experiment with additionalProperties
@@ -51,6 +51,11 @@ allOf:
The contents of the messages to be sent. These are arranged in
a map of user IDs to a map of device IDs to message bodies.
The device ID may also be \*, meaning all known devices for the user.
+ additionalProperties:
+ type:
+ - string
+ - string
+ - object
example: {
"alice@example.org": {
"IWHQUZUIAH": {
