diff --git a/gui/ngXosViews/serviceTopology/src/js/services.js b/gui/ngXosViews/serviceTopology/src/js/services.js
index 93a1edb..640182d 100644
--- a/gui/ngXosViews/serviceTopology/src/js/services.js
+++ b/gui/ngXosViews/serviceTopology/src/js/services.js
@@ -3,7 +3,89 @@
 
   angular.module('xos.serviceTopology')
   .service('Services', function($resource){
-    return $resource('/xos/services');
+    return $resource('/xos/services/:id', {id: '@id'});
+  })
+  .service('Tenant', function($resource){
+    return $resource('/xos/tenants');
+  })
+  .service('ServiceRelation', function($q, _, lodash, Services, Tenant){
+
+    // find all the relation defined for a given root
+    const findLevelRelation = (tenants, rootId) => {
+      return lodash.filter(tenants, service => {
+        return service.subscriber_service === rootId;
+      });
+    };
+
+    // find all the service defined by a given array of relations
+    const findLevelServices = (relations, services) => {
+      const levelServices = [];
+      lodash.forEach(relations, (tenant) => {
+        var service = lodash.find(services, {id: tenant.provider_service});
+        levelServices.push(service);
+      });
+      return levelServices;
+    };
+
+    const buildLevel = (tenants, services, rootService, parentName = null) => {
+
+      const tree = {
+        name: rootService.humanReadableName,
+        parent: parentName,
+        children: []
+      };
+
+      // build an array of unlinked services
+      // these are the services that should still placed in the tree
+      var unlinkedServices = lodash.difference(services, [rootService]);
+
+      // find all relations relative to this rootElement
+      const levelRelation = findLevelRelation(tenants, rootService.id);
+
+      // find all items related to rootElement
+      const levelServices = findLevelServices(levelRelation, services);
+
+      // remove this item from the list (performance
+      unlinkedServices = lodash.difference(unlinkedServices, levelServices);
+
+      lodash.forEach(levelServices, (service) => {
+        tree.children.push(buildLevel(tenants, unlinkedServices, service, rootService.humanReadableName));
+      });
+
+      return tree;
+    };
+
+    const buildServiceTree = (services, tenants) => {
+
+      // find the root service
+      // it is the one attached to subsriber_root
+      // as now we have only one root so this can work
+      const rootServiceId = lodash.find(tenants, {subscriber_root: 1}).provider_service;
+      const rootService = lodash.find(services, {id: rootServiceId});
+
+      const serviceTree = buildLevel(tenants, services, rootService);
+
+      return serviceTree;
+    };
+
+    this.get = () => {
+      var deferred = $q.defer();
+      var services, tenants;
+      Services.query().$promise
+      .then((res) => {
+        services = res;
+        return Tenant.query().$promise;
+      })
+      .then((res) => {
+        tenants = res;
+        deferred.resolve(buildServiceTree(services, tenants));
+      })
+      .catch((e) => {
+        throw new Error(e);
+      });
+
+      return deferred.promise;
+    }
   });
 
 }());
\ No newline at end of file