1 files changed, 6 insertions, 0 deletions
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 44c5ffc6a5..6a5e7171da 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -125,6 +125,8 @@ class EventTypes:
     MSC2716_BATCH: Final = "org.matrix.msc2716.batch"
     MSC2716_MARKER: Final = "org.matrix.msc2716.marker"
 
+    Reaction: Final = "m.reaction"
+
 
 class ToDeviceEventTypes:
     RoomKeyRequest: Final = "m.room_key_request"
@@ -150,6 +152,7 @@ class EduTypes:
 
 class RejectedReason:
     AUTH_ERROR: Final = "auth_error"
+    OVERSIZED_EVENT: Final = "oversized_event"
 
 
 class RoomCreationPreset:
@@ -228,6 +231,9 @@ class EventContentFields:
     # The authorising user for joining a restricted room.
     AUTHORISING_USER: Final = "join_authorised_via_users_server"
 
+    # an unspecced field added to to-device messages to identify them uniquely-ish
+    TO_DEVICE_MSGID: Final = "org.matrix.msgid"
+
 
 class RoomTypes:
     """Understood values of the room_type field of m.room.create events."""