diff --git a/config/firebase/keys.json b/config/firebase/keys.json
new file mode 100644
index 0000000..51d5a14
--- /dev/null
+++ b/config/firebase/keys.json
@@ -0,0 +1,3 @@
+{
+  "SERVER_KEY": ""
+}
diff --git a/models/user/index.js b/models/user/index.js
index 45ef318..96c4674 100755
--- a/models/user/index.js
+++ b/models/user/index.js
@@ -8,6 +8,30 @@ const User = require('../../services/mongo').registerModel(__dirname, 'User');
 export default User;
 
 export const createUser = async (params: any = {}) => new User(params).save();
+/**
+ * Returns an Array of distinct values of the field passed.
+ * @param  {String} field -The field whose distinct values are to be find.
+ * @param  {Object={}} filter -Filter for the query on whose distinct value is to be find.
+ */
+export const getDistinctUserFields = async (
+  field: string,
+  filter: object = {}
+) => {
+  const { promise, resolve, reject } = $q.defer();
+  User.distinct(field, filter, (err, res) => {
+    if (err) {
+      return reject(new ServerError(err));
+    } else if (!res.length) {
+      return reject(
+        new ResourceNotFoundError('No value exists for the field.')
+      );
+    }
+
+    return resolve(res);
+  });
+
+  return promise;
+};
 
 export const findUserByEmail = (email: string) => {
   const { promise, resolve, reject } = $q.defer();
diff --git a/models/user/src/user.js b/models/user/src/user.js
index b91944b..ceed8e1 100755
--- a/models/user/src/user.js
+++ b/models/user/src/user.js
@@ -71,6 +71,10 @@ const User = new mongoose.Schema({
   vendor: {
     type: ObjectId,
     ref: 'Vendor'
+  },
+  deviceId: {
+    type: ['string'],
+    default: []
   }
 });
 
diff --git a/package.json b/package.json
index d12c1b8..42da15d 100644
--- a/package.json
+++ b/package.json
@@ -27,11 +27,12 @@
     "cities": "^1.1.2",
     "crypto-js": "^3.1.9-1",
     "geocoder": "^0.2.3",
-    "grunt-cli": "0.1.13",
     "grunt": "~0.4.5",
+    "grunt-cli": "0.1.13",
     "https-proxy-agent": "^2.2.1",
     "mongoose": "^5.1.0",
     "node-fetch": "^2.1.2",
+    "node-gcm": "^1.0.2",
     "q": "^1.5.1"
   },
   "devDependencies": {
diff --git a/routes/user/update.js b/routes/user/update.js
index 850f985..3cdb222 100755
--- a/routes/user/update.js
+++ b/routes/user/update.js
@@ -41,6 +41,12 @@ module.exports = {
       city: {
         type: 'string',
         trim: true
+      },
+      deviceId: {
+        type: 'string'
+      },
+      newDeviceId: {
+        type: 'string'
       }
     }
   },
@@ -59,7 +65,25 @@ module.exports = {
   },
   async run(req: $Request, res: $Response) {
     try {
-      const user = await findAndUpdateUser({ _id: req.params.id }, req.body);
+      const query = {
+        _id: req.params.id
+      };
+      const updateQuery = {};
+      if (req.body.deviceId) {
+        query.deviceId = req.body.deviceId;
+        delete req.body.deviceId;
+        const newDeviceId = req.body.newDeviceId;
+        delete req.body.newDeviceId;
+        updateQuery.$set = Object.assign(
+          {
+            'deviceId.$': newDeviceId
+          },
+          req.body
+        );
+      } else {
+        updateQuery.$set = Object.assign(req.body);
+      }
+      const user = await findAndUpdateUser(query, updateQuery);
       res.$end(user);
     } catch (e) {
       log.warn('Failed to update user.', e);
diff --git a/services/firebase/index.js b/services/firebase/index.js
new file mode 100644
index 0000000..525789e
--- /dev/null
+++ b/services/firebase/index.js
@@ -0,0 +1 @@
+module.exports = require('./src/firebase');
diff --git a/services/firebase/src/firebase.js b/services/firebase/src/firebase.js
new file mode 100644
index 0000000..0f5ecab
--- /dev/null
+++ b/services/firebase/src/firebase.js
@@ -0,0 +1,49 @@
+import configLoader from 'alfred/services/configLoader';
+import { ServerError } from 'alfred/core/errors';
+import firebase from 'node-gcm';
+
+const config = {};
+const initialize = async () => {
+  await configLoader.init();
+  const firebaseConfig = configLoader.get('firebase');
+  config.serverKey = firebaseConfig.SERVER_KEY;
+};
+
+initialize();
+/**
+ * Sends push notification to the user for the registration IDs passed.
+ * @param  {Object} data = {} -This parameter specifies the custom key-value pairs of the message's payload. 
+ * @param  {Object} notification={} -This parameter specifies the predefined, user-visible key-value pairs of the notification payload.
+ * @param  {Array} registrationTokens=[] -A list of registration tokens Must contain at least 1 and at most 1000 registration tokens.
+ */
+const notify = async (
+  data = {},
+  notification = {},
+  registrationTokens = []
+) => {
+  // Prepare a message to be sent.
+  const sender = new firebase.Sender(config.serverKey);
+  const message = new firebase.Message({
+    data,
+    notification,
+    priority: 'high'
+  });
+  return new Promise((resolve, reject) => {
+    sender.send(
+      message,
+      {
+        registrationTokens
+      },
+      10, // Retrying a specific number of times (10)
+      (err, response) => {
+        if (err) {
+          reject(new ServerError(err));
+        } else {
+          resolve(response);
+        }
+      }
+    );
+  });
+};
+
+export { notify };
diff --git a/yarn.lock b/yarn.lock
index 9636bb4..45e919f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -191,7 +191,7 @@ ajv-keywords@^3.0.0:
   resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-3.2.0.tgz#e86b819c602cf8821ad637413698f1dec021847a"
   integrity sha1-6GuBnGAs+IIa1jdBNpjx3sAhhHo=
 
-ajv@^5.2.3, ajv@^5.3.0:
+ajv@^5.1.0, ajv@^5.2.3, ajv@^5.3.0:
   version "5.5.2"
   resolved "https://registry.yarnpkg.com/ajv/-/ajv-5.5.2.tgz#73b5eeca3fab653e3d3f9422b341ad42205dc965"
   integrity sha1-c7Xuyj+rZT49P5Qis0GtQiBdyWU=
@@ -569,7 +569,7 @@ aws-sign2@~0.7.0:
   resolved "https://registry.yarnpkg.com/aws-sign2/-/aws-sign2-0.7.0.tgz#b46e890934a9591f2d2f6f86d7e6a9f1b3fe76a8"
   integrity sha1-tG6JCTSpWR8tL2+G1+ap8bP+dqg=
 
-aws4@^1.2.1, aws4@^1.8.0:
+aws4@^1.2.1, aws4@^1.6.0, aws4@^1.8.0:
   version "1.8.0"
   resolved "https://registry.yarnpkg.com/aws4/-/aws4-1.8.0.tgz#f0e003d9ca9e7f59c7a508945d7b2ef9a04a542f"
   integrity sha512-ReZxvNHIOv88FlT7rxcXIIC0fPt4KZqZbOlivyWtXLt8ESx84zd3kMC6iK5jVeS2qt+g7ftS7ye4fi06X5rtRQ==
@@ -3007,7 +3007,7 @@ extend-shallow@^3.0.0, extend-shallow@^3.0.2:
     assign-symbols "^1.0.0"
     is-extendable "^1.0.1"
 
-extend@3, extend@~3.0.0, extend@~3.0.2:
+extend@3, extend@~3.0.0, extend@~3.0.1, extend@~3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/extend/-/extend-3.0.2.tgz#f8b1136b4071fbd8eb140aff858b1019ec2915fa"
   integrity sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==
@@ -3313,7 +3313,7 @@ form-data@~0.1.0:
     combined-stream "~0.0.4"
     mime "~1.2.11"
 
-form-data@~2.3.2:
+form-data@~2.3.1, form-data@~2.3.2:
   version "2.3.3"
   resolved "https://registry.yarnpkg.com/form-data/-/form-data-2.3.3.tgz#dcce52c05f644f298c6a7ab936bd724ceffbf3a6"
   integrity sha512-1lLKB2Mu3aGP1Q/2eCOx0fNbRMe7XdwktwOruhfqqd0rIJWwN4Dh+E3hrPSlDCXnSR7UtZ1N38rVXm+6+MEhJQ==
@@ -3817,6 +3817,14 @@ har-validator@~2.0.6:
     is-my-json-valid "^2.12.4"
     pinkie-promise "^2.0.0"
 
+har-validator@~5.0.3:
+  version "5.0.3"
+  resolved "https://registry.yarnpkg.com/har-validator/-/har-validator-5.0.3.tgz#ba402c266194f15956ef15e0fcf242993f6a7dfd"
+  integrity sha1-ukAsJmGU8VlW7xXg/PJCmT9qff0=
+  dependencies:
+    ajv "^5.1.0"
+    har-schema "^2.0.0"
+
 har-validator@~5.1.0:
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/har-validator/-/har-validator-5.1.0.tgz#44657f5688a22cfd4b72486e81b3a3fb11742c29"
@@ -5310,7 +5318,7 @@ micromatch@^3.1.10, micromatch@^3.1.4, micromatch@^3.1.8:
   resolved "https://registry.yarnpkg.com/mime-db/-/mime-db-1.37.0.tgz#0b6a0ce6fdbe9576e25f1f2d2fde8830dc0ad0d8"
   integrity sha512-R3C4db6bgQhlIhPU48fUtdVmKnflq+hRdad7IyKhtFj06VPNVdk2RhiYL3UjQIlso8L+YxAtFkobT0VK+S/ybg==
 
-mime-types@^2.1.11, mime-types@^2.1.12, mime-types@^2.1.3, mime-types@~2.1.18, mime-types@~2.1.19, mime-types@~2.1.6, mime-types@~2.1.7, mime-types@~2.1.9:
+mime-types@^2.1.11, mime-types@^2.1.12, mime-types@^2.1.3, mime-types@~2.1.17, mime-types@~2.1.18, mime-types@~2.1.19, mime-types@~2.1.6, mime-types@~2.1.7, mime-types@~2.1.9:
   version "2.1.21"
   resolved "https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.21.tgz#28995aa1ecb770742fe6ae7e58f9181c744b3f96"
   integrity sha512-3iL6DbwpyLzjR3xHSFNFeb9Nz/M8WDkX33t1GFQnFOllWk8pOrh/LSrB5OXlnlW5P9LH73X6loW/eogc+F5lJg==
@@ -5651,6 +5659,15 @@ node-forge@^0.6.20:
   resolved "https://registry.yarnpkg.com/node-forge/-/node-forge-0.6.49.tgz#f1ee95d5d74623938fe19d698aa5a26d54d2f60f"
   integrity sha1-8e6V1ddGI5OP4Z1piqWibVTS9g8=
 
+node-gcm@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/node-gcm/-/node-gcm-1.0.2.tgz#4e5828b9c92a7635302e0a5ff0952146299f9771"
+  integrity sha512-NEVb5jB06I/e9ZfJGWhHsRhJQLk1zO5iZjbQJ7su8j9vhHrpxc7KJHyBxWbv28+4uWFZ0AfTVHoMIyRpEVISUQ==
+  dependencies:
+    debug "^3.1.0"
+    lodash "^4.17.10"
+    request "2.87.0"
+
 node-pre-gyp@0.9.1:
   version "0.9.1"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.9.1.tgz#f11c07516dd92f87199dbc7e1838eab7cd56c9e0"
@@ -5855,7 +5872,7 @@ oauth-sign@~0.3.0:
   resolved "https://registry.yarnpkg.com/oauth-sign/-/oauth-sign-0.3.0.tgz#cb540f93bb2b22a7d5941691a288d60e8ea9386e"
   integrity sha1-y1QPk7srIqfVlBaRoojWDo6pOG4=
 
-oauth-sign@~0.8.1:
+oauth-sign@~0.8.1, oauth-sign@~0.8.2:
   version "0.8.2"
   resolved "https://registry.yarnpkg.com/oauth-sign/-/oauth-sign-0.8.2.tgz#46a6ab7f0aead8deae9ec0565780b7d4efeb9d43"
   integrity sha1-Rqarfwrq2N6unsBWV4C31O/rnUM=
@@ -6436,7 +6453,7 @@ qs@4.0.0:
   resolved "https://registry.yarnpkg.com/qs/-/qs-4.0.0.tgz#c31d9b74ec27df75e543a86c78728ed8d4623607"
   integrity sha1-wx2bdOwn33XlQ6hseHKO2NRiNgc=
 
-qs@6.5.2, qs@~6.5.2:
+qs@6.5.2, qs@~6.5.1, qs@~6.5.2:
   version "6.5.2"
   resolved "https://registry.yarnpkg.com/qs/-/qs-6.5.2.tgz#cb3ae806e8740444584ef154ce8ee98d403f3e36"
   integrity sha512-N5ZAX4/LxJmF+7wN74pUD6qAh9/wnvdQcjq9TZjevvXzSUo7bfmw91saqMjzGS2xq91/odN2dW/WOl7qQHNDGA==
@@ -6820,6 +6837,32 @@ request@2.74.x:
     tough-cookie "~2.3.0"
     tunnel-agent "~0.4.1"
 
+request@2.87.0:
+  version "2.87.0"
+  resolved "https://registry.yarnpkg.com/request/-/request-2.87.0.tgz#32f00235cd08d482b4d0d68db93a829c0ed5756e"
+  integrity sha512-fcogkm7Az5bsS6Sl0sibkbhcKsnyon/jV1kF3ajGmF0c8HrttdKTPRT9hieOaQHA5HEq6r8OyWOo/o781C1tNw==
+  dependencies:
+    aws-sign2 "~0.7.0"
+    aws4 "^1.6.0"
+    caseless "~0.12.0"
+    combined-stream "~1.0.5"
+    extend "~3.0.1"
+    forever-agent "~0.6.1"
+    form-data "~2.3.1"
+    har-validator "~5.0.3"
+    http-signature "~1.2.0"
+    is-typedarray "~1.0.0"
+    isstream "~0.1.2"
+    json-stringify-safe "~5.0.1"
+    mime-types "~2.1.17"
+    oauth-sign "~0.8.2"
+    performance-now "^2.1.0"
+    qs "~6.5.1"
+    safe-buffer "^5.1.1"
+    tough-cookie "~2.3.3"
+    tunnel-agent "^0.6.0"
+    uuid "^3.1.0"
+
 request@^2.55.0, request@^2.75.0:
   version "2.88.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.88.0.tgz#9c2fca4f7d35b592efe57c7f0a55e81052124fef"
@@ -6990,7 +7033,7 @@ rxjs@^6.1.0:
   dependencies:
     tslib "^1.9.0"
 
-safe-buffer@5.1.2, safe-buffer@^5.0.1, safe-buffer@^5.1.2, safe-buffer@~5.1.0, safe-buffer@~5.1.1:
+safe-buffer@5.1.2, safe-buffer@^5.0.1, safe-buffer@^5.1.1, safe-buffer@^5.1.2, safe-buffer@~5.1.0, safe-buffer@~5.1.1:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
   integrity sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==
@@ -7836,7 +7879,7 @@ tough-cookie@>=0.12.0, tough-cookie@~2.4.3:
     psl "^1.1.24"
     punycode "^1.4.1"
 
-tough-cookie@~2.3.0:
+tough-cookie@~2.3.0, tough-cookie@~2.3.3:
   version "2.3.4"
   resolved "https://registry.yarnpkg.com/tough-cookie/-/tough-cookie-2.3.4.tgz#ec60cee38ac675063ffc97a5c18970578ee83655"
   integrity sha512-TZ6TTfI5NtZnuyy/Kecv+CnoROnyXn2DN97LontgQpCwsX2XyLYCC0ENhYkehSOwAp8rTQKc/NUIF7BkQ5rKLA==
@@ -8159,7 +8202,7 @@ uuid@^2.0.1:
   resolved "https://registry.yarnpkg.com/uuid/-/uuid-2.0.3.tgz#67e2e863797215530dff318e5bf9dcebfd47b21a"
   integrity sha1-Z+LoY3lyFVMN/zGOW/nc6/1Hsho=
 
-uuid@^3.3.2:
+uuid@^3.1.0, uuid@^3.3.2:
   version "3.3.2"
   resolved "https://registry.yarnpkg.com/uuid/-/uuid-3.3.2.tgz#1b4af4955eb3077c501c23872fc6513811587131"
   integrity sha512-yXJmeNaw3DnnKAOKJE51sL/ZaYfWJRl1pK9dr19YFCu0ObS231AB1/LbqTKRAQ5kw8A90rA6fr4riOUpTZvQZA==