Privacy Policy
Last updated: 2026-06-03.
Where the extension runs
WatchSentry runs on watch-listing pages on these marketplaces only: Chrono24, eBay (US/UK/DE), and Watchfinder (UK/US). It does not run on any other site.
What data we collect
- Anonymous user ID — a randomly generated UUID stored locally in your browser via
chrome.storage.local. We do NOT collect your name, email, IP address, or any personally identifying information. The UUID is sent alongside enrichment requests purely to enforce a per-day usage cap; we do not link it to any other identifier. - Listing data — when you view a supported listing page, the extension extracts the brand, model, reference number, condition, and listed price from the page and sends it to our API to look up fair value. We do not log or store individual queries by user; we keep only aggregate per-day usage counts per anonymous ID.
- Auto-discovery signals — when you view a listing for a reference we don't yet track, the extension sends the (brand, model, reference) triple to our API so we can add it to a candidate catalog for future support. This signal carries no anonymous ID and no listing URL.
What we do NOT collect
- Your real name, email, or any personally identifying information
- Your IP address. (Cloudflare may log IPs at the network layer for DDoS protection; we do not access or retain those logs.)
- Your browsing history outside the supported marketplaces listed above
- Any data from any other website
- Listing URLs, seller identifiers, or any data that could identify a specific listing or seller
- Your watch purchases or transactions
Third-party services
Our backend runs on Cloudflare Workers. Pricing data is derived from eBay's public Browse API. Neither service receives your anonymous ID or any data that could identify you.
Your rights
You can clear all locally stored data at any time by removing the extension or clearing site data for the extension in chrome://extensions. Since we do not store personally identifying information server-side, there is no separate account to delete.
Contact
Privacy questions: [email protected]