Youtube api3.如何获得播放列表id不使用API_KEY

我试图通过请求获得它:https://www.googleapis.com/youtube/v3/playlistItems?part=contentDetails&playlistId={my_playlist_id}，但总是有一个错误:

{
    "error": {
    "errors": [
    {
        "domain": "usageLimits",
        "reason": "dailyLimitExceededUnreg",
        "message": "Daily Limit for Unauthenticated Use Exceeded. Continued use requires signup.",
        "extendedHelp": "https://code.google.com/apis/console"
    }
  ],
  "code": 403,
  "message": "Daily Limit for Unauthenticated Use Exceeded. Continued use requires signup."
 }
}

可能是未授权用户的daylillimit设置为0吗?是否可以像api v2

(类似于http://gdata.youtube.com/feeds/api/playlists/{playlist_id})?