Novastrum API

• Quick startYour first request in one minute.
• API referenceEvery endpoint with its parameters. Try requests in the browser.
• OpenAPI documentFor Postman, Insomnia or a generated client.

Base URL

https://api.novastrum.io/api/v1

Every request and response body is JSON (Content-Type: application/json), except chart renderings, which are SVG.

Authentication

Send your API key in the Authorization header of every request:

Authorization: Bearer YOUR_API_KEY

Without a valid key the API answers 401. Keep the key on your server: a key in a web page or app can be read by anyone who uses it. Only /health and this documentation are open.

Quick start

Calculate a birth chart: planet positions, houses and aspects for 15 June 1990, 12:30 UTC, in Berlin.

curl -X POST https://api.novastrum.io/api/v1/calculate/chart \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "datetime": "1990-06-15T12:30:00Z",
    "latitude": 52.52,
    "longitude": 13.405,
    "house_system": "P"
  }'

The response lists every planet with longitude, sign, speed and retrograde state, plus the houses and aspects:

{
  "julian_day": 2448058.0208333335,
  "datetime": "1990-06-15T12:30:00Z",
  "location": { "latitude": 52.52, "longitude": 13.405 },
  "planets": [
    { "name": "Sun", "longitude": 84.154, "sign_name": "Gemini", "retrograde": false, ... },
    ...
  ],
  ...
}

The moon phase for a date

curl -X POST https://api.novastrum.io/api/v1/calculate/moon-phase \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"datetime": "2026-10-04T12:00:00Z"}'

Dates, times and places

• datetime is ISO 8601 or a Julian Day.
• Send times in UTC (ending in Z). The server currently ignores offsets such as +02:00, so a local time with an offset is read as UTC.
• latitude and longitude are decimal degrees, north and east positive.
• house_system is a one-letter code, e.g. P Placidus, K Koch, W whole sign, E equal houses.

What the API covers

The API reference lists every endpoint with its request and response schema.

API keys

With a key you can create further keys, for example one per application, and revoke them again: GET and POST /api/v1/account/keys, POST /api/v1/account/keys/revoke. A new key is shown once, when it is created.

Errors

Errors from authentication come as JSON with a code and a message:

{ "error": { "code": "MissingHeader", "message": "Missing Authorization header. Use 'Authorization: Bearer <api_key>'" } }

Status

GET https://api.novastrum.io/health answers without a key and reports whether the API is up.