predictive

Calculate Primary Directions

Placidus semi-arc primary directions. Promissors are the Sun through Saturn and their Ptolemaic aspects; significators default to the Ascendant, Midheaven, Sun, Moon and Part of Fortune. Two methods: placidus_mundane (the promissor's body, mundane aspects by semi-arc proportion) and placidus_zodiacal (the promissor's aspect degree on the ecliptic, without latitude). Every event names the method that produced it and gives the arc, the age under the Ptolemy and Naibod keys, and the date each key implies. Uses the true obliquity of the birth date. Placidus semi-arcs do not exist at or inside the polar circle; such births return 422.

post/predictive/primary-directions

Request

  • Base URL: https://api.openephemeris.com
  • URL: https://api.openephemeris.com/predictive/primary-directions
  • Auth: one of:
    • HTTP bearer
    • API key in header X-OpenEphemeris-API-Key
    • API key in header X-API-Key
    • API key in header X-Service-Key

Request body

format'json' | 'llm'

Response format: json | llm.

fortune_formula'sect' | 'ptolemy'

How the Part of Fortune is computed. sect (default): Asc + Moon − Sun by day, Asc + Sun − Moon by night, the usual Hellenistic and medieval reversal. ptolemy: Asc + Moon − Sun for every chart, with no night reversal, as Ptolemy gave it. Affects only the Part of Fortune significator; planets[] echoes the formula on the Fortune entry when this field is sent. The mundane lot of Placidus (from the Moon's declination) is not offered.

include_aspectsnumber[]

Aspect angles in degrees (0–180). The conjunction is always included. Every aspect other than 0 and 180 is returned on both sides, sinister and dexter.

include_converseboolean

Also return converse directions in Ptolemy's sense: the significator is carried by primary motion to the promissor (or its aspect). For an angle, the degree on that angle is carried. Not a backward-turning sky.

max_age_yearsnumber double

Drop events whose Naibod age exceeds this.

methodsstring[]

placidus_mundane: the promissor's body (with latitude) is carried to the significator's Placidus mundane position; aspects are mundane (a square is three Placidus houses). placidus_zodiacal: the promissor's aspect degree on the ecliptic, without latitude, is carried to the significator's mundane position (significators also without latitude).

significatorsstring[]

Points that receive directions. fortune is the Part of Fortune by sect (day: Asc + Moon − Sun; night: Asc + Sun − Moon), as an ecliptic point. Add mercury…saturn to direct to the other planets. A body also receives directions of its own aspects (the Sun to the square of its natal place), never of its own body.

Example request

{
  "subject": {
    "birth_datetime": {
      "iso": "1990-06-15T14:30:00"
    },
    "birth_location": {
      "latitude": {
        "decimal": 40.7128
      },
      "longitude": {
        "decimal": -74.006
      },
      "timezone": {
        "iana_name": "America/New_York"
      }
    },
    "name": "John Doe"
  }
}

Response

Successful Response

calculation_metadataobject

Optional calculation provenance metadata (timing, engine flags, ayanamsa, etc.). Free-form; present when the handler attaches it.

geo_latnumber double

Birth latitude (°).

obliquitynumber double

True obliquity of the ecliptic at birth (°).

ramcnumber double

Right ascension of the Midheaven at birth (°).

Changes

No recorded changes to this operation across all 1 revision of this API.