---
title: "Two charts compared: inter-chart aspects with orbs, house overlays both ways and a score per life sphere."
method: POST
path: "/v1/synastry"
tags: ["API Pro"]
---

# Two charts compared: inter-chart aspects with orbs, house overlays both ways and a score per life sphere.

`POST /v1/synastry`

## Request

- Base URL: `https://api.natalchart.ai`
- URL: `https://api.natalchart.ai/v1/synastry`
- Auth: HTTP bearer

## Request body

- object
  - `personA` Birth, required
    - `date` string, date, required: Birth date, YYYY-MM-DD, 1800 to 2399.
    - `time` string, nullable: Local birth time, HH:mm, 24-hour. null when unknown: the chart is computed for noon and everything that depends on the time is withheld.
    - `latitude` number, required
    - `longitude` number, required
    - `timezone` string: IANA time zone. Leave it out to resolve it from the coordinates; historical daylight-saving rules are applied to the date.
  - `personB` Birth, required
    - `date` string, date, required: Birth date, YYYY-MM-DD, 1800 to 2399.
    - `time` string, nullable: Local birth time, HH:mm, 24-hour. null when unknown: the chart is computed for noon and everything that depends on the time is withheld.
    - `latitude` number, required
    - `longitude` number, required
    - `timezone` string: IANA time zone. Leave it out to resolve it from the coordinates; historical daylight-saving rules are applied to the date.

## Response `200`

The calculation, as JSON.

- object

## Other responses

- `400`: An error, always in this shape.
- `401`: An error, always in this shape.
- `403`: An error, always in this shape.
- `429`: An error, always in this shape.

---

[API](https://skmtc.dev/natalchart/apis/natalchart-ai-api.md) · [All operations](https://skmtc.dev/natalchart/apis/natalchart-ai-api/llms.txt) · [OpenAPI document](https://skmtc.dev/natalchart/apis/natalchart-ai-api/revisions/e7032175f336?raw)