diff --git a/kfet/static/kfet/js/kfet.js b/kfet/static/kfet/js/kfet.js
index f0e7a316..bdf5b69b 100644
--- a/kfet/static/kfet/js/kfet.js
+++ b/kfet/static/kfet/js/kfet.js
@@ -27,6 +27,53 @@ $(document).ready(function() {
     }
 });
 
+/*
+ * Generic Websocket class and k-psul ws instanciation
+ */
+
+class KfetWebsocket {
+
+    static get defaults() {
+        return {"relative_url": "", "default_msg": {}, "handlers": []};
+    }
+
+    constructor(data) {
+        $.extend(this, this.constructor.defaults, data);
+    }
+    
+    get url() {
+        var websocket_protocol = window.location.protocol == 'https:' ? 'wss' : 'ws';
+        var location_host = window.location.host;
+        var location_url = window.location.pathname.startsWith('/gestion/') ? location_host + '/gestion' : location_host;
+
+        return websocket_protocol+"://" + location_url + this.relative_url ;
+    }
+
+    add_handler(handler) {
+        if (!this.socket)
+            this.listen();
+
+        this.handlers.push(handler);
+    }
+
+    listen() {
+        var that = this;
+        this.socket = new ReconnectingWebSocket(this.url);
+
+        this.socket.onmessage = function(e) {
+            var data = $.extend({}, that.default_msg, JSON.parse(e.data));
+            for (let handler of that.handlers) {
+                handler(data);
+            }
+        }
+    }
+}
+
+var OperationWebSocket = new KfetWebsocket({
+    'relative_url': '/ws/k-fet/k-psul/',
+    'default_msg': {'opegroups':[],'opes':[],'checkouts':[],'articles':[]},
+});
+
 function dateUTCToParis(date) {
     return moment.tz(date, 'UTC').tz('Europe/Paris');
 }
diff --git a/kfet/templates/kfet/kpsul.html b/kfet/templates/kfet/kpsul.html
index d3b148c9..4ac1354c 100644
--- a/kfet/templates/kfet/kpsul.html
+++ b/kfet/templates/kfet/kpsul.html
@@ -12,7 +12,6 @@
 <script type="text/javascript" src="{% static 'kfet/js/moment.js' %}"></script>
 <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="{% static 'kfet/js/kfet.js' %}"></script>
 <script type="text/javascript" src="{% static 'kfet/js/history.js' %}"></script>
 {% endblock %}
 
@@ -1321,15 +1320,7 @@ $(document).ready(function() {
     // Synchronization
     // -----
 
-    websocket_msg_default = {'opegroups':[],'opes':[],'checkouts':[],'articles':[]}
-
-    var websocket_protocol = window.location.protocol == 'https:' ? 'wss' : 'ws';
-    var location_host = window.location.host;
-    var location_url = window.location.pathname.startsWith('/gestion/') ? location_host + '/gestion' : location_host;
-    socket = new ReconnectingWebSocket(websocket_protocol+"://" + location_url + "/ws/k-fet/k-psul/");
-    socket.onmessage = function(e) {
-        data = $.extend({}, websocket_msg_default, JSON.parse(e.data));
-
+    OperationWebSocket.add_handler(function(data) {
         for (var i=0; i<data['opegroups'].length; i++) {
             if (data['opegroups'][i]['add']) {
                 khistory.addOpeGroup(data['opegroups'][i]);
@@ -1360,7 +1351,7 @@ $(document).ready(function() {
             settings['addcost_amount'] = parseFloat(data['addcost']['amount']);
             displayAddcost();
         }
-    }
+    });
 
     // -----
     // General