YouTube RSS feed endpoint (videos.xml?channel_id=...) returning intermittent 404/500 errors daily since Dec 2025. Affects most channels in a daily 3-hour UTC window. Some channels return HTTP 200 but serve 404 HTML body. Not User-Agent dependent. Both channel_id and playlist_id variants affected. No Google acknowledgment despite 6 months of reports.
Use YouTube Data API v3 playlistItems.list as a drop-in replacement. Cost: 1 quota unit/request, 10K units/day free. telnet23/youtube-rss-server provides a Go proxy that serves the same URL format using the API. The RSS endpoint is still in Google's official push_notifications documentation (updated 2026-04-28) so it's infrastructure decay, not intentional deprecation.