diff --git a/src/OAuth2/Grant/RefreshToken.php b/src/OAuth2/Grant/RefreshToken.php
index b396e2d1..bd7839ca 100644
--- a/src/OAuth2/Grant/RefreshToken.php
+++ b/src/OAuth2/Grant/RefreshToken.php
@@ -1,4 +1,13 @@
 <?php
+/**
+ * OAuth 2.0 Refresh token grant
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Grant;
 
@@ -10,22 +19,47 @@ use OAuth2\Storage\SessionInterface;
 use OAuth2\Storage\ClientInterface;
 use OAuth2\Storage\ScopeInterface;
 
+/**
+ * Referesh token grant
+ */
 class RefreshToken implements GrantTypeInterface {
 
+    /**
+     * Grant identifier
+     * @var string
+     */
     protected $identifier = 'refresh_token';
+
+    /**
+     * Response type
+     * @var string
+     */
     protected $responseType = null;
 
+    /**
+     * Return the identifier
+     * @return string
+     */
     public function getIdentifier()
     {
         return $this->identifier;
     }
 
+    /**
+     * Return the response type
+     * @return string
+     */
     public function getResponseType()
     {
         return $this->responseType;
     }
 
-    public function completeFlow($inputParams = null, $authParams = array())
+    /**
+     * Complete the refresh token grant
+     * @param  null|array $inputParams
+     * @return array
+     */
+    public function completeFlow($inputParams = null)
     {
         // Get the required params
         $authParams = AuthServer::getParam(array('client_id', 'client_secret', 'refresh_token'), 'post', $inputParams);
diff --git a/src/OAuth2/Storage/ClientInterface.php b/src/OAuth2/Storage/ClientInterface.php
index 2abee251..605c42a9 100644
--- a/src/OAuth2/Storage/ClientInterface.php
+++ b/src/OAuth2/Storage/ClientInterface.php
@@ -1,4 +1,13 @@
 <?php
+/**
+ * OAuth 2.0 Client storage interface
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Storage;
 
diff --git a/src/OAuth2/Storage/ScopeInterface.php b/src/OAuth2/Storage/ScopeInterface.php
index 8777aee6..82c71c39 100644
--- a/src/OAuth2/Storage/ScopeInterface.php
+++ b/src/OAuth2/Storage/ScopeInterface.php
@@ -1,4 +1,13 @@
 <?php
+/**
+ * OAuth 2.0 Scope storage interface
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Storage;
 
diff --git a/src/OAuth2/Storage/SessionInterface.php b/src/OAuth2/Storage/SessionInterface.php
index 7e9fd368..1c2632f6 100644
--- a/src/OAuth2/Storage/SessionInterface.php
+++ b/src/OAuth2/Storage/SessionInterface.php
@@ -1,4 +1,13 @@
 <?php
+/**
+ * OAuth 2.0 Session storage interface
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Storage;
 
@@ -16,15 +25,16 @@ interface SessionInterface
      * $accessToken, $stage, UNIX_TIMESTAMP(NOW()), UNIX_TIMESTAMP(NOW()))
      * </code>
      *
-     * @param  string $clientId     The client ID
-     * @param  string $redirectUri  The redirect URI
-     * @param  string $type         The session owner's type (default = "user")
-     * @param  string $typeId       The session owner's ID (default = "null")
-     * @param  string $authCode     The authorisation code (default = "null")
-     * @param  string $accessToken  The access token (default = "null")
-     * @param  string $refreshToken The refresh token (default = "null")
-     * @param  string $stage        The stage of the session (default ="request")
-     * @return  int The session ID
+     * @param  string $clientId          The client ID
+     * @param  string $redirectUri       The redirect URI
+     * @param  string $type              The session owner's type (default = "user")
+     * @param  string $typeId            The session owner's ID (default = "null")
+     * @param  string $authCode          The authorisation code (default = "null")
+     * @param  string $accessToken       The access token (default = "null")
+     * @param  string $refreshToken      The refresh token (default = "null")
+     * @param  int    $accessTokenExpire The expiry time of an access token as a unix timestamp
+     * @param  string $stage             The stage of the session (default ="request")
+     * @return int                       The session ID
      */
     public function createSession(
         $clientId,
@@ -49,11 +59,12 @@ interface SessionInterface
      *  id = $sessionId
      * </code>
      *
-     * @param  string $sessionId    The session ID
-     * @param  string $authCode     The authorisation code (default = "null")
-     * @param  string $accessToken  The access token (default = "null")
-     * @param  string $refreshToken The refresh token (default = "null")
-     * @param  string $stage        The stage of the session (default ="request")
+     * @param  string $sessionId         The session ID
+     * @param  string $authCode          The authorisation code (default = "null")
+     * @param  string $accessToken       The access token (default = "null")
+     * @param  string $refreshToken      The refresh token (default = "null")
+     * @param  int    $accessTokenExpire The expiry time of an access token as a unix timestamp
+     * @param  string $stage             The stage of the session (default ="request")
      * @return  void
      */
     public function updateSession(
@@ -125,6 +136,29 @@ interface SessionInterface
         $authCode
     );
 
+    /**
+     * Validate an access token
+     *
+     * Example SQL query:
+     *
+     * <code>
+     * SELECT id, owner_id, owner_type FROM oauth_sessions WHERE access_token = $accessToken
+     * </code>
+     *
+     * Response:
+     *
+     * <code>
+     * Array
+     * (
+     *     [id] => (int) The session ID
+     *     [owner_type] => (string) The owner type
+     *     [owner_id] => (string) The owner ID
+     * )
+     * </code>
+     *
+     * @param  [type] $accessToken [description]
+     * @return [type]              [description]
+     */
     public function validateAccessToken($accessToken);
 
     /**
@@ -142,6 +176,12 @@ interface SessionInterface
      */
     public function getAccessToken($sessionId);
 
+    /**
+     * Validate a refresh token
+     * @param  string $refreshToken The refresh token
+     * @param  string $clientId     The client ID
+     * @return int                  The session ID
+     */
     public function validateRefreshToken($refreshToken, $clientId);
 
     /**
@@ -174,7 +214,7 @@ interface SessionInterface
      * </code>
      *
      * @param int    $sessionId The session ID
-     * @param string $scope     The scope ID
+     * @param string $scopeId   The scope ID
      * @return void
      */
     public function associateScope($sessionId, $scopeId);
diff --git a/src/OAuth2/Util/RedirectUri.php b/src/OAuth2/Util/RedirectUri.php
index 580758e5..c123b187 100644
--- a/src/OAuth2/Util/RedirectUri.php
+++ b/src/OAuth2/Util/RedirectUri.php
@@ -1,9 +1,28 @@
 <?php
+/**
+ * OAuth 2.0 Redirect URI generator
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Util;
 
+/**
+ * RedirectUri class
+ */
 class RedirectUri
 {
+	/**
+	 * Generate a new redirect uri
+	 * @param  string $uri            The base URI
+	 * @param  array  $params         The query string parameters
+	 * @param  string $queryDelimeter The query string delimeter (default: "?")
+	 * @return string                 The updated URI
+	 */
     public static function make($uri, $params = array(), $queryDelimeter = '?')
     {
         $uri .= (strstr($uri, $queryDelimeter) === false) ? $queryDelimeter : '&';
diff --git a/src/OAuth2/Util/SecureKey.php b/src/OAuth2/Util/SecureKey.php
index 35a55298..d6450146 100644
--- a/src/OAuth2/Util/SecureKey.php
+++ b/src/OAuth2/Util/SecureKey.php
@@ -1,9 +1,26 @@
 <?php
+/**
+ * OAuth 2.0 Secure key generator
+ *
+ * @package     lncd/oauth2
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) 2013 University of Lincoln
+ * @license     http://mit-license.org/
+ * @link        http://github.com/lncd/oauth2
+ */
 
 namespace OAuth2\Util;
 
+/**
+ * SecureKey class
+ */
 class SecureKey
 {
+    /**
+     * Generate a new unique code
+     * @param  integer $len Length of the generated code
+     * @return string
+     */
     public static function make($len = 40)
     {
         // We generate twice as many bytes here because we want to ensure we have