LeagueInsights Connector by Teolicenko

LeagueInsights (https://www.leagueinsights.app) adds standings, draft analysis,
keeper tracking, playoff odds and a live draft lottery to a Yahoo Fantasy league.

This extension is the part that loads your league. Yahoo restricted its public
Fantasy API in 2026, so LeagueInsights can no longer read your league from its
own servers. Instead, this extension reads it from the browser you are already
signed in to Yahoo with, and sends the league data — standings, rosters,
transactions, draft results — to your LeagueInsights account.

WHAT IT DOES

• When the LeagueInsights web app needs your league data, the extension fetches
it from Yahoo's read-only fantasy API in this browser and passes the result to
your LeagueInsights account.
• When you are browsing your own league on Yahoo, the extension tells
LeagueInsights which league you are looking at, so your data can be refreshed
while your Yahoo session is known to be working. It sends the sport and the
league number, and nothing from the page.
• The commissioner of a league can upload a generated schedule back to Yahoo.
This is the only action that changes anything on Yahoo, it happens only when
the commissioner asks for it in the app, and it can only reach the league's
own schedule form.

WHAT IT DOES NOT DO

• It does not read, store or transmit your Yahoo password, cookies or any other
credential. It has no access to your cookies at all — the browser attaches
your Yahoo session to its own requests, which is why the extension never
needs to see it.
• It cannot touch Yahoo Mail, your Yahoo account settings, or any Yahoo site
other than fantasysports.yahoo.com. This is enforced twice: the extension
requests access to no other Yahoo host, and it checks every request against
its own built-in list of permitted addresses before performing it.
• It does not read, inject into or observe any third-party website. Its only
content script runs on leagueinsights.app, where it does one thing: tell the
page that the extension is installed.
• It shows no ads, sells no data, and uses your browser for nothing except your
own league.

TRANSPARENCY

Click the toolbar icon to see exactly what the extension has done: how much data
it has loaded, when it last checked in, and the last eight requests with their
result. Those counters are computed and kept in this browser, and are never
uploaded.

SETUP

1. Create an account at https://www.leagueinsights.app and sign in.
2. Open Settings → Yahoo Sync and copy the pairing code shown there.
3. Click this extension's icon, paste the code, and press "Link account".

Requires a LeagueInsights account and a Yahoo Fantasy league. Not affiliated
with, endorsed by, or sponsored by Yahoo. Yahoo and Yahoo Fantasy are
trademarks of their respective owner.