Sleever is a Chrome extension and web dashboard that finds underpriced football/soccer trading card listings on eBay and Vinted by comparing them to available market evidence. This page explains what data the extension and its backend collect and how it's used.
Sleever's content script runs only on supported eBay and Vinted listing and search pages. It reads the listing details visible on those pages (title, price, seller location, card identifiers) to compare them against known sold prices. It does not read pages outside those supported marketplaces, and it does not read your browsing history, unrelated tabs, or personal files.
To value a listing, Sleever's server also queries eBay's and MySlabs' sold-listing data and Fanatics Collect's sales-history data for comparable sales. These are read-only lookups of public market/price data - Sleever does not sign in to or store any account credentials for these sites.
When a listing's title alone doesn't clearly state the card number or player name (mainly on Vinted, where casual sellers often skip it), the panel can optionally ask you to confirm a suggestion read from the listing's own photo. If you use this, the photo's URL (hosted by eBay or Vinted, never uploaded from your device) is sent to Anthropic's Claude API to read the printed text. We don't store the photo or the AI's response - only a daily usage count per account, to enforce plan limits. The suggestion is never used automatically; you confirm or correct it yourself before it affects any price comparison.
To use Sleever you sign in with an email address (via Clerk, our authentication provider). We store your email, account ID, subscription tier, and daily scan counts on our server so the extension knows your plan and usage. We also store saved watchlist and collection entries, imported research, scan progress, and opportunity data needed by the dashboard. Shared opportunity and trend feeds may contain listing data contributed by authenticated scans, without marketplace passwords. We do not sell this data with third parties.
The dashboard and login page use your browser's local storage (not cookies) to remember your theme, language, and last-viewed tab - this stays on your device and is never sent to our server. Clerk, our authentication provider, sets its own session cookie/storage to keep you signed in; this is required for the Service to work and isn't used for advertising or tracking. Sleever itself doesn't use any advertising, analytics, or third-party tracking cookies, so there's no cookie consent banner on this site - there's nothing optional to consent to.
Subscriptions are billed through Stripe. Sleever's servers never see or store your card number - Stripe handles that directly.
You can review and update your saved data (watchlist, collection, research) directly in the dashboard. You can permanently delete your account and all associated data at any time from the Account tab in the dashboard - this also cancels any active subscription. If you'd rather we do it for you, or have any other request about your data, contact us below.
Questions about this policy or your data: zahutdenis@gmail.com.