# Geo Calc

Coordinate math for agents: geohash, Plus Codes, UTM and MGRS, geodesics, bounding boxes, polygon area and coordinate formats.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://geo-calc.x402tookit.com/openapi.json
- x402 manifest: https://geo-calc.x402tookit.com/.well-known/x402
- Catalog (free): https://geo-calc.x402tookit.com/catalog
- Health (free): https://geo-calc.x402tookit.com/health
- Uptime (free): https://geo-calc.x402tookit.com/uptime

## Endpoints (12)

### GET /bbox-radius — $0.02
Bounding box (min/max latitude and longitude) enclosing a radius in meters around a point, with pole and 180 degree handling.
Params: lat: number, lon: number, radiusM: number
Example: https://geo-calc.x402tookit.com/bbox-radius?lat=40.7128&lon=-74.006&radiusM=5000

### GET /coord-format — $0.02
Convert a coordinate pair between decimal degrees, degrees-minutes-seconds and degrees-decimal-minutes.
Params: coord: string
Example: https://geo-calc.x402tookit.com/coord-format?coord=40%C2%B042%2746.08%22N+74%C2%B000%2721.6%22W

### GET /geodesic-direct — $0.02
Destination latitude/longitude and final bearing from a start point, initial bearing and distance (WGS84, Vincenty).
Params: lat: number, lon: number, bearing: number, distanceM: number
Example: https://geo-calc.x402tookit.com/geodesic-direct?lat=40.6413&lon=-73.7781&bearing=273.5&distanceM=3000000

### GET /geodesic-inverse — $0.02
Ellipsoidal (WGS84, Vincenty) distance and bearings between two points, compared with haversine on a sphere.
Params: lat1: number, lon1: number, lat2: number, lon2: number
Example: https://geo-calc.x402tookit.com/geodesic-inverse?lat1=40.6413&lon1=-73.7781&lat2=33.9416&lon2=-118.4085

### GET /geohash-decode — $0.02
Decode a geohash to its center latitude/longitude, bounding box and the plus-or-minus error in degrees.
Params: geohash: string
Example: https://geo-calc.x402tookit.com/geohash-decode?geohash=ezs42

### GET /geohash-encode — $0.02
Encode latitude/longitude as a geohash (1 to 12 characters) with the cell bounds, center and size in meters.
Params: lat: number, lon: number, precision?: integer
Example: https://geo-calc.x402tookit.com/geohash-encode?lat=57.64911&lon=10.40744&precision=11

### GET /geohash-neighbors — $0.02
The eight adjacent geohash cells (N, NE, E, SE, S, SW, W, NW) for a geohash, wrapping at 180 degrees longitude.
Params: geohash: string
Example: https://geo-calc.x402tookit.com/geohash-neighbors?geohash=ezs42

### GET /pluscode-decode — $0.02
Decode a Plus Code (Open Location Code) to its area and center; recovers short codes near a reference point.
Params: code: string, refLat?: number, refLon?: number
Example: https://geo-calc.x402tookit.com/pluscode-decode?code=8FVC9G8F%2B6W

### GET /pluscode-encode — $0.02
Encode latitude/longitude as an Open Location Code (Plus Code) with its area bounds and a short local form.
Params: lat: number, lon: number, length?: integer
Example: https://geo-calc.x402tookit.com/pluscode-encode?lat=47.36559&lon=8.524997&length=10

### GET /polygon-area — $0.02
Area, perimeter and centroid of a lat,lon polygon using spherical excess on the WGS84 equal-area sphere.
Params: points: string
Example: https://geo-calc.x402tookit.com/polygon-area?points=40%2C-100%3B40%2C-90%3B35%2C-90%3B35%2C-100

### GET /utm-mgrs-reverse — $0.02
Convert a UTM (18T 585628 4511322) or MGRS (18TWL8562811322) reference to WGS84 latitude/longitude.
Params: code: string
Example: https://geo-calc.x402tookit.com/utm-mgrs-reverse?code=18TWL8562811322

### GET /utm-mgrs — $0.02
Convert WGS84 latitude/longitude to UTM (zone, band, easting, northing) and MGRS, with Norway/Svalbard zone rules.
Params: lat: number, lon: number, digits?: integer
Example: https://geo-calc.x402tookit.com/utm-mgrs?lat=40.748433&lon=-73.985656&digits=5

## Terms

Results are computed locally from the coordinates you send using published algorithms (WGS84), provided as is, with no warranty. Not for survey, navigation, aviation or legal boundary use. Verify with a certified source before relying on them.