Your notebooks stay on your machine.
GNKG is a Chrome extension, a local bridge and this website, made by Metaphy LLC (Temecula, CA). This page explains what each part does with data.
Runs inside your signed-in Google session
It reads the session tokens Gemini Notebook already gives your browser, keeps them in memory only, and uses them to call Gemini Notebook on your behalf. It never copies cookies or tokens to disk, to us, or to any third party.
Local only
The MCP bridge listens on 127.0.0.1 on your computer. Your agents talk to it there. If you choose to expose it with a tunnel and token, that is your configuration, not ours.
Static, no accounts
This site sets no cookies and has no login. Vercel, the host, records standard server logs (IP, user agent, URL) for security and operations under its own privacy policy.
What we collect
We do not collect your notebooks, sources, titles or answers, and GNKG runs no analytics beacons and no crash reporting. The extension's settings (bridge port, display mode, optional bridge token) are stored with Chrome's storage API on your device. The one thing that leaves your computer for our server is the license check described next.
The license check
When you activate a seat, the extension sends our license server your key once, over HTTPS, with a random install id, a one-time number and the extension version. About once a week while you are online, and when you deactivate, it sends the install id, a one-time number, a short fingerprint of your key and its current token instead of the key. Each time, the server answers with a signed token. The request body holds only those fields, and none of them comes from your notebooks. Like any web request, it also reaches our host with what your browser and network always send, such as your IP address.
The extension keeps the install id, the token, the key’s fingerprint, the latest server time it has seen and a list of retired signing keys. It does not keep your key.
Our license server keeps a record for each seat. It holds your license key, its fingerprint, the install it is activated on, the Stripe checkout session it came from, when it was purchased, the one-time numbers it has seen, its status, when the record was created, when it was last updated, how many times the key has been recovered (at most 5), once it has been, when each recovery happened, and how many recovery attempts were refused after the limit, if any were.
Everything the license server stores is one of these kinds of entry: a seat record (the fields above), a checkout index that links each checkout session to the fingerprint of its key, a recovery index that links a keyed fingerprint of a checkout email to its checkout sessions, a request counter for each install, a request counter for each known key, a request counter for each checkout session, an overall request counter for each request type, a recovery-attempt counter for each checkout-email fingerprint, and one overall recovery-attempt counter.
The counters exist to limit repeated requests. A counter holds only a count and the time a one-hour window began, no IP address and no header, and expires about an hour after it was last used.
After you pay, the thank-you page sends your checkout session id to the license server to show you your key.
Recovering a lost key
If you use the Recover page, it sends the email and the receipt number from your Stripe receipt to our license server over HTTPS, and nothing else. They are used only to find your purchase. The license server does not store the email itself or the receipt number: it keeps a keyed fingerprint of the email, so that your purchases can be found again. Our hosting provider keeps ordinary request logs, as any website’s host does.
What the extension can access, and why
Gemini Notebook pages on notebooklm.google.com, notebook.google.com and gemini.google.com/notebook (notebooks you own; the extension finds your open notebook tabs by their address, and its health report passes that address to your own agent through the local bridge); localhost (optional services you run on your own computer: the MCP bridge, which also reads text out of source images; the B.I.F.R.O.S.T. server; and a local file handoff; the extension’s own calls to them go to localhost and never leave your machine); gnkg.vercel.app (the web console page-bridge, and the license server: see the license check above), metaphysicsandcomputing.com and gnkg.metaphysicsandcomputing.com (the web console page-bridge), and the console page served from your own machine (localhost or 127.0.0.1), where the GNKG web console page-bridge runs and relays messages between the console and the extension; scripting (runs the extension’s own request code inside your open, signed-in Gemini Notebook tab, so calls come from that page with your session; the function is defined in the extension itself); downloads (files you export); notifications and alarms (long-running jobs); the side panel (its UI). Every permission is used only for those purposes.
Your notebooks
Notebook content stays in your Google account and, when your agents ask for it, on your computer. GNKG never centralises, mirrors or trains on it.
Purchases
A GNKG seat is sold by Metaphy LLC, not by Google. Price: $200 USD plus applicable tax. Refunds within 14 days via logan@metaphysicsandcomputing.com. See Buy a seat. The extension and this site never see card numbers. Buy opens a checkout page hosted by Stripe. You enter your card details there, and Stripe’s own privacy policy applies to that page.
Changes and contact
Changes are posted on this page with a new effective date. Questions: logan@metaphysicsandcomputing.com.
“The bridge was never the server. The bridge was the session.”