# Composite Chart API

> Composite Chart API. Generate a composite chart by calculating midpoints between two natal charts. The composite chart represents the relationship as a

- Capability page: https://roxyapi.com/apis/composite-chart-api
- Full domain: https://roxyapi.com/products/astrology-api
- OpenAPI spec: https://roxyapi.com/api/v2/astrology/openapi.json
- Remote MCP server: https://roxyapi.com/mcp/astrology

## Overview

Generate a composite chart by calculating midpoints between two natal charts. The composite chart represents the relationship as a single entity, showing its core identity, emotional bond, communication style, and growth direction. Returns composite planetary positions, house cusps, Ascendant, Midheaven, aspects, and relationship interpretation. Composite chart API, midpoint chart calculator, relationship astrology, couple chart analysis.

## Endpoints

- `POST /api/v2/astrology/composite-chart` Composite Chart - Midpoint relationship chart with interpretations

## Example request

```bash
curl -X POST "https://roxyapi.com/api/v2/astrology/composite-chart" \
  -H "X-API-Key: YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"person1":{"date":"1990-07-15","time":"14:30:00","latitude":40.7128,"longitude":-74.006,"timezone":-5},"person2":{"date":"1990-07-15","time":"14:30:00","latitude":40.7128,"longitude":-74.006,"timezone":-5}}'
```

## Example response

```json
{
  "person1": {
    "date": "1990-07-15",
    "time": "14:30:00",
    "latitude": 40.7128,
    "longitude": -74.006,
    "timezone": -5
  },
  "person2": {
    "date": "1990-07-15",
    "time": "14:30:00",
    "latitude": 40.7128,
    "longitude": -74.006,
    "timezone": -5
  },
  "compositePlanets": [
    {
      "name": "Sun",
      "longitude": 112.45,
      "latitude": 0.01,
      "sign": "Cancer",
      "degree": 22.45,
      "house": 7,
      "speed": 0.9571,
      "isRetrograde": false
    }
  ],
  "compositeHouses": [
    {
      "number": 1,
      "sign": "Gemini",
      "degree": 15.32,
      "longitude": 75.32
    }
  ],
  "compositeAscendant": {
    "sign": "Gemini",
    "degree": 15.32,
    "longitude": 75.32
  },
  "compositeMidheaven": {
    "sign": "Aquarius",
    "degree": 8.76,
    "longitude": 308.76
  },
  "aspects": [
    {
      "planet1": "Sun",
      "planet2": "Moon",
      "type": "TRINE",
      "angle": 120,
      "orb": 2.5,
      "isApplying": true,
      "strength": 75,
      "interpretation": "harmonious"
    }
  ],
  "interpretation": {
    "summary": "string",
    "strengths": [
      "string"
    ],
    "challenges": [
      "string"
    ]
  }
}
```

## Remote MCP

Every endpoint is a callable tool on the Remote MCP server at https://roxyapi.com/mcp/astrology over Streamable HTTP. Tool name for `POST /astrology/composite-chart`: `post_astrology_composite_chart`. `tools/list` is free; `tools/call` bills the same as REST.

## FAQ

### What does the Composite Chart API return?

Generate a composite chart by calculating midpoints between two natal charts. Every response is structured JSON with documented fields, not free text, so you map it straight into your product.

### How do I authenticate with the Composite Chart API?

Pass your key in the X-API-Key header on every request. Keys are delivered instantly at checkout with no approval queue. Use a secret sk key server side, or mint a publishable pk key locked to your origins for browser and no-code use.

### Does the Composite Chart API support multiple languages?

Yes. Append the lang query parameter to any endpoint for responses in English, German, Spanish, French, Hindi, Portuguese, Russian and Turkish. The translated payload includes the full interpretation text, not just field labels.

### Do I need coordinates to call the Composite Chart API?

No. Call GET /location/search with a city name first, then pass latitude, longitude, and timezone from the first result into the request. Never ask users to type coordinates. Timezone accepts a decimal offset or an IANA name.

### Is the Composite Chart API available over Remote MCP for AI agents?

Yes. Every endpoint is exposed as a callable tool on the Remote MCP server at https://roxyapi.com/mcp/astrology over Streamable HTTP, so Claude, ChatGPT, Cursor, and any MCP client auto-discover it with no local setup or Docker.

### How is the Composite Chart API billed?

Flat pricing: 1 request equals 1 quota unit, REST and MCP identical, with no credit weighting or per-token markup. Every plan includes all 12 domains, so the Composite Chart API is included at no extra cost.

### What lang values does the Composite Chart API accept?

The lang parameter accepts en, tr, de, es, hi, pt, fr, ru. Case-insensitive where it is a path value.

## Full reference

Fetch the OpenAPI spec at https://roxyapi.com/api/v2/astrology/openapi.json. Master agent manifest at https://roxyapi.com/llms.txt.