Determine the FEMA flood zone for a coordinate. Pass lat and lon. Returns the FEMA flood zone code (e.g. AE, VE, X), its subtype, whether the point is in a Special Flood Hazard Area (isSFHA — the 1% annual-chance floodplain where flood insurance is mandatory for federally backed mortgages), a plain-language risk level (high / moderate / minimal / undetermined / unmapped) and description, the static base flood elevation and depth when published, and the source FIRM panel id. Data: FEMA National Flood Hazard Layer (NFHL), free and public-domain. When no flood polygon intersects the point, returns mapped=false (usually Zone X / minimal risk or unmapped — not a guarantee of zero risk). Use for property risk screening, insurance/mortgage context, and siting decisions; geocode an address with /api/geocode/address first to get the coordinate.