diff --git a/device_user_access_manager.py b/device_user_access_manager.py
new file mode 100644
index 0000000..fa989c9
--- /dev/null
+++ b/device_user_access_manager.py
@@ -0,0 +1,153 @@
+# -*- Mode:python; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+#
+# Copyright (C) 2014-2015 Regents of the University of California.
+# Author: Weiwei Liu <summerwing10@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# A copy of the GNU Lesser General Public License is in the file COPYING.
+
+"""
+This module defines the DeviceUserAccessManager class which is the interface of
+operations related to identity, keys, and certificates.
+"""
+
+import sys
+from pyndn.name import Name
+from device_profile import DeviceProfile
+from device_user_access_storage import DeviceUserAccessStorage
+
+class DeviceUserAccessManager(object):
+    """
+    Create a new DeviceUserAccessManager
+    """
+    def __init__(self, databaseFilePath = None):
+        deviceUserAccessStorage = DeviceUserAccessStorage(databaseFilePath)
+        self._deviceUserAccessStorage = deviceUserAccessStorage
+    
+    def createDevice(self, deviceProfile, seed, configurationToken, commandList = None):
+        """
+        Create a device in the database, including it's corresponding commands and serrvice profiles
+        @param DeviceProfile deviceProfile: the device profile
+        @param SymmetricKey seed: the seed of the device
+        @param SymmetricKey configurationToken: the configuration Token of the device
+        @param list commandList: the command list of the device, must have following structure: each element in the list should be a two-tuple (commandName, commandToken), the commandName should be a string, and commandToken should be a SymmetricKey. Here is an example of a valid commandList : [('turn_on', commandToken1), ('turn_off', commandToken2)]
+        return True if succeed, otherwise False
+        """
+        result = False
+
+        #add device
+        deviceId =  self._deviceUserAccessStorage.addDevice(deviceProfile, seed, configurationToken)  
+        if deviceId == 0:
+           raise RuntimeError("device already exists in database") 
+           return result
+        elif deviceId == -1:
+           raise RuntimeError("error occured during adding device into database") 
+           return result
+        
+        #add service profile
+        serviceProfileList = deviceProfile.getServiceProfileList()
+        for serviceProfileName in serviceProfileList:
+            serviceProfileId = self._deviceUserAccessStorage.addServiceProfile(deviceId, serviceProfileName)
+            if serviceProfileId == 0:
+                raise RuntimeError("service profile: " + serviceProfileName + " already exists in database")
+                return result
+            elif serviceProfileId == -1:
+                raise RuntimeError("error occured during adding service profile :" + serviceProfileName)
+                return result
+        #add command
+        for commandTuple in commandList:
+            commandId = self._deviceUserAccessStorage.addCommand(deviceId, commandTuple[0], commandTuple[1])
+            if commandId == 0:
+                raise RuntimeError("command: " + commandTuple[0] + " already exists in database")
+                return result
+            elif commandId == -1:
+                raise RuntimeError("error occured during adding command:" +commandTuple[0])
+                return result
+        result = True
+        return result
+
+    def getDeviceProfile(self, prefix):
+        """
+        get device profile of a specified device
+        :param Name prefix: the device prefix
+        :return device profile of the device if exists, otherwise return None
+        :rtype: DeviceProfile
+        """
+        deviceProfile = self._deviceUserAccessStorage.getDeviceProfileFromDevice(prefix)
+        if deviceProfile == None:
+            return deviceProfile
+        else:
+            # get device Id 
+            deviceId = self._deviceUserAccessStorage.getDeviceId(deviceProfile.getPrefix())
+            if deviceId == 0:
+                raise RuntimeError("device doesn't exist")
+             
+            serviceProfileList = self._deviceUserAccessStorage.getServiceProfilesOfDevice(deviceId)
+            deviceProfile.setServiceProfile(serviceProfileList)
+       
+        return deviceProfile
+
+    def getSeed(self, prefix):
+        """
+        get seed of a specified device
+        :param Name prefix: the device prefix
+        :return seed of the device if exists, otherwise return None
+        :rtype: SymmetricKey
+        """
+        return self._deviceUserAccessStorage.getSeed(prefix)
+
+    def getConfigurationToken(self, prefix):
+        """
+        get configuration token of a specified device
+        :param Name prefix: the device prefix
+        :return seed of the device if exists, otherwise return None
+        :rtype: SymmetricKey
+        """
+        return self._deviceUserAccessStorage.getConfigurationToken(prefix)
+
+    def getCommandToken(self, prefix, commandName):
+        """
+        get command token of a specified command 
+        :param Name prefix: the device prefix 
+        :param str commandName: device name of the command
+        :return command token if command existsm, otherwise None
+        :rtype SymmetricKey
+        """
+        deviceId = self._deviceUserAccessStorage.getDeviceId(prefix)
+        if deviceId == 0:
+            return None
+        return self._deviceUserAccessStorage.getCommandToken(deviceId, commandName)
+
+    def getCommandsOfDevice(self, prefix):
+        """
+        get all the commands of a specified device
+        :param Name prefix: the device prefix
+        :return command name list if any commands exist, otherwise None
+        """
+        deviceId = self._deviceUserAccessStorage.getDeviceId(prefix)
+        if deviceId == 0:
+            return None
+        return self._deviceUserAccessStorage.getCommandsOfDevice(deviceId)
+    
+    def getServiceProfilesOfDevice(self, prefix):
+        """
+        get all the service profiles of a specified device
+        :param Name prefix: the device prefix
+        :return service profiles name list if any service profiles exist, otherwise None
+        """
+        deviceId = self._deviceUserAccessStorage.getDeviceId(prefix)
+        if deviceId == 0:
+            return None
+        return self._deviceUserAccessStorage.getServiceProfilesOfDevice(deviceId)
+