Geodetic equivalent chart API

Given a latitude and longitude the endpoint returns the geodetic Midheaven, Imum Coeli, Ascendant and Descendant in ecliptic degrees, together with the sign index and the degree within the sign for the MC and the Ascendant. Two schools are supported. Sepharial, the default, maps terrestrial longitude straight onto zodiacal longitude, so 30.52 degrees east is 0 degrees 31 minutes of Taurus. Johndro applies an obliquity correction, which shifts the Ascendant relative to the Sepharial value and requires either a year or an explicit obliquity in degrees. Because nothing about a person enters the calculation, the same coordinates always return the same angles, which makes the endpoint cheap to cache and the natural anchor for a place-based rather than person-based feature.

curl -X POST https://api.astroway.info/v1/geodetic \
  -H "X-Api-Key: aw_live_..." \
  -H "Content-Type: application/json" \
  -d '{
  "latitude": 50.45,
  "longitude": 30.52,
  "method": "sepharial"
}'

{
  "ok": true,
  "data": {
    "mc": 30.52,
    "ic": 210.52,
    "asc": 317.7269,
    "dsc": 137.7269,
    "mcSign": 1,
    "mcDegree": 0.52,
    "ascSign": 10,
    "ascDegree": 17.7269,
    "method": "sepharial"
  }
}

Reach for the geodetic chart in mundane work, where the subject is a country, a city, or an event rather than a person. Typical uses are testing whether an eclipse or an ingress falls on the geodetic angles of a capital, building a country profile page that needs a chart but has no defensible founding time, and cross-checking astrocartography with a completely independent method. It also solves a practical problem in consumer products: when a user has no birth time, most chart endpoints degrade badly, but a geodetic chart for their current city is still fully defined and still says something specific about the place. The response is small and deterministic, so it costs a single tier-one call and is safe to compute for a whole list of cities in one pass.

Sepharial and Johndro disagree by design, not by error; both are returned on request rather than one being presented as canonical. The technique originates with Sepharial in the early twentieth century and was extended by L. Edward Johndro. Because the geodetic frame is fixed to the Greenwich meridian, results are stable across time and require no ephemeris lookup, which is why this is the only endpoint in the astro-geography family that does not depend on Swiss Ephemeris.