diff --git a/VERSION b/VERSION
index 8294c18..7693c96 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.1.2
\ No newline at end of file
+0.1.3
\ No newline at end of file
diff --git a/deepracer_env/__init__.py b/deepracer_env/__init__.py
index 4fd11e0..0a61e7d 100644
--- a/deepracer_env/__init__.py
+++ b/deepracer_env/__init__.py
@@ -14,7 +14,7 @@
 #   limitations under the License.                                              #
 #################################################################################
 """DeepRacerEnv modules"""
-from .deepracer_env import DeepRacerEnv
+from .deepracer_env import DeepRacerEnv, DeepRacerEnvObserverInterface
 
 """DeepRacer Environment Config modules"""
 from deepracer_env_config import TrackDirection
diff --git a/deepracer_env/deepracer_env.py b/deepracer_env/deepracer_env.py
index 1ace985..13cc2fa 100644
--- a/deepracer_env/deepracer_env.py
+++ b/deepracer_env/deepracer_env.py
@@ -16,6 +16,7 @@
 """A class for DeepRacerEnv environment."""
 from typing import Dict, Optional, List, Tuple, Any, FrozenSet, Union
 import math
+from threading import RLock
 
 from gym import Space
 
@@ -32,6 +33,43 @@
 )
 
 
+class DeepRacerEnvObserverInterface(object):
+    """
+    DeepRacerEnv Observer Interface
+    """
+    def on_step(self, env: 'DeepRacerEnv', step_result: UDEStepResult) -> None:
+        """
+        On Step callback.
+        - Called after step completed.
+
+        Args:
+            env (DeepRacerEnv): DeepRacer environment.
+            step_result (UDEStepResult): step result (obs, reward, done, last action, info)
+        """
+        pass
+
+    def on_reset(self, env: 'DeepRacerEnv', reset_result: UDEResetResult) -> None:
+        """
+        On Reset callback.
+        - Called after reset completed.
+
+        Args:
+            env (DeepRacerEnv): DeepRacer environment.
+            reset_result (UDEResetResult): reset result (obs, info)
+        """
+        pass
+
+    def on_close(self, env: 'DeepRacerEnv') -> None:
+        """
+        On Close callback.
+        - Called after close completed.
+
+        Args:
+            env (DeepRacerEnv): DeepRacer environment.
+        """
+        pass
+
+
 class DeepRacerEnv(UDEEnvironmentInterface):
     """
     DeepRacerEnv Class.
@@ -76,6 +114,28 @@ def __init__(self,
         area_config = self._deepracer_config.get_area()
         self._track_names = area_config.track_names
         self._shell_names = area_config.shell_names
+        self._observer_lock = RLock()
+        self._observers = set()
+
+    def register(self, observer: DeepRacerEnvObserverInterface) -> None:
+        """
+        Register given observer.
+
+        Args:
+            observer (DeepRacerEnvObserverInterface): observer
+        """
+        with self._observer_lock:
+            self._observers.add(observer)
+
+    def unregister(self, observer: DeepRacerEnvObserverInterface) -> None:
+        """
+        Unregister given observer.
+
+        Args:
+            observer (DeepRacerEnvObserverInterface): observer to discard
+        """
+        with self._observer_lock:
+            self._observers.discard(observer)
 
     def step(self, action_dict: MultiAgentDict) -> UDEStepResult:
         """
@@ -101,7 +161,13 @@ def step(self, action_dict: MultiAgentDict) -> UDEStepResult:
                math.isnan(speed) or math.isinf(speed):
                 raise ValueError("Agent's action value cannot contain nan or inf: {{}: {}}".format(agent_id,
                                                                                                    action))
-        return self._env.step(action_dict=action_dict)
+        step_result = self._env.step(action_dict=action_dict)
+
+        with self._observer_lock:
+            observers = self._observers.copy()
+        for observer in observers:
+            observer.on_step(env=self, step_result=step_result)
+        return step_result
 
     def reset(self) -> UDEResetResult:
         """
@@ -111,13 +177,23 @@ def reset(self) -> UDEResetResult:
         Returns:
             UDEResetResult: first observation and info in new episode.
         """
-        return self._env.reset()
+        reset_result = self._env.reset()
+
+        with self._observer_lock:
+            observers = self._observers.copy()
+        for observer in observers:
+            observer.on_reset(env=self, reset_result=reset_result)
+        return reset_result
 
     def close(self) -> None:
         """
         Close the environment, and environment will be no longer available to be used.
         """
-        return self._env.close()
+        self._env.close()
+        with self._observer_lock:
+            observers = self._observers.copy()
+        for observer in observers:
+            observer.on_close(env=self)
 
     @property
     def observation_space(self) -> Dict[AgentID, Space]:
diff --git a/test/deepracer_env/test_deepracer_env.py b/test/deepracer_env/test_deepracer_env.py
index e8eecfd..13aaa6c 100644
--- a/test/deepracer_env/test_deepracer_env.py
+++ b/test/deepracer_env/test_deepracer_env.py
@@ -20,13 +20,26 @@
 
 import math
 
-from deepracer_env import DeepRacerEnv
-from ude import Compression
-
+from deepracer_env import DeepRacerEnv, DeepRacerEnvObserverInterface
+from ude import Compression, UDEResetResult, UDEStepResult
 
 myself: Callable[[], Any] = lambda: inspect.stack()[1][3]
 
 
+class DummyObserver(DeepRacerEnvObserverInterface):
+    def __init__(self):
+        self.mock = MagicMock()
+
+    def on_step(self, env: 'DeepRacerEnv', step_result: UDEStepResult) -> None:
+        self.mock.on_step(env=env, step_result=step_result)
+
+    def on_reset(self, env: 'DeepRacerEnv', reset_result: UDEResetResult) -> None:
+        self.mock.on_reset(env=env, reset_result=reset_result)
+
+    def on_close(self, env: 'DeepRacerEnv') -> None:
+        self.mock.on_close(env=env)
+
+
 @patch("deepracer_env.deepracer_env.Client")
 @patch("deepracer_env.deepracer_env.UDEEnvironment")
 @patch("deepracer_env.deepracer_env.RemoteEnvironmentAdapter")
@@ -94,6 +107,31 @@ def test_initialize_with_param(self,
         assert env.track_names == deepracer_config_mock.return_value.get_area.return_value.track_names
         assert env.shell_names == deepracer_config_mock.return_value.get_area.return_value.shell_names
 
+    def test_register(self,
+                      remote_env_adapter_mock,
+                      ude_env_mock,
+                      deepracer_config_mock):
+        address = "test_ip"
+        env = DeepRacerEnv(address=address)
+        observer_mock = DummyObserver()
+        env.register(observer=observer_mock)
+
+        assert observer_mock in env._observers
+
+    def test_unregister(self,
+                        remote_env_adapter_mock,
+                        ude_env_mock,
+                        deepracer_config_mock):
+        address = "test_ip"
+        env = DeepRacerEnv(address=address)
+        observer_mock = DummyObserver()
+        env.register(observer=observer_mock)
+
+        assert observer_mock in env._observers
+
+        env.unregister(observer=observer_mock)
+        assert observer_mock not in env._observers
+
     def test_step(self,
                   remote_env_adapter_mock,
                   ude_env_mock,
@@ -136,7 +174,6 @@ def test_step_ignore_more_than_two_value(self,
         ude_env_mock.return_value.step.assert_called_once_with(action_dict=expected_action_dict)
         assert step_result == ude_env_mock.return_value.step.return_value
 
-
     def test_step_nan_or_inf(self,
                              remote_env_adapter_mock,
                              ude_env_mock,
@@ -168,6 +205,23 @@ def test_step_nan_or_inf(self,
         with self.assertRaises(ValueError):
             _ = env.step(action_dict=action_dict)
 
+    def test_step_with_observer(self,
+                                remote_env_adapter_mock,
+                                ude_env_mock,
+                                deepracer_config_mock):
+        address = "test_ip"
+
+        env = DeepRacerEnv(address=address)
+        observer_mock = DummyObserver()
+        env.register(observer=observer_mock)
+
+        action_dict = {"agent1": (1.0, 2.0)}
+
+        step_result = env.step(action_dict=action_dict)
+        ude_env_mock.return_value.step.assert_called_once_with(action_dict=action_dict)
+        assert step_result == ude_env_mock.return_value.step.return_value
+        observer_mock.mock.on_step.assert_called_once_with(env=env,
+                                                           step_result=step_result)
 
     def test_reset(self,
                    remote_env_adapter_mock,
@@ -179,6 +233,21 @@ def test_reset(self,
         ude_env_mock.return_value.reset.assert_called_once()
         assert reset_result == ude_env_mock.return_value.reset.return_value
 
+    def test_reset_with_observer(self,
+                                 remote_env_adapter_mock,
+                                 ude_env_mock,
+                                 deepracer_config_mock):
+        address = "test_ip"
+        env = DeepRacerEnv(address=address)
+        observer_mock = DummyObserver()
+        env.register(observer=observer_mock)
+
+        reset_result = env.reset()
+        ude_env_mock.return_value.reset.assert_called_once()
+        assert reset_result == ude_env_mock.return_value.reset.return_value
+        observer_mock.mock.on_reset.assert_called_once_with(env=env,
+                                                            reset_result=reset_result)
+
     def test_close(self,
                    remote_env_adapter_mock,
                    ude_env_mock,
@@ -188,6 +257,18 @@ def test_close(self,
         env.close()
         ude_env_mock.return_value.close.assert_called_once()
 
+    def test_close_with_observer(self,
+                                 remote_env_adapter_mock,
+                                 ude_env_mock,
+                                 deepracer_config_mock):
+        address = "test_ip"
+        env = DeepRacerEnv(address=address)
+        observer_mock = DummyObserver()
+        env.register(observer=observer_mock)
+        env.close()
+        ude_env_mock.return_value.close.assert_called_once()
+        observer_mock.mock.on_close.assert_called_once_with(env=env)
+
     def test_observation_space(self,
                                remote_env_adapter_mock,
                                ude_env_mock,