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Western Astrology API — Tropical zodiac, relationship deep cuts.

Synastry & composite that go beyond the basics. Davison midpoint charts, solar returns, and progression engines tuned for production traffic.

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10+
Endpoints
4 house systems
Coverage
<50ms
Median latency
JSON
Documented fields

4 house systems

Placidus, Whole Sign, Equal, Koch — switch in a request param. Returns Ascendant and Midheaven for all four.

Synastry & Composite

Inter-aspects, house overlays, midpoint composite, Davison time-space midpoint — relationship astrology done right.

Returns & Progressions

Solar return, lunar return, secondary progressions, solar arc directions. Predictive techniques that actually predict.

Aspect grids

Major and minor aspects with applying/separating flags, exact orbs, and harmony scoring.

02 / Tropical Zodiac · Modern Western

All Western Astrology endpoints

Every endpoint returns structured JSON with documented fields, validated coordinates, and IANA timezone IDs.

10+
Endpoints

Natal Chart

2 EP

Planets, houses (Placidus / Whole Sign / Equal / Koch), aspects with orbs.

  • POST /v2/western/natal
  • POST /v2/western/natal-extended

Synastry

2 EP

Inter-aspects, house overlays, compatibility scoring across two charts.

  • POST /v2/western/synastry
  • POST /v2/western/synastry-grid

Composite Chart

1 EP

Midpoint composite — the chart of the relationship itself.

  • POST /v2/western/composite

Davison Chart

1 EP

Time-space midpoint — a real chart calculated for the average moment.

  • POST /v2/western/davison

Solar & Lunar Returns

2 EP

Annual rebirth chart with relocated and natal-location variants.

  • POST /v2/western/solar-return
  • POST /v2/western/lunar-return

Progressions

2 EP

Secondary progressions, solar arc directions for predictive timing.

  • POST /v2/western/progressed
  • POST /v2/western/solar-arc
Frequently asked

Questions developers ask before integrating.

Which house systems does the API support?
Four house systems: Placidus (default), Whole Sign, Equal House, and Koch. Switch between them via a single request parameter. Returns Ascendant and Midheaven for all four.
How does synastry compatibility work?
Synastry compares two natal charts across all planetary pairs, returning inter-aspects, applying/separating flags, exact orbs, harmony scoring, and a 0–100 compatibility score with breakdowns for romantic, emotional, intellectual, and physical compatibility.
Can I generate composite and Davison charts?
Yes. Composite charts use midpoints between two natal charts; Davison charts use the time-space midpoint (a real astronomical chart calculated for the average moment).
Are secondary progressions and solar arc directions supported?
Yes. Secondary progressions, solar arc directions, solar return charts, and lunar return charts are all included — with relocated and natal-location variants.
What aspect orbs does the API use?
Sensible astrological defaults (conjunction 10°, opposition 9°, trine/square 8°, sextile 6°), but orbs can be customised per request for both major and minor aspects.
Does the API render natal chart wheel images?
Yes — fully customisable wheel charts in PNG and SVG with brandable themes, per-planet colors, and your choice of house system.
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