4/MeteredDecoder.java