Privacy

Caelus is an open-source library and its documentation site. It collects no personal data, runs no analytics, and sets no advertising or tracking cookies.

What stays on your device

The Playground computes charts entirely in your browser using the engine itself. The birth date, time, and place you enter are never sent to a server. A share link encodes those inputs in the URL fragment (the part after #), which browsers do not transmit; it travels only if you copy the link and send it yourself.

The one thing kept locally is your light or dark theme preference, stored in localStorage so the site remembers it on your next visit. Nothing else is stored, and clearing site data removes it.

The hosted API

The optional REST and MCP endpoints are stateless: they receive only the parameters a request sends (such as date, latitude, and longitude), compute a result, and return it. They keep no logs of birth data and store nothing between requests.

Questions

The code is MIT licensed and fully auditable on GitHub. If something here is unclear, open an issue there.