https://github.com/rafaelvieiras/jellyfin-exporter
Jellyfin Exporter is a Prometheus exporter for Jellyfin metrics. It fetches data from the Jellyfin API and exposes it in a format that Prometheus can consume.
Features
Fetch Jellyfin server metrics
Expose data for Prometheus
Metrics include: active streams, active users, library statistics, etc
Excellent alternative to Toutulli for plex