Extension privacy policy

Ledger Underdog Sync (Chrome extension) · updated September 1, 2026

The short version

The whole policy in four lines

The extension reads the Underdog draft pages you are already signed into, and only when you ask it to. It never sees your Underdog password. It sends nothing anywhere until you click Pull rooms in Dynasty Ledger, and then it sends only draft data — never credentials.

No analytics, no trackers, no advertising, and nothing is sold or shared with third parties.

What it collects

Draft data, and only when you press a button

Draft rooms

Picks, draft order, seat numbers, opponent usernames, contest title, entry fee, prize pool, and Underdog’s own projections — for the completed drafts you capture.

Your identity

Your Underdog user id and username, read from the session your browser already holds, so the extension knows which seat in each room is yours.

Never collected

Your Underdog password, payment or banking details, browsing history, and any page outside Underdog and Dynasty Ledger.

Where the data goes

Your device, then your Ledger account

Captured rooms are stored on your own computer using Chrome’s extension storage. They stay there until you upload them or clear them — Clear captured data in the extension popup removes them immediately.

When you click Pull rooms on Dynasty Ledger, the draft data above is sent to your Dynasty Ledger account and stored against it, so the site can score the rosters and rank the rooms. Deleting your Ledger account deletes that data.

Your Underdog session token is used only inside the Underdog page, to ask Underdog for your own draft data. It is never transmitted to Dynasty Ledger and never stored on disk.

Why each permission exists

The manifest, in plain words

storage

Keeps captured rooms on your device until you upload them.

activeTab, scripting

Reads the Underdog draft page you have open, which is how a room is captured at all.

tabs

Finds your Underdog tab when you start a capture from the extension popup.

Underdog sites

Reads your completed drafts through Underdog’s own interface, using your existing session.

Dynasty Ledger sites

Hands the captured rooms to Ledger when you click Pull rooms. This is the only destination.

Questions

And how to verify any of this

The extension’s complete source is public in the Dynasty Ledger repository under extensions/underdog-sync, and the download is built from it — you can read every line before installing.

Dynasty Ledger is not affiliated with, endorsed by, or operated by Underdog Fantasy.