PageDog is a local-first macOS app for monitoring exact website changes without repeatedly checking pages. Select a page area, define a testable goal—such as a price drop, restock, ticket sale, or appointment opening—and choose a schedule. PageDog checks through your local browser session and uses hosted AI to decide whether the goal happened. Browser sessions and history stay on your Mac; only selected evidence is sent for AI evaluation. The free plan includes 20 completed AI checks per month.