diff --git a/inc/API.php b/inc/API.php
index b8aa454..f1763ea 100644
--- a/inc/API.php
+++ b/inc/API.php
@@ -144,8 +144,12 @@
         break;
 
       case 'getClasses':
-        self::checkSignInStatus();
-        // @TODO: Implement this method
+        $body = self::getJSONBody();
+        $response = Classes::handleAPIGetClasses($body);
+        if ($response === false)
+          self::returnError();
+        else
+          self::returnPayload($response);
         break;
 
       case 'setClassState':
diff --git a/inc/Classes.php b/inc/Classes.php
new file mode 100644
index 0000000..5059040
--- /dev/null
+++ b/inc/Classes.php
@@ -0,0 +1,62 @@
+<?php
+namespace DAFME\Covid;
+
+class Classes {
+  public static function getCurrentClasses() {
+    global $con;
+
+    $isSignedIn = Users::isSignedIn();
+
+    $sentence = 'SELECT c.id, c.calendar_name, c.room, c.begins, c.ends, s.id subject_id, s.friendly_name'.($isSignedIn ? ', u_s.id user_subject_id' : '').'
+        FROM classes c
+        INNER JOIN subjects s
+          ON c.calendar_name = s.calendar_name
+        '.($isSignedIn ? 'LEFT OUTER JOIN user_subjects u_s
+          ON s.id = u_s.subject_id
+        ' : '').
+        'WHERE
+          c.begins < NOW() AND
+          c.ends > NOW()'.($isSignedIn ? ' AND
+          (
+            u_s.user_id = :user_id OR
+            u_s.subject_id IS NULL
+          )': '');
+    $query = $con->prepare($sentence);
+    
+    if (!$query->execute(($isSignedIn ? ['user_id' => Users::getUserId()] : [])))
+      return false;
+
+    $classes = $query->fetchAll(\PDO::FETCH_ASSOC);
+
+    foreach ($classes as &$class) {
+      if ($isSignedIn)
+        $class['user_subject_id'] = null;
+
+      $class['user_selected'] = $class['user_subject_id'] !== null;
+    }
+
+    return $classes;
+  }
+
+  public static function handleAPIGetClasses($body) {
+    if (!isset($body['type']))
+      return false;
+
+    $response = [];
+
+    switch ($body['type']) {
+      case 'current':
+        $classes = self::getCurrentClasses();
+        if ($classes === false)
+          return false;
+
+        $response['classes'] = $classes;
+        break;
+
+      default:
+        return false;
+    }
+
+    return $response;
+  }
+}