Hello,

I am the developer of a Yahoo app (App ID: Ui70cQAv) that uses the Yahoo Fantasy Sports API with OAuth 2.0.

OAuth is working correctly — my app completes the authorization flow, the token exchange returns HTTP 200, and I hold valid access and refresh tokens. However, every call to the Fantasy Sports API is rejected with HTTP 403.

Example request:
GET https://fantasysports.yahooapis.com/fantasy/v2/users;use_login=1/games;game_codes=nba

Response:
"This application is not authorized to perform this action."

The app has Fantasy Sports permissions selected, and the redirect URI is https://marginfantasy.com/auth/yahoo/callback. My understanding is that Fantasy API access has to be authorized on Yahoo's side for each application.

Could you please confirm whether my application needs to be approved for Fantasy Sports API access, and enable it if so? The app (marginfantasy.com) is a read-only dashboard: after a user signs in with Yahoo, it displays that user's own leagues, rosters, and standings back to them. No writes, no posting, no third-party data sharing.

Thank you,
Joseph Jezioranski