Frontend Hints

Copy-paste references for cards/automations consuming cap_alerts.

Fetching geometry by geometry_ref

Every alert entity exposes a geometry_ref attribute (e.g. nws:OKX.SV.W.0042.2026) and a bbox: [min_lon, min_lat, max_lon, max_lat]. Full polygons live out-of-band — fetch lazily when rendering a map.

Websocket (preferred for live cards)

const result = await hass.connection.sendMessagePromise({
  type: "cap_alerts/geometry",
  geometry_ref: attrs.geometry_ref,
});
// result = { type: "FeatureCollection", features: [ { type: "Feature", geometry, properties: { ref } } ] }

Unknown refs send an error frame (not_found).

REST

curl -H "Authorization: Bearer $HA_TOKEN" \
     "http://homeassistant.local:8123/api/cap_alerts/geometry/nws:OKX.SV.W.0042.2026"

Returns the same FeatureCollection; 404 for unknown refs.