Map share card

PNG of a region's published snow forecast map laid out to share: a 4:5 post or a 9:16 story, in the map reel's type, with the snow key, the Mapbox credit and the region's link printed (snowsure.ai/map/{region}). The same card the app shares. An unknown region is a 404.

Auth: none.

Caching: Cache-Control: public, max-age=3600, s-maxage=3600, stale-while-revalidate=21600, no-transform. The map it draws is regenerated twice a day; an hour keeps its date line current. Never immutable, so browsers, social scrapers and the CDN fetch a fresh render once the window passes. A changing query parameter (e.g. &d=2026-09-15) still forces a fresh render; unknown parameters are ignored.