Local Space astrology API

The endpoint builds the natal chart, converts each planet from ecliptic coordinates into the horizon frame of the birth location, and returns its azimuth in degrees clockwise from true north together with its altitude above or below the horizon. It then projects each azimuth as a great circle outward from the birthplace and returns the resulting path as a series of coordinates, so a line drawn on a world map stays a true bearing rather than a straight line on a flat projection. Thirteen bodies are covered, each carrying a stable colour so a rendered map keeps the same palette as the rest of the suite. Altitude matters as much as azimuth here: a planet below the horizon at birth reads differently from one high in the sky in the same direction.

curl -X POST https://api.astroway.info/v1/local-space \
  -H "X-Api-Key: aw_live_..." \
  -H "Content-Type: application/json" \
  -d '{
  "date": "1990-05-15",
  "time": "14:30:00",
  "timezoneOffset": 3,
  "latitude": 50.45,
  "longitude": 30.52
}'

{
  "ok": true,
  "data": {
    "birthplace": { "latitude": 50.45, "longitude": 30.52 },
    "count": 13,
    "lines": [
      {
        "planetId": 0,
        "planetName": "Sun",
        "azimuth": 219.8018,
        "altitude": 53.1309,
        "color": "#FFB300",
        "points": [{ "lat": 50.45, "lng": 30.52 }, "…"]
      }
    ]
  }
}

Use local space when the product is about direction and distance from a fixed home rather than absolute position on the globe. Two cases dominate. The first is relocation at any scale, from choosing which city lies along a favourable bearing to deciding which way to move within one country, because a great circle from the birthplace crosses far more usable territory than a handful of astrocartography meridians. The second is interior and site work, where the same azimuths are read at room scale inside a dwelling: the endpoint returns the bearings, and the /local-space/influence-zone companion turns one of them into a cone polygon you can draw. If you already render astrocartography, adding local space is the cheapest way to double the depth of a relocation feature, since it uses the same birth input and the same map surface.

Positions come from the Swiss Ephemeris (Astrodienst) compiled to WASM. Azimuth is measured clockwise from true north, not magnetic north, so no declination correction is applied or needed. The great-circle path is returned as sampled coordinates rather than as a formula, which keeps the client free of spherical geometry. The technique in this form was developed by Michael Erlewine and is documented in his Astrophysical Directions.