diff --git a/src/main/java/com/uber/cadence/converter/JsonDataConverter.java b/src/main/java/com/uber/cadence/converter/JsonDataConverter.java
index 72337cec3..aed0c91e5 100644
--- a/src/main/java/com/uber/cadence/converter/JsonDataConverter.java
+++ b/src/main/java/com/uber/cadence/converter/JsonDataConverter.java
@@ -28,6 +28,7 @@
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
+import com.uber.m3.tally.Scope;
 import java.io.IOException;
 import java.lang.reflect.Type;
 import java.nio.charset.StandardCharsets;
@@ -48,12 +49,22 @@ public final class JsonDataConverter implements DataConverter {
   private static final String TYPE_FIELD_NAME = "type";
   private static final String JSON_CONVERTER_TYPE = "JSON";
   private static final String CLASS_NAME_FIELD_NAME = "className";
+  private static Scope metricsScope;
   private final Gson gson;
 
   public static DataConverter getInstance() {
     return INSTANCE;
   }
 
+  /**
+   * Used to set the metrics scope for this class.
+   *
+   * @param metricsScope metrics scope to set
+   */
+  public static void setMetricsScope(Scope metricsScope) {
+    JsonDataConverter.metricsScope = metricsScope;
+  }
+
   private JsonDataConverter() {
     this((b) -> b);
   }
@@ -68,7 +79,7 @@ public JsonDataConverter(Function<GsonBuilder, GsonBuilder> builderInterceptor)
         new GsonBuilder()
             .serializeNulls()
             .registerTypeAdapterFactory(new ThrowableTypeAdapterFactory())
-            .registerTypeAdapterFactory(new TBaseTypeAdapterFactory())
+            .registerTypeAdapterFactory(new TBaseTypeAdapterFactory(metricsScope))
             .registerTypeAdapterFactory(new TEnumTypeAdapterFactory());
     GsonBuilder intercepted = builderInterceptor.apply(gsonBuilder);
     gson = intercepted.create();
diff --git a/src/main/java/com/uber/cadence/converter/TBaseTypeAdapterFactory.java b/src/main/java/com/uber/cadence/converter/TBaseTypeAdapterFactory.java
index c27580b4c..c2f4d2b5b 100644
--- a/src/main/java/com/uber/cadence/converter/TBaseTypeAdapterFactory.java
+++ b/src/main/java/com/uber/cadence/converter/TBaseTypeAdapterFactory.java
@@ -23,6 +23,7 @@
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
+import com.uber.m3.tally.Scope;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import org.apache.thrift.TBase;
@@ -30,6 +31,8 @@
 import org.apache.thrift.TException;
 import org.apache.thrift.TSerializer;
 import org.apache.thrift.protocol.TJSONProtocol;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Special handling of TBase message serialization and deserialization. This is to support for
@@ -37,6 +40,13 @@
  */
 public class TBaseTypeAdapterFactory implements TypeAdapterFactory {
 
+  private static final Logger logger = LoggerFactory.getLogger(TBaseTypeAdapterFactory.class);
+  private final Scope metricsScope;
+
+  public TBaseTypeAdapterFactory(Scope metricsScope) {
+    this.metricsScope = metricsScope;
+  }
+
   @Override
   public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
     // this class only serializes 'TBase' and its subtypes
@@ -47,10 +57,16 @@ public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
         new TypeAdapter<T>() {
           @Override
           public void write(JsonWriter jsonWriter, T value) throws IOException {
+            if (metricsScope != null) {
+              metricsScope.counter("tbase_message_write").inc(1);
+            }
             try {
               String result =
                   newThriftSerializer().toString((TBase) value, StandardCharsets.UTF_8.name());
               jsonWriter.value(result);
+              logger.warn(
+                  "TBase message will no longer be support in cadence-java-client V4, payload {}",
+                  result);
             } catch (TException e) {
               throw new DataConverterException("Failed to serialize TBase", e);
             }
@@ -58,8 +74,14 @@ public void write(JsonWriter jsonWriter, T value) throws IOException {
 
           @Override
           public T read(JsonReader jsonReader) throws IOException {
+            if (metricsScope != null) {
+              metricsScope.counter("tbase_message_read").inc(1);
+            }
             String value = jsonReader.nextString();
             try {
+              logger.warn(
+                  "TBase message will no longer be support in cadence-java-client V4, payload {}",
+                  value);
               @SuppressWarnings("unchecked")
               T instance = (T) typeToken.getRawType().getConstructor().newInstance();
               newThriftDeserializer()
diff --git a/src/main/java/com/uber/cadence/worker/WorkerFactory.java b/src/main/java/com/uber/cadence/worker/WorkerFactory.java
index 06113e067..c5f9ef93c 100644
--- a/src/main/java/com/uber/cadence/worker/WorkerFactory.java
+++ b/src/main/java/com/uber/cadence/worker/WorkerFactory.java
@@ -24,6 +24,7 @@
 import com.uber.cadence.PollForDecisionTaskResponse;
 import com.uber.cadence.client.WorkflowClient;
 import com.uber.cadence.converter.DataConverter;
+import com.uber.cadence.converter.JsonDataConverter;
 import com.uber.cadence.internal.common.InternalUtils;
 import com.uber.cadence.internal.metrics.MetricsTag;
 import com.uber.cadence.internal.replay.DeciderCache;
@@ -107,6 +108,9 @@ public WorkerFactory(WorkflowClient workflowClient, WorkerFactoryOptions factory
       return;
     }
 
+    // initialize the JsonDataConverter with the metrics scope
+    JsonDataConverter.setMetricsScope(workflowClient.getOptions().getMetricsScope());
+
     Scope stickyScope =
         workflowClient
             .getOptions()