diff --git a/synapse/storage/relations.py b/synapse/storage/relations.py
new file mode 100644
index 0000000000..a4905162e0
--- /dev/null
+++ b/synapse/storage/relations.py
@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector 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.
+
+import logging
+
+from synapse.api.constants import RelationTypes
+from synapse.storage._base import SQLBaseStore
+
+logger = logging.getLogger(__name__)
+
+
+class RelationsStore(SQLBaseStore):
+ def _handle_event_relations(self, txn, event):
+ """Handles inserting relation data during peristence of events
+
+ Args:
+ txn
+ event (EventBase)
+ """
+ relation = event.content.get("m.relates_to")
+ if not relation:
+ # No relations
+ return
+
+ rel_type = relation.get("rel_type")
+ if rel_type not in (
+ RelationTypes.ANNOTATION,
+ RelationTypes.REFERENCES,
+ RelationTypes.REPLACES,
+ ):
+ # Unknown relation type
+ return
+
+ parent_id = relation.get("event_id")
+ if not parent_id:
+ # Invalid relation
+ return
+
+ aggregation_key = relation.get("key")
+
+ self._simple_insert_txn(
+ txn,
+ table="event_relations",
+ values={
+ "event_id": event.event_id,
+ "relates_to_id": parent_id,
+ "relation_type": rel_type,
+ "aggregation_key": aggregation_key,
+ },
+ )
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