---
title: "Synastry Interpretation"
method: POST
path: "/interpret/synastry"
tags: ["AI Interpretations"]
---

# Synastry Interpretation

`POST /interpret/synastry`

AI interpretation of synastry between two charts — relationship dynamics, attractions, friction points, long-term outlook.

## Query parameters

- `lang` 'uk' | 'en' | 'de' | 'ru' | 'pl' | 'es' | 'pt' | 'fr' | 'it' | 'nl' | 'cs' | 'ro' | 'hu' | 'el' | 'tr' | 'ar' | 'hi' | 'ja' | 'ko' | 'vi' | 'id'

## Headers

- `Accept-Language` 'uk' | 'en' | 'de' | 'ru' | 'pl' | 'es' | 'pt' | 'fr' | 'it' | 'nl' | 'cs' | 'ro' | 'hu' | 'el' | 'tr' | 'ar' | 'hi' | 'ja' | 'ko' | 'vi' | 'id'

## Request body

- InterpretSynastry — Pair of natal charts for relationship calculations: synastry, composite, davison.
  - `chart1` ChartInput, required — Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss). Coordinates are latitude and longitude in decimal degrees, plus timezoneOffset in hours from UTC; the short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD. Omitting the coordinates is not the same as skipping them: houses, angles and everything derived from them are then computed for 0°N 0°E at UTC, which is a wrong answer rather than a neutral default.
    - `date` string, required
    - `time` string, required
    - `timezoneOffset` number, nullable
    - `latitude` number, nullable
    - `longitude` number, nullable
    - `houseSystem` string
    - `name` string
    - `city` string
    - `zodiacType` 'tropical' | 'sidereal'
    - `ayanamsaId` number, nullable
    - `cosmogram` boolean
  - `chart2` ChartInput, required — Birth data for a single natal chart. Required: date (YYYY-MM-DD), time (HH:mm:ss). Coordinates are latitude and longitude in decimal degrees, plus timezoneOffset in hours from UTC; the short forms lat, lon, lng and tz are rejected with 400 INVALID_FIELD. Omitting the coordinates is not the same as skipping them: houses, angles and everything derived from them are then computed for 0°N 0°E at UTC, which is a wrong answer rather than a neutral default.
    - `date` string, required
    - `time` string, required
    - `timezoneOffset` number, nullable
    - `latitude` number, nullable
    - `longitude` number, nullable
    - `houseSystem` string
    - `name` string
    - `city` string
    - `zodiacType` 'tropical' | 'sidereal'
    - `ayanamsaId` number, nullable
    - `cosmogram` boolean
  - `language` 'uk' | 'en' | 'de' | 'pl' | 'es' | 'pt' | 'fr' | 'it' | 'nl' | 'cs' | 'ro' | 'hu' | 'el' | 'tr' | 'ar' | 'hi' | 'ja' | 'ko' | 'vi' | 'id' | 'ru'
  - `disclaimer_inline` boolean

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `language` string, nullable
    - `summary` string, nullable
    - `dynamics` string, nullable
    - `outlook` string, nullable

## Other responses

- `400` — Validation error
- `401` — Missing or invalid API key

---

[API](https://skmtc.dev/astroway/apis/astroway-calculation-api.md) · [All operations](https://skmtc.dev/astroway/apis/astroway-calculation-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/astroway/astroway-calculation-api/revisions/793e5c2dbcdf/schema)