# OpenSky

Provides public aircraft state data for regional air-activity hotspots.

- Auth: public queries work without credentials.
- Failure modes: timeouts, `HTTP 429`, and empty regions.
- Behavior: source health is marked degraded on API errors. The dashboard may use the most recent non-empty air snapshot from `runs/` and marks it in `airMeta.fallback`.
- Test: start a sweep and inspect `/api/health` plus `airMeta` from `/api/data`.
- Operator note: Crucix does not bypass OpenSky throttles. Increase `REFRESH_INTERVAL_MINUTES` if the source degrades repeatedly.