The official PlayFab Node.js SDK by PlayFab calls the Playfab REST API to access game backend services. Features include analytics, player accounts, and virtual goods. TLS v1.1 is needed to connect to the Playfab service.
Check your team, look up player stats and see the league's latest transactions, all from Yahoo's latest API. Fantasy baseball and football are both supported now, with options for hockey and basketball expected in time for their seasons. And the API supports OAuth, so developers could create new interfaces to almost every feature of Yahoo Fantasy Sports.