POSTalphaRelationships

Synastry Chart

Return owned geocentric tropical synastry data and relationship aspect overlays without calling an external astrology API.

POST /v1/charts/synastryQuickstart OpenAPI JSON

Credits

3 credits per pair

Minimum Plan

Core Compute+

Billing Lane

No AI core

SDK Helper

synastryChart / synastry_chart

Inputs

+subject birth data
+partner birth data
+orb policy
+max aspects

Outputs

+interchart aspects
+relationship signals
+calculation basis
+sidecar metadata

Tool Functions

Capabilities behind this endpoint

4 functions

chart.synastry.calculate

Computes interchart aspects through the owned sidecar path.

interchart.aspects.rank

Ranks conjunctions, oppositions, trines, squares, sextiles, and tight orbs.

relationship.signals.extract

Extracts Moon, Venus, Mars, Saturn, and Pluto relationship signals.

calculation.basis.report

Reports geocentric tropical calculation basis.

Synastry Pair request

{
  "subject": {
    "id": "person_a",
    "dob": "1990-07-23",
    "tob": "14:30",
    "pob": "New York, US"
  },
  "partner": {
    "id": "person_b",
    "dob": "1992-11-08",
    "tob": "09:15",
    "pob": "Los Angeles, US"
  },
  "max_aspects": 40
}

Synastry Pair response

{
  "request_id": "req_...",
  "data": {
    "pair_id": "person_a:person_b",
    "calculation_basis": {
      "frame": "geocentric",
      "zodiac": "tropical",
      "system": "owned sidecar"
    },
    "aspects": [],
    "relationship_signals": []
  },
  "usage": { "lane": "core", "credits": 3, "billableUnits": 1 }
}

curl

curl https://theleokingai.com/api/v1/charts/synastry \
  -X POST \
  -H "Accept: application/json" \
  -H "x-api-key: $LEOKING_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: synastry-chart-subject-123-v1" \
  -d '{
  "subject": {
    "id": "person_a",
    "dob": "1990-07-23",
    "tob": "14:30",
    "pob": "New York, US"
  },
  "partner": {
    "id": "person_b",
    "dob": "1992-11-08",
    "tob": "09:15",
    "pob": "Los Angeles, US"
  },
  "max_aspects": 40
}'

Node SDK

import { TheLeoKingApi } from "@theleoking/ai-api";

const api = new TheLeoKingApi({
  apiKey: process.env.LEOKING_API_KEY,
  baseUrl: "https://theleokingai.com/api"
});

const result = await api.synastryChart(
  {
  "subject": {
    "id": "person_a",
    "dob": "1990-07-23",
    "tob": "14:30",
    "pob": "New York, US"
  },
  "partner": {
    "id": "person_b",
    "dob": "1992-11-08",
    "tob": "09:15",
    "pob": "Los Angeles, US"
  },
  "max_aspects": 40
},
  "synastry-chart-subject-123-v1"
);

console.log(result.request_id);
console.log(result.usage.credits);

Python SDK

import os
from theleoking_ai_api import TheLeoKingApi

api = TheLeoKingApi(
    api_key=os.environ["LEOKING_API_KEY"],
    base_url="https://theleokingai.com/api",
)

result = api.synastry_chart(
    {
        "subject": {
            "id": "person_a",
            "dob": "1990-07-23",
            "tob": "14:30",
            "pob": "New York, US",
        },
        "partner": {
            "id": "person_b",
            "dob": "1992-11-08",
            "tob": "09:15",
            "pob": "Los Angeles, US",
        },
        "max_aspects": 40,
    },
    idempotency_key="synastry-chart-subject-123-v1",
)

print(result["request_id"])
print(result["usage"]["credits"])

Error Behavior

HTTP	Code	Partner Action
400	`INVALID_REQUEST`	Fix the payload shape, enum value, required field, or request body before retrying.
401	`AUTH_REQUIRED`	Send x-api-key from a trusted server environment. Do not expose keys in browser code.
401	`AUTH_INVALID`	Check the key prefix, rotate compromised keys, and verify the target environment.
402	`CREDITS_EXHAUSTED`	Upgrade the plan, add credits, or switch to a lower-cost Core Compute route.
403	`AUTH_FORBIDDEN`	Use a key scoped for this endpoint or upgrade to the required plan.
404	`NOT_FOUND`	Verify the job id, environment, API key, and whether the job belongs to the same workspace.
409	`IDEMPOTENCY_CONFLICT`	Reuse idempotency keys only for the same logical operation and identical request payload.
429	`RATE_LIMITED`	Back off, retry later, reduce concurrency, or request enterprise limits.

Related Endpoints

POSTalpha

Compatibility Score

/v1/compatibility/score