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post/geo-postal/v1/us_census3 credits

United States census-grade geocode: street ADDRESS, ZIP, or coordinates → state, county (+5-digit FIPS), census TRACT GEOID, census BLOCK GEOID, ZCTA, and tract/ZCTA land-area — with match_type + confidence. Coordinates/ZIP resolve the ZCTA offline from pinned TIGER/ZCTA-2024 polygons (zero egress); the authoritative tract/block GEOID + address geocoding come from the US Census Geocoder, cached. US-Gov public domain (Title 17 §105).

Working example
Parameters

One-line US street address to geocode to its census tract/block (uses the Census Geocoder; rooftop interpolation, not a deliverability/CASS claim).

Postal code to resolve. Spaces/dashes are ignored, case-insensitive (e.g. '10115', '75001', 'SW1A1AA').

WGS84 latitude of the point to resolve (decimal degrees). (-90–90)

WGS84 longitude of the point to resolve (decimal degrees). (-180–180)

If true, include the (simplified) boundary polygon as GeoJSON. Default false — geometries are large; lookups never depend on this.

If true (default) and an exact tract/block GEOID is needed, query the Census Geocoder (cached). Set false for offline-only (ZCTA polygon + nearest-tract centroid) with no .gov call.

request preview
curl -X POST https://api.reefapi.com/geo-postal/v1/us_census \
  -H "x-api-key: $REEF_KEY" \
  -H "content-type: application/json" \
  -d '{"lat":"40.7505","lon":"-73.9967","live":"false"}'

Hit Send to run this endpoint live.