What problem does it solve? Manually checking RSS feeds, GitHub repos, and JSON APIs for updates is repetitive and error-prone. This Skill polls external sources on an interval, tracks previously-seen items in a watermark state file, and emits only genuinely new items so cron jobs and agents never re-report old content. ## Core Features & Use Cases - Three ready-made watcher scripts: watch_rss.py for RSS 2.0/Atom feeds, watch_github.py for GitHub issues/pulls/releases/commits, and watch_http_json.py for arbitrary JSON endpoints with configurable ID fields and dotted item paths. - Shared watermark helper: _watermark.py provides atomic state writes, a bounded 500-ID seen set, and first-run baseline recording so existing feed content is never replayed. - Silent-on-empty output contract: scripts print Markdown only when new items exist, letting cron jobs treat empty stdout as silent and avoid notification spam. - Use Case: Schedule a cron job every 15 minutes to poll the Hacker News RSS feed; when new stories appear, the agent summarizes the headlines and delivers them, otherwise it stays silent. ## Quick Start Ask the agent to run the RSS watcher script with a name and feed URL, for example to watch https://news.ycombinator.com/rss, and report any new items it prints.