diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index f801fb532..92f64619c 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -31,10 +31,11 @@ class ApplicationService(object):
     # values.
     NS_LIST = [NS_USERS, NS_ALIASES, NS_ROOMS]
 
-    def __init__(self, token, url=None, namespaces=None):
+    def __init__(self, token, url=None, namespaces=None, txn_id=None):
         self.token = token
         self.url = url
         self.namespaces = self._check_namespaces(namespaces)
+        self.txn_id = None
 
     def _check_namespaces(self, namespaces):
         # Sanity check that it is of the form:
diff --git a/synapse/appservice/api.py b/synapse/appservice/api.py
index 803f97ea4..158aded66 100644
--- a/synapse/appservice/api.py
+++ b/synapse/appservice/api.py
@@ -13,3 +13,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
+class ApplicationServiceApi(object):
+    """This class manages HS -> AS communications, including querying and
+    pushing.
+    """
+
+    def __init__(self,  hs):
+        self.hs_token = "_hs_token_"  # TODO extract hs token
+
+    def query_user(self, service, user_id):
+        pass
+
+    def query_alias(self, service, alias):
+        pass
+
+    def push_bulk(self, service, events):
+        pass
+
+    def push(self, service, event):
+        pass
+
diff --git a/synapse/handlers/appservice.py b/synapse/handlers/appservice.py
index f05b57bcb..9cdeaa2d9 100644
--- a/synapse/handlers/appservice.py
+++ b/synapse/handlers/appservice.py
@@ -18,6 +18,7 @@ from twisted.internet import defer
 from ._base import BaseHandler
 from synapse.api.errors import Codes, StoreError, SynapseError
 from synapse.appservice import ApplicationService
+from synapse.appservice.api import ApplicationServiceApi
 
 import logging
 
@@ -29,6 +30,7 @@ class ApplicationServicesHandler(BaseHandler):
 
     def __init__(self, hs):
         super(ApplicationServicesHandler, self).__init__(hs)
+        self.appservice_api = ApplicationServiceApi(hs)
 
     @defer.inlineCallbacks
     def register(self, app_service):
@@ -97,7 +99,12 @@ class ApplicationServicesHandler(BaseHandler):
             )
             for user_service in user_query_services:
                 # this needs to block XXX: Need to feed response back to caller
-                pass  # TODO poke User Query API
+                is_known_user = self.appservice_api.query_user(
+                    user_service, event
+                )
+                if is_known_user:
+                    # the user exists now,so don't query more ASes.
+                    break
 
         # Do we know this room alias exists? If not, poke the room alias query
         # API for all services which match that room alias regex.
@@ -109,8 +116,13 @@ class ApplicationServicesHandler(BaseHandler):
             )
             for alias_service in alias_query_services:
                 # this needs to block XXX: Need to feed response back to caller
-                pass  # TODO poke Room Alias Query API
+                is_known_alias = self.appservice_api.query_alias(
+                    alias_service, event
+                )
+                if is_known_alias:
+                    # the alias exists now so don't query more ASes.
+                    break
 
         # Fork off pushes to these services - XXX First cut, best effort
         for service in services:
-            pass  # TODO push event to service
+            self.appservice_api.push(service, event)
diff --git a/synapse/storage/appservice.py b/synapse/storage/appservice.py
index 48bc7e0fe..abb617f04 100644
--- a/synapse/storage/appservice.py
+++ b/synapse/storage/appservice.py
@@ -216,6 +216,7 @@ class ApplicationServiceStore(SQLBaseStore):
             except IndexError:
                 logger.error("Bad namespace enum '%s'. %s", ns_int, res)
 
+        # TODO get last successful txn id f.e. service
         for service in services.values():
             logger.info("Found application service: %s", service)
             self.cache.services.append(ApplicationService(