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()