diff --git a/openmessaging-api/src/main/java/io/openmessaging/api/Producer.java b/openmessaging-api/src/main/java/io/openmessaging/api/Producer.java
index 76573660..ed5595a7 100644
--- a/openmessaging-api/src/main/java/io/openmessaging/api/Producer.java
+++ b/openmessaging-api/src/main/java/io/openmessaging/api/Producer.java
@@ -16,13 +16,15 @@
  */
 package io.openmessaging.api;
 
+import java.util.Properties;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+
 import io.openmessaging.api.exception.OMSDestinationException;
 import io.openmessaging.api.exception.OMSMessageFormatException;
 import io.openmessaging.api.exception.OMSRuntimeException;
 import io.openmessaging.api.exception.OMSSecurityException;
 import io.openmessaging.api.exception.OMSTimeOutException;
-import java.util.Properties;
-import java.util.concurrent.ExecutorService;
 
 /**
  * A {@code Producer} is a simple object used to send messages on behalf of a {@code MessagingAccessPoint}. An instance
@@ -43,6 +45,23 @@
  */
 public interface Producer extends Admin {
 
+    /**
+     * Get metadata about the partitions for a given topic. This method will issue a remote call to the server if it
+     * does not already have any metadata about the given topic.
+     *
+     * @param topic
+     * @return
+     */
+    Set<TopicPartition> topicPartitions(String topic);
+
+    /**
+     * Register a callback for sensing topic metadata changes.
+     *
+     * @param topic
+     * @param callback
+     */
+    void registerTopicPartitionChangedListener(String topic, TopicPartitionChangeListener callback);
+
     /**
      * Sends a message to the specified destination synchronously, the destination should be preset to {@link
      * Message#setTopic(String)}, other header fields as well.
@@ -57,6 +76,20 @@ public interface Producer extends Admin {
      */
     SendResult send(final Message message);
 
+    /**
+     * Sends a message to the specified partition synchronously.
+     *
+     * @param message a message will be sent.
+     * @param topicPartition {@link TopicPartition}.
+     * @return the successful {@code SendResult}.
+     * @throws OMSSecurityException when have no authority to send messages to a given destination.
+     * @throws OMSMessageFormatException when an invalid message is specified.
+     * @throws OMSTimeOutException when the given timeout elapses before the send operation completes.
+     * @throws OMSDestinationException when have no given destination in the server.
+     * @throws OMSRuntimeException when the {@code Producer} fails to send the message due to some internal error.
+     */
+    SendResult send(final Message message, TopicPartition topicPartition);
+
     /**
      * <p>
      * There is no {@code Promise} related or {@code RuntimeException} thrown. The calling thread doesn't care about the
@@ -66,6 +99,16 @@ public interface Producer extends Admin {
      */
     void sendOneway(final Message message);
 
+    /**
+     * <p>
+     * There is no {@code Promise} related or {@code RuntimeException} thrown. The calling thread doesn't care about the
+     * send result and also have no context to get the result.
+     *
+     * @param message a message will be sent.
+     * @param topicPartition {@link TopicPartition}.
+     */
+    void sendOneway(final Message message, TopicPartition topicPartition);
+
     /**
      * Sends a message to the specified destination asynchronously, the destination should be preset to {@link
      * Message#setTopic(String)}, other header fields as well.
@@ -78,6 +121,18 @@ public interface Producer extends Admin {
      */
     void sendAsync(final Message message, final SendCallback sendCallback);
 
+    /**
+     * Sends a message to the specified partition asynchronously.
+     * <p>
+     * The returned {@code Promise} will have the result once the operation completes, and the registered {@link
+     * SendCallback} will be invoked, either because the operation was successful or because of an error.
+     *
+     * @param message a message will be sent.
+     * @param topicPartition {@link TopicPartition}.
+     * @param sendCallback {@link SendCallback}
+     */
+    void sendAsync(final Message message, TopicPartition topicPartition, final SendCallback sendCallback);
+
     /**
      * Set call back excutor
      * @param callbackExecutor
diff --git a/openmessaging-api/src/main/java/io/openmessaging/api/TopicPartitionChangeListener.java b/openmessaging-api/src/main/java/io/openmessaging/api/TopicPartitionChangeListener.java
new file mode 100644
index 00000000..36c1bced
--- /dev/null
+++ b/openmessaging-api/src/main/java/io/openmessaging/api/TopicPartitionChangeListener.java
@@ -0,0 +1,13 @@
+package io.openmessaging.api;
+
+import java.util.Set;
+
+public interface TopicPartitionChangeListener {
+    /**
+     * This method will be invoked in the condition of partition numbers changed, These scenarios occur when the
+     * topic is expanded or shrunk.
+     *
+     * @param topicPartitions
+     */
+    void onChanged(Set<TopicPartition> topicPartitions);
+}
\ No newline at end of file