Synastry Chart Endpoint #

`POST /api/v5/chart/synastry` #

View Complete Example

This endpoint generates a synastry chart (relationship compatibility chart) as a dual-wheel SVG visualization. Synastry is the astrological technique of comparing two birth charts to analyze relationship dynamics, compatibility, and potential challenges between two people.

Chart Preview #

Synastry Chart Example

The chart displays:

Inner Wheel: The first subject’s natal chart
Outer Wheel: The second subject’s natal chart
Inter-Aspects: The astrological aspects (connections) between the two charts
Optional House Comparison Table: Shows how each person’s planets fall into the other’s houses

Use cases:

Romantic Compatibility Analysis: Evaluate relationship potential between partners
Business Partnerships: Assess professional compatibility
Family Dynamics: Understand parent-child or sibling relationships
Friendship Analysis: Explore platonic connections

Request Body #

first_subject (object, required): Inner wheel subject. See Subject Object Reference.

{
    "name": "Inner",
    "year": 1990,
    "month": 1,
    "day": 1,
    "hour": 12,
    "minute": 0,
    "city": "London",
    "nation": "GB",
    "longitude": -0.1278,
    "latitude": 51.5074,
    "timezone": "Europe/London"
}

second_subject (object, required): Outer wheel subject. Same structure as first_subject.

{
    "name": "Outer",
    "year": 1992,
    "month": 5,
    "day": 15,
    "hour": 18,
    "minute": 30,
    "city": "New York",
    "nation": "US",
    "longitude": -74.006,
    "latitude": 40.7128,
    "timezone": "America/New_York"
}

Synastry-specific options (optional):

include_house_comparison (boolean): Include house overlay comparison in the data. Default: true.
include_relationship_score (boolean): Include relationship score analysis in the data. Default: true.

Computation options (optional):

active_points (array of strings): Override which celestial points are included. See Active Points.
active_aspects (array of objects): Override which aspects are calculated and their orbs. See Active Aspects.
distribution_method (string): "weighted" (default) or "pure_count".
custom_distribution_weights (object): Custom weights map for weighted distribution.

Rendering options (optional):

theme (string): Visual theme. Default: "classic". See Themes.
language (string): Language for chart labels. Default: "EN". See Languages.
style (string): "classic" (default) or "modern".
split_chart (boolean): Return separate chart_wheel and chart_grid SVGs. Default: false.
transparent_background (boolean): Render with transparent background. Default: false.
custom_title (string): Override the chart title (max 40 characters).
show_house_position_comparison (boolean): Show the house comparison table. Default: true.
show_cusp_position_comparison (boolean): Show cusp comparison grids for both subjects. Default: true.
show_degree_indicators (boolean): Show radial lines and degree numbers. Default: true.
show_aspect_icons (boolean): Show aspect icons on aspect lines. Default: true.
show_zodiac_background_ring (boolean): Show colored zodiac wedges ("modern" style only). Default: true.
double_chart_aspect_grid_type (string): Aspect display layout — "list" (default, vertical) or "table" (grid matrix).

Complete Request Example #

{
    "first_subject": {
        "name": "Inner",
        "year": 1990,
        "month": 1,
        "day": 1,
        "hour": 12,
        "minute": 0,
        "city": "London",
        "nation": "GB",
        "longitude": -0.1278,
        "latitude": 51.5074,
        "timezone": "Europe/London"
    },
    "second_subject": {
        "name": "Outer",
        "year": 1992,
        "month": 5,
        "day": 15,
        "hour": 18,
        "minute": 30,
        "city": "New York",
        "nation": "US",
        "longitude": -74.006,
        "latitude": 40.7128,
        "timezone": "America/New_York"
    },
    "theme": "classic",
    "style": "modern",
    "show_zodiac_background_ring": true,
    "double_chart_aspect_grid_type": "list",
    "split_chart": true
}

Response Body #

status (string): "OK".
chart_data (object): Synastry data (same structure as the Synastry Chart Data endpoint).
chart (string): SVG string (when split_chart is false).
chart_wheel (string): SVG of the dual wheel (when split_chart is true).
chart_grid (string): SVG of the aspect grid (when split_chart is true).

Complete Response Example #

{
  "status": "OK",
  "chart_data": { ... },
  "chart_wheel": "<svg ...> ... </svg>",
  "chart_grid": "<svg ...> ... </svg>"
}