diff --git a/modules/sms_sendtophone/sms_sendtophone.module b/modules/sms_sendtophone/sms_sendtophone.module
index d4a01e5..f071090 100644
--- a/modules/sms_sendtophone/sms_sendtophone.module
+++ b/modules/sms_sendtophone/sms_sendtophone.module
@@ -429,7 +429,7 @@ function sms_sendtophone_form_validate($form, &$form_state) {
  * @see http://drupal.org/node/1354
  */
 function sms_sendtophone_form_submit($form, &$form_state) {
-  if (sms_send($form_state['values']['number'], $form_state['values']['message'], $form_state['values']['gateway'])) {
+  if (sms_send($form_state['values']['number'], $form_state['values']['message'], (array) $form_state['values']['gateway'])) {
     drupal_set_message(t('The message "@message" sent to @number.', array('@message' => $form_state['values']['message'], '@number' => $form_state['values']['number'])));
   }
 }
diff --git a/modules/sms_track/sms_track.module b/modules/sms_track/sms_track.module
index 03cc7c9..f35b561 100644
--- a/modules/sms_track/sms_track.module
+++ b/modules/sms_track/sms_track.module
@@ -8,6 +8,8 @@
  */
 
 use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\sms\Gateway\GatewayInterface;
+use Drupal\sms\Message\SmsMessageInterface;
 use Drupal\views\Plugin\views\query\QueryPluginBase;
 use \Drupal\views\ViewExecutable;
 
@@ -42,7 +44,9 @@ function sms_track_cron() {
 /**
  * Implements hook_sms_send().
  */
-function sms_track_sms_send($number, $message, &$options = array(), $gateway) {
+function sms_track_sms_send(SmsMessageInterface $sms, array $options, GatewayInterface $gateway) {
+  $message = $sms->getMessage();
+  $number = $sms->getRecipients()[0];
   // Tracking.
   // Place a tracking reference on a sent message if we need to.
   if (!empty($options) && !array_key_exists('reference', $options)) {
@@ -55,23 +59,23 @@ function sms_track_sms_send($number, $message, &$options = array(), $gateway) {
  *
  * @param string $op
  *   Operation string (pre process, process, post process).
- * @param string $number
- *   MSISDN of recipient.
- * @param string $message
- *   SMS message body.
+ * @param \Drupal\sms\Message\SmsMessageInterface $sms
+ *   The sms message object.
  * @param array $options
  *   Additional options array including sender.
- * @param array $gateway
+ * @param \Drupal\sms\Gateway\GatewayInterface $gateway
  *   Gateway array for the active gateway.
  * @param array $result
  *   Result array from the gateway response handler.
  */
-function sms_track_sms_send_process($op, $number, $message, $options, $gateway, $result) {
+function sms_track_sms_send_process($op, SmsMessageInterface $sms, $options, GatewayInterface $gateway, $result) {
+  $message = $sms->getMessage();
+  $number = $sms->getRecipients()[0];
   if ($op == 'post process') {
     // Archiving (outgoing == 0)
     $dir = 0;
     $options = (isset($options) && is_array($options))? $options : array();
-    $options['gateway_id'] = $gateway['identifier'];
+    $options['gateway_id'] = $gateway->getIdentifier();
     $options['result']  = $result;
     sms_track_archive_write($dir, $number, $message, $options);
   }
@@ -83,14 +87,14 @@ function sms_track_sms_send_process($op, $number, $message, $options, $gateway,
  *
  * @param string $op
  *   SMS incoming operation string (pre process, process, post process).
- * @param string $number
- *   MSISDN of sender.
- * @param string $message
- *   SMS message body string.
+ * @param \Drupal\sms\Message\SmsMessageInterface $sms
+ *   The sms message object.
  * @param array $options
  *   Additional options including receiver MSISDN.
  */
-function sms_track_sms_incoming($op, $number, $message, $options) {
+function sms_track_sms_incoming($op, SmsMessageInterface $sms, $options) {
+  $number = $sms->getRecipients()[0];
+  $message = $sms->getMessage();
   if ($op == 'pre process' && isset($number)) {
     // Archiving (incoming == 1)
     $dir = 1;
@@ -156,10 +160,10 @@ function sms_track_archive_write($dir, $number, $message, $options = array()) {
       // Or render a status code from a simple true/false result
       if (! $status) {
         if ($options['result']) {
-          $status = SMS_GW_OK;
+          $status = GatewayInterface::STATUS_OK;
         }
         else {
-          $status = SMS_GW_ERR_OTHER;
+          $status = GatewayInterface::STATUS_ERR_OTHER;
         }
       }
       // Add the author and recipient
@@ -175,7 +179,7 @@ function sms_track_archive_write($dir, $number, $message, $options = array()) {
     if ($archive_dir == SMS_DIR_ALL || $archive_dir == SMS_DIR_IN) {
       $reference = NULL;
       // Inbound message status is always the same.
-      $status = SMS_MSG_STATUS_OK;
+      $status = SmsMessageInterface::STATUS_OK;
       // Add the author and recipient
       $recipient = $user->id();
       $author = ($remote_user) ? $remote_user : 0;
diff --git a/modules/sms_user/sms_user.module b/modules/sms_user/sms_user.module
index 8e077b2..67ad11e 100644
--- a/modules/sms_user/sms_user.module
+++ b/modules/sms_user/sms_user.module
@@ -8,6 +8,8 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Url;
+use Drupal\sms\Gateway\GatewayInterface;
+use Drupal\sms\Message\SmsMessageInterface;
 use Drupal\user\Entity\User;
 use Drupal\user\UserInterface;
 use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
@@ -37,7 +39,7 @@ function sms_user_send($uid, $message) {
   // Check if the user is enabled to receive SMS.
   if ($account->hasPermission('receive sms')) {
     if ($account->sms_user['status'] >= SMS_USER_CONFIRMED) {
-      return sms_send($account->sms_user['number'], $message, $account->sms_user['gateway']);
+      return sms_send($account->sms_user['number'], $message, (array) $account->sms_user['gateway']);
     }
     else {
       \Drupal::logger('sms_user')->alert("User %user has not validated mobile number", array('%user' => $account->getUsername()));
@@ -97,18 +99,25 @@ function sms_user_get_uid($number, $status = NULL) {
 
 /**
  * Implements hook_sms_send().
+ *
+ * Aborts sending if the user has opted out or is in sleep mode.
  */
-function sms_user_sms_send(&$number, &$message, &$options, &$gateway) {
-  if (\Drupal::config('sms_user.settings')->get('enable_sleep', 1) && $uid = sms_user_get_uid($number)) {
-    $account = User::load($uid);
+function sms_user_sms_send_process($step, SmsMessageInterface $sms, array $options, GatewayInterface $gateway) {
+  if ($step == 'pre process') {
+    $number = $sms->getRecipients()[0];
+    if (\Drupal::config('sms_user.settings')->get('enable_sleep', 1) && $uid = sms_user_get_uid($number)) {
+      $account = User::load($uid);
 
-    if (_sms_user_opted_out($account)) {
-      unset($gateway['send']);
-      \Drupal::logger('sms_user')->info('Message was not sent to @user because user opted out.', array('@user' => $account->getUsername()));
-    }
-    else if (_sms_user_sleep_active($account)) {
-      unset($gateway['send']);
-      \Drupal::logger('sms_user')->info('Message was not sent to @user due to sleep settings.', array('@user' => $account->getUsername()));
+      if (_sms_user_opted_out($account)) {
+        \Drupal::logger('sms_user')->info('Message was not sent to @user because user opted out.', array('@user' => $account->getUsername()));
+        return FALSE;
+      }
+      else {
+        if (_sms_user_sleep_active($account)) {
+          \Drupal::logger('sms_user')->info('Message was not sent to @user due to sleep settings.', array('@user' => $account->getUsername()));
+          return FALSE;
+        }
+      }
     }
   }
 }
@@ -374,7 +383,7 @@ function sms_user_user_cancel($edit, $account, $method) {
 function sms_user_user_login(AccountInterface $account) {
   // Check if it's the user's first time logging in.
   if (!$account->getLastAccessedTime() && !empty($account->sms_user['number']) && $account->sms_user['status'] <= SMS_USER_CONFIRMED) {
-    sms_user_send_confirmation($account, $account->sms_user['number'], $account->sms_user['gateway']);
+    sms_user_send_confirmation($account, $account->sms_user['number'], (array) $account->sms_user['gateway']);
     drupal_set_message(t('A confirmation message has been sent to your mobile phone. Please @link.', array('@link' => l(t('confirm your number'), 'user/' . $account->id() . '/edit/mobile'))), 'status');
   }
 }
@@ -560,7 +569,9 @@ function sms_user_token_info() {
 /**
  * Implements hook_sms_incoming().
  */
-function sms_user_sms_incoming($op, $number, $message, $options) {
+function sms_user_sms_incoming($op, SmsMessageInterface $sms, $options) {
+  $number = $sms->getRecipients()[0];
+  $message = $sms->getMessage();
   $config = \Drupal::config('sms_user.settings');
   switch ($op) {
     case 'pre process':
diff --git a/modules/sms_user/src/Form/SettingsAddForm.php b/modules/sms_user/src/Form/SettingsAddForm.php
index eef1697..e9447c2 100644
--- a/modules/sms_user/src/Form/SettingsAddForm.php
+++ b/modules/sms_user/src/Form/SettingsAddForm.php
@@ -55,7 +55,7 @@ class SettingsAddForm extends ConfigFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $account = User::load($form_state->getValue('uid'));
-    sms_user_send_confirmation($account, $form_state->getValue('number'), $form_state->getValue('gateway'));
+    sms_user_send_confirmation($account, $form_state->getValue('number'), (array) $form_state->getValue('gateway'));
   }
 
   /**
diff --git a/modules/sms_user/src/Tests/SmsUserWebTest.php b/modules/sms_user/src/Tests/SmsUserWebTest.php
index 6ffac29..90edcc8 100644
--- a/modules/sms_user/src/Tests/SmsUserWebTest.php
+++ b/modules/sms_user/src/Tests/SmsUserWebTest.php
@@ -27,7 +27,10 @@ class SmsUserWebTest extends WebTestBase {
    */
   public function testNumberConfirmationAndSmsUserSend() {
     // Set up test default gateway.
-    $this->config('sms.settings')->set('default_gateway', 'test')->save();
+    /** @var \Drupal\sms\Gateway\GatewayManagerInterface $gateway_manager */
+    $gateway_manager = $this->container->get('plugin.manager.sms_gateway');
+    $gateway_manager->setEnabledGateways(['test']);
+    $gateway_manager->setDefaultGateway('test');
     $user = $this->drupalCreateUser(array('receive sms', 'edit own sms number'));
     $this->drupalLogin($user);
 
diff --git a/sms.module b/sms.module
index 4db981b..14b5e6a 100644
--- a/sms.module
+++ b/sms.module
@@ -6,6 +6,7 @@
  * sending and receiving SMS messages.
  */
 
+use Drupal\Core\Form\FormState;
 use Drupal\Core\Form\FormStateInterface;
 
 // Direction codes.
@@ -60,7 +61,8 @@ function sms_cron_queue_info() {
  * @see sms_handle_result().
  */
 function sms_send($number, $message, $options = array()) {
-  $sms = new SmsMessage($options['sender'], explode(',', $number), $message, $options);
+  $sender = isset($options['sender']) ? $options['sender'] : '';
+  $sms = new SmsMessage($sender, explode(',', $number), $message, $options);
   return \Drupal::service('sms_provider.default')->send($sms, $options);
 }
 
@@ -93,7 +95,8 @@ function sms_incoming_queue_worker(array $item) {
  *   An array of additional options.
  */
 function sms_incoming($number, $message, $options = array()) {
-  $sms = new SmsMessage($options['sender'], explode(',', $number), $message, $options);
+  $sender = isset($options['sender']) ? $options['sender'] : '';
+  $sms = new SmsMessage($sender, explode(',', $number), $message, $options);
   \Drupal::service('sms_provider.default')->incoming($sms, $options);
 }
 
@@ -193,7 +196,7 @@ function sms_send_form($required = FALSE) {
   );
 
   // Add gateway defined fields
-  $form_state = array();
+  $form_state = new FormState();
   $form['gateway']['#tree'] = TRUE;
   $form['gateway'] = array_merge($gateway->sendForm($form, $form_state), $form['gateway']);
 
diff --git a/src/Gateway/GatewayManager.php b/src/Gateway/GatewayManager.php
index 7b77bd6..105b633 100644
--- a/src/Gateway/GatewayManager.php
+++ b/src/Gateway/GatewayManager.php
@@ -132,8 +132,8 @@ class GatewayManager extends DefaultPluginManager implements GatewayManagerInter
   /**
    * {@inheritdoc}
    */
-  public function setEnabledGateways(array $gateways) {
-    foreach ($gateways as $gateway_id) {
+  public function setEnabledGateways(array $gateway_ids) {
+    foreach ($gateway_ids as $gateway_id) {
       $gateway = $this->getGateway($gateway_id);
       $gateway->setEnabled(TRUE);
       $this->saveGateway($gateway);
diff --git a/src/Gateway/GatewayManagerInterface.php b/src/Gateway/GatewayManagerInterface.php
index 5c173ec..a127611 100644
--- a/src/Gateway/GatewayManagerInterface.php
+++ b/src/Gateway/GatewayManagerInterface.php
@@ -44,10 +44,10 @@ interface GatewayManagerInterface {
   /**
    * Sets the list of gateways that are enabled.
    *
-   * @param array $gateways
+   * @param array $gateway_ids
    *   An array of ids of the gateways to be enabled.
    */
-  public function setEnabledGateways(array $gateways);
+  public function setEnabledGateways(array $gateway_ids);
 
   /**
    * Sets the default sms gateway for messaging.
diff --git a/src/Message/SmsMessageResult.php b/src/Message/SmsMessageResult.php
index c21508a..31cdd46 100644
--- a/src/Message/SmsMessageResult.php
+++ b/src/Message/SmsMessageResult.php
@@ -54,6 +54,7 @@ class SmsMessageResult implements SmsMessageResultInterface {
    *   Information to be used to instantiate the SmsMessageResult.
    */
   public function __construct($data) {
+    $data += $this->defaultData();
     $this->status = $data['status'];
     $this->creditBalance = $data['credit_balance'];
     $this->creditsUsed = $data['credit_used'];
@@ -137,4 +138,17 @@ class SmsMessageResult implements SmsMessageResultInterface {
     }
   }
 
+  /**
+   * Returns default data for initializing the value object.
+   */
+  protected function defaultData() {
+    return array(
+      'status' => '',
+      'error_message' => '',
+      'credit_used' => 0,
+      'credit_balance' => 0,
+      'report' => array(),
+    );
+  }
+
 }
diff --git a/src/Plugin/Gateway/LogGateway.php b/src/Plugin/Gateway/LogGateway.php
index a3a8309..4e5c08d 100644
--- a/src/Plugin/Gateway/LogGateway.php
+++ b/src/Plugin/Gateway/LogGateway.php
@@ -8,6 +8,7 @@ namespace Drupal\sms\Plugin\Gateway;
 
 use Drupal\sms\Gateway\GatewayBase;
 use Drupal\sms\Message\SmsMessageInterface;
+use Drupal\sms\Message\SmsMessageResult;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -26,8 +27,8 @@ class LogGateway extends GatewayBase {
    */
   public function send(SmsMessageInterface $sms, array $options) {
     $this->logger()->notice('SMS message sent to %number with the text: @message',
-      array('%number' => implode(', ', $sms->getRecipients()), '@message' => $sms->getMessage()));
-//    return array('status' => TRUE);
+      ['%number' => implode(', ', $sms->getRecipients()), '@message' => $sms->getMessage()]);
+    return new SmsMessageResult(['status' => TRUE]);
   }
 
 
diff --git a/src/Provider/DefaultSmsProvider.php b/src/Provider/DefaultSmsProvider.php
index 17961c6..e1a603e 100644
--- a/src/Provider/DefaultSmsProvider.php
+++ b/src/Provider/DefaultSmsProvider.php
@@ -97,9 +97,9 @@ class DefaultSmsProvider implements SmsProviderInterface {
    */
   protected function preProcess(SmsMessageInterface $sms, array $options, GatewayInterface $gateway) {
     // Call the send pre process hooks.
-    $return = $this->moduleHandler->invokeAll('sms_send_process', ['pre process', $sms, $options, $gateway]);
+    $return = $this->moduleHandler->invokeAll('sms_send_process', ['pre process', $sms, $options, $gateway, NULL]);
     // Return FALSE if any of the hooks returned FALSE.
-    return !in_array(FALSE, $return);
+    return !in_array(FALSE, $return, TRUE);
   }
 
   /**
@@ -116,7 +116,7 @@ class DefaultSmsProvider implements SmsProviderInterface {
    */
   protected function postProcess(SmsMessageInterface $sms, array $options, GatewayInterface $gateway, $result) {
     // Call the send post process hooks.
-    $this->moduleHandler->invokeAll('sms_send_process', ['post process', $sms, $options, $gateway]);
+    $this->moduleHandler->invokeAll('sms_send_process', ['post process', $sms, $options, $gateway, $result]);
   }
 
   /**
@@ -151,15 +151,15 @@ class DefaultSmsProvider implements SmsProviderInterface {
   /**
    * {@inheritdoc}
    */
-  public function incoming(SmsMessageInterface $message, array $options) {
+  public function incoming(SmsMessageInterface $sms, array $options) {
 //    if (module_exists('rules')) {
 //      $options += array('number' => $number, 'message' => $message);
 //      rules_invoke_event('sms_incoming', $options);
 //    }
     // Execute three phases
-    $this->moduleHandler->invokeAll('sms_incoming', array('pre process', $message, $options));
-    $this->moduleHandler->invokeAll('sms_incoming', array('process', $message, $options));
-    $this->moduleHandler->invokeAll('sms_incoming', array('post process', $message, $options));
+    $this->moduleHandler->invokeAll('sms_incoming', array('pre process', $sms, $options));
+    $this->moduleHandler->invokeAll('sms_incoming', array('process', $sms, $options));
+    $this->moduleHandler->invokeAll('sms_incoming', array('post process', $sms, $options));
   }
 
   /**
diff --git a/tests/modules/sms_test_gateway/sms_test_gateway.module b/tests/modules/sms_test_gateway/sms_test_gateway.module
index 1d527a8..81cf65b 100644
--- a/tests/modules/sms_test_gateway/sms_test_gateway.module
+++ b/tests/modules/sms_test_gateway/sms_test_gateway.module
@@ -70,14 +70,14 @@ function sms_test_gateway_result($reset = FALSE) {
 /**
  * Implements hook_sms_incoming().
  */
-function sms_test_gateway_sms_incoming($op, $number, $message, $options) {
+function sms_test_gateway_sms_incoming($op, SmsMessageInterface $message, $options) {
   // Save incoming result for later retrieval.
   $key = 'sms_test_gateway_get_incoming' . $op;
   $result = &drupal_static($key);
 
-  if (!is_null($number) && !is_null($message)) {
-    $result['number'] = $number;
-    $result['message'] = $message;
+  if (!is_null($message->getRecipients()) && !is_null($message->getMessage())) {
+    $result['number'] = $message->getRecipients()[0];
+    $result['message'] = $message->getMessage();
     $result['options'] = $options;
     \Drupal::state()->set($key, $result);
   }