---
title: "Cyclic Index"
method: POST
path: "/cyclic-index"
tags: ["Calendar & Cycles"]
---

# Cyclic Index

`POST /cyclic-index`

Calculate the André Barbault Cyclic Index, sum of all outer planet separations, for a date range to indicate global crisis periods.

## Request body

- CyclicIndex
  - `startYear` number, nullable, required
  - `endYear` number, nullable, required
  - `pairs` unknown

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `data` object[], nullable
      - `date` string, nullable
      - `index` number, nullable
    - `minimum` object, nullable
      - `date` string, nullable
      - `value` number, nullable

## Other responses

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

---

[API](https://skmtc.net/astroway/apis/astroway-calculation-api.md) · [All operations](https://skmtc.net/astroway/apis/astroway-calculation-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/astroway/astroway-calculation-api/revisions/6828e5609564/schema)