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