diff --git a/composer.json b/composer.json
index f7e2407b..69ee3c1a 100644
--- a/composer.json
+++ b/composer.json
@@ -6,11 +6,11 @@
 	"license": "MIT",
 	"require": {
 		"php": ">=5.4.0",
-		"symfony/http-foundation": "v2.4.*"
+		"symfony/http-foundation": "2.4.*"
 	},
 	"require-dev": {
-		"mockery/mockery": ">=0.7.2",
-		"league/phpunit-coverage-listener": "~1.0"
+		"league/phpunit-coverage-listener": "~1.0",
+        "phpdocumentor/phpdocumentor": "2.*"
 	},
 	"repositories": [
 		{
diff --git a/src/League/OAuth2/Server/Authorization.php b/src/League/OAuth2/Server/Authorization.php
index 8c7337cf..a4b91d10 100644
--- a/src/League/OAuth2/Server/Authorization.php
+++ b/src/League/OAuth2/Server/Authorization.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Authorization Server
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -16,6 +16,7 @@ use League\OAuth2\Server\Grant\GrantTypeInterface;
 use League\OAuth2\Server\Exception\ClientException;
 use League\OAuth2\Server\Exception\ServerException;
 use League\OAuth2\Server\Exception\InvalidGrantTypeException;
+use League\OAuth2\Server\Storage\StorageWrapper;
 use League\OAuth2\Server\Storage\ClientInterface;
 use League\OAuth2\Server\Storage\AccessTokenInterface;
 use League\OAuth2\Server\Storage\AuthCodeInterface;
@@ -231,45 +232,49 @@ class Authorization
 
     /**
      * Set the client storage
-     * @param ClientInterface $client
+     * @param ClientInterface $storage
      * @return self
      */
-    public function setClientStorage(ClientInterface $client)
+    public function setClientStorage(ClientInterface $storage)
     {
-        $this->storages['client'] = $client;
+        $storage->setServer($this);
+        $this->storages['client'] = $storage;
         return $this;
     }
 
     /**
      * Set the session storage
-     * @param SessionInterface $session
+     * @param SessionInterface $storage
      * @return self
      */
-    public function setSessionStorage(SessionInterface $session)
+    public function setSessionStorage(SessionInterface $storage)
     {
-        $this->storages['session'] = $session;
+        $storage->setServer($this);
+        $this->storages['session'] = $storage;
         return $this;
     }
 
     /**
      * Set the access token storage
-     * @param AccessTokenInterface $accessToken
+     * @param AccessTokenInterface $storage
      * @return self
      */
-    public function setAccessTokenStorage(AccessTokenInterface $accessToken)
+    public function setAccessTokenStorage(AccessTokenInterface $storage)
     {
-        $this->storages['access_token'] = $accessToken;
+        $storage->setServer($this);
+        $this->storages['access_token'] = $storage;
         return $this;
     }
 
     /**
      * Set the refresh token storage
-     * @param RefreshTokenInteface $refreshToken
+     * @param RefreshTokenInteface $storage
      * @return self
      */
-    public function setRefreshTokenStorage(RefreshTokenInterface $refreshToken)
+    public function setRefreshTokenStorage(RefreshTokenInterface $storage)
     {
-        $this->storages['refresh_token'] = $refreshToken;
+        $storage->setServer($this);
+        $this->storages['refresh_token'] = $storage;
         return $this;
     }
 
@@ -280,18 +285,20 @@ class Authorization
      */
     public function setAuthCodeStorage(AuthCodeInterface $authCode)
     {
+        $storage->setServer($this);
         $this->storages['auth_code'] = $authCode;
         return $this;
     }
 
     /**
      * Set the scope storage
-     * @param ScopeInterface $scope
+     * @param ScopeInterface $storage
      * @return self
      */
-    public function setScopeStorage(ScopeInterface $scope)
+    public function setScopeStorage(ScopeInterface $storage)
     {
-        $this->storages['scope'] = $scope;
+        $storage->setServer($this);
+        $this->storages['scope'] = $storage;
         return $this;
     }
 
@@ -359,7 +366,8 @@ class Authorization
     }
 
     /**
-     * Default scope to be used if none is provided and requireScopeParam is false
+     * Default scope to be used if none is provided and requireScopeParam() is false
+     * @param string $default Name of the default scope
      * @param self
      */
     public function setDefaultScope($default = null)
diff --git a/src/League/OAuth2/Server/Entities/AbstractToken.php b/src/League/OAuth2/Server/Entities/AbstractToken.php
index 7a839a9d..c5b5b391 100644
--- a/src/League/OAuth2/Server/Entities/AbstractToken.php
+++ b/src/League/OAuth2/Server/Entities/AbstractToken.php
@@ -1,64 +1,80 @@
 <?php
+/**
+ * OAuth 2.0 Abstract token
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
 use League\OAuth2\Server\Storage\SessionStorageInterface;
-use Symfony\Component\HttpFoundation\ParameterBag;
 use League\OAuth2\Server\Util\SecureKey;
+use League\OAuth2\Server\Exception\ServerException;
+use \League\OAuth2\Server\Authorization;
+use \League\OAuth2\Server\Resource;
+use Symfony\Component\HttpFoundation\ParameterBag;
 
+/**
+ * Abstract token class
+ */
 abstract class AbstractToken
 {
     /**
      * Access token ID
      * @var string
      */
-    protected $token = null;
+    protected $token;
 
     /**
-     * Access token storage
-     * @var \League\OAuth2\Server\Storage\AccessTokenInterface
+     * Session ID
+     * @var string
      */
-    protected $storage = null;
-
-    /**
-     * Session storage
-     * @var \League\OAuth2\Server\Storage\SessionInterface
-     */
-    protected $sessionStorage = null;
+    protected $sessionId;
 
     /**
      * Associated session
      * @var \League\OAuth2\Server\Session
      */
-    protected $session = null;
+    protected $session;
 
     /**
      * Session scopes
      * @var \Symfony\Component\HttpFoundation\ParameterBag
      */
-    protected $scopes = null;
+    protected $scopes;
+
+    /**
+     * Token expire time
+     * @var int
+     */
+    protected $expireTime = 0;
+
+    /**
+     * Authorization or resource server
+     * @var \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource
+     */
+    protected $server;
 
     /**
      * __construct
-     * @param mixed $storage
+     * @param \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
      * @return self
      */
-    public function __construct($storage)
+    public function __construct($server)
     {
-        $this->storage = $storage;
+        if (! $server instanceof Authorization && ! $server instanceof Resource) {
+            throw new ServerException('No instance of Authorization or Resource server injected');
+        }
+
+        $this->server = $server;
         $this->scopes = new ParameterBag();
         return $this;
     }
 
-    /**
-     * Get storage
-     * @return AccessTokenInterface
-     */
-    public function getStorage()
-    {
-        return $this->storage;
-    }
-
     /**
      * Set session
      * @param \League\OAuth2\Server\Session $session
@@ -76,55 +92,35 @@ abstract class AbstractToken
      */
     public function getSession()
     {
-        return $this->session;
+        if ($this->session instanceof Session) {
+            return $this->session;
+        }
+
+        if ($this->sessionId !== null) {
+            $session = $this->server->getStorage('session')->getSession($this->sessionId);
+        }
+
+        throw new ServerException('No session ID set for this token');
     }
 
     /**
-     * Set token TTL
-     * @param integer $ttl TTL in seconds
+     * Set the expire time of the token
+     * @param integer $expireTime Unix time stamp
      * @return self
      */
-    public function setTTL($ttl = 0)
+    public function setExpireTime($expireTime)
     {
-        $this->ttl = $ttl;
+        $this->expireTime = $expireTime;
         return $this;
     }
 
     /**
-     * Get token TTL
-     * @return integer
-     */
-    public function getTTL()
-    {
-        return $this->ttl;
-    }
-
-    /**
-     * Set the creation timestamp
-     * @param integer $timestamp Unix timestamp
-     * @return self
-     */
-    public function setTimestamp($timestamp = 0)
-    {
-        $this->timestamp = $timestamp;
-    }
-
-    /**
-     * Get access token creation timestamp
-     * @return integer Unix timestamp
-     */
-    public function getTimestamp()
-    {
-        return $this->timestamp;
-    }
-
-    /**
-     * Return creation timestamp + TTL
+     * Return token expire time
      * @return int
      */
     public function getExpireTime()
     {
-        return $this->getTimestamp() + $this->getTTL();
+        return $this->expireTime;
     }
 
     /**
@@ -181,8 +177,14 @@ abstract class AbstractToken
     }
 
     /**
-     * Save the token to the database
-     * @return self
+     * Expire the token
+     * @return void
      */
-    abstract function save();
+    abstract public function expire();
+
+    /**
+     * Save the token
+     * @return void
+     */
+    abstract public function save();
 }
diff --git a/src/League/OAuth2/Server/Entities/AccessToken.php b/src/League/OAuth2/Server/Entities/AccessToken.php
index 4f52d32f..5c48c2d4 100644
--- a/src/League/OAuth2/Server/Entities/AccessToken.php
+++ b/src/League/OAuth2/Server/Entities/AccessToken.php
@@ -1,28 +1,33 @@
 <?php
+/**
+ * OAuth 2.0 Access token entity
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
 use League\OAuth2\Server\Storage\SessionStorageInterface;
 use League\OAuth2\Server\Storage\AccessTokenInterface;
-use Symfony\Component\HttpFoundation\ParameterBag;
 use League\OAuth2\Server\Util\SecureKey;
 use League\OAuth2\Server\Exception\InvalidAccessTokenException;
+use Symfony\Component\HttpFoundation\ParameterBag;
 
+/**
+ * Access token entity class
+ */
 class AccessToken extends AbstractToken
 {
     /**
-     * __construct
-     * @param AccessTokenInterface $storage
-     * @return self
+     * {@inheritdoc}
      */
-    public function __construct(AccessTokenInterface $storage)
-    {
-        parent::__construct($storage);
-    }
-
     public function save()
     {
-        $this->getStorage()->createAccessToken(
+        $this->server->getStorage('access_token')->createAccessToken(
             $this->getToken(),
             $this->getExpireTime(),
             $this->getSession()->getId()
@@ -30,7 +35,7 @@ class AccessToken extends AbstractToken
 
         // Associate the scope with the token
         foreach ($this->getScopes() as $scope) {
-            $this->getStorage()->associateScope($this->getToken(), $scope->getId());
+            $this->server->getStorage('access_token')->associateScope($this->getToken(), $scope->getId());
         }
 
         return $this;
diff --git a/src/League/OAuth2/Server/Entities/Client.php b/src/League/OAuth2/Server/Entities/Client.php
index 59781892..684a86db 100644
--- a/src/League/OAuth2/Server/Entities/Client.php
+++ b/src/League/OAuth2/Server/Entities/Client.php
@@ -1,58 +1,144 @@
 <?php
+/**
+ * OAuth 2.0 Client entity
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
+use League\OAuth2\Server\Exception\ServerException;
+use League\OAuth2\Server\Authorization;
+use League\OAuth2\Server\Resource;
+
+/**
+ * Client entity class
+ */
 class Client
 {
+    /**
+     * Client identifier
+     * @var string
+     */
     protected $id = null;
 
+    /**
+     * Client secret
+     * @var string
+     */
     protected $secret = null;
 
+    /**
+     * Client name
+     * @var string
+     */
     protected $name = null;
 
+    /**
+     * Client redirect URI
+     * @var string
+     */
     protected $redirectUri = null;
 
+    /**
+     * Authorization or resource server
+     * @var \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource
+     */
+    protected $server;
+
+    /**
+     * __construct
+     * @param \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
+     * @return self
+     */
+    public function __construct($server)
+    {
+        if (! $server instanceof Authorization && ! $server instanceof Resource) {
+            throw new ServerException('No instance of Authorization or Resource server injected');
+        }
+    }
+
+    /**
+     * Set the client identifier
+     * @param string $id
+     * @return self
+     */
     public function setId($id)
     {
         $this->id = $id;
         return $this;
     }
 
+    /**
+     * Return the client identifier
+     * @return string
+     */
     public function getId()
     {
         return $this->id;
     }
 
+    /**
+     * Set the client secret
+     * @param string $secret
+     * @return self
+     */
     public function setSecret($secret)
     {
         $this->secret = $secret;
         return $this;
     }
 
+    /**
+     * Return the client secret
+     * @return string
+     */
     public function getSecret()
     {
         return $this->secret;
     }
 
+    /**
+     * Set the client name
+     * @param string $name
+     * @return self
+     */
     public function setName($name)
     {
         $this->name = $name;
         return $this;
     }
 
+    /**
+     * Get the client name
+     * @return string
+     */
     public function getName()
     {
         return $this->name;
     }
 
+    /**
+     * Set the client redirect URI
+     * @param string $redirectUri
+     * @return self
+     */
     public function setRedirectUri($redirectUri)
     {
         $this->redirectUri = $redirectUri;
         return $this;
     }
 
+    /**
+     * Returnt the client redirect URI
+     * @return string
+     */
     public function getRedirectUri()
     {
         return $this->redirectUri;
     }
-}
\ No newline at end of file
+}
diff --git a/src/League/OAuth2/Server/Entities/RefreshToken.php b/src/League/OAuth2/Server/Entities/RefreshToken.php
index e8a89d59..8be3fc43 100644
--- a/src/League/OAuth2/Server/Entities/RefreshToken.php
+++ b/src/League/OAuth2/Server/Entities/RefreshToken.php
@@ -1,30 +1,36 @@
 <?php
+/**
+ * OAuth 2.0 Refresh token entity
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
 use League\OAuth2\Server\Storage\SessionStorageInterface;
 use League\OAuth2\Server\Storage\RefreshTokenInterface;
-use Symfony\Component\HttpFoundation\ParameterBag;
 use League\OAuth2\Server\Util\SecureKey;
 use League\OAuth2\Server\Exception\InvalidAccessTokenException;
+use Symfony\Component\HttpFoundation\ParameterBag;
 
+/**
+ * Refresh token entity class
+ */
 class RefreshToken extends AbstractToken
 {
+    /**
+     * Access token associated to refresh token
+     * @var \League\OAuth2\Server\Entities\AccessToken
+     */
     protected $accessToken;
 
-    /**
-     * __construct
-     * @param RefreshTokenInterface $storage
-     * @return self
-     */
-    public function __construct(RefreshTokenInterface $storage)
-    {
-        parent::__construct($storage);
-    }
-
     /**
      * Associate an access token
-     * @param AccessToken $accessToken
+     * @param \League\OAuth2\Server\Entities\AccessToken $accessToken
      * @return self
      */
     public function setAccessToken(AccessToken $accessToken)
@@ -43,11 +49,11 @@ class RefreshToken extends AbstractToken
     }
 
     /**
-     * (@inheritdoc)
+     * {@inheritdoc}
      */
     public function save()
     {
-        $this->getStorage()->createAccessToken(
+        $this->server->getStorage('refresh_token')->createAccessToken(
             $this->getToken(),
             $this->getExpireTime(),
             $this->getAccessToken()->getToken()
@@ -55,7 +61,7 @@ class RefreshToken extends AbstractToken
 
         // Associate the scope with the token
         foreach ($this->getScopes() as $scope) {
-            $this->getStorage()->associateScope($this->getToken(), $scope->getId());
+            $this->server->getStorage('refresh_token')->associateScope($this->getToken(), $scope->getId());
         }
     }
 }
diff --git a/src/League/OAuth2/Server/Entities/Scope.php b/src/League/OAuth2/Server/Entities/Scope.php
index 0b7be0fd..8d6ec4bd 100644
--- a/src/League/OAuth2/Server/Entities/Scope.php
+++ b/src/League/OAuth2/Server/Entities/Scope.php
@@ -1,30 +1,87 @@
 <?php
+/**
+ * OAuth 2.0 scope entity
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
+/**
+ * Scope entity class
+ */
 class Scope
 {
-    protected $id = null;
+    /**
+     * Scope identifier
+     * @var string
+     */
+    protected $id;
 
-    protected $description = null;
+    /**
+     * Scope description
+     * @var string
+     */
+    protected $description;
 
+    /**
+     * Authorization or resource server
+     * @var \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource
+     */
+    protected $server;
+
+    /**
+     * __construct
+     * @param \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
+     * @return self
+     */
+    public function __construct($server)
+    {
+        if (! $server instanceof Authorization && ! $server instanceof Resource) {
+            throw new ServerException('No instance of Authorization or Resource server injected');
+        }
+        return $this;
+    }
+
+    /**
+     * Set the scope identifer
+     * @param string $id The scope identifier
+     * @return self
+     */
     public function setId($id)
     {
         $this->id = $id;
         return $this;
     }
 
+    /**
+     * Return the scope identifer
+     * @return string
+     */
     public function getId()
     {
         return $this->id;
     }
 
+    /**
+     * Set the scope's descripton
+     * @param string $description
+     * @return self
+     */
     public function setDescription($description)
     {
         $this->description = $description;
         return $this;
     }
 
+    /**
+     * Return the scope's description
+     * @return string
+     */
     public function getDescription()
     {
         return $this->description;
diff --git a/src/League/OAuth2/Server/Entities/Session.php b/src/League/OAuth2/Server/Entities/Session.php
index 38b89877..050f4c5e 100644
--- a/src/League/OAuth2/Server/Entities/Session.php
+++ b/src/League/OAuth2/Server/Entities/Session.php
@@ -1,71 +1,112 @@
 <?php
+/**
+ * OAuth 2.0 session entity
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
 
 namespace League\OAuth2\Server\Entities;
 
-use OutOfBoundsException;
 use League\OAuth2\Server\Exception\OAuth2Exception;
 use League\OAuth2\Server\Storage\SessionInterface;
+use League\OAuth2\Server\Exception\ServerException;
+use League\OAuth2\Server\Authorization;
+use League\OAuth2\Server\Resource;
 use Symfony\Component\HttpFoundation\ParameterBag;
 
+/**
+ * Session entity grant
+ */
 class Session
 {
     /**
-     * Session ID
+     * Session identifier
      * @var string
      */
-    protected $id = null;
-
-    protected $clientId = null;
-
-    protected $ownerId = null;
-
-    protected $ownerType = null;
-
-    protected $authCode = null;
-
-    protected $accessToken = null;
-
-    protected $refreshToken = null;
+    protected $id;
 
     /**
-     * Session storage
-     * @var \League\OAuth2\Server\Storage\SessionInterface
+     * Client identifier
+     * @var string
      */
-    protected $storage = null;
+    protected $clientId;
+
+    /**
+     * Session owner identifier
+     * @var string
+     */
+    protected $ownerId;
+
+    /**
+     * Session owner type (e.g. "user")
+     * @var string
+     */
+    protected $ownerType;
+
+    /**
+     * Auth code
+     * @var \League\OAuth2\Server\Entities\AuthCode
+     */
+    protected $authCode;
+
+    /**
+     * Access token
+     * @var \League\OAuth2\Server\Entities\AccessToken
+     */
+    protected $accessToken;
+
+    /**
+     * Refresh token
+     * @var \League\OAuth2\Server\Entities\RefreshToken
+     */
+    protected $refreshToken;
 
     /**
      * Session scopes
      * @var \Symfony\Component\HttpFoundation\ParameterBag
      */
-    protected $scopes = null;
+    protected $scopes;
 
     /**
-     * Constuctor
-     * @param SessionInterface $storage
+     * Authorization or resource server
+     * @var \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource
+     */
+    protected $server;
+
+    /**
+     * __construct
+     * @param \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
      * @return self
      */
-    public function __construct(SessionInterface $storage)
+    public function __construct($server)
     {
-        $this->storage = $storage;
+        if (! $server instanceof Authorization && ! $server instanceof Resource) {
+            throw new ServerException('No instance of Authorization or Resource server injected');
+        }
+
         $this->scopes = new ParameterBag();
         return $this;
     }
 
     /**
-     * Get storage
-     * @return SessionInterface
+     * Set the session identifier
+     * @param string $id
+     * @return self
      */
-    public function getStorage()
-    {
-        return $this->storage;
-    }
-
     public function setId($id)
     {
         $this->id = $id;
         return $this;
     }
 
+    /**
+     * Return the session identifier
+     * @return string
+     */
     public function getId()
     {
         return $this->id;
@@ -95,41 +136,62 @@ class Session
         return $this->scopes->has($scope);
     }
 
+    /**
+     * Return all scopes associated with the session
+     * @return array Array of \League\OAuth2\Server\Entities\Scope
+     */
     public function getScopes()
     {
-        return $this->scopes;
-    }
-
-    public function associateAccessToken(AccessToken $accessToken)
-    {
-        $this->accessToken = $accessToken;
-    }
-
-    public function associateRefreshToken(RefreshToken $refreshToken)
-    {
-        $this->refreshToken = $refreshToken;
-    }
-
-    public function associateAuthCode(AuthCode $authCode)
-    {
-        $this->authCode = $authCode;
+        return $this->scopes->all();
     }
 
     /**
-     * Associate a client
-     * @param  League\OAuth2\Server\Client $client The client
+     * Associate an access token with the session
+     * @param  \League\OAuth2\Server\Entities\AccessToken $accessToken
+     * @return self
+     */
+    public function associateAccessToken(AccessToken $accessToken)
+    {
+        $this->accessToken = $accessToken;
+        return $this;
+    }
+
+    /**
+     * Associate a refresh token with the session
+     * @param  \League\OAuth2\Server\Entities\RefreshToken $refreshToken
+     * @return self
+     */
+    public function associateRefreshToken(RefreshToken $refreshToken)
+    {
+        $this->refreshToken = $refreshToken;
+        return $this;
+    }
+
+    /**
+     * Associate an authorization code with the session
+     * @param  \League\OAuth2\Server\Entities\AuthCode $authCode
+     * @return self
+     */
+    public function associateAuthCode(AuthCode $authCode)
+    {
+        $this->authCode = $authCode;
+        return $this;
+    }
+
+    /**
+     * Associate a client with the session
+     * @param  League\OAuth2\Server\Entities\Client $client The client
      * @return self
      */
     public function associateClient(Client $client)
     {
         $this->client = $client;
-
         return $this;
     }
 
     /**
-     * Return client
-     * @return League\OAuth2\Server\Client
+     * Return the session client
+     * @return League\OAuth2\Server\Entities\Client
      */
     public function getClient()
     {
@@ -139,7 +201,7 @@ class Session
     /**
      * Set the session owner
      * @param string $type The type of the owner (e.g. user, app)
-     * @param string $id   The ID of the owner
+     * @param string $id   The identifier of the owner
      * @return self
      */
     public function setOwner($type, $id)
@@ -151,7 +213,7 @@ class Session
     }
 
     /**
-     * Return session owner ID
+     * Return session owner identifier
      * @return string
      */
     public function getOwnerId()
@@ -168,10 +230,14 @@ class Session
         return $this->ownerType;
     }
 
+    /**
+     * Save the session
+     * @return void
+     */
     public function save()
     {
-        // Save the session and get an ID
-        $id = $this->getStorage()->createSession(
+        // Save the session and get an identifier
+        $id = $this->server->getStorage('session')->createSession(
             $this->getOwnerType(),
             $this->getOwnerId(),
             $this->getClient()->getId(),
@@ -182,7 +248,7 @@ class Session
 
         // Associate the scope with the session
         foreach ($this->getScopes() as $scope) {
-            $this->getStorage()->associateScope($this->getId(), $scope->getId());
+            $this->server->getStorage('session')->associateScope($this->getId(), $scope->getId());
         }
     }
 }
diff --git a/src/League/OAuth2/Server/Exception/ClientException.php b/src/League/OAuth2/Server/Exception/ClientException.php
index e9839a74..e7f60dd9 100644
--- a/src/League/OAuth2/Server/Exception/ClientException.php
+++ b/src/League/OAuth2/Server/Exception/ClientException.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Client Exception
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Exception/InvalidAccessTokenException.php b/src/League/OAuth2/Server/Exception/InvalidAccessTokenException.php
index b9bb5462..2f285094 100644
--- a/src/League/OAuth2/Server/Exception/InvalidAccessTokenException.php
+++ b/src/League/OAuth2/Server/Exception/InvalidAccessTokenException.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Invalid Access Token Exception
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Exception/InvalidGrantTypeException.php b/src/League/OAuth2/Server/Exception/InvalidGrantTypeException.php
index c6318f8f..7d797c7f 100644
--- a/src/League/OAuth2/Server/Exception/InvalidGrantTypeException.php
+++ b/src/League/OAuth2/Server/Exception/InvalidGrantTypeException.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Invalid Grant Type Exception
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Exception/OAuth2Exception.php b/src/League/OAuth2/Server/Exception/OAuth2Exception.php
index 0b8f68a8..d618a47d 100644
--- a/src/League/OAuth2/Server/Exception/OAuth2Exception.php
+++ b/src/League/OAuth2/Server/Exception/OAuth2Exception.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Base Exception
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Exception/ServerException.php b/src/League/OAuth2/Server/Exception/ServerException.php
index 4827f47f..8f7adcfa 100644
--- a/src/League/OAuth2/Server/Exception/ServerException.php
+++ b/src/League/OAuth2/Server/Exception/ServerException.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Server Exception
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Grant/GrantTrait.php b/src/League/OAuth2/Server/Grant/AbstractGrant.php
similarity index 58%
rename from src/League/OAuth2/Server/Grant/GrantTrait.php
rename to src/League/OAuth2/Server/Grant/AbstractGrant.php
index 438e34f2..cb27b2ca 100644
--- a/src/League/OAuth2/Server/Grant/GrantTrait.php
+++ b/src/League/OAuth2/Server/Grant/AbstractGrant.php
@@ -1,10 +1,10 @@
 <?php
 /**
- * OAuth 2.0 Client credentials grant
+ * OAuth 2.0 Abstract grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -12,16 +12,42 @@
 namespace League\OAuth2\Server\Grant;
 
 use League\OAuth2\Server\Authorization;
+use League\OAuth2\Server\Entities\Scope;
 
-trait GrantTrait {
+/**
+ * Abstract grant class
+ */
+abstract class AbstractGrant implements GrantTypeInterface
+{
+    /**
+     * Grant identifier
+     * @var string
+     */
+    protected $identifier = '';
 
     /**
-     * Constructor
-     * @return void
+     * Response type
+     * @var string
      */
-    public function __construct()
-    {
-    }
+    protected $responseType = null;
+
+    /**
+     * Callback to authenticate a user's name and password
+     * @var function
+     */
+    protected $callback = null;
+
+    /**
+     * AuthServer instance
+     * @var AuthServer
+     */
+    protected $server = null;
+
+    /**
+     * Access token expires in override
+     * @var int
+     */
+    protected $accessTokenTTL = null;
 
     /**
      * Return the identifier
@@ -74,6 +100,12 @@ trait GrantTrait {
         return $this;
     }
 
+    /**
+     * Given a list of scopes, validate them and return an arrary of Scope entities
+     * @param string $scopeParam A string of scopes (e.g. "profile email birthday")
+     * @return array
+     * @throws ClientException If scope is invalid, or no scopes passed when required
+     */
     public function validateScopes($scopeParam = '')
     {
         $scopesList = explode($this->server->getScopeDelimeter(), $scopeParam);
@@ -100,24 +132,37 @@ trait GrantTrait {
         $scopes = [];
 
         foreach ($scopesList as $scopeItem) {
-            $scopeDetails = $this->server->getStorage('scope')->getScope(
+            $scope = $this->server->getStorage('scope')->getScope(
                 $scopeItem,
-                $client->getId(),
                 $this->getIdentifier()
             );
 
-            if ($scopeDetails === false) {
+            if (($scope instanceof Scope) === false) {
                 throw new ClientException(sprintf($this->server->getExceptionMessage('invalid_scope'), $scopeItem), 4);
             }
 
-            $scope = new Scope($this->server->getStorage('scope'));
-            $scope->setId($scopeDetails['id']);
-            $scope->setName($scopeDetails['name']);
-
             $scopes[] = $scope;
         }
 
         return $scopes;
     }
 
+    /**
+     * Complete the grant flow
+     *
+     * Example response:
+     * <pre>
+     *  array(
+     *      'access_token'  =>  (string),   // The access token
+     *      'refresh_token' =>  (string),   // The refresh token (only set if the refresh token grant is enabled)
+     *      'token_type'    =>  'bearer',   // Almost always "bearer" (exceptions: JWT, SAML)
+     *      'expires'       =>  (int),      // The timestamp of when the access token will expire
+     *      'expires_in'    =>  (int)       // The number of seconds before the access token will expire
+     *  )
+     * </pre>
+     *
+     * @return array                   An array of parameters to be passed back to the client
+     */
+    abstract public function completeFlow();
+
 }
diff --git a/src/League/OAuth2/Server/Grant/AuthCode.php b/src/League/OAuth2/Server/Grant/AuthCode.php
index bf968980..41f0de13 100644
--- a/src/League/OAuth2/Server/Grant/AuthCode.php
+++ b/src/League/OAuth2/Server/Grant/AuthCode.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Auth code grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Grant/ClientCredentials.php b/src/League/OAuth2/Server/Grant/ClientCredentials.php
index 7d9bff3b..5e718e1d 100644
--- a/src/League/OAuth2/Server/Grant/ClientCredentials.php
+++ b/src/League/OAuth2/Server/Grant/ClientCredentials.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Client credentials grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -25,10 +25,8 @@ use League\OAuth2\Server\Storage\ScopeInterface;
 /**
  * Client credentials grant class
  */
-class ClientCredentials implements GrantTypeInterface
+class ClientCredentials extends AbstractGrant
 {
-    use GrantTrait;
-
     /**
      * Grant identifier
      * @var string
@@ -78,35 +76,30 @@ class ClientCredentials implements GrantTypeInterface
         }
 
         // Validate client ID and client secret
-        $clientDetails = $this->server->getStorage('client')->getClient(
+        $client = $this->server->getStorage('client')->getClient(
             $clientId,
             $clientSecret,
             null,
             $this->getIdentifier()
         );
 
-        if ($clientDetails === false) {
+        if (($client instanceof Client) === false) {
             throw new ClientException(Authorization::getExceptionMessage('invalid_client'), 8);
         }
 
-        $client = new Client;
-        $client->setId($clientDetails['id']);
-        $client->setSecret($clientDetails['secret']);
-
         // Validate any scopes that are in the request
         $scopeParam = $this->server->getRequest()->request->get('scope', '');
         $scopes = $this->validateScopes($scopeParam);
 
         // Create a new session
-        $session = new Session($this->server->getStorage('session'));
+        $session = new Session();
         $session->setOwner('client', $client->getId());
         $session->associateClient($client);
 
         // Generate an access token
-        $accessToken = new AccessToken($this->server->getStorage('access_token'));
-        $accessToken->setId(SecureKey::make());
-        $accessToken->setTimestamp(time());
-        $accessToken->setTTL($this->server->getAccessTokenTTL());
+        $accessToken = new AccessToken();
+        $accessToken->setToken(SecureKey::make());
+        $accessToken->setExpireTime($this->server->getAccessTokenTTL() + time());
 
         // Associate scopes with the session and access token
         foreach ($scopes as $scope) {
@@ -115,18 +108,17 @@ class ClientCredentials implements GrantTypeInterface
         }
 
         // Save everything
-        $session->save();
+        $session->save($this->server->getStorage('session'));
         $accessToken->setSession($session);
-        $accessToken->save();
+        $accessToken->save($this->server->getStorage('access_token'));
 
         $response = [
-            'access_token'  =>  $accessToken->getId(),
+            'access_token'  =>  $accessToken->getToken(),
             'token_type'    =>  'Bearer',
             'expires'       =>  $accessToken->getExpireTime(),
-            'expires_in'    =>  $accessToken->getTTL()
+            'expires_in'    =>  $this->server->getAccessTokenTTL()
         ];
 
         return $response;
     }
-
 }
diff --git a/src/League/OAuth2/Server/Grant/GrantTypeInterface.php b/src/League/OAuth2/Server/Grant/GrantTypeInterface.php
index 18ef774b..f71d6186 100644
--- a/src/League/OAuth2/Server/Grant/GrantTypeInterface.php
+++ b/src/League/OAuth2/Server/Grant/GrantTypeInterface.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Grant type interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -19,30 +19,14 @@ use League\OAuth2\Server\Storage\SessionInterface;
 use League\OAuth2\Server\Storage\ClientInterface;
 use League\OAuth2\Server\Storage\ScopeInterface;
 
+/**
+ * Grant type interface
+ */
 interface GrantTypeInterface
 {
-    /**
-     * Constructor
-     *
-     * @return void
-     */
-    public function __construct();
-
     /**
      * Complete the grant flow
-     *
-     * Example response:
-     * <code>
-     * 	array(
-     *  	'access_token'  =>  (string),	// The access token
-     *      'refresh_token' =>  (string),	// The refresh token (only set if the refresh token grant is enabled)
-     *      'token_type'    =>  'bearer',	// Almost always "bearer" (exceptions: JWT, SAML)
-     *      'expires'       =>  (int),		// The timestamp of when the access token will expire
-     *      'expires_in'    =>  (int)		// The number of seconds before the access token will expire
-     *  )
-     * </code>
-     *
-     * @return array                   An array of parameters to be passed back to the client
+     * @return  array
      */
     public function completeFlow();
 }
diff --git a/src/League/OAuth2/Server/Grant/Implicit.php b/src/League/OAuth2/Server/Grant/Implicit.php
index a41c05a6..33eb3491 100644
--- a/src/League/OAuth2/Server/Grant/Implicit.php
+++ b/src/League/OAuth2/Server/Grant/Implicit.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 implicit grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -52,10 +52,9 @@ class Implicit implements GrantTypeInterface {
 
     /**
      * Complete the client credentials grant
-     * @param  null|array $inputParams
      * @return array
      */
-    public function completeFlow($authParams = null)
+    public function completeFlow()
     {
         // Remove any old sessions the user might have
         $this->authServer->getStorage('session')->deleteSession($authParams['client_id'], 'user', $authParams['user_id']);
diff --git a/src/League/OAuth2/Server/Grant/Password.php b/src/League/OAuth2/Server/Grant/Password.php
index 91e6e5c3..85231dff 100644
--- a/src/League/OAuth2/Server/Grant/Password.php
+++ b/src/League/OAuth2/Server/Grant/Password.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Password grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -27,10 +27,8 @@ use League\OAuth2\Server\Storage\ScopeInterface;
 /**
  * Password grant class
  */
-class Password implements GrantTypeInterface {
-
-    use GrantTrait;
-
+class Password extends AbstractGrant
+{
     /**
      * Grant identifier
      * @var string
@@ -109,23 +107,17 @@ class Password implements GrantTypeInterface {
         }
 
         // Validate client ID and client secret
-        $clientDetails = $this->server->getStorage('client')->getClient(
+        $client = $this->server->getStorage('client')->getClient(
             $clientId,
             $clientSecret,
             null,
             $this->getIdentifier()
         );
 
-        if ($clientDetails === false) {
+        if (($client instanceof Client) === false) {
             throw new ClientException(Authorization::getExceptionMessage('invalid_client'), 8);
         }
 
-        $client = new Client;
-        $client->setId($clientDetails['id']);
-        $client->setSecret($clientDetails['secret']);
-
-
-
         $username = $this->server->getRequest()->request->get('username', null);
         if (is_null($username)) {
             throw new ClientException(
@@ -146,7 +138,7 @@ class Password implements GrantTypeInterface {
         $userId = call_user_func($this->getVerifyCredentialsCallback(), $username, $password);
 
         if ($userId === false) {
-            throw new Exception\ClientException($this->authServer->getExceptionMessage('invalid_credentials'), 0);
+            throw new ClientException($this->server->getExceptionMessage('invalid_credentials'), 0);
         }
 
         // Validate any scopes that are in the request
@@ -154,15 +146,14 @@ class Password implements GrantTypeInterface {
         $scopes = $this->validateScopes($scopeParam);
 
         // Create a new session
-        $session = new Session($this->server->getStorage('session'));
+        $session = new Session($this->server);
         $session->setOwner('user', $userId);
         $session->associateClient($client);
 
         // Generate an access token
-        $accessToken = new AccessToken($this->server->getStorage('access_token'));
-        $accessToken->setId(SecureKey::make());
-        $accessToken->setTimestamp(time());
-        $accessToken->setTTL($this->server->getAccessTokenTTL());
+        $accessToken = new AccessToken($this->server);
+        $accessToken->setToken(SecureKey::make());
+        $accessToken->setExpireTime($this->server->getAccessTokenTTL() + time());
 
         // Associate scopes with the session and access token
         foreach ($scopes as $scope) {
@@ -171,29 +162,28 @@ class Password implements GrantTypeInterface {
         }
 
         $response = [
-            'access_token'  =>  $accessToken->getId(),
+            'access_token'  =>  $accessToken->getToken(),
             'token_type'    =>  'Bearer',
             'expires'       =>  $accessToken->getExpireTime(),
-            'expires_in'    =>  $accessToken->getTTL()
+            'expires_in'    =>  $this->server->getAccessTokenTTL()
         ];
 
         // Associate a refresh token if set
         if ($this->server->hasGrantType('refresh_token')) {
-            $refreshToken = new RefreshToken($this->server->getStorage('refresh_token'));
-            $refreshToken->setId(SecureKey::make());
-            $refreshToken->setTimestamp(time());
-            $refreshToken->setTTL($this->server->getGrantType('refresh_token')->getRefreshTokenTTL());
-            $response['refresh_token'] = $refreshToken->getId();
+            $refreshToken = new RefreshToken($this->server);
+            $refreshToken->setToken(SecureKey::make());
+            $refreshToken->setExpireTime($this->server->getGrantType('refresh_token')->getRefreshTokenTTL() + time());
+            $response['refresh_token'] = $refreshToken->getToken();
         }
 
         // Save everything
-        $session->save();
+        $session->save($this->server->getStorage('session'));
         $accessToken->setSession($session);
-        $accessToken->save();
+        $accessToken->save($this->server->getStorage('access_token'));
 
         if ($this->server->hasGrantType('refresh_token')) {
             $refreshToken->setAccessToken($accessToken);
-            $refreshToken->save();
+            $refreshToken->save($this->server->getStorage('refresh_token'));
         }
 
         return $response;
diff --git a/src/League/OAuth2/Server/Grant/RefreshToken.php b/src/League/OAuth2/Server/Grant/RefreshToken.php
index baea674a..067aaa8a 100644
--- a/src/League/OAuth2/Server/Grant/RefreshToken.php
+++ b/src/League/OAuth2/Server/Grant/RefreshToken.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Refresh token grant
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -18,50 +18,27 @@ use League\OAuth2\Server\Util\SecureKey;
 use League\OAuth2\Server\Storage\SessionInterface;
 use League\OAuth2\Server\Storage\ClientInterface;
 use League\OAuth2\Server\Storage\ScopeInterface;
+use League\OAuth2\Server\Entities\RefreshToken as RT;
+use League\OAuth2\Server\Entities\AccessToken;
+use League\OAuth2\Server\Entities\Session;
+use League\OAuth2\Server\Exception\ClientException;
 
 /**
  * Referesh token grant
  */
-class RefreshToken implements GrantTypeInterface {
-
-    use GrantTrait;
-
+class RefreshToken extends AbstractGrant
+{
     /**
-     * Grant identifier
-     * @var string
+     * {@inheritdoc}
      */
     protected $identifier = 'refresh_token';
 
     /**
-     * Response type
-     * @var string
-     */
-    protected $responseType = null;
-
-    /**
-     * AuthServer instance
-     * @var AuthServer
-     */
-    protected $authServer = null;
-
-    /**
-     * Access token expires in override
-     * @var int
-     */
-    protected $accessTokenTTL = null;
-
-    /**
-     * Refresh token TTL
+     * Refresh token TTL (default = 604800 | 1 week)
      * @var integer
      */
     protected $refreshTokenTTL = 604800;
 
-    /**
-     * Rotate refresh tokens
-     * @var boolean
-     */
-    protected $rotateRefreshTokens = false;
-
     /**
      * Set the TTL of the refresh token
      * @param int $refreshTokenTTL
@@ -82,126 +59,110 @@ class RefreshToken implements GrantTypeInterface {
     }
 
     /**
-     * When a new access is token, expire the refresh token used and issue a new one.
-     * @param  boolean $rotateRefreshTokens Set to true to enable (default = false)
-     * @return void
+     * {@inheritdoc}
      */
-    public function rotateRefreshTokens($rotateRefreshTokens = false)
+    public function completeFlow()
     {
-        $this->rotateRefreshTokens = $rotateRefreshTokens;
-    }
-
-    /**
-     * Complete the refresh token grant
-     * @param  null|array $inputParams
-     * @return array
-     */
-    public function completeFlow($inputParams = null)
-    {
-        // Get the required params
-        $authParams = $this->authServer->getParam(array('client_id', 'client_secret', 'refresh_token', 'scope'), 'post', $inputParams);
-
-        if (is_null($authParams['client_id'])) {
-            throw new Exception\ClientException(sprintf($this->authServer->getExceptionMessage('invalid_request'), 'client_id'), 0);
+        $clientId = $this->server->getRequest()->request->get('client_id', null);
+        if (is_null($clientId)) {
+            throw new Exception\ClientException(
+                sprintf($this->server->getExceptionMessage('invalid_request'), 'client_id'),
+                0
+            );
         }
 
-        if (is_null($authParams['client_secret'])) {
-            throw new Exception\ClientException(sprintf($this->authServer->getExceptionMessage('invalid_request'), 'client_secret'), 0);
+        $clientSecret = $this->server->getRequest()->request->get('client_secret', null);
+        if (is_null($clientSecret)) {
+            throw new Exception\ClientException(
+                sprintf($this->server->getExceptionMessage('invalid_request'), 'client_secret'),
+                0
+            );
         }
 
         // Validate client ID and client secret
-        $clientDetails = $this->authServer->getStorage('client')->getClient($authParams['client_id'], $authParams['client_secret'], null, $this->identifier);
+        $client = $this->server->getStorage('client')->getClient(
+            $clientId,
+            $clientSecret,
+            null,
+            $this->getIdentifier()
+        );
 
-        if ($clientDetails === false) {
-            throw new Exception\ClientException($this->authServer->getExceptionMessage('invalid_client'), 8);
+        if ($client === null) {
+            throw new ClientException(Authorization::getExceptionMessage('invalid_client'), 8);
         }
 
-        $authParams['client_details'] = $clientDetails;
-
-        if (is_null($authParams['refresh_token'])) {
-            throw new Exception\ClientException(sprintf($this->authServer->getExceptionMessage('invalid_request'), 'refresh_token'), 0);
+        $oldRefreshTokenParam = $this->server->getRequest()->request->get('refresh_token', null);
+        if ($oldRefreshTokenParam === null) {
+            throw new Exception\ClientException(
+                sprintf($this->server->getExceptionMessage('invalid_request'), 'refresh_token'),
+                0
+            );
         }
 
         // Validate refresh token
-        $accessTokenId = $this->authServer->getStorage('session')->validateRefreshToken($authParams['refresh_token'], $authParams['client_id']);
+        $oldRefreshToken = $this->server->getStorage('refresh_token')->getToken($oldRefreshTokenParam);
 
-        if ($accessTokenId === false) {
-            throw new Exception\ClientException($this->authServer->getExceptionMessage('invalid_refresh'), 0);
+        if (($oldRefreshToken instanceof RT) === false) {
+            throw new Exception\ClientException($this->server->getExceptionMessage('invalid_refresh'), 0);
         }
 
-        // Get the existing access token
-        $accessTokenDetails = $this->authServer->getStorage('session')->getAccessToken($accessTokenId);
+        $oldAccessToken = $oldRefreshToken->getAccessToken();
 
-        // Get the scopes for the existing access token
-        $scopes = $this->authServer->getStorage('session')->getScopes($accessTokenDetails['access_token']);
+        // Get the scopes for the original session
+        $session = $oldAccessToken->getSession();
+        $scopes = $session->getScopes();
 
-        // Generate new tokens and associate them to the session
-        $accessToken = SecureKey::make();
-        $accessTokenExpiresIn = ($this->accessTokenTTL !== null) ? $this->accessTokenTTL : $this->authServer->getAccessTokenTTL();
-        $accessTokenExpires = time() + $accessTokenExpiresIn;
+        // Get and validate any requested scopes
+        $requestedScopesString = $this->server->getRequest()->request->get('scope', '');
+        $requestedScopes = $this->validateScopes($requestedScopesString);
 
-        // Associate the new access token with the session
-        $newAccessTokenId = $this->authServer->getStorage('session')->associateAccessToken($accessTokenDetails['session_id'], $accessToken, $accessTokenExpires);
+        // If no new scopes are requested then give the access token the original session scopes
+        if (count($requestedScopes) === 0) {
+            $newScopes = $scopes;
+        } else {
+            // The OAuth spec says that a refreshed access token can have the original scopes or fewer so ensure
+            //  the request doesn't include any new scopes
 
-        if ($this->rotateRefreshTokens === true) {
+            foreach ($requestedScopes as $requestedScope) {
+                // if ()
+            }
 
-            // Generate a new refresh token
-            $refreshToken = SecureKey::make();
-            $refreshTokenExpires = time() + $this->getRefreshTokenTTL();
-
-            // Revoke the old refresh token
-            $this->authServer->getStorage('session')->removeRefreshToken($authParams['refresh_token']);
-
-            // Associate the new refresh token with the new access token
-            $this->authServer->getStorage('session')->associateRefreshToken($newAccessTokenId, $refreshToken, $refreshTokenExpires, $authParams['client_id']);
+            $newScopes = $requestedScopes;
         }
 
-        // There isn't a request for reduced scopes so assign the original ones (or we're not rotating scopes)
-        if ( ! isset($authParams['scope'])) {
+        // Generate a new access token and assign it the correct sessions
+        $newAccessToken = new AccessToken();
+        $newAccessToken->setToken(SecureKey::make());
+        $newAccessToken->setExpireTime($this->server->getAccessTokenTTL() + time());
+        $newAccessToken->setSession($session);
 
-            foreach ($scopes as $scope) {
-                $this->authServer->getStorage('session')->associateScope($newAccessTokenId, $scope['id']);
-            }
-
-        } elseif ( isset($authParams['scope']) && $this->rotateRefreshTokens === true) {
-
-            // The request is asking for reduced scopes and rotate tokens is enabled
-            $reqestedScopes = explode($this->authServer->getScopeDelimeter(), $authParams['scope']);
-
-            for ($i = 0; $i < count($reqestedScopes); $i++) {
-                $reqestedScopes[$i] = trim($reqestedScopes[$i]);
-                if ($reqestedScopes[$i] === '') unset($reqestedScopes[$i]); // Remove any junk scopes
-            }
-
-            // Check that there aren't any new scopes being included
-            $existingScopes = array();
-            foreach ($scopes as $s) {
-                $existingScopes[] = $s['scope'];
-            }
-
-            foreach ($reqestedScopes as $reqScope) {
-                if ( ! in_array($reqScope, $existingScopes)) {
-                    throw new Exception\ClientException(sprintf($this->authServer->getExceptionMessage('invalid_request'), 'scope'), 0);
-                }
-
-                // Associate with the new access token
-                $scopeDetails = $this->authServer->getStorage('scope')->getScope($reqScope, $authParams['client_id'], $this->identifier);
-                $this->authServer->getStorage('session')->associateScope($newAccessTokenId, $scopeDetails['id']);
-            }
+        foreach ($newScopes as $newScope) {
+            $newAccessToken->associateScope($newScope);
         }
 
-        $response = array(
-            'access_token'  =>  $accessToken,
-            'token_type'    =>  'bearer',
-            'expires'       =>  $accessTokenExpires,
-            'expires_in'    =>  $accessTokenExpiresIn
-        );
+        // Expire the old token and save the new one
+        $oldAccessToken->expire($this->server->getStorage('access_token'));
+        $newAccessToken->save($this->server->getStorage('access_token'));
 
-        if ($this->rotateRefreshTokens === true) {
-            $response['refresh_token'] = $refreshToken;
-        }
+        $response = [
+            'access_token'  =>  $newAccessToken->getToken(),
+            'token_type'    =>  'Bearer',
+            'expires'       =>  $newAccessToken->getExpireTime(),
+            'expires_in'    =>  $this->server->getAccessTokenTTL()
+        ];
+
+        // Expire the old refresh token
+        $oldRefreshToken->expire($this->server->getStorage('refresh_token'));
+
+        // Generate a new refresh token
+        $newRefreshToken = new RT();
+        $newRefreshToken->setToken(SecureKey::make());
+        $newRefreshToken->setExpireTime($this->getRefreshTokenTTL() + time());
+        $newRefreshToken->setAccessToken($newAccessToken);
+        $newRefreshToken->save($this->server->getStorage('refresh_token'));
+
+        $response['refresh_token'] = $newRefreshToken->getToken();
 
         return $response;
     }
-
 }
diff --git a/src/League/OAuth2/Server/Resource.php b/src/League/OAuth2/Server/Resource.php
index ab9b91e6..1e2ea1f4 100644
--- a/src/League/OAuth2/Server/Resource.php
+++ b/src/League/OAuth2/Server/Resource.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Resource Server
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
@@ -257,10 +257,8 @@ class Resource
 
     /**
      * Checks if the presented access token has the given scope(s)
-     *
-     * @param array|string  An array of scopes or a single scope as a string
-     *
-     * @return bool         Returns bool if all scopes are found, false if any fail
+     * @param array|string $scopes An array of scopes or a single scope as a string
+     * @return bool Returns bool if all scopes are found, false if any fail
      */
     public function hasScope($scopes)
     {
diff --git a/src/League/OAuth2/Server/Storage/AccessTokenInterface.php b/src/League/OAuth2/Server/Storage/AccessTokenInterface.php
index e2e5086d..79d2edb9 100644
--- a/src/League/OAuth2/Server/Storage/AccessTokenInterface.php
+++ b/src/League/OAuth2/Server/Storage/AccessTokenInterface.php
@@ -1,24 +1,56 @@
 <?php
-
 /**
  * OAuth 2.0 Access token storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Access token interface
+ */
 interface AccessTokenInterface
 {
+    /**
+     * Get an instance of Entites\AccessToken
+     * @param  string $token The access token
+     * @return \League\OAuth2\Server\Entities\AccessToken
+     */
     public function getToken($token);
 
+    /**
+     * Get the scopes for an access token
+     * @param  string $token The access token
+     * @return array Array of \League\OAuth2\Server\Entities\Scope
+     */
     public function getTokenScopes($token);
 
+    /**
+     * Creates a new access token
+     * @param  string $token The access token
+     * @param  integer $expireTime The expire time expressed as a unix timestamp
+     * @param  string|integer $sessionId The session ID
+     * @return \League\OAuth2\Server\Entities\AccessToken
+     */
     public function createAccessToken($token, $expireTime, $sessionId);
 
-    public function associateScope($token, $scopeId);
+    /**
+     * Associate a scope with an acess token
+     * @param  string $token The access token
+     * @param  string $scope The scope
+     * @return void
+     */
+    public function associateScope($token, $scope);
+
+    /**
+     * Delete an access token
+     * @param  string $token The access token to delete
+     * @return void
+     */
+    public function delete($token);
 }
diff --git a/src/League/OAuth2/Server/Storage/Adapter.php b/src/League/OAuth2/Server/Storage/Adapter.php
new file mode 100644
index 00000000..07414491
--- /dev/null
+++ b/src/League/OAuth2/Server/Storage/Adapter.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * OAuth 2.0 storage adapter
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
+ * @license     http://mit-license.org/
+ * @link        http://github.com/php-loep/oauth2-server
+ */
+
+namespace League\OAuth2\Server\Storage;
+
+/**
+ * Storage adapter class
+ */
+class Adapter
+{
+    /**
+     * Server
+     * @var \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
+     */
+    protected $server;
+
+    /**
+     * Set the server
+     * @param \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource $server
+     */
+    public function setServer($server)
+    {
+        $this->server = $server;
+        return $this;
+    }
+
+    /**
+     * Return the server
+     * @return \League\OAuth2\Server\Authorization|\League\OAuth2\Server\Resource
+     */
+    protected function getServer()
+    {
+        return $this->server;
+    }
+}
diff --git a/src/League/OAuth2/Server/Storage/AuthCodeInterface.php b/src/League/OAuth2/Server/Storage/AuthCodeInterface.php
index c8e4831f..58add25d 100644
--- a/src/League/OAuth2/Server/Storage/AuthCodeInterface.php
+++ b/src/League/OAuth2/Server/Storage/AuthCodeInterface.php
@@ -1,18 +1,25 @@
 <?php
-
 /**
- * OAuth 2.0 Refresh token storage interface
+ * OAuth 2.0 Auth code storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Auth code storage interface
+ */
 interface AuthCodeInterface
 {
+    /**
+     * Get the auth code
+     * @param  string $code
+     * @return \League\OAuth2\Server\Entities\AuthCode
+     */
     public function getCode($code);
 }
diff --git a/src/League/OAuth2/Server/Storage/ClientInterface.php b/src/League/OAuth2/Server/Storage/ClientInterface.php
index 2732976b..b21e4194 100644
--- a/src/League/OAuth2/Server/Storage/ClientInterface.php
+++ b/src/League/OAuth2/Server/Storage/ClientInterface.php
@@ -2,15 +2,18 @@
 /**
  * OAuth 2.0 Client storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Client storage interface
+ */
 interface ClientInterface
 {
     /**
@@ -38,23 +41,11 @@ interface ClientInterface
      *  oauth_client_endpoints.redirect_uri = :redirectUri
      * </code>
      *
-     * Response:
-     *
-     * <code>
-     * Array
-     * (
-     *     [id]             => (string) The client ID
-     *     [secret]         => (string) The client secret
-     *     [redirect_uri]   => (string) The redirect URI used in this request
-     *     [name]           => (string) The name of the client
-     * )
-     * </code>
-     *
      * @param  string     $clientId     The client's ID
      * @param  string     $clientSecret The client's secret (default = "null")
      * @param  string     $redirectUri  The client's redirect URI (default = "null")
      * @param  string     $grantType    The grant type used in the request (default = "null")
-     * @return bool|array               Returns false if the validation fails, array on success
+     * @return League\OAuth2\Server\Entities\Client|null
      */
     public function getClient($clientId, $clientSecret = null, $redirectUri = null, $grantType = null);
 }
diff --git a/src/League/OAuth2/Server/Storage/RefreshTokenInterface.php b/src/League/OAuth2/Server/Storage/RefreshTokenInterface.php
index 68026121..e77fe37d 100644
--- a/src/League/OAuth2/Server/Storage/RefreshTokenInterface.php
+++ b/src/League/OAuth2/Server/Storage/RefreshTokenInterface.php
@@ -1,18 +1,41 @@
 <?php
-
 /**
  * OAuth 2.0 Refresh token storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Refresh token interface
+ */
 interface RefreshTokenInterface
 {
-    public function getToken($token, $clientId);
+    /**
+     * Return a new instance of \League\OAuth2\Server\Entities\RefreshToken
+     * @param  string $token
+     * @return \League\OAuth2\Server\Entities\RefreshToken
+     */
+    public function getToken($token);
+
+    /**
+     * Create a new refresh token_name
+     * @param  string $token
+     * @param  integer $expireTime
+     * @param  string $accessToken
+     * @return \League\OAuth2\Server\Entities\RefreshToken
+     */
+    public function createRefreshToken($token, $expireTime, $accessToken);
+
+    /**
+     * Delete the refresh token
+     * @param  string $token
+     * @return void
+     */
+    public function delete($token);
 }
diff --git a/src/League/OAuth2/Server/Storage/ScopeInterface.php b/src/League/OAuth2/Server/Storage/ScopeInterface.php
index 60efd9ca..a6d8b6ac 100644
--- a/src/League/OAuth2/Server/Storage/ScopeInterface.php
+++ b/src/League/OAuth2/Server/Storage/ScopeInterface.php
@@ -2,15 +2,18 @@
 /**
  * OAuth 2.0 Scope storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Scope interface
+ */
 interface ScopeInterface
 {
     /**
@@ -22,22 +25,9 @@ interface ScopeInterface
      * SELECT * FROM oauth_scopes WHERE scope = :scope
      * </code>
      *
-     * Response:
-     *
-     * <code>
-     * Array
-     * (
-     *     [id] => (int) The scope's ID
-     *     [scope] => (string) The scope itself
-     *     [name] => (string) The scope's name
-     *     [description] => (string) The scope's description
-     * )
-     * </code>
-     *
      * @param  string     $scope     The scope
-     * @param  string     $clientId  The client ID (default = "null")
      * @param  string     $grantType The grant type used in the request (default = "null")
      * @return bool|array If the scope doesn't exist return false
      */
-    public function getScope($scope, $clientId = null, $grantType = null);
+    public function getScope($scope, $grantType = null);
 }
diff --git a/src/League/OAuth2/Server/Storage/SessionInterface.php b/src/League/OAuth2/Server/Storage/SessionInterface.php
index a5cd62f7..c5bc767e 100644
--- a/src/League/OAuth2/Server/Storage/SessionInterface.php
+++ b/src/League/OAuth2/Server/Storage/SessionInterface.php
@@ -1,27 +1,24 @@
 <?php
-
 /**
  * OAuth 2.0 Session storage interface
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
 
 namespace League\OAuth2\Server\Storage;
 
+/**
+ * Session storage interface
+ */
 interface SessionInterface
 {
     /**
      * Get a session
      *
-     * Response:
-     * <code>
-     *
-     * </code>
-     *
      * @param  int $sessionId
      * @return array (As described above)
      */
diff --git a/src/League/OAuth2/Server/Util/RedirectUri.php b/src/League/OAuth2/Server/Util/RedirectUri.php
index ced04113..517fca1a 100644
--- a/src/League/OAuth2/Server/Util/RedirectUri.php
+++ b/src/League/OAuth2/Server/Util/RedirectUri.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Redirect URI generator
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */
diff --git a/src/League/OAuth2/Server/Util/RequestInterface.php b/src/League/OAuth2/Server/Util/RequestInterface.php
deleted file mode 100644
index 00b8dc8e..00000000
--- a/src/League/OAuth2/Server/Util/RequestInterface.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-/**
- * OAuth 2.0 Request class interface
- *
- * @package     php-loep/oauth2-server
- * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
- * @license     http://mit-license.org/
- * @link        http://github.com/php-loep/oauth2-server
- */
-
-namespace League\OAuth2\Server\Util;
-
-interface RequestInterface
-{
-
-    public function get($index = null);
-
-    public function post($index = null);
-
-    public function cookie($index = null);
-
-    public function file($index = null);
-
-    public function server($index = null);
-
-    public function header($index = null);
-
-}
diff --git a/src/League/OAuth2/Server/Util/SecureKey.php b/src/League/OAuth2/Server/Util/SecureKey.php
index 8ff762c3..6aee6dc1 100644
--- a/src/League/OAuth2/Server/Util/SecureKey.php
+++ b/src/League/OAuth2/Server/Util/SecureKey.php
@@ -2,9 +2,9 @@
 /**
  * OAuth 2.0 Secure key generator
  *
- * @package     php-loep/oauth2-server
+ * @package     league/oauth2-server
  * @author      Alex Bilbie <hello@alexbilbie.com>
- * @copyright   Copyright (c) 2013 PHP League of Extraordinary Packages
+ * @copyright   Copyright (c) PHP League of Extraordinary Packages
  * @license     http://mit-license.org/
  * @link        http://github.com/php-loep/oauth2-server
  */