Turn this on for daily or recurring monitoring. The first run returns every matching product as NEW. Later runs normally return only NEW, UPDATED and REAPPEARED products. What is compared: every returned field (price, original price, discount, installments, shipping, seller, stock, rating and review count, title, images and so on); changedFields names the ones that moved. What is excluded: scrapedAt (changes on every scrape), reviews (the review rows themselves; a new review still shows up through the review count and rating), and the search-context fields searchPosition (rank on the page), totalResults (size of the result set), searchKeyword (the query that found the product), resultType and sponsored (how this run found the row) and highlight (the ranking badge); these depend on the page and query, not on the product. A changed promotions entry does count as a change. Add more with Ignore fields when detecting changes. Turn on Emit unchanged or Emit expired only when you also want those rows returned (and billed). State is kept separately for each keyword, filter and detail setup; use State key to name or deliberately share a monitoring campaign. To continue one specific interrupted run instead, use Resume from a previous run above.