Webhook Event Schema

The event data that is sent to my webhook looks like below. My access token has both activity:write and activity:read_all scopes.

{
   "":"http://json-schema.org/draft-04/schema#",
   "title":"StravaPushModel",
   "type":"object",
   "required":[
      "event_time",
      "object_id",
      "object_type",
      "owner_id"
   ],
   "properties":{
      "event_time":{
         "type":"integer"
      },
      "object_id":{
         "type":"integer"
      },
      "object_type":{
         "type":"string"
      },
      "owner_id":{
         "type":"integer"
      }
   }
}