kuvasz

Kuvasz is a self-hosted uptime monitor. It checks your endpoints on a schedule, measures response times, and alerts you when something breaks. That's it. Does one thing, does it cleanly.

Kotlin, Apache 2.0. Built on Quarkus (a Java framework optimized for containers). Supports HTTP monitoring with configurable check intervals, Slack and Telegram notifications, and SSL certificate expiry monitoring. Stores historical data in Postgres.

Fully free, self-hosted only. No cloud version, no paid tier. Run it in Docker alongside a Postgres instance and you're set. Solo developers: Docker Compose with Kuvasz + Postgres monitors your side projects for the cost of a $5/mo VPS. Small teams: same setup, more endpoints. Medium to large teams: you'll likely want something with more features: dashboards, incident management, status pages.

The catch: this is a small, niche project. The feature set is minimal compared to Uptime Kuma (which has a much larger community) or commercial tools. No status page, no multi-region checking, no advanced alerting rules. If basic HTTP monitoring and SSL checks are all you need, Kuvasz works. For anything more, look at the alternatives.