# Type Alias AvailabilityLevel

AvailabilityLevel: "Full" | "Degraded" | "Sparse" | "Unavailable" | "Unknown"

Overall feed availability level.

Level | Condition | Description
--- | --- | ---
Full | ≥10/13 ok | Normal operation
Degraded | 5–9/13 ok | Reduced data quality expected
Sparse | 1–4/13 ok | Minimal data, analysis-only mode likely
Unavailable | 0/13 ok AND ≥1 probed feed errored | All probed feeds failing
Unknown | 0/13 ok AND 0 errors (no probes yet) | Cache is empty — status cannot be determined without a live probe

`Unknown` is distinct from `Unavailable` to prevent consumers from interpreting "no cached data" as "feeds are down". See issue #1.

- Defined in services/FeedHealthTracker.ts:50