diff --git a/xblocks_contrib/word_cloud/static/js/src/word_cloud.js b/xblocks_contrib/word_cloud/static/js/src/word_cloud.js
index 728e652..475f1fd 100644
--- a/xblocks_contrib/word_cloud/static/js/src/word_cloud.js
+++ b/xblocks_contrib/word_cloud/static/js/src/word_cloud.js
@@ -27,44 +27,20 @@ function generateUniqueId(wordCloudId, counter) {
 }
 
 function WordCloudBlock(runtime, element) {
-
-  // eslint-disable-next-line no-undef
-  const wordCloudEl = $(element).find(blockIdentifier);
-
-  // Get the URL to which we will post the users words.
-  const ajax_url = wordCloudEl.data('ajax-url');
-
-  // Hide WordCloud container until Ajax request is complete.
-  wordCloudEl.hide();
-
-  // Fetch initial state via AJAX request. Attach a callback that will
-  // be fired on server's response.
-  // eslint-disable-next-line no-undef
-  $.postWithPrefix(
-    `${ajax_url}/get_state`,
-    null,
-    (response) => {
-      if (response.status !== 'success') {
-        console.error('Failed to fetch state');
-        return;
+  $.ajax({
+    type: "POST",
+    url: runtime.handlerUrl(element, 'handle_get_state'),
+    data: JSON.stringify(null),
+    success: function (response) {
+      if (response && response.submitted) {
+        showWordCloud(response, element);
       }
-
-      configJson = response;
-      if (configJson && configJson.submitted) {
-        showWordCloud(configJson, wordCloudEl);
-      }
-
-    },
-  )
-    .done(() => {
-      // Show WordCloud container after Ajax request done
-      wordCloudEl.show();
-    });
-
-  // eslint-disable-next-line no-undef
-  $(element).find('.save').on('click', () => {
-    submitAnswer(ajax_url, wordCloudEl);
+    }
   });
+
+  $('.save', element).on('click', () =>
+    submitAnswer(runtime, element)
+  );
 }
 
 /**
@@ -74,32 +50,23 @@ function WordCloudBlock(runtime, element) {
  * server, and upon receiving correct response, will call the function to generate the
  * word cloud.
  */
-function submitAnswer(ajax_url, wordCloudEl)
-{
+function submitAnswer(runtime, element) {
+  const wordCloudEl = $(element).find(blockIdentifier);
   const data = {student_words: []};
 
-  // Populate the data to be sent to the server with user's words.
   wordCloudEl.find('input.input-cloud').each((index, value) => {
     // eslint-disable-next-line no-undef
     data.student_words.push($(value).val());
   });
 
-  // Send the data to the server as an AJAX request. Attach a callback that will
-  // be fired on server's response.
-  // eslint-disable-next-line no-undef
-  $.postWithPrefix(
-    `${ajax_url}/submit`,
-    // eslint-disable-next-line no-undef
-    $.param(data),
-    (response) => {
-      if (response.status !== 'success') {
-        console.error('Submission failed');
-        return;
-      }
-
-      showWordCloud(response, wordCloudEl);
-    },
-  );
+  $.ajax({
+    type: "POST",
+    url: runtime.handlerUrl(element, 'handle_submit_state'),
+    data: JSON.stringify(data),
+    success: function (response) {
+      showWordCloud(response, element);
+    }
+  });
 }
 
 /**
@@ -111,7 +78,7 @@ function submitAnswer(ajax_url, wordCloudEl)
  * This function will set up everything for d3 and launch the draw method. Among other things,
  * iw will determine maximum word size.
  */
-function showWordCloud(response, wordCloudEl)
+function showWordCloud(response, element)
 {
   const words = response.top_words;
   let maxSize = 0;
@@ -120,6 +87,7 @@ function showWordCloud(response, wordCloudEl)
   let maxFontSize = 200;
   const minFontSize = 16;
 
+  const wordCloudEl = $(element).find(blockIdentifier);
   wordCloudEl.find('.input_cloud_section').hide();
 
   // Find the word with the maximum percentage. I.e. the most popular word.
diff --git a/xblocks_contrib/word_cloud/templates/word_cloud.html b/xblocks_contrib/word_cloud/templates/word_cloud.html
index 7c57b37..ec009a5 100644
--- a/xblocks_contrib/word_cloud/templates/word_cloud.html
+++ b/xblocks_contrib/word_cloud/templates/word_cloud.html
@@ -2,8 +2,7 @@
 
 <div
     id="word_cloud_{{ element_id }}"
-    class="word_cloud_block"
-    data-ajax-url="{{ ajax_url }}">
+    class="word_cloud_block">
     {% if display_name %}
         <h3 class="hd hd-3" id="word_cloud_{{ element_id }}_heading">{{ display_name }}</h3>
     {% endif %}
diff --git a/xblocks_contrib/word_cloud/word_cloud.py b/xblocks_contrib/word_cloud/word_cloud.py
index d40ebde..387625f 100644
--- a/xblocks_contrib/word_cloud/word_cloud.py
+++ b/xblocks_contrib/word_cloud/word_cloud.py
@@ -13,8 +13,6 @@
 from xblock.utils.resources import ResourceLoader
 from xblock.utils.studio_editable import StudioEditableXBlockMixin
 
-from xblocks_contrib.utils.mixins.x_module import XModuleToXBlockMixin
-
 resource_loader = ResourceLoader(__name__)
 
 
@@ -37,11 +35,7 @@ def pretty_bool(value):
     return value in bool_dict
 
 
-class WordCloudBlock(
-    StudioEditableXBlockMixin,
-    XBlock,
-    XModuleToXBlockMixin,
-):
+class WordCloudBlock(StudioEditableXBlockMixin, XBlock):
     """
     Word Cloud XBlock.
     """
@@ -135,7 +129,6 @@ def student_view(self, context=None):  # pylint: disable=W0613
         frag = Fragment()
         frag.add_content(resource_loader.render_django_template(
             "templates/word_cloud.html", {
-                'ajax_url': self.ajax_url,
                 'display_name': self.display_name,
                 'instructions': self.instructions,
                 'element_id': self.scope_ids.usage_id.html_id(),
@@ -176,6 +169,92 @@ def top_dict(self, dict_obj, amount):
             )[:amount]
         )
 
+    def get_state(self):
+        """Return success json answer for client."""
+        if self.submitted:
+            total_count = sum(self.all_words.values())
+            return {
+                'status': 'success',
+                'submitted': True,
+                'display_student_percents': pretty_bool(
+                    self.display_student_percents
+                ),
+                'student_words': {
+                    word: self.all_words[word] for word in self.student_words
+                },
+                'total_count': total_count,
+                'top_words': self.prepare_words(self.top_words, total_count),
+            }
+        else:
+            return {
+                'status': 'success',
+                'submitted': False,
+                'display_student_percents': False,
+                'student_words': {},
+                'total_count': 0,
+                'top_words': {}
+            }
+
+    @XBlock.json_handler
+    def handle_get_state(self, data, suffix=''):  # pylint: disable=unused-argument
+        """
+        AJAX handler to get the current state of the XBlock
+
+        Args:
+            data: dict having request get parameters
+
+        Returns:
+            json string
+        """
+        return self.get_state()
+
+    @XBlock.json_handler
+    def handle_submit_state(self, data, suffix=''):  # pylint: disable=unused-argument
+        """
+        AJAX handler to submit the current state of the XBlock
+
+        Args:
+            data: dict having request get parameters
+
+        Returns:
+            json string
+        """
+
+        if self.submitted:
+            return {
+                'status': 'fail',
+                'error': 'You have already posted your data.'
+            }
+
+        # Student words from client.
+        # FIXME: we must use raw JSON, not a post data (multipart/form-data)
+        raw_student_words = data.get('student_words')
+        student_words = [word for word in map(self.good_word, raw_student_words) if word]
+
+        self.student_words = student_words
+
+        # FIXME: fix this, when xblock will support mutable types.
+        # Now we use this hack.
+        # speed issues
+        temp_all_words = self.all_words
+
+        self.submitted = True
+
+        # Save in all_words.
+        for word in self.student_words:
+            temp_all_words[word] = temp_all_words.get(word, 0) + 1
+
+        # Update top_words.
+        self.top_words = self.top_dict(
+            temp_all_words,
+            self.num_top_words
+        )
+
+        # Save all_words in database.
+        self.all_words = temp_all_words
+
+        return self.get_state()
+
     def prepare_words(self, top_words, total_count):
         """Convert words dictionary for client API.
 
@@ -286,29 +365,3 @@ def handle_ajax(self, dispatch, data):
                 'status': 'fail',
                 'error': 'Unknown Command!'
             })
-
-    def get_state(self):
-        """Return success json answer for client."""
-        if self.submitted:
-            total_count = sum(self.all_words.values())
-            return json.dumps({
-                'status': 'success',
-                'submitted': True,
-                'display_student_percents': pretty_bool(
-                    self.display_student_percents
-                ),
-                'student_words': {
-                    word: self.all_words[word] for word in self.student_words
-                },
-                'total_count': total_count,
-                'top_words': self.prepare_words(self.top_words, total_count)
-            })
-        else:
-            return json.dumps({
-                'status': 'success',
-                'submitted': False,
-                'display_student_percents': False,
-                'student_words': {},
-                'total_count': 0,
-                'top_words': {}
-            })