Documented scope, not a complete tradition engine

Hellenistic Astrology API Building Blocks

AstroAPI is not a complete Hellenistic astrology system. It provides selected building blocks—most notably tropical chart calculations, whole-sign houses, and beta structured fields involving sect—that developers can combine with their own historically grounded rules and editorial judgment.

Read the houses contract Review methodology

What is supported today?

Tropical zodiac output is AstroAPI's default. The chart engine returns planetary longitudes, the Ascendant and Midheaven, aspects, lunar-node fields, and equal and whole-sign house layouts. Selecting whole_sign places the first cusp at the beginning of the Ascendant's sign and advances subsequent cusps in 30-degree steps.

Tropical natal chart data

Apparent geocentric positions for ten bodies, chart angles, motion fields, aspects, and nodes.

Whole-sign houses

A documented house option alongside equal houses; no quadrant house systems are implemented.

Aspect geometry

Fixed modern endpoint rules for angular separation and orbs, ready for your own interpretation layer.

Sect-oriented fields Beta

The documented beta response can include chart_sect, planet_sect, and planet_nature.

The beta horoscope endpoint is deterministic and rule based. Its sect-related values are product heuristics—not a claim of scholarly consensus, a complete reconstruction of an ancient technique, or generated astrological advice.

What is not implemented?

Whole-sign houses alone do not make a complete Hellenistic astrology engine. AstroAPI does not currently calculate or interpret the broader systems commonly required for a dedicated Hellenistic product.

  • Lots such as Fortune and Spirit
  • Annual profections, zodiacal releasing, or other time-lord procedures
  • Bounds or terms, triplicity rulers, decans, or complete traditional dignity logic
  • Primary directions, solar returns, progressions, or electional search
  • Traditional condition scoring, house-overlay scoring, or prose delineations
  • A historically authoritative orb model or applying/separating aspect state

Appropriate product uses

These endpoints can supply calculation geometry for a product whose authors independently implement and document their own Hellenistic rules. Suitable uses include:

  • Whole-sign chart wheels and accessible chart tables
  • Educational interfaces that explain which values come from the API and which come from editorial rules
  • Research prototypes that compare an explicitly documented interpretation model with raw chart data
  • Custom engines where lots, dignities, time lords, and textual delineation remain application-owned

AstroAPI does not establish whether an interpretation is historically correct. Products should cite their sources and identify their chosen school, definitions, and exceptions.

Shared calculation boundaries

Zodiac
Tropical by default
House choices
Whole sign or equal
Date range
1900-01-01 through 2050-12-31

Houses use the engine's documented fixed mean-obliquity approximation. Lunar nodes use a mean-node polynomial, and the current true field is not a distinct true-node calculation. See the methodology page for the complete boundary.