By default exposes a standard Prometheus endpoint at http://0.0.0.0:9000/, which can be changed in the config file.
All exposed stats are documented in the normal format for Prometheus.
Requires a Prometheus (prometheus.io) server to scrape the data, and a Prometheus front-end such as PromDash to display the data in a useful form.
Includes code from the Jetty:// Web Server (Eclipse Foundation) and Prometheus Java simple_client (SoundCloud), which are property of their respective owners.