diff --git a/xos/coreapi/protos/utility.proto b/xos/coreapi/protos/utility.proto
index 4717581..6d5f18f 100644
--- a/xos/coreapi/protos/utility.proto
+++ b/xos/coreapi/protos/utility.proto
@@ -57,4 +57,11 @@
             body: "*"
         };
   }
+
+  rpc NoOp(google.protobuf.Empty) returns (google.protobuf.Empty) {
+        option (google.api.http) = {
+            post: "/xosapi/v1/utility/noop"
+            body: "*"
+        };
+  }
 };
diff --git a/xos/coreapi/xos_utility_api.py b/xos/coreapi/xos_utility_api.py
index f595849..7377c91 100644
--- a/xos/coreapi/xos_utility_api.py
+++ b/xos/coreapi/xos_utility_api.py
@@ -104,3 +104,6 @@
 
         return response
 
+    def NoOp(self, request, context):
+        return Empty()
+
diff --git a/xos/synchronizers/new_base/modelaccessor.py b/xos/synchronizers/new_base/modelaccessor.py
index 765b5d5..c715095 100644
--- a/xos/synchronizers/new_base/modelaccessor.py
+++ b/xos/synchronizers/new_base/modelaccessor.py
@@ -13,6 +13,9 @@
 from xos.config import Config
 from diag import update_diag
 
+from xos.logger import Logger, logging
+logger = Logger(level=logging.INFO)
+
 class ModelAccessor(object):
     def __init__(self):
         self.all_model_classes = self.get_all_model_classes()
@@ -94,6 +97,27 @@
                 self.into=into
         globals()["ModelLink"] = ModelLink
 
+def keep_trying(client, reactor):
+    # Keep checking the connection to wait for it to become unavailable.
+    # Then reconnect.
+
+    # logger.info("keep_trying")   # message is unneccesarily verbose
+
+    from xosapi.xos_grpc_client import Empty
+
+    try:
+        client.utility.NoOp(Empty())
+    except:
+        # If we caught an exception, then the API has become unavailable.
+        # So reconnect.
+
+        logger.log_exc("exception in NoOp")
+        client.connected = False
+        client.connect()
+        return
+
+    reactor.callLater(1, functools.partial(keep_trying, client, reactor))
+
 def grpcapi_reconnect(client, reactor):
     global model_accessor
 
@@ -102,6 +126,33 @@
 
     from apiaccessor import CoreApiModelAccessor
     model_accessor = CoreApiModelAccessor(orm = client.xos_orm)
+
+    # If required_models is set, then check to make sure the required_models
+    # are present. If not, then the synchronizer needs to go to sleep until
+    # the models show up.
+
+    required_models = getattr(Config(), "observer_required_models", None)
+    if required_models:
+        required_models = required_models.split(",")
+        required_models = [x.strip() for x in required_models]
+
+        missing = []
+        found = []
+        for model in required_models:
+            if model_accessor.has_model_class(model):
+                found.append(model)
+            else:
+                missing.append(model)
+
+        logger.info("required_models: found %s" % ", ".join(found))
+        if missing:
+            logger.warning("required_models: missing %s" % ", ".join(missing))
+            # We're missing a required model. Give up and wait for the connection
+            # to reconnect, and hope our missing model has shown up.
+            reactor.callLater(1, functools.partial(keep_trying, client, reactor))
+            return
+
+    # import all models to global space
     import_models_to_globals()
 
     # Synchronizer framework isn't ready to embrace reactor yet...
diff --git a/xos/xos_client/xosapi/xos_grpc_client.py b/xos/xos_client/xosapi/xos_grpc_client.py
index 8213662..aaaa97f 100644
--- a/xos/xos_client/xosapi/xos_grpc_client.py
+++ b/xos/xos_client/xosapi/xos_grpc_client.py
@@ -57,7 +57,9 @@
                 try:
                     sys.path.append(self.work_dir)
                     m_protos = __import__(api + "_pb2")
+                    reload(m_protos)
                     m_grpc = __import__(api + "_pb2_grpc")
+                    reload(m_grpc)
                 finally:
                     sys.path = orig_sys_path