diff --git a/src/grpc_client/KEYS.reference.py b/src/grpc_client/KEYS.reference.py
new file mode 100644
index 0000000..fd8c776
--- /dev/null
+++ b/src/grpc_client/KEYS.reference.py
@@ -0,0 +1,75 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#########################################################################
+#                                                                       #
+# This file is here for reference, the used one is generate by xos-genx #
+#                                                                       #
+#########################################################################
+
+TOSCA_KEYS = {
+    'XOSBase': [],
+    'User': ['email'],
+    'Privilege': [],
+    'AddressPool': ['name'],
+    'Controller': ['name'],
+    'ControllerImages': [],
+    'ControllerNetwork': [],
+    'ControllerRole': [],
+    'ControllerSite': [],
+    'ControllerPrivilege': [],
+    'ControllerSitePrivilege': [],
+    'ControllerSlice': [],
+    'ControllerSlicePrivilege': [],
+    'ControllerUser': [],
+    'Deployment': ['name'],
+    'DeploymentPrivilege': [],
+    'DeploymentRole': [],
+    'Diag': ['name'],
+    'Flavor': ['name'],
+    'Image': ['name'],
+    'ImageDeployments': [],
+    'Instance': ['name'],
+    'Network': ['name'],
+    'NetworkParameter': [],
+    'NetworkParameterType': ['name'],
+    'NetworkSlice': ['network', 'slice'],
+    'NetworkTemplate': ['name'],
+    'Node': ['name'],
+    'NodeLabel': ['name'],
+    'Port': [],
+    'Role': [],
+    'Service': ['name'],
+    'ServiceAttribute': ['name'],
+    'ServiceDependency': ['provider_service'],
+    'ServiceMonitoringAgentInfo': ['name'],
+    'ServicePrivilege': [],
+    'ServiceRole': [],
+    'Site': ['name'],
+    'SiteDeployment': ['site', 'deployment'],
+    'SitePrivilege': ['site', 'role'],
+    'SiteRole': [],
+    'Slice': ['name'],
+    'SlicePrivilege': [],
+    'SliceRole': [],
+    'Tag': ['name'],
+    'InterfaceType': ['name'],
+    'ServiceInterface': ['service', 'interface_type'],
+    'ServiceInstance': ['name'],
+    'ServiceInstanceLink': ['provider_service_instance'],
+    'ServiceInstanceAttribute': ['name'],
+    'TenantWithContainer': ['name'],
+    'XOS': ['name'],
+    'XOSGuiExtension': ['name'],
+}
\ No newline at end of file
diff --git a/src/grpc_client/models_accessor.py b/src/grpc_client/models_accessor.py
index b51ee90..918c04d 100644
--- a/src/grpc_client/models_accessor.py
+++ b/src/grpc_client/models_accessor.py
@@ -27,39 +27,46 @@
         Give a Model Class Name and some data, check if that exits or instantiate a new one
         """
 
-        if data.get('name'):
-            used_key = 'name'
-        else:
-            if len(data.keys()) > 0:
-                # FIXME apparently we're not matching model without a name field
-                used_key = data.keys()[0]
-            else:
-                used_key = None
+        # NOTE: we need to import this later as it's generated by main.py
+        from KEYS import TOSCA_KEYS
+
+        # get the key for this model
+        try:
+            filter_keys = TOSCA_KEYS[class_name]
+        except KeyError, e:
+            raise Exception("[XOS-TOSCA] Model %s doesn't have a tosca_key specified" % (class_name))
+
+        if len(filter_keys) == 0:
+            raise Exception("[XOS-TOSCA] Model %s doesn't have a tosca_key specified" % (class_name))
+
+        filter = {}
+        for k in filter_keys:
+            try:
+                filter[k] = data[k]
+            except KeyError, e:
+                raise Exception("[XOS-TOSCA] Model %s doesn't have a property for the specified tosca_key (%s)" % (class_name, e))
 
         key = "%s~%s" % (username, password)
         if not key in RESOURCES:
             raise Exception("[XOS-TOSCA] User '%s' does not have ready resources" % username)
         if class_name not in RESOURCES[key]:
-            raise Exception('[XOS-TOSCA] The model you are trying to create (%s: %s, class: %s) is not know by xos-core' % (used_key, data[used_key], class_name))
+            raise Exception('[XOS-TOSCA] The model you are trying to create (class: %s, properties, %s) is not know by xos-core' % (class_name, str(filter)))
 
         cls = RESOURCES[key][class_name]
-        if used_key:
-            models = cls.objects.filter(**{used_key: data[used_key]})
-        else:
-            # NOTE if we don't have a way to track the model, create a new one
-            models = []
+
+        models = cls.objects.filter(**filter)
 
         if len(models) == 1:
-            print "[XOS-Tosca] Model %s already exist, retrieving instance..." % data[used_key]
+            print "[XOS-Tosca] Model of class %s and properties %s already exist, retrieving instance..." % (class_name, str(filter))
             model = models[0]
         elif len(models) == 0:
 
             if 'must-exist' in data and data['must-exist']:
-                raise Exception("[XOS-TOSCA] Model %s:%s has property 'must-exist' but cannot be found" % (class_name, data[used_key]))
+                raise Exception("[XOS-TOSCA] Model of class %s and properties %s has property 'must-exist' but cannot be found" % (class_name, str(filter)))
 
             model = cls.objects.new()
-            print "[XOS-Tosca] Model %s is new, creating new instance..." % data[used_key] if used_key else class_name
+            print "[XOS-Tosca] Model (%s) is new, creating new instance..." % str(filter)
         else:
-            raise Exception("[XOS-Tosca] Model %s has multiple instances, I can't handle it" % data[used_key])
+            raise Exception("[XOS-Tosca] Model of class %s and properties %s has multiple instances, I can't handle it" % (class_name, str(filter)))
 
         return model
\ No newline at end of file