diff --git a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudAbstractAPI.java b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudAbstractAPI.java
index 49ef8fc..0f10356 100644
--- a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudAbstractAPI.java
+++ b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudAbstractAPI.java
@@ -16,10 +16,55 @@
  * The inheritors of this interface should be passed to NotificationService.
  */
 public interface NextcloudAbstractAPI extends StatusCheckable {
+    /**
+     * Gets all notifications from server
+     * @param service PollUpdateListener which handles notifications
+     * @return notifications response as a JSONObject
+     */
     JSONObject getNotifications(PollUpdateListener service);
+
+    /**
+     * Removes notification from server
+     * @param id id of notification to remove
+     */
     void removeNotification(int id);
+
+    /**
+     * Sends reply to talk chatroom
+     * @param chatroom id of a chat
+     * @param message message to send
+     * @throws IOException in case of network error
+     */
     void sendTalkReply(String chatroom, String message) throws IOException;
+
+    /**
+     * Get user avatar
+     * @param userId username to get avatar of
+     * @return avatar bitmap
+     * @throws Exception in case of any errors
+     */
     Bitmap getUserAvatar(String userId) throws Exception;
+
+    /**
+     * Gets image preview from server
+     * @param path path to image
+     * @return bitmap received from server
+     * @throws Exception in case of any errors
+     */
     Bitmap getImagePreview(String path) throws Exception;
+
+    /**
+     * Executes action which is inside of notifications
+     * @param link Link to action
+     * @param method method which should be used for querying link
+     * @throws Exception in case of any errors
+     */
     void sendAction(String link, String method) throws Exception;
+
+    /**
+     * @doc Checks new notifications without querying all of them directly
+     * @return true if there is new notifications on server
+     * @throws Exception in case of any error
+     */
+    boolean checkNewNotifications() throws Exception;
 }
diff --git a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudHttpAPI.java b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudHttpAPI.java
index b732e6a..0bf3a98 100644
--- a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudHttpAPI.java
+++ b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudHttpAPI.java
@@ -177,6 +177,12 @@ public void sendAction(String link,
                 + link + "--" + responseCode);
     }
 
+    @Override
+    public boolean checkNewNotifications() throws Exception {
+        //TODO: implement checking that new notifications available via HEAD request
+        return false;
+    }
+
     @Override
     public JSONObject getNotifications(PollUpdateListener service) {
         try {
diff --git a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudSSOAPI.java b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudSSOAPI.java
index 686ce86..476e7d3 100644
--- a/app/src/main/java/com/polar/nextcloudservices/API/NextcloudSSOAPI.java
+++ b/app/src/main/java/com/polar/nextcloudservices/API/NextcloudSSOAPI.java
@@ -166,6 +166,12 @@ public void sendAction(String link, String method) throws Exception {
         API.performNetworkRequest(request);
     }
 
+    @Override
+    public boolean checkNewNotifications() throws Exception {
+        //TODO: implement checking that new notifications available via HEAD request
+        return false;
+    }
+
     @Override
     public Status getStatus(Context context) {
         if(lastPollSuccessful){
diff --git a/app/src/main/java/com/polar/nextcloudservices/Services/NotificationService.java b/app/src/main/java/com/polar/nextcloudservices/Services/NotificationService.java
index 81e7f4a..64d7e16 100644
--- a/app/src/main/java/com/polar/nextcloudservices/Services/NotificationService.java
+++ b/app/src/main/java/com/polar/nextcloudservices/Services/NotificationService.java
@@ -29,10 +29,19 @@
 import com.polar.nextcloudservices.Services.Status.StatusController;
 
 class PollTask extends AsyncTask<NotificationService, Void, JSONObject> {
-
+    private static final String TAG = "NotificationService.PollTask";
     @Override
     protected JSONObject doInBackground(NotificationService... services) {
-        return services[0].getAPI().getNotifications(services[0]);
+        NextcloudAbstractAPI api = services[0].getAPI();
+        try {
+            if(api.checkNewNotifications()) {
+                return api.getNotifications(services[0]);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "Can not check new notifications");
+            e.printStackTrace();
+        }
+        return null;
     }
 }
 
@@ -57,7 +66,9 @@ public String getStatus() {
     }
 
     public void onPollFinished(JSONObject response) {
-        mNotificationController.onNotificationsUpdated(response);
+        if(response != null) {
+            mNotificationController.onNotificationsUpdated(response);
+        }
     }
 
     @Override