BASERUNNER Privacy Policy

BASERUNNER is a browser extension that enhances your fantasy baseball experience by connecting your fantasy league data with live MLB game information. This privacy policy explains what data the extension collects, how it is stored, and how it is used.

As of v1.0.1, BASERUNNER is free during beta. The Stripe integration described below is not currently charging users, but the code remains active so paid tiers can be re-enabled in a future version.

What Data BASERUNNER Collects

• OAuth tokens for Yahoo Fantasy Sports (access tokens and refresh tokens obtained through Yahoo's official OAuth 2.0 flow)
• Fantasy league information such as league IDs, team rosters, and player lists retrieved from Yahoo Fantasy, ESPN, Sleeper, and Fantrax
• User preferences and settings such as selected leagues, display options, and platform connection status
• Subscription email and a randomly generated device identifier, used only to verify an active subscription

Where Data Is Stored

All user data is stored locally on your device using the browser's chrome.storage.local API. No user data is stored in any external database or on any remote server.

What the Backend Server Does

BASERUNNER operates a lightweight backend server that serves three purposes:

1. OAuth token exchange — when you connect your Yahoo Fantasy account, the backend handles the OAuth authorization code exchange with Yahoo's servers and returns the resulting tokens to the extension. Tokens are held in server memory only temporarily (up to 10 minutes) to allow the extension to retrieve them, then they are automatically purged.
2. API proxy — the backend proxies requests to the Yahoo Fantasy API on your behalf to avoid browser CORS restrictions. Your access token is used only for the duration of the request and is not logged or stored.
3. Subscription verification — the backend communicates with Stripe to verify your subscription status. Only your email and device identifier are transmitted; billing details are handled entirely by Stripe and never reach the extension or our server.

The backend server does not persistently store any user data or personal information beyond the minimum required to provide subscription access.

Third-Party Services

• MLB Stats API (statsapi.mlb.com) — for live game data, scores, and schedules
• Yahoo Fantasy Sports API — for fantasy league rosters and player data (requires OAuth authorization)
• ESPN Fantasy API — for ESPN fantasy league data
• Sleeper API — for Sleeper fantasy league data
• Fantrax API — for Fantrax fantasy league data
• Stripe — for subscription billing
• Resend — for delivering install and bug-report notifications to the BASERUNNER developer. Only your device identifier, extension version, user agent, and any message you voluntarily submit via the bug-report form are transmitted.

Each of these services has its own privacy policy governing how they handle your data. BASERUNNER only requests the minimum data needed to provide its features.

Data Sharing and Advertising

• BASERUNNER does not sell your data to any third party.
• BASERUNNER does not share your data with any third party for advertising or marketing purposes.
• BASERUNNER does not display ads or use any advertising tracking.
• BASERUNNER does not use analytics or telemetry services.

How to Delete Your Data

• Disconnecting platforms — use the extension's settings page to disconnect any connected fantasy platforms. This removes stored tokens and league data from local storage.
• Uninstalling the extension — removing the extension from your browser automatically deletes all data stored in chrome.storage.local.
• Cancelling your subscription — you can cancel at any time from your Stripe customer portal; email us and we will remove your subscription record from our server.

Changes to This Policy

If this privacy policy is updated, the changes will be noted with a revised "Last updated" date at the top of this document.

Contact

If you have questions or concerns about this privacy policy or BASERUNNER's data practices, please contact: colevissicchio98@gmail.com