Self-hosted error tracking and privacy-friendly analytics in one small binary.

Status: v0.2 "analytics", an early release (Docker image only). Error tracking works end to end in 26 languages: the official Sentry SDKs send events, which are scrubbed of personal data, grouped into issues and stored; issue and event pages with search, live updates, stack traces and triage; iOS and macOS crashes symbolicated from dSYMs uploaded with sentry-cli; alerts for new issues, regressions, spikes and a release's first crash to ~40 notification channels (Slack, Discord, Teams, Telegram, ntfy, email, webhooks …); release health with crash-free sessions and users; and a REST API, OpenAPI document and MCP tools for all of it. Web analytics: a script under 2 KB, no cookies and no stored IP addresses, a Web tab with visitors, pageviews, pages, referrers, UTM, browsers and devices, filters and live current visitors, and it respects Global Privacy Control. App analytics with the KestrelKit Swift package: an App tab with daily, weekly and monthly active users, sessions, signal types, version adoption, OS versions, devices and locales, a signal explorer for payloads, and each release's adoption next to its crash-free rate. Installers and Unraid/Proxmox templates come by v1.0. The translations are unreviewed drafts. Sending errors to Kestrel shows how to point each SDK at it, upload dSYMs and set up alerts; Web analytics shows how to add the snippet and what is kept; App analytics does the same for KestrelKit. The design is in docs/design.md; to build and run it, see docs/development.md.

Keen Kestrel answers two questions about the apps and sites you run:

• What broke? Errors and crashes from the official Sentry SDKs (iOS/Swift, JavaScript, Rust, Python, Go and more) work unchanged. Issues are grouped, alerts go to the same ~40 channels as Vigilant Vole, and iOS crashes are symbolicated from the dSYMs that sentry-cli uploads.
• How is it used? App signals and website pageviews without cookies or stored IP addresses, with dashboards for users, versions, devices, pages and referrers.

One Rust binary and SQLite: no Kafka, ClickHouse, Redis or Postgres. It shares its design language and foundations with Vigilant Vole and runs on Docker, Unraid, Proxmox or plain Linux.

Install

Kestrel runs as one container with its data in a single folder:

mkdir keen-kestrel && cd keen-kestrel
curl -fsSLO https://raw.githubusercontent.com/Ferdinand99/Keen-Kestrel/main/docker-compose.yml
docker compose up -d

Then open http://<host>:3002/setup to create the first admin, create a project and copy its DSN. Set the address your apps use under Settings → General (public URL), or as KK_PUBLIC_URL in docker-compose.yml, which is stored there at every start: it goes into the DSNs and alert links. Put Kestrel behind HTTPS with KK_TRUST_PROXY=1 when it's reachable from the internet. Images are on GHCR for amd64 and arm64: ghcr.io/ferdinand99/keen-kestrel:<version> or :latest.

Planned for v1

Not in v1: performance tracing, session replay, JavaScript source maps (planned for v1.1), funnels and cohorts. See docs/design.md for the full scope and the phases.

License

MIT