Jackett works as a proxy server: it translates queries from apps
(Sonarr, Radarr, SickRage, CouchPotato, Mylar, etc) into
tracker-site-specific http queries, parses the html response, then sends
results back to the requesting software. This allows for getting recent
uploads (like RSS) and performing searches. Jackett is a single
repository of maintained indexer scraping & translation logic - removing
the burden from other apps.