SiteSentry is built with a local-first, privacy-by-design architecture:

1. Data Storage: All monitored URLs, element selectors, rule configurations, and historical check results are stored locally inside your Firefox browser using IndexedDB.
2. Zero Tracking: SiteSentry does not collect, sell, or transmit any browsing history, cookies, personal identifiers, or telemetry to third parties.
3. Network Requests: The extension only connects to the specific target websites configured by the user for monitoring purposes, and optionally to configured webhook endpoints (Telegram, Discord, Slack) to deliver user-requested alerts.
4. Payments: Payments for the optional Pro tier are processed externally via NOWPayments. No wallet private keys or financial credentials are ever accessed or handled by the extension.