diff --git a/src/Mailgun/Mailgun.php b/src/Mailgun/Mailgun.php
index fc9224b..5dea5ad 100644
--- a/src/Mailgun/Mailgun.php
+++ b/src/Mailgun/Mailgun.php
@@ -2,36 +2,53 @@
 
 namespace Mailgun;
 
-require_once 'Constants/Constants.php';
-
-use Mailgun\Messages\Messages;
+use Mailgun\Constants\ExceptionMessages;
 use Mailgun\Messages\Exceptions;
 use Mailgun\Connection\RestClient;
 use Mailgun\Messages\BatchMessage;
 use Mailgun\Lists\OptInHandler;
 use Mailgun\Messages\MessageBuilder;
 
-/*
-   This class is the base class for the Mailgun SDK.
-   See the official documentation for usage instructions.
-*/
-
+/**
+ * This class is the base class for the Mailgun SDK.
+ * See the official documentation (link below) for usage instructions.
+ *
+ * @link https://github.com/mailgun/mailgun-php/blob/master/README.md
+ */
 class Mailgun{
-    protected $workingDomain;
+
+    /**
+     * @var RestClient
+     */
     protected $restClient;
+
+    /**
+     * @var null|string
+     */
     protected $apiKey;
-    
+
+    /**
+     * @param string|null $apiKey
+     * @param string $apiEndpoint
+     * @param string $apiVersion
+     * @param bool $ssl
+     */
     public function __construct($apiKey = null, $apiEndpoint = "api.mailgun.net", $apiVersion = "v2", $ssl = true){
         $this->apiKey = $apiKey;
         $this->restClient = new RestClient($apiKey, $apiEndpoint, $apiVersion, $ssl);
     }
 
+    /**
+     *  This function allows the sending of a fully formed message OR a custom
+     *  MIME string. If sending MIME, the string must be passed in to the 3rd
+     *  position of the function call.
+     *
+     * @param string $workingDomain
+     * @param array $postData
+     * @param array $postFiles
+     * @throws Exceptions\MissingRequiredMIMEParameters
+     */
     public function sendMessage($workingDomain, $postData, $postFiles = array()){
-        /*
-         *  This function allows the sending of a fully formed message OR a custom
-         *  MIME string. If sending MIME, the string must be passed in to the 3rd
-         *  position of the function call.
-        */
         if(is_array($postFiles)){
             return $this->post("$workingDomain/messages", $postData, $postFiles);
         }
@@ -47,21 +64,24 @@ class Mailgun{
             return $result;
         }
         else{
-            throw new Exceptions\MissingRequiredMIMEParameters(EXCEPTION_MISSING_REQUIRED_MIME_PARAMETERS);
+            throw new Exceptions\MissingRequiredMIMEParameters(ExceptionMessages::EXCEPTION_MISSING_REQUIRED_MIME_PARAMETERS);
         }
     }
-    
+
+    /**
+     * This function checks the signature in a POST request to see if it is
+     * authentic.
+     *
+     * Pass an array of parameters.  If you pass nothing, $_POST will be
+     * used instead.
+     *
+     * If this function returns FALSE, you must not process the request.
+     * You should reject the request with status code 403 Forbidden.
+     *
+     * @param array|null $postData
+     * @return bool
+     */
     public function verifyWebhookSignature($postData = NULL) {
-        /*
-         * This function checks the signature in a POST request to see if it is
-         * authentic.
-         *
-         * Pass an array of parameters.  If you pass nothing, $_POST will be
-         * used instead.
-         *
-         * If this function returns FALSE, you must not process the request.
-         * You should reject the request with status code 403 Forbidden.
-        */
         if(is_null($postData)) {
             $postData = $_POST;
         }
@@ -76,30 +96,61 @@ class Mailgun{
         }
     }
 
+    /**
+     * @param string $endpointUrl
+     * @param array $postData
+     * @param array $files
+     * @return \stdClass
+     */
     public function post($endpointUrl, $postData = array(), $files = array()){
         return $this->restClient->post($endpointUrl, $postData, $files);
     }
 
+    /**
+     * @param string $endpointUrl
+     * @param array $queryString
+     * @return \stdClass
+     */
     public function get($endpointUrl, $queryString = array()){
         return $this->restClient->get($endpointUrl, $queryString);
     }
 
+    /**
+     * @param string $endpointUrl
+     * @return \stdClass
+     */
     public function delete($endpointUrl){
         return $this->restClient->delete($endpointUrl);
     }
 
+    /**
+     * @param string $endpointUrl
+     * @param array $putData
+     * @return \stdClass
+     */
     public function put($endpointUrl, $putData){
         return $this->restClient->put($endpointUrl, $putData);
     }
 
+    /**
+     * @return MessageBuilder
+     */
     public function MessageBuilder(){
         return new MessageBuilder();
     }
 
+    /**
+     * @return OptInHandler
+     */
     public function OptInHandler(){
         return new OptInHandler();
     }
 
+    /**
+     * @param string $workingDomain
+     * @param bool $autoSend
+     * @return BatchMessage
+     */
     public function BatchMessage($workingDomain, $autoSend = true){
         return new BatchMessage($this->restClient, $workingDomain, $autoSend);
     }