What the extension reads, and what it sends

The short version

Nothing about a page leaves your device unless you ask for it. A small script does run on every page you visit, for one reason, and there is a section below saying exactly why, because we would rather tell you than have you find it in the manifest.

What it does

The Whetstone maps the argument of a page you choose: its skeleton of claims and premises, where it sits in a contested conversation, the strongest published voice on the other side, and, only when something load-bearing and checkable is broken, a plainly worded error tab. Results appear in Chrome's side panel.

You trigger everything yourself. There is one optional mode, switched off when you install it, described below.

What leaves your device

When you map a page, a selection, or pasted text, that text is sent over HTTPS to The Whetstone at thewhetstone.review, which runs up to three passes: structure extraction, placement against our audited briefings, and the reasoning audit. To produce those, the service passes the text to Google's Gemini API. The text is not stored: no database, no log, no file. Once the analysis returns, it is discarded.

Placement caching. When a mapping includes the page's address, the resulting placement may be cached on our side for up to seven days, keyed by that address with tracking parameters stripped. What is cached is the contested question, a stance, a camp and one verbatim sentence from the piece. Never the article text. The cache exists so the same public article is not re-analysed for every reader, and no account, identifier or reading history is attached to any entry.

The one script that runs everywhere

A small script runs on the pages you visit, and it starts as soon as the page loads whether you asked for anything or not. It exists so that when you select a sentence, the "Audit this" pill can appear next to it. To do that it has to watch for selections, which means it is present and looking on every site.

It stays on your machine. It sends nothing anywhere until you click. Whole articles are read only when you press a button in the panel.

We used to write this as "the extension never reads pages in the background". That was a fair description of what the extension does with your pages and an inaccurate description of what runs on them, so we replaced it. The claim we will hold to is the one that is actually true: nothing about a page leaves your device unless you ask for it.

Ambient mode, off by default

The panel has a switch labelled Ambient surfaces, off until you turn it on. While it is off, that content script does nothing on any page. If you turn it on:

• When you finish reading a long article-shaped page, its text is sent once, as above, to place it. A small card appears only if a placement exists.
• When you hover an outbound link inside an article, the link's address is sent for a cache lookup only, never an analysis, and a card appears only if that address had already been placed.

Turning the switch off stops both immediately. This is the only behaviour that ever sends anything without a per-action click, and it never runs the reasoning audit.

Accounts and sign-in

The extension does not ask you to sign in. If you are already signed in to thewhetstone.review in the same browser, it reads the whetstone_session cookie to recognise your tier so the right request limits apply. It reads no other cookie, from this site or any other.

Anonymous usage counts

If usage analytics are on, the extension sends anonymous product events to PostHog. The switch is in the panel under Options, alongside the ambient one, and it takes effect immediately.

Recorded: event names, timestamps, latency, counts, and a randomly generated local identifier tied to no account or email.
Never recorded: the text you map, page addresses or paths, page titles, or anything that identifies you.

Stored on your device

Chrome's local extension storage holds your preferences (the ambient switch and the analytics switch), a cached copy of your sign-in status, per-page dismissals of the ambient card, a diagnostic copy of the extension's own last internal error, and, if you save clips, the clips themselves: source address, title, the verbatim quote, the draft citation row, the argument skeleton and the mapped text. Clips exist only on your device, are visible under the panel's clips tab, and are gone when you delete them or uninstall.

Third parties

• Cloudflare hosts the service the extension calls. Privacy policy
• Google (Gemini API) processes text to generate analyses. API terms
• PostHog processes anonymous usage events, only when that switch is on. Privacy policy

These are service providers that process data only to make the product work. Your data is never sold, and never shared for any purpose beyond delivering the analysis.

What it does not do

• No page content leaves your device until you act: the pill, a panel button, or the ambient switch.
• No record of which websites you visit.
• No server-side storage of page content, analysis results, or browsing history.
• No advertising, ad targeting, or sale of data.
• No cross-site tracking.

If a result looks wrong

Every error tab links to our feedback page. Automated analysis can be wrong, and telling us is part of the product. For anything about this policy, write to hello@thewhetstone.review.