diff --git a/VERSION b/VERSION
index b9975ae..78c4baa 100644
--- a/VERSION
+++ b/VERSION
@@ -1,2 +1,2 @@
-2.1.37
+2.1.38
 
diff --git a/containers/chameleon/Dockerfile.chameleon b/containers/chameleon/Dockerfile.chameleon
index 56da03e..0c6bd0a 100644
--- a/containers/chameleon/Dockerfile.chameleon
+++ b/containers/chameleon/Dockerfile.chameleon
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/chameleon
-FROM xosproject/xos-base:2.1.36
+FROM xosproject/xos-base:2.1.38
 
 # xos-base already has protoc and dependencies installed
 
diff --git a/containers/xos/Dockerfile.client b/containers/xos/Dockerfile.client
index cc8c026..1cfe9be 100644
--- a/containers/xos/Dockerfile.client
+++ b/containers/xos/Dockerfile.client
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-client
-FROM xosproject/xos-libraries:2.1.37
+FROM xosproject/xos-libraries:2.1.38
 
 # Install XOS client
 COPY lib/xos-api /tmp/xos-api
diff --git a/containers/xos/Dockerfile.libraries b/containers/xos/Dockerfile.libraries
index 66f9f01..28f06b7 100644
--- a/containers/xos/Dockerfile.libraries
+++ b/containers/xos/Dockerfile.libraries
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-libraries
-FROM xosproject/xos-base:2.1.37
+FROM xosproject/xos-base:2.1.38
 
 # Add libraries
 COPY lib /opt/xos/lib
diff --git a/containers/xos/Dockerfile.synchronizer-base b/containers/xos/Dockerfile.synchronizer-base
index 9230cd9..457ddb5 100644
--- a/containers/xos/Dockerfile.synchronizer-base
+++ b/containers/xos/Dockerfile.synchronizer-base
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-synchronizer-base
-FROM xosproject/xos-client:2.1.37
+FROM xosproject/xos-client:2.1.38
 
 COPY xos/synchronizers/new_base /opt/xos/synchronizers/new_base
 COPY xos/xos/logger.py /opt/xos/xos/logger.py
diff --git a/containers/xos/Dockerfile.xos-core b/containers/xos/Dockerfile.xos-core
index 0a92707..23246d2 100644
--- a/containers/xos/Dockerfile.xos-core
+++ b/containers/xos/Dockerfile.xos-core
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-core
-FROM xosproject/xos-libraries:2.1.37
+FROM xosproject/xos-libraries:2.1.38
 
 # Install XOS
 ADD xos /opt/xos
diff --git a/lib/xos-genx/xosgenx/targets/mock_classes.xtarget b/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
index 69efe92..61c2f1f 100644
--- a/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
+++ b/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
@@ -170,10 +170,20 @@
         AllMockObjectStores.append(store)
     return store
 
-class ModelAccessor:
-    def check_db_connection_ok(self):
+class ModelAccessor(object):
+    def check_db_connection_okay(self):
         return True
 
+    def connection_close(self):
+        pass
+
+    def journal_object(self, *args, **kwargs):
+        pass
+
+    def obj_exists(self, o):
+        # gRPC will default id to '0' for uninitialized objects
+        return (o.id is not None) and (o.id != 0)
+
     def fetch_pending(self, model, deleted = False):
         num = random.randint(1, 5)
         object_list = []
@@ -200,6 +210,19 @@
     def get_model_class(self, classname):
         return globals()[classname]
 
+    def has_model_class(self, classname):
+        return classname in globals()
+
+    def __getattr__(self, name):
+        """ Wrapper for getattr to facilitate retrieval of classes """
+        has_model_class = self.__getattribute__("has_model_class")
+        get_model_class = self.__getattribute__("get_model_class")
+        if has_model_class(name):
+            return get_model_class(name)
+
+        # Default behaviour
+        return self.__getattribute__(name)
+
 model_accessor = ModelAccessor()
 
 class ObjectSet(object):
diff --git a/lib/xos-synchronizer/tests/event_steps/event_step.py b/lib/xos-synchronizer/tests/event_steps/event_step.py
index 601b8df..d04f5a5 100644
--- a/lib/xos-synchronizer/tests/event_steps/event_step.py
+++ b/lib/xos-synchronizer/tests/event_steps/event_step.py
@@ -22,8 +22,8 @@
     topics = ["sometopic"]
     pattern = None
 
-    def __init__(self, log, *args, **kwargs):
-        super(TestEventStep, self).__init__(log, *args, **kwargs)
+    def __init__(self, model_accessor, log, *args, **kwargs):
+        super(TestEventStep, self).__init__(model_accessor, log, *args, **kwargs)
 
     def process_event(self, event):
         print("received an event", event)
diff --git a/lib/xos-synchronizer/tests/steps/sync_container.py b/lib/xos-synchronizer/tests/steps/sync_container.py
index baf108f..8cbabcb 100644
--- a/lib/xos-synchronizer/tests/steps/sync_container.py
+++ b/lib/xos-synchronizer/tests/steps/sync_container.py
@@ -21,7 +21,6 @@
 import time
 from xossynchronizer.steps.SyncInstanceUsingAnsible import SyncInstanceUsingAnsible
 from xossynchronizer.steps.syncstep import DeferredException
-from xossynchronizer.mock_modelaccessor import *
 
 # hpclibrary will be in steps/..
 parentdir = os.path.join(os.path.dirname(__file__), "..")
@@ -29,19 +28,18 @@
 
 
 class SyncContainer(SyncInstanceUsingAnsible):
-    provides = [Instance]
-    observes = Instance
+    observes = "Instance"
     template_name = "sync_container.yaml"
 
     def __init__(self, *args, **kwargs):
         super(SyncContainer, self).__init__(*args, **kwargs)
 
     def fetch_pending(self, deletion=False):
-        i = Instance()
+        i = self.model_accessor.Instance()
         i.name = "Spectacular Sponge"
-        j = Instance()
+        j = self.model_accessor.Instance()
         j.name = "Spontaneous Tent"
-        k = Instance()
+        k = self.model_accessor.Instance()
         k.name = "Embarrassed Cat"
 
         objs = [i, j, k]
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_images.py b/lib/xos-synchronizer/tests/steps/sync_controller_images.py
index 84a43b1..ef85983 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_images.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_images.py
@@ -16,17 +16,15 @@
 import os
 import base64
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncControllerImages(SyncStep):
-    provides = [ControllerImages]
-    observes = ControllerImages
+    observes = "ControllerImages"
     requested_interval = 0
     playbook = "sync_controller_images.yaml"
 
     def fetch_pending(self, deleted):
-        ci = ControllerImages()
-        i = Image()
+        ci = self.model_accessor.ControllerImages()
+        i = self.model_accessor.Image()
         i.name = "Lush Loss"
         ci.i = i
         return [ci]
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_networks.py b/lib/xos-synchronizer/tests/steps/sync_controller_networks.py
index 1133545..55dfe4e 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_networks.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_networks.py
@@ -19,20 +19,18 @@
 import socket
 from netaddr import IPAddress, IPNetwork
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncControllerNetworks(SyncStep):
     requested_interval = 0
-    provides = [Network]
-    observes = ControllerNetwork
-    external_dependencies = [User]
+    observes = "ControllerNetwork"
+    external_dependencies = ["User"]
     playbook = "sync_controller_networks.yaml"
 
     def fetch_pending(self, deleted):
-        ci = ControllerNetwork()
-        i = Network()
+        ci = self.model_accessor.ControllerNetwork()
+        i = self.model_accessor.Network()
         i.name = "Lush Loss"
-        s = Slice()
+        s = self.model_accessor.Slice()
         s.name = "Ghastly Notebook"
         i.owner = s
         ci.i = i
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_site_privileges.py b/lib/xos-synchronizer/tests/steps/sync_controller_site_privileges.py
index 65d3985..e286ef8 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_site_privileges.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_site_privileges.py
@@ -17,12 +17,10 @@
 import base64
 import json
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncControllerSitePrivileges(SyncStep):
-    provides = [SitePrivilege]
     requested_interval = 0
-    observes = ControllerSitePrivilege
+    observes = "ControllerSitePrivilege"
     playbook = "sync_controller_users.yaml"
 
     def map_sync_inputs(self, controller_site_privilege):
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_sites.py b/lib/xos-synchronizer/tests/steps/sync_controller_sites.py
index 509a45c..24aa76f 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_sites.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_sites.py
@@ -17,12 +17,10 @@
 import base64
 import json
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncControllerSites(SyncStep):
     requested_interval = 0
-    provides = [Site]
-    observes = ControllerSite
+    observes = "ControllerSite"
     playbook = "sync_controller_sites.yaml"
 
     def fetch_pending(self, deleted=False):
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_slice_privileges.py b/lib/xos-synchronizer/tests/steps/sync_controller_slice_privileges.py
index ec0667c..09b63e6 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_slice_privileges.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_slice_privileges.py
@@ -17,12 +17,10 @@
 import base64
 import json
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncControllerSlicePrivileges(SyncStep):
-    provides = [SlicePrivilege]
     requested_interval = 0
-    observes = ControllerSlicePrivilege
+    observes = "ControllerSlicePrivilege"
     playbook = "sync_controller_users.yaml"
 
     def map_sync_inputs(self, controller_slice_privilege):
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_slices.py b/lib/xos-synchronizer/tests/steps/sync_controller_slices.py
index 0f43bad..31c62f1 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_slices.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_slices.py
@@ -15,13 +15,12 @@
 
 import os
 import base64
-from xossynchronizer.steps.syncstep import SyncStep, DeferredException
-from xossynchronizer.mock_modelaccessor import *
+from xossynchronizer.steps.syncstep import DeferredException
+from xossynchronizer.steps.ansiblesyncstep import AnsibleSyncStep
 
-class SyncControllerSlices(SyncStep):
-    provides = [Slice]
+class SyncControllerSlices(AnsibleSyncStep):
     requested_interval = 0
-    observes = ControllerSlice
+    observes = "ControllerSlice"
     playbook = "sync_controller_slices.yaml"
 
     def map_sync_inputs(self, controller_slice):
diff --git a/lib/xos-synchronizer/tests/steps/sync_controller_users.py b/lib/xos-synchronizer/tests/steps/sync_controller_users.py
index 881e78a..a039257 100644
--- a/lib/xos-synchronizer/tests/steps/sync_controller_users.py
+++ b/lib/xos-synchronizer/tests/steps/sync_controller_users.py
@@ -16,13 +16,11 @@
 import os
 import base64
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 
 class SyncControllerUsers(SyncStep):
-    provides = [User]
     requested_interval = 0
-    observes = ControllerUser
+    observes = "ControllerUser"
     playbook = "sync_controller_users.yaml"
 
     def map_sync_inputs(self, controller_user):
diff --git a/lib/xos-synchronizer/tests/steps/sync_images.py b/lib/xos-synchronizer/tests/steps/sync_images.py
index 2284ed2..b3ed9bd 100644
--- a/lib/xos-synchronizer/tests/steps/sync_images.py
+++ b/lib/xos-synchronizer/tests/steps/sync_images.py
@@ -13,15 +13,11 @@
 # limitations under the License.
 
 
-import os
-import base64
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 class SyncImages(SyncStep):
-    provides = [Image]
     requested_interval = 0
-    observes = [Image]
+    observes = ["Image"]
 
     def sync_record(self, role):
         # do nothing
diff --git a/lib/xos-synchronizer/tests/steps/sync_instances.py b/lib/xos-synchronizer/tests/steps/sync_instances.py
index 479b87d..1a70884 100644
--- a/lib/xos-synchronizer/tests/steps/sync_instances.py
+++ b/lib/xos-synchronizer/tests/steps/sync_instances.py
@@ -14,13 +14,7 @@
 
 
 import os
-import base64
-import socket
-from xossynchronizer.steps import syncstep
-from xossynchronizer.mock_modelaccessor import *
-
-RESTAPI_HOSTNAME = socket.gethostname()
-RESTAPI_PORT = "8000"
+from xossynchronizer.steps import ansiblesyncstep
 
 
 def escape(s):
@@ -28,10 +22,10 @@
     return s
 
 
-class SyncInstances(syncstep.SyncStep):
-    provides = [Instance]
+class SyncInstances(ansiblesyncstep.AnsibleSyncStep):
     requested_interval = 0
-    observes = Instance
+    # This observes is intentionally a list of one string, to test steps where observes is a list of strings.
+    observes = ["Instance"]
     playbook = "sync_instances.yaml"
 
     def fetch_pending(self, deletion=False):
diff --git a/lib/xos-synchronizer/tests/steps/sync_ports.py b/lib/xos-synchronizer/tests/steps/sync_ports.py
index 77209a5..a7eb7d1 100644
--- a/lib/xos-synchronizer/tests/steps/sync_ports.py
+++ b/lib/xos-synchronizer/tests/steps/sync_ports.py
@@ -16,13 +16,13 @@
 import os
 import base64
 from xossynchronizer.steps.syncstep import SyncStep
-from xossynchronizer.mock_modelaccessor import *
 
 
 class SyncPort(SyncStep):
-    requested_interval = 0  # 3600
-    provides = [Port]
-    observes = Port
+    requested_interval = 0
+
+    # This observes is intentionally a string, to test steps where observes is a string
+    observes = "Port"
 
     def call(self, failed=[], deletion=False):
         if deletion:
diff --git a/lib/xos-synchronizer/tests/steps/sync_roles.py b/lib/xos-synchronizer/tests/steps/sync_roles.py
index e8b1364..7298a64 100644
--- a/lib/xos-synchronizer/tests/steps/sync_roles.py
+++ b/lib/xos-synchronizer/tests/steps/sync_roles.py
@@ -20,8 +20,9 @@
 
 
 class SyncRoles(SyncStep):
-    provides = [Role]
     requested_interval = 0
+
+    # This observes is intentionally a list of three classes, to test steps where observes is a list of classes.
     observes = [SiteRole, SliceRole, ControllerRole]
 
     def sync_record(self, role):
diff --git a/lib/xos-synchronizer/tests/test_event_engine.py b/lib/xos-synchronizer/tests/test_event_engine.py
index 13972c6..a09b3d0 100644
--- a/lib/xos-synchronizer/tests/test_event_engine.py
+++ b/lib/xos-synchronizer/tests/test_event_engine.py
@@ -128,6 +128,8 @@
 
         build_mock_modelaccessor(sync_lib_dir, xos_dir, services_dir=None, service_xprotos=[])
 
+        from xossynchronizer.modelaccessor import model_accessor
+
         # The test config.yaml references files in `test/` so make sure we're in the parent directory of the
         # test directory.
         os.chdir(os.path.join(test_path, ".."))
@@ -135,7 +137,7 @@
         from xossynchronizer.event_engine import XOSKafkaThread, XOSEventEngine
 
         self.event_steps_dir = Config.get("event_steps_dir")
-        self.event_engine = XOSEventEngine(log)
+        self.event_engine = XOSEventEngine(model_accessor=model_accessor, log=log)
 
     def tearDown(self):
         sys.path = self.sys_path_save
diff --git a/lib/xos-synchronizer/tests/test_load.py b/lib/xos-synchronizer/tests/test_load.py
index 8f9813d..3802dd7 100644
--- a/lib/xos-synchronizer/tests/test_load.py
+++ b/lib/xos-synchronizer/tests/test_load.py
@@ -52,10 +52,12 @@
         import xossynchronizer.backend
         reload(xossynchronizer.backend)
 
-        b = xossynchronizer.backend.Backend()
+        from xossynchronizer.modelaccessor import model_accessor
+
+        b = xossynchronizer.backend.Backend(model_accessor=model_accessor)
         steps_dir = Config.get("steps_dir")
         self.steps = b.load_sync_step_modules(steps_dir)
-        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps)
+        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps, model_accessor)
 
     def tearDown(self):
         sys.path = self.sys_path_save
@@ -92,6 +94,9 @@
         self.assertIn(
             ("ControllerSlice", ["SyncControllerSlices"]), model_to_step.items()
         )
+        self.assertIn(
+            ("Port", ["SyncPort"]), model_to_step.items()
+        )
         self.assertIn(("SiteRole", ["SyncRoles"]), model_to_step.items())
 
         for k, v in model_to_step.items():
@@ -100,7 +105,13 @@
             if not isinstance(observes, list):
                 observes = [observes]
 
-            observed_names = [o.__name__ for o in observes]
+            observed_names = []
+            for o in observes:
+                if isinstance(o,str):
+                    observed_names.append(o)
+                else:
+                    observed_names.append(o.__name__)
+
             self.assertIn(k, observed_names)
 
 
diff --git a/lib/xos-synchronizer/tests/test_model_policy_tenantwithcontainer.py b/lib/xos-synchronizer/tests/test_model_policy_tenantwithcontainer.py
index fa3c774..b15240d 100644
--- a/lib/xos-synchronizer/tests/test_model_policy_tenantwithcontainer.py
+++ b/lib/xos-synchronizer/tests/test_model_policy_tenantwithcontainer.py
@@ -60,12 +60,9 @@
         ) in xossynchronizer.model_policies.model_policy_tenantwithcontainer.model_accessor.all_model_classes.items():
             globals()[k] = v
 
-        # TODO: Mock_model_accessor lacks save or delete methods
-        # Instance.save = mock.Mock
-        # Instance.delete = mock.Mock
-        # TenantWithContainer.save = mock.Mock
+        from xossynchronizer.modelaccessor import model_accessor
 
-        self.policy = TenantWithContainerPolicy()
+        self.policy = TenantWithContainerPolicy(model_accessor=model_accessor)
         self.user = User(email="testadmin@test.org")
         self.tenant = TenantWithContainer(creator=self.user)
         self.flavor = Flavor(name="m1.small")
diff --git a/lib/xos-synchronizer/tests/test_payload.py b/lib/xos-synchronizer/tests/test_payload.py
index 6bd1cfc..cfba52d 100644
--- a/lib/xos-synchronizer/tests/test_payload.py
+++ b/lib/xos-synchronizer/tests/test_payload.py
@@ -99,26 +99,25 @@
         # import all class names to globals
         for (k, v) in model_accessor.all_model_classes.items():
             globals()[k] = v
-        b = xossynchronizer.backend.Backend()
+        b = xossynchronizer.backend.Backend(model_accessor = model_accessor)
         steps_dir = Config.get("steps_dir")
         self.steps = b.load_sync_step_modules(steps_dir)
-        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps)
+        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps, model_accessor)
 
     def tearDown(self):
         sys.path = self.sys_path_save
         os.chdir(self.cwd_save)
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_delete_record(self, mock_run_template, mock_modelaccessor):
+    def test_delete_record(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save:
             o = Instance()
             o.name = "Sisi Pascal"
 
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor = self.synchronizer.model_accessor)
             self.synchronizer.delete_record(o, log)
 
             a = get_ansible_output()
@@ -126,16 +125,15 @@
             o.save.assert_called_with(update_fields=["backend_need_reap"])
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template_fail,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_delete_record_fail(self, mock_run_template, mock_modelaccessor):
+    def test_delete_record_fail(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save:
             o = Instance()
             o.name = "Sisi Pascal"
 
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor = self.synchronizer.model_accessor)
 
             with self.assertRaises(Exception) as e:
                 self.synchronizer.delete_record(o, log)
@@ -145,16 +143,15 @@
             )
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_sync_record(self, mock_run_template, mock_modelaccessor):
+    def test_sync_record(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save:
             o = Instance()
             o.name = "Sisi Pascal"
 
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor = self.synchronizer.model_accessor)
             self.synchronizer.sync_record(o, log)
 
             a = get_ansible_output()
@@ -169,11 +166,10 @@
             )
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_sync_cohort(self, mock_run_template, mock_modelaccessor):
+    def test_sync_cohort(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save, mock.patch.object(
             ControllerSlice, "save"
         ) as controllerslice_save:
@@ -186,8 +182,10 @@
             o.slice = s
 
             cohort = [cs, o]
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
-            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor = self.synchronizer.model_accessor)
+            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices(
+                model_accessor = self.synchronizer.model_accessor
+            )
 
             self.synchronizer.sync_cohort(cohort, False)
 
@@ -211,11 +209,10 @@
             )
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_deferred_exception(self, mock_run_template, mock_modelaccessor):
+    def test_deferred_exception(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save:
             cs = ControllerSlice()
             s = Slice(name="SP SP")
@@ -227,8 +224,10 @@
             o.slice = s
 
             cohort = [cs, o]
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
-            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor=self.synchronizer.model_accessor)
+            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices(
+                model_accessor=self.synchronizer.model_accessor
+            )
 
             self.synchronizer.sync_cohort(cohort, False)
             o.save.assert_called_with(
@@ -241,11 +240,10 @@
             self.assertIn("Failed due to", o.backend_status)
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_backend_status(self, mock_run_template, mock_modelaccessor):
+    def test_backend_status(self, mock_run_template):
         with mock.patch.object(Instance, "save") as instance_save:
             cs = ControllerSlice()
             s = Slice(name="SP SP")
@@ -257,8 +255,9 @@
             o.slice = s
 
             cohort = [cs, o]
-            o.synchronizer_step = steps.sync_instances.SyncInstances()
-            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices()
+            o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor=self.synchronizer.model_accessor)
+            cs.synchronizer_step = steps.sync_controller_slices.SyncControllerSlices(
+                model_accessor=self.synchronizer.model_accessor)
 
             self.synchronizer.sync_cohort(cohort, False)
             o.save.assert_called_with(
@@ -269,11 +268,10 @@
             self.assertIn("Failed due to", o.backend_status)
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_fetch_pending(self, mock_run_template, mock_accessor, *_other_accessors):
+    def test_fetch_pending(self, mock_run_template):
         pending_objects, pending_steps = self.synchronizer.fetch_pending()
         pending_objects2 = list(pending_objects)
 
@@ -295,12 +293,11 @@
         self.assertEqual(set(flat_objects), set(pending_objects))
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
     def test_fetch_pending_with_external_dependencies(
-        self, mock_run_template, mock_accessor, *_other_accessors
+        self, mock_run_template,
     ):
         pending_objects, pending_steps = self.synchronizer.fetch_pending()
         pending_objects2 = list(pending_objects)
@@ -322,11 +319,10 @@
         self.assertIsNotNone(any_user)
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_external_dependency_exception(self, mock_run_template, mock_modelaccessor):
+    def test_external_dependency_exception(self, mock_run_template):
         cs = ControllerSlice()
         s = Slice(name="SP SP")
         cs.slice = s
@@ -337,7 +333,7 @@
 
         cohort = [cs, o]
         o.synchronizer_step = None
-        o.synchronizer_step = steps.sync_instances.SyncInstances()
+        o.synchronizer_step = steps.sync_instances.SyncInstances(model_accessor=self.synchronizer.model_accessor)
 
         self.synchronizer.sync_cohort(cohort, False)
 
diff --git a/lib/xos-synchronizer/tests/test_run.py b/lib/xos-synchronizer/tests/test_run.py
index f5815f2..65651d9 100644
--- a/lib/xos-synchronizer/tests/test_run.py
+++ b/lib/xos-synchronizer/tests/test_run.py
@@ -14,10 +14,7 @@
 
 import json
 import unittest
-from mock import patch
 import mock
-import pdb
-import networkx as nx
 
 import os
 import sys
@@ -70,10 +67,12 @@
         for (k, v) in model_accessor.all_model_classes.items():
             globals()[k] = v
 
-        b = xossynchronizer.backend.Backend()
+        from xossynchronizer.modelaccessor import model_accessor
+
+        b = xossynchronizer.backend.Backend(model_accessor=model_accessor)
         steps_dir = Config.get("steps_dir")
         self.steps = b.load_sync_step_modules(steps_dir)
-        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps)
+        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps, model_accessor)
         try:
             os.remove("/tmp/sync_ports")
         except OSError:
@@ -88,12 +87,10 @@
         os.chdir(self.cwd_save)
 
     @mock.patch(
-        "steps.sync_instances.syncstep.run_template",
+        "steps.sync_instances.ansiblesyncstep.run_template",
         side_effect=run_fake_ansible_template,
     )
-    @mock.patch("xossynchronizer.event_loop.model_accessor")
-    def test_run_once(self, mock_run_template, mock_accessor, *_other_accessors):
-
+    def test_run_once(self, mock_run_template):
         pending_objects, pending_steps = self.synchronizer.fetch_pending()
         pending_objects2 = list(pending_objects)
 
diff --git a/lib/xos-synchronizer/tests/test_scheduler.py b/lib/xos-synchronizer/tests/test_scheduler.py
index afbf036..12e5ce0 100644
--- a/lib/xos-synchronizer/tests/test_scheduler.py
+++ b/lib/xos-synchronizer/tests/test_scheduler.py
@@ -65,7 +65,7 @@
         b = xossynchronizer.backend.Backend()
         steps_dir = Config.get("steps_dir")
         self.steps = b.load_sync_step_modules(steps_dir)
-        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps)
+        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps, model_accessor)
 
     def tearDown(self):
         sys.path = self.sys_path_save
diff --git a/lib/xos-synchronizer/tests/test_services.py b/lib/xos-synchronizer/tests/test_services.py
index 2456c27..c41ed05 100644
--- a/lib/xos-synchronizer/tests/test_services.py
+++ b/lib/xos-synchronizer/tests/test_services.py
@@ -57,10 +57,10 @@
         for (k, v) in model_accessor.all_model_classes.items():
             globals()[k] = v
 
-        b = xossynchronizer.backend.Backend()
+        b = xossynchronizer.backend.Backend(model_accessor=model_accessor)
         steps_dir = Config.get("steps_dir")
         self.steps = b.load_sync_step_modules(steps_dir)
-        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps)
+        self.synchronizer = xossynchronizer.event_loop.XOSObserver(self.steps, model_accessor)
 
     def tearDown(self):
         sys.path = self.sys_path_save
diff --git a/lib/xos-synchronizer/xossynchronizer/backend.py b/lib/xos-synchronizer/xossynchronizer/backend.py
index b404864..d4b7e67 100644
--- a/lib/xos-synchronizer/xossynchronizer/backend.py
+++ b/lib/xos-synchronizer/xossynchronizer/backend.py
@@ -24,7 +24,6 @@
 from xossynchronizer.model_policy_loop import XOSPolicyEngine
 from xossynchronizer.event_engine import XOSEventEngine
 from xossynchronizer.pull_step_engine import XOSPullStepEngine
-from xossynchronizer.modelaccessor import *
 
 from xosconfig import Config
 from multistructlog import create_logger
@@ -33,7 +32,8 @@
 
 
 class Backend:
-    def __init__(self, log=log):
+    def __init__(self, model_accessor, log=log):
+        self.model_accessor = model_accessor
         self.log = log
 
     def load_sync_step_modules(self, step_dir):
@@ -100,8 +100,8 @@
             # if we have at least one sync_step
             if len(sync_steps) > 0:
                 # start the observer
-                self.log.info("Starting XOSObserver", sync_steps=sync_steps)
-                observer = XOSObserver(sync_steps, self.log)
+                self.log.info("Starting XOSObserver", sync_steps=sync_steps, model_accessor=self.model_accessor)
+                observer = XOSObserver(sync_steps, self.model_accessor, self.log)
                 observer_thread = threading.Thread(
                     target=observer.run, name="synchronizer"
                 )
@@ -113,7 +113,7 @@
         pull_steps_dir = Config.get("pull_steps_dir")
         if pull_steps_dir:
             self.log.info("Starting XOSPullStepEngine", pull_steps_dir=pull_steps_dir)
-            pull_steps_engine = XOSPullStepEngine()
+            pull_steps_engine = XOSPullStepEngine(model_accessor=self.model_accessor)
             pull_steps_engine.load_pull_step_modules(pull_steps_dir)
             pull_steps_thread = threading.Thread(
                 target=pull_steps_engine.start, name="pull_step_engine"
@@ -125,7 +125,7 @@
         event_steps_dir = Config.get("event_steps_dir")
         if event_steps_dir:
             self.log.info("Starting XOSEventEngine", event_steps_dir=event_steps_dir)
-            event_engine = XOSEventEngine(self.log)
+            event_engine = XOSEventEngine(model_accessor=self.model_accessor, log=self.log)
             event_engine.load_event_step_modules(event_steps_dir)
             event_engine.start()
         else:
@@ -134,7 +134,7 @@
         # start model policies thread
         policies_dir = Config.get("model_policies_dir")
         if policies_dir:
-            policy_engine = XOSPolicyEngine(policies_dir=policies_dir, log=self.log)
+            policy_engine = XOSPolicyEngine(policies_dir=policies_dir, model_accessor=self.model_accessor, log=self.log)
             model_policy_thread = threading.Thread(
                 target=policy_engine.run, name="policy_engine"
             )
diff --git a/lib/xos-synchronizer/xossynchronizer/event_engine.py b/lib/xos-synchronizer/xossynchronizer/event_engine.py
index e5e18d1..694a1a8 100644
--- a/lib/xos-synchronizer/xossynchronizer/event_engine.py
+++ b/lib/xos-synchronizer/xossynchronizer/event_engine.py
@@ -43,11 +43,12 @@
         function is called for each event.
     """
 
-    def __init__(self, step, bootstrap_servers, log, *args, **kwargs):
+    def __init__(self, step, bootstrap_servers, model_accessor, log, *args, **kwargs):
         super(XOSKafkaThread, self).__init__(*args, **kwargs)
         self.consumer = None
         self.step = step
         self.bootstrap_servers = bootstrap_servers
+        self.model_accessor = model_accessor
         self.log = log
         self.daemon = True
 
@@ -129,7 +130,7 @@
                 )
 
                 try:
-                    self.step(log=self.log).process_event(event_msg)
+                    self.step(model_accessor=self.model_accessor, log=self.log).process_event(event_msg)
 
                 except BaseException:
                     self.log.exception(
@@ -151,9 +152,10 @@
                         will be called before start().
     """
 
-    def __init__(self, log):
+    def __init__(self, model_accessor, log):
         self.event_steps = []
         self.threads = []
+        self.model_accessor = model_accessor
         self.log = log
 
     def load_event_step_modules(self, event_step_dir):
@@ -205,7 +207,7 @@
 
         for step in self.event_steps:
             if step.technology == "kafka":
-                thread = XOSKafkaThread(step, [eventbus_endpoint], self.log)
+                thread = XOSKafkaThread(step, [eventbus_endpoint], self.model_accessor, self.log)
                 thread.start()
                 self.threads.append(thread)
             else:
diff --git a/lib/xos-synchronizer/xossynchronizer/event_loop.py b/lib/xos-synchronizer/xossynchronizer/event_loop.py
index 96ce727..bdff10b 100644
--- a/lib/xos-synchronizer/xossynchronizer/event_loop.py
+++ b/lib/xos-synchronizer/xossynchronizer/event_loop.py
@@ -30,7 +30,6 @@
 from networkx.algorithms.dag import topological_sort
 
 from xossynchronizer.steps.syncstep import InnocuousException, DeferredException, SyncStep
-from xossynchronizer.modelaccessor import *
 
 from xosconfig import Config
 from multistructlog import create_logger
@@ -71,9 +70,9 @@
 class XOSObserver(object):
     sync_steps = []
 
-    def __init__(self, sync_steps, log=log):
-        # The Condition object via which events are received
+    def __init__(self, sync_steps, model_accessor, log=log):
         self.log = log
+        self.model_accessor = model_accessor
 
         self.step_lookup = {}
         self.sync_steps = sync_steps
@@ -153,9 +152,13 @@
                 observes = [s.observes]
             else:
                 observes = s.observes
-
             for m in observes:
-                model_to_step[m.__name__].append(s.__name__)
+                if isinstance(m, str):
+                    # observes is a string that names the model
+                    model_to_step[m].append(s.__name__)
+                else:
+                    # observes is the model class
+                    model_to_step[m.__name__].append(s.__name__)
 
             try:
                 external_dependencies.extend(s.external_dependencies)
@@ -173,7 +176,7 @@
 
     def reset_model_accessor(self, o=None):
         try:
-            model_accessor.reset_queries()
+            self.model_accessor.reset_queries()
         except BaseException:
             # this shouldn't happen, but in case it does, catch it...
             if o:
@@ -190,13 +193,13 @@
 
         if getattr(o, "backend_need_reap", False):
             # the object has already been deleted and marked for reaping
-            model_accessor.journal_object(o, "syncstep.call.already_marked_reap")
+            self.model_accessor.journal_object(o, "syncstep.call.already_marked_reap")
         else:
             step = getattr(o, "synchronizer_step", None)
             if not step:
                 raise ExternalDependencyFailed
 
-            model_accessor.journal_object(o, "syncstep.call.delete_record")
+            self.model_accessor.journal_object(o, "syncstep.call.delete_record")
 
             dr_log.debug("Deleting object", **o.tologdict())
 
@@ -206,7 +209,7 @@
 
             dr_log.debug("Deleted object", **o.tologdict())
 
-            model_accessor.journal_object(o, "syncstep.call.delete_set_reap")
+            self.model_accessor.journal_object(o, "syncstep.call.delete_set_reap")
             o.backend_need_reap = True
             o.save(update_fields=["backend_need_reap"])
 
@@ -228,7 +231,7 @@
             o.backend_need_delete = True
             o.save(update_fields=["backend_need_delete"])
 
-        model_accessor.journal_object(o, "syncstep.call.sync_record")
+        self.model_accessor.journal_object(o, "syncstep.call.sync_record")
 
         sr_log.debug("Syncing object", **o.tologdict())
 
@@ -243,7 +246,7 @@
         o.backend_register = json.dumps(scratchpad)
         o.backend_status = "OK"
         o.backend_code = 1
-        model_accessor.journal_object(o, "syncstep.call.save_update")
+        self.model_accessor.journal_object(o, "syncstep.call.save_update")
         o.save(
             update_fields=[
                 "enacted",
@@ -339,7 +342,7 @@
 
         # TOFIX:
         # DatabaseError: value too long for type character varying(140)
-        if model_accessor.obj_exists(o):
+        if self.model_accessor.obj_exists(o):
             try:
                 o.backend_status = o.backend_status[:1024]
                 o.save(
@@ -397,16 +400,16 @@
                     cohort_emptied = True
         finally:
             self.reset_model_accessor()
-            model_accessor.connection_close()
+            self.model_accessor.connection_close()
 
     def tenant_class_name_from_service(self, service_name):
         """ This code supports legacy functionality. To be cleaned up. """
         name1 = service_name + "Instance"
-        if hasattr(Slice().stub, name1):
+        if hasattr(self.model_accessor.Slice().stub, name1):
             return name1
         else:
             name2 = service_name.replace("Service", "Tenant")
-            if hasattr(Slice().stub, name2):
+            if hasattr(self.model_accessor.Slice().stub, name2):
                 return name2
             else:
                 return None
@@ -427,14 +430,14 @@
 
         s_model_names = [v for k, v in ugly_tuples]
         s_models0 = [
-            getattr(Slice().stub, model_name, None) for model_name in s_model_names
+            getattr(self.model_accessor.Slice().stub, model_name, None) for model_name in s_model_names
         ]
         s_models1 = [model.objects.first() for model in s_models0]
         s_models = [m for m in s_models1 if m is not None]
 
         dependencies = []
         for model in s_models:
-            deps = ServiceDependency.objects.filter(subscriber_service_id=model.id)
+            deps = self.model_accessor.ServiceDependency.objects.filter(subscriber_service_id=model.id)
             if deps:
                 services = [
                     self.tenant_class_name_from_service(
@@ -450,7 +453,7 @@
 
     def compute_service_instance_dependencies(self, objects):
         link_set = [
-            ServiceInstanceLink.objects.filter(subscriber_service_instance_id=o.id)
+            self.model_accessor.ServiceInstanceLink.objects.filter(subscriber_service_instance_id=o.id)
             for o in objects
         ]
 
@@ -490,17 +493,22 @@
 
         for e in self.external_dependencies:
             s = SyncStep
-            s.observes = e
+            if isinstance(e,str):
+                # external dependency is a string that names a model class
+                s.observes = self.model_accessor.get_model_class(e)
+            else:
+                # external dependency is a model class
+                s.observes = e
             step_list.append(s)
 
         for step_class in step_list:
-            step = step_class(driver=self.driver)
+            step = step_class(driver=self.driver, model_accessor=self.model_accessor)
             step.log = self.log.new(step=step)
 
             if not hasattr(step, "call"):
                 pending = step.fetch_pending(deletion)
                 for obj in pending:
-                    step = step_class(driver=self.driver)
+                    step = step_class(driver=self.driver, model_accessor=self.model_accessor)
                     step.log = self.log.new(step=step)
                     obj.synchronizer_step = step
 
@@ -719,7 +727,7 @@
 
         try:
             # Why are we checking the DB connection here?
-            model_accessor.check_db_connection_okay()
+            self.model_accessor.check_db_connection_okay()
 
             loop_start = time.time()
 
diff --git a/lib/xos-synchronizer/xossynchronizer/event_steps/eventstep.py b/lib/xos-synchronizer/xossynchronizer/event_steps/eventstep.py
index 9596248..84ea74b 100644
--- a/lib/xos-synchronizer/xossynchronizer/event_steps/eventstep.py
+++ b/lib/xos-synchronizer/xossynchronizer/event_steps/eventstep.py
@@ -25,12 +25,15 @@
     topics = []
     pattern = None
 
-    def __init__(self, log, **kwargs):
+    def __init__(self, model_accessor, log, **kwargs):
         """
         Initialize a pull step. Override this function to include any initialization. Make sure to call the original
         __init__() from your method.
         """
 
+        # self.model_accessor can be used to create and query models
+        self.model_accessor = model_accessor
+
         # self.log can be used to emit logging messages.
         self.log = log
 
diff --git a/lib/xos-synchronizer/xossynchronizer/mock_modelaccessor_build.py b/lib/xos-synchronizer/xossynchronizer/mock_modelaccessor_build.py
index 5c389cf..99b2d46 100644
--- a/lib/xos-synchronizer/xossynchronizer/mock_modelaccessor_build.py
+++ b/lib/xos-synchronizer/xossynchronizer/mock_modelaccessor_build.py
@@ -28,6 +28,12 @@
 def build_mock_modelaccessor(
     dest_dir, xos_dir, services_dir, service_xprotos, target="mock_classes.xtarget"
 ):
+    # TODO: deprecate the dest_dir argument
+
+    # force modelaccessor to be found in /tmp
+    dest_dir="/tmp/mock_modelaccessor"
+    if not os.path.exists(dest_dir):
+        os.makedirs(dest_dir)
     dest_fn = os.path.join(dest_dir, "mock_modelaccessor.py")
 
     args = ["xosgenx", "--target", target]
@@ -69,3 +75,38 @@
 
     # Save the context of this invocation of xosgenx
     open(context_fn, "w").write(cPickle.dumps(this_context))
+
+# generate model from xproto
+def get_models_fn(services_dir, service_name, xproto_name):
+    name = os.path.join(service_name, "xos", xproto_name)
+    if os.path.exists(os.path.join(services_dir, name)):
+        return name
+    else:
+        name = os.path.join(service_name, "xos", "synchronizer", "models", xproto_name)
+        if os.path.exists(os.path.join(services_dir, name)):
+            return name
+    raise Exception("Unable to find service=%s xproto=%s" % (service_name, xproto_name))
+# END generate model from xproto
+
+def mock_modelaccessor_config(test_dir, services):
+    """ Automatically configure the mock modelaccessor.
+
+        We start from the test directory, and then back up until we find the orchestration directory. From there we
+        can find the other xproto (core, services) that we need to build the mock modelaccessor.
+    """
+
+    orchestration_dir = test_dir
+    while not orchestration_dir.endswith("orchestration"):
+        # back up a level
+        orchestration_dir = os.path.dirname(orchestration_dir)
+        if len(orchestration_dir)<10:
+            raise Exception("Failed to autodiscovery repository tree")
+
+    xos_dir = os.path.join(orchestration_dir, "xos", "xos")
+    services_dir = os.path.join(orchestration_dir, "xos_services")
+
+    service_xprotos=[]
+    for (service_name, xproto_name) in services:
+        service_xprotos.append(get_models_fn(services_dir, service_name, xproto_name))
+
+    build_mock_modelaccessor(None, xos_dir, services_dir, service_xprotos)
diff --git a/lib/xos-synchronizer/xossynchronizer/model_policies/policy.py b/lib/xos-synchronizer/xossynchronizer/model_policies/policy.py
index b455c79..5877279 100644
--- a/lib/xos-synchronizer/xossynchronizer/model_policies/policy.py
+++ b/lib/xos-synchronizer/xossynchronizer/model_policies/policy.py
@@ -36,5 +36,6 @@
             handle_delete ... called when a model is deleted
     """
 
-    def __init__(self):
+    def __init__(self, model_accessor):
+        self.model_accessor = model_accessor
         self.logger = log
diff --git a/lib/xos-synchronizer/xossynchronizer/model_policy_loop.py b/lib/xos-synchronizer/xossynchronizer/model_policy_loop.py
index c23e47c..20144a5 100644
--- a/lib/xos-synchronizer/xossynchronizer/model_policy_loop.py
+++ b/lib/xos-synchronizer/xossynchronizer/model_policy_loop.py
@@ -14,18 +14,18 @@
 
 
 from __future__ import print_function
-from xossynchronizer.modelaccessor import *
 from xossynchronizer.dependency_walker_new import *
-from xossynchronizer.policy import Policy
+from xossynchronizer.model_policies.policy import Policy
 
 import imp
-import pdb
+import inspect
 import time
 import traceback
 
 
 class XOSPolicyEngine(object):
-    def __init__(self, policies_dir, log):
+    def __init__(self, policies_dir, model_accessor, log):
+        self.model_accessor = model_accessor
         self.model_policies = self.load_model_policies(policies_dir)
         self.policies_by_name = {}
         self.policies_by_class = {}
@@ -94,26 +94,28 @@
                     # provides field (this eliminates the abstract base classes
                     # since they don't have a provides)
 
-                    if (
-                        inspect.isclass(c)
-                        and issubclass(c, Policy)
-                        and hasattr(c, "model_name")
-                        and (c not in policies)
-                    ):
-                        if not c.model_name:
-                            log.info(
-                                "load_model_policies: skipping model policy",
-                                classname=classname,
-                            )
-                            continue
-                        if not model_accessor.has_model_class(c.model_name):
-                            log.error(
-                                "load_model_policies: unable to find model policy",
-                                classname=classname,
-                                model=c.model_name,
-                            )
-                        c.model = model_accessor.get_model_class(c.model_name)
-                        policies.append(c)
+                    if inspect.isclass(c):
+                        base_names = [b.__name__ for b in c.__bases__]
+
+                        if (
+                            "Policy" in base_names
+                            and hasattr(c, "model_name")
+                            and (c not in policies)
+                        ):
+                            if not c.model_name:
+                                log.info(
+                                    "load_model_policies: skipping model policy",
+                                    classname=classname,
+                                )
+                                continue
+                            if not self.model_accessor.has_model_class(c.model_name):
+                                log.error(
+                                    "load_model_policies: unable to find model policy",
+                                    classname=classname,
+                                    model=c.model_name,
+                                )
+                            c.model = self.model_accessor.get_model_class(c.model_name)
+                            policies.append(c)
 
         log.info("Loaded model policies", policies=policies)
         return policies
@@ -141,7 +143,7 @@
                         policy=policy.__name__,
                         method=method_name,
                     )
-                    getattr(policy(), method_name)(instance)
+                    getattr(policy(model_accessor=self.model_accessor), method_name)(instance)
                     log.debug(
                         "MODEL POLICY: completed handler",
                         sender_name=sender_name,
@@ -171,7 +173,7 @@
                 instance.save(update_fields=["policed", "policy_status", "policy_code"])
 
                 if hasattr(policy, "after_policy_save"):
-                    policy().after_policy_save(instance)
+                    policy(model_accessor=self.model_accessor).after_policy_save(instance)
 
                 log.info("MODEL_POLICY: Saved", o=instance)
             except BaseException:
@@ -199,10 +201,10 @@
     def run_policy_once(self):
         models = self.policies_by_class.keys()
 
-        model_accessor.check_db_connection_okay()
+        self.model_accessor.check_db_connection_okay()
 
-        objects = model_accessor.fetch_policies(models, False)
-        deleted_objects = model_accessor.fetch_policies(models, True)
+        objects = self.model_accessor.fetch_policies(models, False)
+        deleted_objects = self.model_accessor.fetch_policies(models, True)
 
         for o in objects:
             if o.deleted:
@@ -217,7 +219,7 @@
             self.execute_model_policy(o, "delete")
 
         try:
-            model_accessor.reset_queries()
+            self.model_accessor.reset_queries()
         except Exception as e:
             # this shouldn't happen, but in case it does, catch it...
             log.exception("MODEL POLICY: exception in reset_queries", e)
diff --git a/lib/xos-synchronizer/xossynchronizer/modelaccessor.py b/lib/xos-synchronizer/xossynchronizer/modelaccessor.py
index 6084579..1418cc6 100644
--- a/lib/xos-synchronizer/xossynchronizer/modelaccessor.py
+++ b/lib/xos-synchronizer/xossynchronizer/modelaccessor.py
@@ -285,6 +285,11 @@
 
 def config_accessor_mock():
     global model_accessor
+
+    # the mock model accessor always gets built to a temporary location
+    if not "/tmp/mock_modelaccessor" in sys.path:
+        sys.path.append("/tmp/mock_modelaccessor")
+
     from mock_modelaccessor import model_accessor as mock_model_accessor
 
     model_accessor = mock_model_accessor
diff --git a/lib/xos-synchronizer/xossynchronizer/pull_step_engine.py b/lib/xos-synchronizer/xossynchronizer/pull_step_engine.py
index 3f4732d..ece77bc 100644
--- a/lib/xos-synchronizer/xossynchronizer/pull_step_engine.py
+++ b/lib/xos-synchronizer/xossynchronizer/pull_step_engine.py
@@ -30,8 +30,9 @@
         The thread's pull_records() function is called for every five seconds.
     """
 
-    def __init__(self, steps, *args, **kwargs):
+    def __init__(self, steps, model_accessor, *args, **kwargs):
         self.steps = steps
+        self.model_accessor = model_accessor
 
     def run(self):
         while True:
@@ -43,7 +44,7 @@
 
         threads = []
         for step in self.steps:
-            thread = threading.Thread(target=step().pull_records, name="pull_step")
+            thread = threading.Thread(target=step(model_accessor=self.model_accessor).pull_records, name="pull_step")
             threads.append(thread)
 
         for t in threads:
@@ -67,7 +68,8 @@
                         will be called before start().
     """
 
-    def __init__(self):
+    def __init__(self, model_accessor):
+        self.model_accessor = model_accessor
         self.pull_steps = []
 
     def load_pull_step_modules(self, pull_step_dir):
@@ -98,5 +100,5 @@
         log.info("Starting pull steps engine", steps=self.pull_steps)
 
         for step in self.pull_steps:
-            sched = XOSPullStepScheduler(steps=self.pull_steps)
+            sched = XOSPullStepScheduler(steps=self.pull_steps, model_accessor=self.model_accessor)
             sched.run()
diff --git a/lib/xos-synchronizer/xossynchronizer/pull_steps/pullstep.py b/lib/xos-synchronizer/xossynchronizer/pull_steps/pullstep.py
index adbc0b1..290ab92 100644
--- a/lib/xos-synchronizer/xossynchronizer/pull_steps/pullstep.py
+++ b/lib/xos-synchronizer/xossynchronizer/pull_steps/pullstep.py
@@ -23,8 +23,10 @@
         Initialize a pull step
         :param kwargs:
         -- observed_model: name of the model that is being polled
+        -- model_accessor: used to create and update models
         """
         self.observed_model = kwargs.get("observed_model")
+        self.model_accessor = kwargs.get("model_accessor")
 
     def pull_records(self):
         self.log.debug(
diff --git a/lib/xos-synchronizer/xossynchronizer/steps/SyncInstanceUsingAnsible.py b/lib/xos-synchronizer/xossynchronizer/steps/SyncInstanceUsingAnsible.py
index 6ed656c..1bc54ce 100644
--- a/lib/xos-synchronizer/xossynchronizer/steps/SyncInstanceUsingAnsible.py
+++ b/lib/xos-synchronizer/xossynchronizer/steps/SyncInstanceUsingAnsible.py
@@ -23,7 +23,6 @@
 
 from xossynchronizer.steps.syncstep import SyncStep, DeferredException
 from xossynchronizer.ansible_helper import run_template_ssh
-from xossynchronizer.modelaccessor import *
 
 
 class SyncInstanceUsingAnsible(SyncStep):
diff --git a/lib/xos-synchronizer/xossynchronizer/steps/ansiblesyncstep.py b/lib/xos-synchronizer/xossynchronizer/steps/ansiblesyncstep.py
new file mode 100644
index 0000000..116f8c2
--- /dev/null
+++ b/lib/xos-synchronizer/xossynchronizer/steps/ansiblesyncstep.py
@@ -0,0 +1,60 @@
+# 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.
+
+from xossynchronizer.ansible_helper import run_template
+from syncstep import SyncStep
+
+class AnsibleSyncStep(SyncStep):
+    def sync_record(self, o):
+        self.log.debug("In default sync record", **o.tologdict())
+
+        tenant_fields = self.map_sync_inputs(o)
+        if tenant_fields == SyncStep.SYNC_WITHOUT_RUNNING:
+            return
+
+        main_obj = self.observes_classes[0]
+
+        path = "".join(main_obj.__name__).lower()
+        res = run_template(self.playbook, tenant_fields, path=path, object=o)
+
+        if hasattr(self, "map_sync_outputs"):
+            self.map_sync_outputs(o, res)
+
+        self.log.debug("Finished default sync record", **o.tologdict())
+
+    def delete_record(self, o):
+        self.log.debug("In default delete record", **o.tologdict())
+
+        # If there is no map_delete_inputs, then assume deleting a record is a no-op.
+        if not hasattr(self, "map_delete_inputs"):
+            return
+
+        tenant_fields = self.map_delete_inputs(o)
+
+        main_obj = self.observes_classes[0]
+
+        path = "".join(main_obj.__name__).lower()
+
+        tenant_fields["delete"] = True
+        res = run_template(self.playbook, tenant_fields, path=path)
+
+        if hasattr(self, "map_delete_outputs"):
+            self.map_delete_outputs(o, res)
+        else:
+            # "rc" is often only returned when something bad happens, so assume that no "rc" implies a successful rc
+            # of 0.
+            if res[0].get("rc", 0) != 0:
+                raise Exception("Nonzero rc from Ansible during delete_record")
+
+        self.log.debug("Finished default delete record", **o.tologdict())
\ No newline at end of file
diff --git a/lib/xos-synchronizer/xossynchronizer/steps/sync_object.py b/lib/xos-synchronizer/xossynchronizer/steps/sync_object.py
deleted file mode 100644
index 1fb5894..0000000
--- a/lib/xos-synchronizer/xossynchronizer/steps/sync_object.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# 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.
-
-
-from synchronizers.new_base.syncstep import *
-
-
-class SyncObject(SyncStep):
-    provides = []  # Caller fills this in
-    requested_interval = 0
-    observes = []  # Caller fills this in
-
-    def sync_record(self, r):
-        raise DeferredException("Waiting for Service dependency: %r" % r)
diff --git a/lib/xos-synchronizer/xossynchronizer/steps/syncstep.py b/lib/xos-synchronizer/xossynchronizer/steps/syncstep.py
index 2f31e3e..7644822 100644
--- a/lib/xos-synchronizer/xossynchronizer/steps/syncstep.py
+++ b/lib/xos-synchronizer/xossynchronizer/steps/syncstep.py
@@ -13,19 +13,6 @@
 # limitations under the License.
 
 
-import os
-import base64
-
-from xosconfig import Config
-from xossynchronizer.modelaccessor import *
-from xossynchronizer.ansible_helper import run_template
-
-# from tests.steps.mock_modelaccessor import model_accessor
-
-import json
-import time
-import pdb
-
 from xosconfig import Config
 from functools import reduce
 
@@ -86,13 +73,16 @@
     def __init__(self, **args):
         """Initialize a sync step
            Keyword arguments:
-                   name -- Name of the step
-                provides -- XOS models sync'd by this step
+               model_accessor: class used to access models
+               driver: used by openstack synchronizer (DEPRECATED)
+               error_map: used by openstack synchronizer (DEPRECATED)
         """
-        dependencies = []
+        self.model_accessor = args.get("model_accessor")
         self.driver = args.get("driver")
         self.error_map = args.get("error_map")
 
+        assert self.model_accessor is not None
+
         try:
             self.soft_deadline = int(self.get_prop("soft_deadline_seconds"))
         except BaseException:
@@ -103,56 +93,40 @@
 
         return
 
+    @property
+    def observes_classes(self):
+        """ Return a list of classes that this syncstep observes. The "observes" class member can be either a list of
+            items or a single item. Those items may be either classes or names of classes. This function always returns
+            a list of classes.
+        """
+        if not self.observes:
+            return []
+        if isinstance(self.observes, list):
+            observes = self.observes
+        else:
+            observes = [self.observes]
+        result = []
+        for class_or_name in observes:
+            if isinstance(class_or_name, str):
+                result.append(self.model_accessor.get_model_class(class_or_name))
+            else:
+                result.append(class_or_name)
+        return result
+
+
     def fetch_pending(self, deletion=False):
         # This is the most common implementation of fetch_pending
         # Steps should override it if they have their own logic
         # for figuring out what objects are outstanding.
 
-        return model_accessor.fetch_pending(self.observes, deletion)
+        return self.model_accessor.fetch_pending(self.observes_classes, deletion)
+
 
     def sync_record(self, o):
-        self.log.debug("In default sync record", **o.tologdict())
+        self.log.debug("In abstract sync record", **o.tologdict())
+        # This method should be overridden by the service
 
-        tenant_fields = self.map_sync_inputs(o)
-        if tenant_fields == SyncStep.SYNC_WITHOUT_RUNNING:
-            return
-
-        main_objs = self.observes
-        if isinstance(main_objs, list):
-            main_objs = main_objs[0]
-
-        path = "".join(main_objs.__name__).lower()
-        res = run_template(self.playbook, tenant_fields, path=path, object=o)
-
-        if hasattr(self, "map_sync_outputs"):
-            self.map_sync_outputs(o, res)
-
-        self.log.debug("Finished default sync record", **o.tologdict())
 
     def delete_record(self, o):
-        self.log.debug("In default delete record", **o.tologdict())
-
-        # If there is no map_delete_inputs, then assume deleting a record is a no-op.
-        if not hasattr(self, "map_delete_inputs"):
-            return
-
-        tenant_fields = self.map_delete_inputs(o)
-
-        main_objs = self.observes
-        if isinstance(main_objs, list):
-            main_objs = main_objs[0]
-
-        path = "".join(main_objs.__name__).lower()
-
-        tenant_fields["delete"] = True
-        res = run_template(self.playbook, tenant_fields, path=path)
-
-        if hasattr(self, "map_delete_outputs"):
-            self.map_delete_outputs(o, res)
-        else:
-            # "rc" is often only returned when something bad happens, so assume that no "rc" implies a successful rc
-            # of 0.
-            if res[0].get("rc", 0) != 0:
-                raise Exception("Nonzero rc from Ansible during delete_record")
-
-        self.log.debug("Finished default delete record", **o.tologdict())
+        self.log.debug("In abstract delete record", **o.tologdict())
+        # This method should be overridden by the service
diff --git a/lib/xos-synchronizer/xossynchronizer/synchronizer.py b/lib/xos-synchronizer/xossynchronizer/synchronizer.py
index 9a530d7..30d3ca0 100644
--- a/lib/xos-synchronizer/xossynchronizer/synchronizer.py
+++ b/lib/xos-synchronizer/xossynchronizer/synchronizer.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-import sys
 import time
 
 from xosconfig import Config
@@ -60,7 +58,7 @@
         from backend import Backend
 
         log_closure = self.log.bind(synchronizer_name=Config().get("name"))
-        backend = Backend(log=log_closure)
+        backend = Backend(log=log_closure, model_accessor=self.model_accessor)
         backend.run()