Watchkeeper Joins the Studio as a Tiny Browser That Shows Who Is Watching

Watchkeeper is the studio’s twenty-eighth project, and its first desktop app. It’s a small browser with a panel beside the page. As the page loads, the panel lists the other sites it tells about your visit, the cookies it leaves, the keys it writes to your computer and the scripts that read the features used to fingerprint a device, each named by site: “canvas by adnetwork.example”. How web tracking works explains why none of that shows in an ordinary window.

It runs on the engine each system already has, WebView2, WKWebView or WebKitGTK, through Tauri 2 and Rust, so the installers are about 2 MB. Every session starts empty and is deleted on close. Four releases on Oct 23 built it up: the browser and live panel in 0.1.0, fingerprinting by site and a Last visit comparison in 0.2.0, a Save report button writing HTML and JSON in 0.3.0, and an address bar fix in 0.3.1. Three case studies, a shop page that calls five sites before its cookie banner is answered, a blog adding trackers between visits and a report sent to an agency, run on made-up pages served from the repository.

The testing checks the panel against test servers’ own logs. In one recorded Linux run it saw 14 of the 14 tracker addresses it could, and a hostile page that replaced built-ins, forged 4,207 messages and flooded the collector still had its real tracker seen, with 73,827 junk events counted as left out. The self-test’s 28 checks also run on Windows and macOS and with each installer before it’s published. Independent reviews found problems in every version, all fixed before release.

Open source under Apache 2.0, with installers for Windows, macOS and Linux.