diff --git a/lib/recurly/base_client.php b/lib/recurly/base_client.php
index 6562e723..78d0dabe 100644
--- a/lib/recurly/base_client.php
+++ b/lib/recurly/base_client.php
@@ -8,7 +8,7 @@ abstract class BaseClient
 
     private $_baseUrl = 'https://v3.recurly.com';
     private $_api_key;
-    protected $_http;
+    protected $http;
 
     /**
      * Constructor
@@ -18,7 +18,7 @@ abstract class BaseClient
     public function __construct(string $api_key)
     {
         $this->_api_key = $api_key;
-        $this->_http = new HttpAdapter;
+        $this->http = new HttpAdapter;
     }
 
     /**
@@ -61,7 +61,7 @@ private function _getResponse(string $method, string $path, ?array $body = [], ?
         $request = new \Recurly\Request($method, $path, $body, $params);
 
         $url = $this->_buildPath($path, $params);
-        list($result, $response_header) = $this->_http->execute($method, $url, $body, $this->_headers());
+        list($result, $response_header) = $this->http->execute($method, $url, $body, $this->_headers());
 
         // TODO: The $request should be added to the $response
         $response = new \Recurly\Response($result);
diff --git a/lib/recurly/http_adapter.php b/lib/recurly/http_adapter.php
index 4ec87411..ae7c9480 100644
--- a/lib/recurly/http_adapter.php
+++ b/lib/recurly/http_adapter.php
@@ -1,13 +1,13 @@
 <?php
-
-namespace Recurly;
-
 /**
  * This class abstracts away all the PHP-level HTTP
  * code. This allows us to easily mock out the HTTP
  * calls in BaseClient by injecting a mocked version of
  * this adapter.
  */
+
+namespace Recurly;
+
 class HttpAdapter
 {
     private static $_default_options = [
@@ -15,21 +15,26 @@ class HttpAdapter
     ];
 
     /**
-     * @param string $method   HTTP method to use
-     * @param string $url      Fully qualified URL
-     * @param array  $body     The request body
-     * @param array  $headers  HTTP headers
+     * Performs HTTP request
+     * 
+     * @param string $method  HTTP method to use
+     * @param string $url     Fully qualified URL
+     * @param array  $body    The request body
+     * @param array  $headers HTTP headers
+     * 
+     * @return array The API response as a string and the headers as an array
      */
-    public function execute($method, $url, $body, $headers)
+    public function execute($method, $url, $body, $headers): array
     {
-        $body = empty($body) ? NULL : json_encode($body);
-        $options = array_replace(self::$_default_options, [
+        $body = empty($body) ? null : json_encode($body);
+        $options = array_replace(
+            self::$_default_options, [
             'method' => $method,
             'content' => $body,
-        ]);
+            ]
+        );
         $headers_str = "";
-        foreach ($headers as $k => $v)
-        {
+        foreach ($headers as $k => $v) {
             $headers_str .= "$k: $v\r\n";
         }
         $options['header'] = $headers_str;
diff --git a/lib/recurly/recurly_traits.php b/lib/recurly/recurly_traits.php
index bf4770df..4e5f00bd 100644
--- a/lib/recurly/recurly_traits.php
+++ b/lib/recurly/recurly_traits.php
@@ -4,13 +4,25 @@
 
 trait RecurlyTraits
 {
+    /**
+     * Generates User-Agent for API requests
+     * 
+     * @return string Recurly client User-Agent string
+     */
     protected static function getUserAgent(): string
     {
         $php_version = phpversion();
         return "Recurly/" . \Recurly\Version::CURRENT . "; php " . $php_version;
     }
 
-    protected static function encodeApiKey($key): string
+    /**
+     * Base64 encodes the API key
+     * 
+     * @param string $key The API key to encode
+     * 
+     * @return string base64 encoded API key
+     */
+    protected static function encodeApiKey(string $key): string
     {
         return base64_encode($key);
     }
diff --git a/tests/mock_client.php b/tests/mock_client.php
index 667b4000..f0f371ec 100644
--- a/tests/mock_client.php
+++ b/tests/mock_client.php
@@ -14,7 +14,7 @@ class MockClient extends BaseClient
     public function __construct()
     {
         parent::__construct("apikey");
-        $this->_http = (new Generator())->getMock(HttpAdapter::class);
+        $this->http = (new Generator())->getMock(HttpAdapter::class);
     }
 
     protected function apiVersion(): string
@@ -55,7 +55,7 @@ public function deleteResource(string $resource_id): \Recurly\EmptyResource
     public function addScenario($method, $url, $body, $result, $status): void
     {
         $resp_header = self::_generateRespHeader($status);
-        $this->_http->method('execute')->with(
+        $this->http->method('execute')->with(
             $method,
             $url,
             $body,
@@ -65,7 +65,7 @@ public function addScenario($method, $url, $body, $result, $status): void
 
     public function clearScenarios(): void
     {
-        $this->_http = (new Generator())->getMock(HttpAdapter::class);
+        $this->http = (new Generator())->getMock(HttpAdapter::class);
     }
 
     private static function _generateRespHeader($status): array