sample PushEvent

PushEvent.json

{
   "repository":{
      "url":"https://github.com/igrigorik/spdy",
      "has_downloads":false,
      "created_at":"2012/01/19 14:15:34 -0800",
      "has_issues":true,
      "description":"SPDY is an experiment with protocols for the web",
      "forks":10,
      "fork":false,
      "has_wiki":false,
      "homepage":"http://www.igvita.com/2011/04/07/life-beyond-http-11-googles-spdy/",
      "size":420,
      "private":false,
      "name":"spdy",
      "owner":"igrigorik",
      "open_issues":4,
      "watchers":206,
      "pushed_at":"2012/01/11 10:38:16 -0700",
      "language":"Ruby"
   },
   "actor_attributes":{
      "gravatar_id":"a17f0025641b4be419a6cd3845e55dd2",
      "type":"User",
      "login":"igrigorik"
   },
   "created_at":"2012/02/11 10:38:16 -0700",
   "public":true,
   "actor":"igrigorik",
   "payload":{
      "head":"98f44cab69becb274c6f3b9035ef8e0bd7b2b1b7",
      "size":1,
      "shas":[
         [
            "98f44cab69becb274c6f3b9035ef8e0bd7b2b1b7",
            "ilya@igvita.com",
            "Unpack a SYN_STREAM before calling the callback.",
            "igrigorik",
            true
         ]
      ],
      "ref":"refs/heads/master"
   },
   "url":"https://github.com/igrigorik/spdy/compare/5b74597e88...98f44cab69b",
   "type":"PushEvent"
}

What's the difference between the created_at on top level and that inside the repository?

Cheers 🍻

One is the creation time of the respository; the other is the creation time of the push event.

The value payload > size, is that the number of lines of code affected by the push?
Is it the same number regardless of the edit being an addition or deletion?
Is that the only information about the content of the push that's included (besides the commit comment)?