diff --git a/ask-sdk-core/lib/util/RequestEnvelopeUtils.ts b/ask-sdk-core/lib/util/RequestEnvelopeUtils.ts
index a97f2f84..5ba2e720 100644
--- a/ask-sdk-core/lib/util/RequestEnvelopeUtils.ts
+++ b/ask-sdk-core/lib/util/RequestEnvelopeUtils.ts
@@ -108,7 +108,7 @@ export function getApiAccessToken(requestEnvelope : RequestEnvelope) : string {
  * @return {string}
  */
 export function getDeviceId(requestEnvelope : RequestEnvelope) : string {
-    return requestEnvelope.context.System.device.deviceId;
+    return requestEnvelope.context.System.device ? requestEnvelope.context.System.device.deviceId : null;
 }
 
 /**
diff --git a/ask-sdk-core/tst/util/RequestEnvelopeUtil.spec.ts b/ask-sdk-core/tst/util/RequestEnvelopeUtil.spec.ts
index 62bb6b20..6021dcf6 100644
--- a/ask-sdk-core/tst/util/RequestEnvelopeUtil.spec.ts
+++ b/ask-sdk-core/tst/util/RequestEnvelopeUtil.spec.ts
@@ -64,6 +64,9 @@ describe('RequestEnvelopeUtils', () => {
     const outOfSessionRequest : RequestEnvelope = JsonProvider.requestEnvelope();
     delete outOfSessionRequest.session;
 
+    const requestEnvelopeWithNoDevice : RequestEnvelope = JsonProvider.requestEnvelope();
+    delete requestEnvelopeWithNoDevice.context.System.device;
+
     it('should be able to get locale', () => {
         expect(getLocale(requestEnvelope)).eq('en-US');
     });
@@ -94,6 +97,10 @@ describe('RequestEnvelopeUtils', () => {
         expect(getDeviceId(requestEnvelope)).eq('mockDeviceId');
     });
 
+    it('should return null if there is no device info', () => {
+        expect(getDeviceId(requestEnvelopeWithNoDevice)).eq(null);
+    });
+
     it('should be able to get dialog state', () => {
         expect(getDialogState(intentRequestEnvelope)).eq('STARTED');
     });
diff --git a/ask-sdk-dynamodb-persistence-adapter/package.json b/ask-sdk-dynamodb-persistence-adapter/package.json
index 16aff15b..f25fbe5a 100644
--- a/ask-sdk-dynamodb-persistence-adapter/package.json
+++ b/ask-sdk-dynamodb-persistence-adapter/package.json
@@ -34,7 +34,7 @@
     "@types/mocha": "^5.0.0",
     "@types/node": "^9.6.1",
     "ask-sdk-core": "^2.5.1",
-    "ask-sdk-model": "^1.0.0",
+    "ask-sdk-model": "^1.9.0",
     "aws-sdk-mock": "^4.1.0",
     "chai": "^4.1.2",
     "del": "^3.0.0",
diff --git a/ask-sdk-s3-persistence-adapter/package.json b/ask-sdk-s3-persistence-adapter/package.json
index 9cd1be6f..9d3ed0d6 100644
--- a/ask-sdk-s3-persistence-adapter/package.json
+++ b/ask-sdk-s3-persistence-adapter/package.json
@@ -30,7 +30,7 @@
     "@types/mocha": "^5.0.0",
     "@types/node": "^9.6.1",
     "ask-sdk-core": "^2.5.1",
-    "ask-sdk-model": "^1.0.0",
+    "ask-sdk-model": "^1.9.0",
     "aws-sdk-mock": "^4.1.0",
     "chai": "^4.1.2",
     "del": "^3.0.0",
diff --git a/docs/en/ASK-SDK-Utilities.rst b/docs/en/ASK-SDK-Utilities.rst
new file mode 100644
index 00000000..46fc4dc9
--- /dev/null
+++ b/docs/en/ASK-SDK-Utilities.rst
@@ -0,0 +1,54 @@
+*****************
+ASK SDK Utilities
+*****************
+
+The SDK provides mutiple utility functions that aims to reduce boilerplate code so that you can focus on skill business logic.
+
+RequestEnvelopeUtils
+====================
+
+The ``RequestEnvelopeUtils`` provides functions for getting frequently used attributes from the ``RequestEnvelope`` with error checking logic.
+
+Available Methods
+-----------------
+
+.. code-block:: typescript
+
+    getLocale(requestEnvelope: RequestEnvelope): string;
+    getRequestType(requestEnvelope: RequestEnvelope): string;
+    getIntentName(requestEnvelope: RequestEnvelope): string;
+    getAccountLinkingAccessToken(requestEnvelope: RequestEnvelope): string;
+    getApiAccessToken(requestEnvelope: RequestEnvelope): string;
+    getDeviceId(requestEnvelope: RequestEnvelope): string;
+    getDialogState(requestEnvelope: RequestEnvelope): string;
+    getSlot(requestEnvelope: RequestEnvelope, slotName: string): Slot;
+    getSlotValue(requestEnvelope: RequestEnvelope, slotName: string): string;
+    getSupportedInterfaces(requestEnvelope: RequestEnvelope): SupportedInterfaces;
+    isNewSession(requestEnvelope: RequestEnvelope): boolean;
+
+SsmlUtils
+=========
+
+The ``SsmlUtils`` provides a function for escaping invalid SSML characters in a speech string.
+
+Available Methods
+-----------------
+
+.. code-block:: typescript
+
+    escapeXmlCharacters(input: string): string
+
+ViewportUtils
+=============
+
+The ``ViewportUtils`` provides functions for checking the viewport profile and other device characteristics such as display size or dpi in the ``RequestEnvelope``.
+
+Available Methods
+-----------------
+
+.. code-block:: typescript
+
+    getViewportOrientation(width: number, height: number): ViewportOrientation;
+    getViewportSizeGroup(size: number): ViewportSizeGroup;
+    getViewportDpiGroup(dpi: number): ViewportDpiGroup;
+    getViewportProfile(requestEnvelope: RequestEnvelope): ViewportProfile;
\ No newline at end of file
diff --git a/docs/en/index.rst b/docs/en/index.rst
index 68c11f26..ec8e35a7 100644
--- a/docs/en/index.rst
+++ b/docs/en/index.rst
@@ -15,6 +15,7 @@
    Managing-Attributes
    Calling-Alexa-Service-APIs
    Configuring-Skill-Instance
+   ASK-SDK-Utilities
 
 .. toctree::
    :caption: TYPEDOC REFERENCE
@@ -135,6 +136,11 @@ Covers how to use service clients in your skill to access Alexa APIs.
 
 Covers how to configure and construct a skill instance.
 
+`ASK SDK Utilities`_
+--------------------
+
+Covers how to use utility function provided by ASK SDK
+
 
 Got Feedback?
 =============
@@ -149,3 +155,4 @@ Request and vote for Alexa features `here <https://alexa.uservoice.com/forums/90
 .. _Managing Attributes: Managing-Attributes.html
 .. _Calling Alexa Service APIs: Calling-Alexa-Service-APIs.html
 .. _Configuring Skill Instance: Configuring-Skill-Instance.html
+.. _ASK SDK Utilities: ASK-SDK-Utilities.html