Natal Chart API

The natal-chart endpoint resolves the birth date, clock time, and UTC offset to a precise Julian day, then asks the Swiss Ephemeris engine for the geocentric longitude, latitude, and speed of every body — the ten classical planets plus the lunar nodes, Chiron, and the Black Moon Lilith. It derives the Ascendant and Midheaven from the birth latitude and longitude, divides the houses by your chosen system, assigns each planet to its sign and house, and computes the full aspect grid with applying/separating flags and exact orbs. Retrograde motion is flagged from the body speed, and the chart sect (day or night birth) is returned so downstream interpretation can weight the benefics and malefics correctly.

curl -X POST https://api.astroway.info/v1/chart \
  -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,
    "houseSystem": "P"
  }'

{
  "ok": true,
  "data": {
    "planets": [
      { "name": "Sun", "longitude": 54.23, "sign": "Taurus", "house": 10, "retrograde": false },
      { "name": "Moon", "longitude": 282.7, "sign": "Capricorn", "house": 6 }
    ],
    "houses": { "ascendant": 160.4, "mc": 70.1, "cusps": [160.4, 190.3, ...] },
    "aspects": [ { "body1": "Sun", "body2": "Moon", "type": "trine", "orb": 1.2 } ]
  }
}

Reach for this endpoint whenever you need the structural backbone of a horoscope: a birth-chart widget, a natal report, an onboarding flow that personalises content by Sun/Moon/Rising, or an AI agent that needs the raw placements before it interprets anything. It is the prerequisite call for synastry, transits, progressions, and most report types — compute the chart once, cache the JSON, and feed it into the heavier endpoints instead of recomputing each time. Because the response is pure data (no prose, no images), it drops cleanly into any stack: render it yourself, pass it to an LLM, or hand it to one of our SVG render endpoints.

Defaults follow mainstream Western convention: tropical zodiac, Placidus houses, Sun–Moon–Ascendant "Big Three". The engine is Swiss Ephemeris (Astrodienst) compiled to WASM and shared with the in-browser calculator, so server and client agree to the arc-second. Houses fall back to Porphyry above the polar circle where Placidus is undefined.