The extension adds controls on YouTube and a small popup that links to the web app. It requests permissions needed to show that UI on YouTube, open ShakeTheSpear in a tab when you choose, store optional sign-in state, and call our API—the same authenticated backend as the website. We do not design the extension to collect your general browsing history for analytics or advertising. Content scripts run only on YouTube hostnames we declare so the on-page features can work. If you use Connect in the extension, OAuth completes through the browser’s secure flow; we do not embed YouTube Data API keys in the extension. Use of YouTube is also subject to Google’s and YouTube’s terms and policies where applicable.