Retrieve information about multiple players across multiple leagues in a single request.
Users can only retrieve data for private leagues of which they are a member if they have provided a valid OAuthToken upon authenticating your application. Leagues that have been designated as public can be queried without user authentication.
const YahooFantasy = require('yahoo-fantasy');
const yf = new YahooFantasy(
  Y!APPLICATION_KEY,
  Y!APPLICATION_SECRET,
  tokenCallbackFn, // optional
  redirectUri // optional
);
yf.setUserToken(
  Y!OAuthAccessToken
);
// promise based
try {
  const players = await yf.players.leagues(
    [league_keys],
    {filters}, // optional
    [subresources], // optional
  );
} catch (e) {
  // handle error
}
// callback based
yf.players.leagues(
  [league_keys], 
  {filters}, // optional
  [subresources], // optional
  callbackFn
);
[
  {
    "league_key": "328.l.34014",
    "league_id": "34014",
    "name": "Freddy Beach Baseball",
    "url": "http://baseball.fantasysports.yahoo.com/archive/mlb/2014/34014",
    "league_chat_id": "",
    "draft_status": "postdraft",
    "num_teams": 12,
    "edit_key": "2015-02-04",
    "weekly_deadline": "intraday",
    "league_update_timestamp": "1411979069",
    "scoring_type": "head",
    "league_type": "private",
    "renew": "308_51222",
    "renewed": "346_1106",
    "short_invitation_url": "https://yho.com/mlb?l=34014&k=0a2bf56970bb200c",
    "is_pro_league": "0",
    "current_week": "25",
    "start_week": "1",
    "start_date": "2014-03-22",
    "end_week": "25",
    "end_date": "2014-09-28",
    "is_finished": 1,
    "players": [
      {
        "player_key": "328.p.7264",
        "player_id": "7264",
        "name": {
          "full": "José Bautista",
          "first": "José",
          "last": "Bautista",
          "ascii_first": "Jose",
          "ascii_last": "Bautista"
        },
        "editorial_player_key": "mlb.p.7264",
        "editorial_team_key": "mlb.t.14",
        "editorial_team_full_name": "Toronto Blue Jays",
        "editorial_team_abbr": "Tor",
        "uniform_number": "19",
        "display_position": "1B,OF",
        "headshot": {
          "url": "http://l.yimg.com/iu/api/res/1.2/9V26x2764H1l8ST0R6eajg--/YXBwaWQ9eXZpZGVvO…g--/http://l.yimg.com/j/assets/i/us/sp/v/mlb/players_l/20130405/7264.1.jpg",
          "size": "small"
        },
        "is_undroppable": "0",
        "position_type": "B",
        "eligible_positions": [
          "1B",
          "OF",
          "Util"
        ],
        "draft_analysis": {
          "average_pick": "30.8",
          "average_round": "3.3",
          "average_cost": "27.0",
          "percent_drafted": "1.00"
        }
      },
      {
        "player_key": "328.p.8644",
        "player_id": "8644",
        "name": {
          "full": "Domonic Brown",
          "first": "Domonic",
          "last": "Brown",
          "ascii_first": "Domonic",
          "ascii_last": "Brown"
        },
        "editorial_player_key": "mlb.p.8644",
        "editorial_team_key": "mlb.t.22",
        "editorial_team_full_name": "Philadelphia Phillies",
        "editorial_team_abbr": "Phi",
        "uniform_number": "9",
        "display_position": "OF",
        "headshot": {
          "url": "http://l.yimg.com/iu/api/res/1.2/wkPExRUb.XyjBpPKmHWUFQ--/YXBwaWQ9eXZpZGVvO…g--/http://l.yimg.com/j/assets/i/us/sp/v/mlb/players_l/20130405/8644.1.jpg",
          "size": "small"
        },
        "is_undroppable": "0",
        "position_type": "B",
        "eligible_positions": [
          "OF",
          "Util"
        ],
        "draft_analysis": {
          "average_pick": "124.7",
          "average_round": "11.8",
          "average_cost": "9.4",
          "percent_drafted": "1.00"
        }
      },
      {
        "player_key": "328.p.7498",
        "player_id": "7498",
        "name": {
          "full": "Shin-Soo Choo",
          "first": "Shin-Soo",
          "last": "Choo",
          "ascii_first": "Shin-Soo",
          "ascii_last": "Choo"
        },
        "editorial_player_key": "mlb.p.7498",
        "editorial_team_key": "mlb.t.13",
        "editorial_team_full_name": "Texas Rangers",
        "editorial_team_abbr": "Tex",
        "uniform_number": "17",
        "display_position": "OF",
        "headshot": {
          "url": "http://l.yimg.com/iu/api/res/1.2/vpGz9xTjYIf.3trxbXZvgw--/YXBwaWQ9eXZpZGVvO…g--/http://l.yimg.com/j/assets/i/us/sp/v/mlb/players_l/20130405/7498.1.jpg",
          "size": "small"
        },
        "is_undroppable": "0",
        "position_type": "B",
        "eligible_positions": [
          "OF",
          "Util"
        ],
        "draft_analysis": {
          "average_pick": "42.0",
          "average_round": "4.4",
          "average_cost": "25.1",
          "percent_drafted": "1.00"
        }
      },
      {
        "player_key": "328.p.6983",
        "player_id": "6983",
        "name": {
          "full": "Coco Crisp",
          "first": "Coco",
          "last": "Crisp",
          "ascii_first": "Coco",
          "ascii_last": "Crisp"
        },
        "editorial_player_key": "mlb.p.6983",
        "editorial_team_key": "mlb.t.11",
        "editorial_team_full_name": "Oakland Athletics",
        "editorial_team_abbr": "Oak",
        "uniform_number": "4",
        "display_position": "OF",
        "headshot": {
          "url": "http://l.yimg.com/iu/api/res/1.2/gTI1sn2_l8sDR3B_epsvpA--/YXBwaWQ9eXZpZGVvO…g--/http://l.yimg.com/j/assets/i/us/sp/v/mlb/players_l/20130405/6983.1.jpg",
          "size": "small"
        },
        "is_undroppable": "0",
        "position_type": "B",
        "eligible_positions": [
          "OF",
          "Util"
        ],
        "draft_analysis": {
          "average_pick": "128.0",
          "average_round": "12.1",
          "average_cost": "7.1",
          "percent_drafted": "1.00"
        }
      },
      {
        "player_key": "328.p.7934",
        "player_id": "7934",
        "name": {
          "full": "Carlos González",
          "first": "Carlos",
          "last": "González",
          "ascii_first": "Carlos",
          "ascii_last": "Gonzalez"
        },
        "editorial_player_key": "mlb.p.7934",
        "editorial_team_key": "mlb.t.27",
        "editorial_team_full_name": "Colorado Rockies",
        "editorial_team_abbr": "Col",
        "uniform_number": "5",
        "display_position": "OF",
        "headshot": {
          "url": "http://l.yimg.com/iu/api/res/1.2/CAaVkp7i4ZdyshkVpkk5Kw--/YXBwaWQ9eXZpZGVvO…g--/http://l.yimg.com/j/assets/i/us/sp/v/mlb/players_l/20130405/7934.1.jpg",
          "size": "small"
        },
        "is_undroppable": "0",
        "position_type": "B",
        "eligible_positions": [
          "OF",
          "Util"
        ],
        "draft_analysis": {
          "average_pick": "6.9",
          "average_round": "1.1",
          "average_cost": "43.8",
          "percent_drafted": "1.00"
        }
      }
    ]
  }
]