diff --git a/lib/xos-genx/__init__.py b/lib/xos-genx/__init__.py
new file mode 100644
index 0000000..42722a8
--- /dev/null
+++ b/lib/xos-genx/__init__.py
@@ -0,0 +1,14 @@
+
+# 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.
diff --git a/lib/xos-genx/xos-genx-tests/test_tosca.py b/lib/xos-genx/xos-genx-tests/test_tosca.py
index a771cbb..f829273 100644
--- a/lib/xos-genx/xos-genx-tests/test_tosca.py
+++ b/lib/xos-genx/xos-genx-tests/test_tosca.py
@@ -122,4 +122,49 @@
         args.target = self.target_tosca_keys
         output = XOSGenerator.generate(args)
         self.assertNotIn('name', output)
-        self.assertIn('provider_service_instance_id', output)
\ No newline at end of file
+        self.assertIn('provider_service_instance_id', output)
+
+    def test_xproto_model_to_oneof_key(self):
+        """
+        [XOS-GenX] in some models we need to have a combine key on variable fields, for example, keys can be subscriber_service_id + oneof(provider_service_id, provider_network_id)
+        """
+        xproto = \
+            """
+            option app_label = "test";
+
+            message Foo {
+            
+                option tosca_key = "key1, oneof(key_2, key_3)";
+            
+                required string name = 1 [ null = "False", blank="False"];
+                required string key_1 = 2 [ null = "False", blank="False", tosca_key_one_of = "key_2"];
+                required string key_2 = 3 [ null = "False", blank="False", tosca_key_one_of = "key_1"];
+                required string key_3 = 4 [ null = "False", blank="False", tosca_key_one_of = "key_4"];
+                required string key_4 = 5 [ null = "False", blank="False", tosca_key_one_of = "key_3"];
+            }
+            """
+
+        args = FakeArgs()
+        args.inputs = xproto
+        args.target = self.target_tosca_keys
+        output = XOSGenerator.generate(args)
+        self.assertIn("['name', ['key_4', 'key_3'], ['key_1', 'key_2']]", output)
+
+        xproto = \
+            """
+            option app_label = "test";
+
+            message Foo {
+
+                option tosca_key = "key1, oneof(key_2, key_3)";
+
+                required string name = 1 [ null = "False", blank="False"];
+                required manytoone key_1->Bar:key_1s = 2;
+                required manytoone key_2->Bar:key_2s = 3 [tosca_key_one_of = "key_1"];
+                required manytoone key_3->Bar:key_3s = 4 [tosca_key_one_of = "key_1"];
+            }
+            """
+
+        args.inputs = xproto
+        output = XOSGenerator.generate(args)
+        self.assertIn("['name', ['key_1_id', 'key_3_id', 'key_2_id']]", output)
\ No newline at end of file
diff --git a/lib/xos-genx/xosgenx/jinja2_extensions/tosca.py b/lib/xos-genx/xosgenx/jinja2_extensions/tosca.py
index a46770d..51cd2bb 100644
--- a/lib/xos-genx/xosgenx/jinja2_extensions/tosca.py
+++ b/lib/xos-genx/xosgenx/jinja2_extensions/tosca.py
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from xosgenx.jinja2_extensions import xproto_field_graph_components
+
 def xproto_tosca_required(null, blank, default=None):
 
     if null == 'True' or blank == 'True' or default != 'False':
@@ -32,14 +34,32 @@
         return type
 
 def xproto_fields_to_tosca_keys(fields):
-	keys = []
-	# look for explicit keys
-	for f in fields:
-		if 'tosca_key' in f['options'] and f['options']['tosca_key'] and 'link' not in f:
-			keys.append(f['name'])
-		if 'tosca_key' in f['options'] and f['options']['tosca_key'] and ('link' in f and f['link']):
-			keys.append("%s_id" % f['name'])
-	# if not keys are specified and there is a name field, use that as key.
-	if len(keys) == 0 and 'name' in map(lambda f: f['name'], fields):
-		keys.append('name')
-	return keys
\ No newline at end of file
+    keys = []
+
+    # look for one_of keys
+    _one_of = xproto_field_graph_components(fields, 'tosca_key_one_of')
+    one_of = [list(i) for i in _one_of]
+
+    # look for explicit keys
+    for f in fields:
+        if 'tosca_key' in f['options'] and f['options']['tosca_key'] and 'link' not in f:
+            keys.append(f['name'])
+        if 'tosca_key' in f['options'] and f['options']['tosca_key'] and ('link' in f and f['link']):
+            keys.append("%s_id" % f['name'])
+    # if not keys are specified and there is a name field, use that as key.
+    if len(keys) == 0 and 'name' in map(lambda f: f['name'], fields):
+        keys.append('name')
+
+    for of in one_of:
+        # check if the field is a link, and in case add _id
+        for index, f in enumerate(of):
+            try:
+                field = [x for x in fields if x['name'] == f and ('link' in x and x['link'])][0]
+                of[index] = "%s_id" % f
+            except IndexError, e:
+                # the field is not a link
+                pass
+
+        keys.append(of)
+
+    return keys
\ No newline at end of file