New Numerology API

Chart basics

Sidereal zodiac in Vedic astrology

The sidereal zodiac ties the 12 signs to the background stars. Vedic astrology uses it. The Western (tropical) zodiac ties the signs to the seasons instead, starting Aries at the spring equinox. Because of a slow wobble of the Earth's axis, the two drift apart by about 50 arc seconds a year. The gap between them is the ayanamsa.

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© API for Astrology (apiforastrology.com). "Glossary houses chart". All rights reserved. Not to be copied or reused.123456789101112A North Indian chart has 12 houses

Sidereal zodiac: how the API computes it

Every planet position the API returns is sidereal. The API first works out the tropical longitude, the one most Western tools show. Then it subtracts the ayanamsa, using the Lahiri value for the date.

Today the ayanamsa is a little over 24 degrees. So a planet's sidereal longitude is about 24 degrees less than its tropical one. That is why the Sun is in Aries from about April 14 in the sidereal zodiac, not from March 21.

For most people the sign shifts back by one. A person who reads as Taurus in a Western magazine is often an Aries here. But people born in the last days of a Western sign may stay in the same sign.

The API does not return tropical positions. Lahiri is the default ayanamsa. KP (Krishnamurti) and Raman are available too, with the ayanamsa field.

Each response has a meta block that names the ayanamsa and shows its value at that moment. If you compare results with other software, first check that both use the sidereal zodiac with the same ayanamsa.

Get it from the API

Planet positions and the ascendant. Here is the call to API for Astrology (apiforastrology.com) for our sample, John Doe, born Aug 15, 1990, 10:30 AM, New York.

POST /v1/planets

# John Doe, born Aug 15, 1990, 10:30 AM, New York
curl -X POST "https://apiforastrology.com/api/astrology/v1/planets" \
  -H "Authorization: Bearer $ASTROLOGY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"year":1990,"month":8,"day":15,"hour":10,"minute":30,"second":0,"latitude":40.7128,"longitude":-74.006,"timezone":"America/New_York"}'
Answer (long lists shortened)200 OK
{
  "meta": {
    "ayanamsa": "lahiri",
    "ayanamsa_value": 23.7260727,
    "julian_day": 2448119.10483,
    "ephemeris": "JPL DE440s",
    "node": "true",
    "timezone": {
      "source": "zone",
      "offset_hours": -4,
      "zone": "America/New_York",
      "abbreviation": "EDT",
      "dst": true,
      "dst_hours": 1,
      "ambiguous_resolved_by_fold": null,
      "note": "read from the IANA tz database at this instant, so daylight saving and historical offset changes are included"
    }
  },
  "ascendant": {
    "name": "Ascendant",
    "longitude": 169.934155,
    "sign": "Virgo",
    "sign_number": 6,
    "degree_in_sign": 19.934155,
    "degree_dms": "19 : 56 : 03",
    "house": 1,
    "nakshatra": "Hast",
    "nakshatra_lord": "Moon",
    "pada": 3,
    "speed": 0,
    "retrograde": false,
    "combust": false,
    "dignity": "n/a",
    "vargottama": false,
    "pushkara": {
      "navamsa": false,
      "navamsa_number": 6,
      "bhaga": false,
      "bhaga_degree": 9,
      "bhaga_by_element": false,
      "bhaga_degree_by_element": 14,
      "sources_agree": true,
      "orb_degrees": 1
    }
  },
  "positions": [
    {
      "name": "Sun",
      "longitude": 118.7753409,
      "sign": "Cancer",
      "sign_number": 4,
      "degree_in_sign": 28.7753409,
      "degree_dms": "28 : 46 : 31",
      "house": 11,
      "nakshatra": "Ashlesha",
      "nakshatra_lord": "Mercury",
      "pada": 4,
      "speed": 0.9610665,
      "retrograde": false,
      "combust": false,
      "dignity": "friend",
      "vargottama": false,
      "pushkara": {
        "navamsa": false,
        "navamsa_number": 9,
        "bhaga": false,
        "bhaga_degree": 8,
        "bhaga_by_element": false,
        "bhaga_degree_by_element": 7,
        "sources_agree": true,
        "orb_degrees": 1
      }
    },
    {
      "name": "Moon",
      "longitude": 54.5750352,
      "sign": "Taurus",
      "sign_number": 2,
      "degree_in_sign": 24.5750352,
      "degree_dms": "24 : 34 : 30",
      "house": 9,
      "nakshatra": "Mrigashira",
      "nakshatra_lord": "Mars",
      "pada": 1,
      "speed": 14.258194,
      "retrograde": false,
      "combust": false,
      "dignity": "mulatrikona",
      "vargottama": false,
      "pushkara": {
        "navamsa": false,
        "navamsa_number": 8,
        "bhaga": false,
        "bhaga_degree": 14,
        "bhaga_by_element": false,
        "bhaga_degree_by_element": 14,
        "sources_agree": true,
        "orb_degrees": 1
      }
    },
    {
      "name": "Mars",
      "longitude": 27.7149328,
      "sign": "Aries",
      "sign_number": 1,
      "degree_in_sign": 27.7149328,
      "degree_dms": "27 : 42 : 54",
      "house": 8,
      "nakshatra": "Krittika",
      "nakshatra_lord": "Sun",
      "pada": 1,
      "speed": 0.5753266,
      "retrograde": false,
      "combust": false,
      "dignity": "own sign",
      "vargottama": false,
      "pushkara": {
        "navamsa": true,
        "navamsa_number": 9,
        "bhaga": false,
        "bhaga_degree": 21,
        "bhaga_by_element": false,
        "bhaga_degree_by_element": 21,
        "sources_agree": true,
        "orb_degrees": 1
      }
    }
  ],
  "planetary_war": []
}

Where the API returns it

POST/v1/planetsPlanet positions and the ascendant
POST/v1/varshaphalThe Tajik annual chart (varshaphal) for one year

What the API reference says

Each line is quoted from the reference page of the endpoint named above it.

  • POST /v1/planets · Planet positions and the ascendantFor each one you get its sidereal longitude, sign and house.
  • POST /v1/varshaphal · The Tajik annual chart (varshaphal) for one yearThe moment is found to the second, in the sidereal zodiac.

Feature page: Kundli and birth charts. Who uses it: Astrology apps. The classical rules the API follows are in the rulebook.

How we check the numbers

Every value here starts from planet positions worked out from NASA JPL planet data (DE440). We test them against NASA JPL Horizons, NASA's planet position service. On 25,571 positions from 1850 to 2149, the Sun and planets agree within 0.001 arc seconds. The Moon agrees within 0.011. On 2,000 random birth charts, the rising sign agrees with Swiss Ephemeris within 0.004 arc seconds. An arc second is 1/3,600 of a degree. A practicing astrologer reviews the rules behind these answers. See how we test.

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Astrology API

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Your first answer

John Doe, New York

POST /v1/planets200 OK
  • RisingVirgoHast
  • SunCancerAshlesha
  • MoonTaurusMrigashira
  • MarsAriesKrittika

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