diff --git a/kfet/static/kfet/js/kfet.api.js b/kfet/static/kfet/js/kfet.api.js
index 348fe57b..293ff6a2 100644
--- a/kfet/static/kfet/js/kfet.api.js
+++ b/kfet/static/kfet/js/kfet.api.js
@@ -4,65 +4,6 @@
  * @license MIT
  */
 
-/**
- * Get and store K-Psul config from API.
- * <br><br>
- *
- * Config should be accessed statically only.
- */
-class Config {
-
-    /**
-     * Get or create config object.
-     * @private
-     * @return  {object} object - config keys/values
-     */
-    static _get_or_create_config() {
-        if (window.config === undefined)
-            window.config = {};
-        return window.config;
-    }
-
-    /**
-     * Get config from API.
-     * @param   {jQueryAjaxComplete} [callback] - A function to be called when
-     *                               the request finishes.
-     */
-    static reset(callback) {
-        $.getJSON(Urls['kfet.kpsul.get_settings']())
-            .done(function(data) {
-                for (var key in data) {
-                    Config.set(key, data[key]);
-                }
-            })
-            .always(callback);
-    }
-
-    /**
-     * Get value for key in config.
-     * @param   {string} key
-     */
-    static get(key) {
-        return this._get_or_create_config()[key];
-    }
-
-    /**
-     * Set value for key in config.
-     * @param   {string} key
-     * @param   {*} value
-     */
-    static set(key, value) {
-        // API currently returns string for Decimal type
-        if (['addcost_amount', 'subvention_cof'].indexOf(key) > -1)
-            value = floatCheck(value);
-        this._get_or_create_config()[key] = value;
-    }
-
-}
-
-
-/* ---------- ---------- */
-
 
 /**
  * Virtual namespace for models.
@@ -143,14 +84,23 @@ class ModelObject {
      */
     from(data) {
         // TODO: add restrict
-        $.extend(this, this.constructor.default_data, data);
+        this.clear();
+        this.update(data);
+    }
+
+    /**
+     * Update properties of this instance from data ones.
+     * @param   {Object} data
+     */
+    update(data) {
+        $.extend(this, data);
     }
 
     /**
      * Clear properties to {@link Models.ModelObject.default_data|default_data}.
      */
     clear() {
-        this.from({});
+        $.extend(this, this.constructor.default_data);
     }
 
 
@@ -161,10 +111,12 @@ class ModelObject {
      * @param   {Formatters.Formatter}
      *          [formatter={@link Models.ModelObject#formatter|this.formatter()}]
      *          Formatter class to use.
+     * @return  {jQuery} The DOM element $container, allowing methods chaining.
      */
     display($container, options, formatter) {
         formatter = formatter || this.formatter();
-        return formatter.render(this, $container, options);
+        formatter.render(this, $container, options);
+        return $container;
     }
 
     /**
diff --git a/kfet/static/kfet/js/kfet.js b/kfet/static/kfet/js/kfet.js
index 0fb5c0e1..cf120fd4 100644
--- a/kfet/static/kfet/js/kfet.js
+++ b/kfet/static/kfet/js/kfet.js
@@ -40,6 +40,63 @@ function booleanCheck(v) {
 }
 
 
+/**
+ * Get and store K-Psul config from API.
+ * <br><br>
+ *
+ * Config should be accessed statically only.
+ */
+class Config {
+
+    /**
+     * Get or create config object.
+     * @private
+     * @return  {object} object - config keys/values
+     */
+    static _get_or_create_config() {
+        if (window.config === undefined)
+            window.config = {};
+        return window.config;
+    }
+
+    /**
+     * Get config from API.
+     * @param   {jQueryAjaxComplete} [callback] - A function to be called when
+     *                               the request finishes.
+     */
+    static reset(callback) {
+        $.getJSON(Urls['kfet.kpsul.get_settings']())
+            .done(function(data) {
+                for (var key in data) {
+                    Config.set(key, data[key]);
+                }
+            })
+            .always(callback);
+    }
+
+    /**
+     * Get value for key in config.
+     * @param   {string} key
+     */
+    static get(key) {
+        return this._get_or_create_config()[key];
+    }
+
+    /**
+     * Set value for key in config.
+     * @param   {string} key
+     * @param   {*} value
+     */
+    static set(key, value) {
+        // API currently returns string for Decimal type
+        if (['addcost_amount', 'subvention_cof'].indexOf(key) > -1)
+            value = floatCheck(value);
+        this._get_or_create_config()[key] = value;
+    }
+
+}
+
+
 $(document).ready(function() {
     $(window).scroll(function() {
         if ($(window).width() >= 768 && $(this).scrollTop() > 72.6) {
diff --git a/kfet/templates/kfet/kpsul.html b/kfet/templates/kfet/kpsul.html
index 1657ba6d..af957944 100644
--- a/kfet/templates/kfet/kpsul.html
+++ b/kfet/templates/kfet/kpsul.html
@@ -13,7 +13,6 @@
 <script type="text/javascript" src="{% static 'kfet/js/moment-fr.js' %}"></script>
 <script type="text/javascript" src="{% static 'kfet/js/moment-timezone-with-data-2010-2020.js' %}"></script>
 <script type="text/javascript" src="{% url 'js_reverse' %}"></script>
-<script type="text/javascript" src="{% static 'kfet/js/kfet.js' %}"></script>
 <script type="text/javascript" src="{% static 'kfet/js/history.js' %}"></script>
 <script type="text/javascript" src="{% static 'kfet/js/kfet.api.js' %}"></script>
 <script type="text/javascript" src="{% static 'kfet/js/kpsul.js' %}"></script>
@@ -346,7 +345,7 @@ $(document).ready(function() {
 
     function amountEuroPurchase(article, nb) {
         var amount_euro = - article.price * nb ;
-        if (Config.get('addcost_for') && Config.get('addcost_amount') && account_manager.account.trigramme != Config.get('addcost_for'))
+        if (Config.get('addcost_for') && Config.get('addcost_amount') && kpsul.account_manager.account.trigramme != Config.get('addcost_for'))
             amount_euro -= Config.get('addcost_amount') * nb;
         var reduc_divisor = 1;
         if (kpsul.account_manager.account.is_cof)
@@ -655,7 +654,7 @@ $(document).ready(function() {
             addcost_html
                 .find('.addcost_for').text(Config.get('addcost_for')).end()
                 .find('.addcost_amount').text(Config.get('addcost_amount').toFixed(2)).end();
-            checkout_container.prepend(addcost_html);
+            kpsul.checkout_manager._$container.prepend(addcost_html);
             $('body').css('animation', 'colorchange 3s infinite');
         }
     }
@@ -712,7 +711,7 @@ $(document).ready(function() {
                     }
                 });
             },
-            onClose: function() { this._lastFocused = account_manager._$input_trigramme; }
+            onClose: function() { this._lastFocused = kpsul.account_manager.selection._$input; }
         });
     }