Bugsink is an error tracker you can self-host or use as a hosted service, both fully compatible with the Sentry SDK.
Self-hosted: Data stays fully under your control, no external services required. Hosted: Fully managed EU-based service.
Grouped issues, real-time alerts, and detailed stack traces (including code and local variables). The pricing for the hosted version is not on a per-event basis like at Sentry.