# natalcharts.com — full machine-readable site description

natalcharts.com computes natal charts from a birth date, optional time, and place. The full natal chart is free. No login is required to calculate or view it. Optional account tools can save a chart or email a signed PDF link. English only. No ads.

## Engine (verifiable in the repository)

- Ephemeris: NASA/JPL DE440 (`de440.bsp`) via Skyfield. Not affiliated with NASA, JPL, or Astrodienst.
- Civil coverage: 1550-01-01 … 2650-01-24 UTC.
- Chiron and asteroids Ceres, Pallas, Juno, Vesta: 1600-01-01 … 2500-12-31. Natal charts omit those bodies outside the window.
- 47 ayanamsas for sidereal charts.
- 22 house systems. CI tests match Swiss Ephemeris (pyswisseph) within 1 arcsecond on the documented grids.
- True and mean lunar nodes; true Lilith (osculating) on the free funnel; mean Lilith when a setting asks for it.
- The engine also implements synastry, midpoint composite, and Davison. Those are not public website products in this launch.
- Calendar: `auto`, `gregorian`, or `julian`.
- Birth data is POST JSON only. It is not placed in URLs.

## Public pages

- `/` free natal chart
- `/methodology`
- `/house-systems`
- `/unknown-birth-time`
- `/signs`
- `/reports`
- `/mercury-retrograde` and `/mercury-retrograde/YYYY-MM` archive pages
- `/credits`
- `/editorial-policy`
- `/about`
- `/contact` (hello@natalcharts.com)

## Private / disallowed

- `/c/` saved charts
- `/account` sign-in tools
- `/lab/` internal preview
- `/api/` including `/api/chart`, `/api/geocode`, `/api/tz`, `/api/account/*`, `/api/pdf/*`, `/api/email-image/*`

## What this site does not claim

- No user counts, testimonials, or “54 languages”.
- No live readings, shop prices, or compatibility percentage scores.
- A 3D sky / wheel-to-sky view exists as a noindex preview at /sky.

Interpretation is a tradition and a mirror, not prediction or advice.