Declination Aspects API

From the birth date, time, UTC offset, and coordinates the endpoint computes each body's declination — how far north or south of the celestial equator it sits, off the ecliptic plane that longitude is measured on — and then compares those declinations across bodies. Where two bodies share the same declination on the same side of the equator it records a parallel, the declination counterpart of a conjunction; where they share the same declination on opposite sides it records a contraparallel, the counterpart of an opposition. Each contact is returned under data.parallels with the bodies involved. The endpoint also surfaces out-of-bounds context — when a body's declination exceeds the Sun's maximum, carrying it beyond the band the Sun ever reaches, a condition traditionally read as the planet operating without its usual restraint. This gives you a layer of contact that pure longitude misses entirely: two planets with no longitudinal aspect can still be locked in a tight parallel.

curl -X POST https://api.astroway.info/v1/parallel-aspects \
  -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": {
    "parallels": [
      {
        "planet1": "Sun",
        "planet2": "Moon",
        "type": "contra-parallel",
        "orb": 0.49
      }
    ]
  }
}

Use this endpoint when an aspect engine should not stop at the ecliptic — a serious chart analyser, a synastry or transit tool that wants the declination layer, or a report that explains why two planets feel linked despite forming no longitude aspect. Parallels and contraparallels are exactly the contacts a longitude-only grid drops, so adding them fills a real gap rather than duplicating the natal-chart aspect output. The out-of-bounds flag is independently useful: it marks planets the tradition treats as running unchecked, which makes a clean highlight in a chart report. Send the same birth data you used elsewhere and the declination contacts will refer to the same bodies as your longitude aspects, letting you present both grids as two readings of one chart.

Parallels and contraparallels follow the traditional declination doctrine, treating equal-declination contacts as the analogues of conjunction and opposition; the out-of-bounds reading draws on the work of Kt Boehrer. Declinations are computed by the Swiss Ephemeris (Astrodienst) WASM engine in the tropical frame, on the same bodies as the longitude-based natal endpoints.