Developer documentation

Build from a calculation contract you can inspect.

Start with the request model, then move into endpoint references. Tropical, geocentric calculations are the default; sidereal mode is an explicit coordinate choice.

Authenticate a request Open the API reference
  • Server-to-server JSON
  • DE421 ephemeris
  • 1900–2050 public date window
AstroAPI request and calculation diagram A request moves through authentication into a celestial calculation and returns JSON. POST { JSON } { } 200 authenticated calculation boundary