matrix-spec-proposals/api/client-server/definitions/event.json

{
  "type": "object",
  "title": "Event",
  "properties": {
    "content": {
      "type": "object",
      "title": "EventContent",
      "description": "The content of this event. The fields in this object will vary depending on the type of event."
    },
    "origin_server_ts": {
      "type": "integer",
      "format": "int64",
      "description": "Timestamp in milliseconds on originating homeserver when this event was sent."
    },
    "sender": {
      "type": "string",
      "description": "The MXID of the user who sent this event."
    },
    "state_key": {
      "type": "string",
      "description": "Optional. This key will only be present for state events. A unique key which defines the overwriting semantics for this piece of room state."
    },
    "type": {
      "type": "string",
      "description": "The type of event."
    },
    "unsigned": {
      "type": "object",
      "title": "Unsigned",
      "description": "Information about this event which was not sent by the originating homeserver",
      "properties": {
        "age": {
          "type": "integer",
          "format": "int64",
          "description": "Time in milliseconds since the event was sent."
        },
        "prev_content": {
          "title": "EventContent",
          "type": "object",
          "description": "Optional. The previous ``content`` for this state. This will be present only for state events appearing in the ``timeline``. If this is not a state event, or there is no previous content, this key will be missing."
        },
        "transaction_id": {
          "type": "string",
          "description": "Optional. The transaction ID set when this message was sent. This key will only be present for message events sent by the device calling this API."
        }
      }
    }
  }
}