allOf: - $ref: room_event.yaml description: In addition to the Room Event fields, State Events have the following additional fields. properties: prev_content: description: Optional. The previous ``content`` for this event. If there is no previous content, this key will be missing. title: EventContent type: object state_key: description: A unique key which defines the overwriting semantics for this piece of room state. This value is often a zero-length string. The presence of this key makes this event a State Event. The key MUST NOT start with '_'. type: string required: - state_key title: State Event type: object