Add /_matrix/versions to report supported versions

synapse/app/homeserver.py

@@ -185,6 +185,7 @@ class SynapseHomeServer(HomeServer):
                         "/_matrix/client/r0": client_resource,
                         "/_matrix/client/unstable": client_resource,
                         "/_matrix/client/v2_alpha": client_resource,
+                        "/_matrix/client/versions": client_resource,
                     })
 
                 if name == "federation":

synapse/rest/__init__.py

@@ -13,6 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from synapse.rest.client import (
+    versions,
+)
+
 from synapse.rest.client.v1 import (
     room,
     events,
@@ -53,6 +57,8 @@ class ClientRestResource(JsonResource):
 
     @staticmethod
     def register_servlets(client_resource, hs):
+        versions.register_servlets(client_resource)
+
         # "v1"
         room.register_servlets(hs, client_resource)
         events.register_servlets(hs, client_resource)

synapse/rest/client/versions.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# 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 synapse.http.servlet import RestServlet
+
+import logging
+import re
+
+logger = logging.getLogger(__name__)
+
+
+class VersionsRestServlet(RestServlet):
+    PATTERNS = [re.compile("^/_matrix/client/versions$")]
+
+    def on_GET(self, request):
+        return (200, {
+            "versions": [
+                "r0.0.1",
+            ]
+        })
+
+
+def register_servlets(http_server):
+    VersionsRestServlet().register(http_server)