The Vessels layer now retunes the server-side AISStream subscription to the
client viewport instead of a static AISSTREAM_BBOX. The frontend POSTs its
quantized viewport box to /api/vessels/subscribe on moveend; the ais_stream
worker coalesces and applies it at the service's 1 subscription/s cap, then
last-known positions for the new area arrive within a couple of seconds (the
frontend does one follow-up fetch after retuning). Bounds the in-memory
vessel store across regions. Key stays server-side.
Reuse one TLS pool for overlay upstreams (8s/3s timeouts). Gzip JSON
over 1 KB. Aircraft/vessels Cache-Control max-age=5, alerts/perimeters 30.
Lifespan replaces deprecated on_event startup.
Wire the free data streams from docs/free-data-streams.md into the
dashboard as layer-panel toggles. Third-party APIs are proxied/cached
in FastAPI; raster tiles (IEM, RainViewer, GIBS) stay in the browser.
- Aircraft via ADSB.lol viewport poll (bbox required, radius ≤ 150 nm)
- Amtraker trains, NHC storms, WFIGS incidents/perimeters
- NWS + IEM SBW as /api/weather-alerts (does not collide with /api/alerts)
- AISStream worker is server-side only and idles without AISSTREAM_API_KEY
- Caltrans CWWP2 D1–D12 camera parser; FIRMS dual-write NOAA-20/21
