astro-lib

JavaScript library for ephemeris calculations, natal charts, transits, aspects, and Jyotish (Ashta Kuta). Uses the ephemeris package only — no Python required.

Installation

From npm (when published):

npm install astro-lib

From GitHub:

npm install github:USER/astro-lib

From a local clone:

git clone https://github.com/USER/astro-lib.git
cd astro-lib
npm install

API

Natal chart (Western)

const astro = require('astro-lib');

const birth = new Date('1990-05-15T14:30:00Z');
const chart = astro.getNatalChart(birth, 55.75, 37.62);
// chart.planetPositions, chart.asc, chart.jd

Options: { ayanamsaMode: 'tropical' | 'lahiri' } — default is tropical.

Transits and Moon

const transits = astro.getTransits(new Date(), { lat: 55.75, lon: 37.62 });
const moonRhythm = astro.getMoonRhythm(); // { sign, phase }
const moonPhase = astro.getMoonPhase(new Date()); // sign, phase, phaseRatio

Aspects

const aspects = astro.getAspectsBetween(natalPositions, transitPositions);
const best = astro.findStrongestHarmoniousAspect(chart1, chart2);
const transitAspects = astro.getTransitAspects(transitsData, natalChart);

Jyotish (sidereal chart, Lahiri)

const jyotishChart = astro.getJyotishChart(birthDate, lat, lon);
// jyotishChart.planetPositions, lagnaRasi, chandraRasi, chandraNakshatra

Compatibility (Ashta Kuta)

const result = await astro.getJyotishCompatibility(
  { date: new Date('1990-05-15'), lat: 55.75, lon: 37.62 },
  { date: new Date('1992-08-20'), lat: 55.75, lon: 37.62 }
);
// result.compatibility_score, verdict_key, analysis, charts

Low-level (planet positions)

const data = astro.getPositions(date, lat, lon, { ayanamsaMode: 'lahiri' });
// data.positions, data.jd, data.asc

Structure

• lib/ephemeris-adapter.js — wrapper around ephemeris, optional sidereal (Lahiri).
• lib/ayanamsa.js — Lahiri ayanamsa.
• lib/chart.js — natal chart.
• lib/transits.js — transits, Moon phase.
• lib/aspects.js — aspects between charts/transits.
• lib/jyotish-data.js — nakshatras, rasis, Kuta tables.
• lib/jyotish.js — Jyotish chart and Ashta Kuta.

Use in another project

From the repo root:

const astro = require('./astro_lib');

Or copy the astro_lib folder, run npm install inside it, and require by path.

License

MIT.