---
title: "MCP Multi-Chart Context"
method: POST
path: "/mcp/multi-chart-context"
tags: ["AI & MCP"]
---

# MCP Multi-Chart Context

`POST /mcp/multi-chart-context`

Compact context for MCP agents working across multiple charts.

## Request body

- MultiChart — Group of 2-10 natal charts for collective calculations: group synastry, penta-chart, etc.
  - `inputs` ChartInput[], required
    - `date` string, required
    - `time` string, required
    - `timezoneOffset` number, nullable — Hours from UTC at the given moment, not minutes. Fractional zones are hours too: 5.5 for India, 5.75 for Nepal, -3.5 for Newfoundland. Defaults to 0, meaning UTC.
    - `latitude` number, required
    - `longitude` number, required
    - `houseSystem` string
    - `name` string
    - `city` string
    - `zodiacType` 'tropical' | 'sidereal'
    - `ayanamsaId` number, nullable
    - `ayanamsa` 'fagan-bradley' | 'lahiri' | 'de-luce' | 'raman' | 'krishnamurti' | 'kp' | 'yukteshwar' | 'jn-bhasin' | 'true-citra' | 'djwhal-khul' — Sidereal school by name. Lahiri when omitted. Equivalent to ayanamsaId; send either.
    - `cosmogram` boolean

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `contextHash` string, nullable
    - `chartCount` number, nullable
    - `intent` string, nullable
    - `summaries` object[], nullable
      - `index` number, nullable
      - `name` string, nullable
      - `bigThree` object, nullable
        - `sun` string, nullable
        - `moon` string, nullable
        - `ascendant` string, nullable
    - `summaryString` string, nullable
    - `notes` string[], nullable

## Other responses

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

## Changes

- **2026-08-24** `8ab5a768b521` — 2 breaking, 8 info
  - the response property `data/summaries/items/` became nullable for the status `200`
  - the `data/summaries/items/` response's property type/format changed from ``/`` to `object`/`` for status `200`
  - added the optional property `data/chartCount` to the response with the `200` status
  - added the optional property `data/contextHash` to the response with the `200` status
  - …6 more
- **2026-08-18** `dd3764875e7a` — 1 info
  - added the new optional request property `inputs/items/ayanamsa`
- **2026-08-15** `e637d1a9911b` — 2 warning
  - the `inputs/items/timezoneOffset` request property's max was set to `14.00`
  - the `inputs/items/timezoneOffset` request property's min was set to `-14.00`
- **2026-08-11** `b0533bcc12c0` — 4 breaking, 4 warning, 2 info
  - the request property `inputs/items/latitude` became not nullable
  - the request property `inputs/items/longitude` became not nullable
  - the request property `inputs/items/latitude` became required
  - the request property `inputs/items/longitude` became required
  - …6 more

[Change history](https://skmtc.dev/astroway/apis/astroway-calculation-api/changes/mcp/multi-chart-context/post.md)

---

[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/8ab5a768b521/schema)