Jyotish · Vedic Astrology Web App

A modern, web-based Vedic (Jyotish) astrology application — the successor to desktop tools like Parashara's Light. Built to serve both professional astrologers (full computational depth) and everyday consumers (a clean, simple experience).

Status: Feature-complete core (Phases 1–5)

Working today:

• High-precision sidereal engine (Lahiri ayanamsa) — validated against Mesha Sankranti and known ephemeris positions.
• Birth chart (Rāśi / D-1) in both North Indian and South Indian styles, with a full planet table (sign, degree, nakshatra, pada, house, ℞).
• 16 divisional charts (D1–D60) — Shodashavarga, classical BPHS rules, switchable from a dropdown.
• Vimshottari Daśā — mahadashas + antardashas, current period highlighted.
• Ashtakavarga — Bhinnashtakavarga per planet + Sarvashtakavarga (bindu totals validated: 48/49/39/54/56/52/39, SAV = 337).
• Transits + Sade Sati — current sky vs. natal chart, Sade Sati phase detection (rising / peak / setting) and lesser Śani.
• Compatibility (Guṇa Milan) — full 8-koota / 36-point Ashtakoota match with dosha detection and a verdict.
• Hybrid interpretation — classical rule-based analysis + Claude-written natural-language reading (graceful fallback with no API key).
• Save / share / print — localStorage saved charts, shareable ?c= links that auto-load, print-to-PDF.
• Tabbed UI with a Birth-Chart vs. Compatibility mode toggle.

Tech stack

• Next.js 16 (App Router) + TypeScript + Tailwind CSS v4
• astronomy-engine for planetary positions (arc-second accuracy, pure JS)
• Ephemeris provider is swappable — Swiss Ephemeris can drop in later for certified pro-grade accuracy.

Architecture

lib/astro/          Pure calculation engine (no UI, fully testable)
  constants.ts      Signs, nakshatras, planets, dasha data
  time.ts           Julian day, sidereal time, obliquity, TZ handling
  ayanamsa.ts       Lahiri ayanamsa (sidereal correction)
  ephemeris.ts      Planet / node / ascendant sidereal longitudes
  chart.ts          Assembles a full chart (houses, nakshatras, padas)
  dasha.ts          Vimshottari mahadasha + antardasha
  selftest.ts       Runnable validation:  npx tsx lib/astro/selftest.ts
components/         React UI (charts, table, dasha tree, form)
app/api/chart/      POST birth data -> chart + dasha JSON

Run locally

cd jyotish-app
npm install
npm run dev          # http://localhost:3000
npx tsx lib/astro/selftest.ts   # validate the engine

What's next

• More yogas (Raja, Dhana, Neecha Bhanga, Pancha Mahapurusha).
• Real geocoding — replace the small hardcoded city list with a lookup.
• Accounts & cloud sync, richer branded PDF reports.
• Swiss Ephemeris swap for certified pro-grade accuracy.

Notes

• Currently: sidereal (Lahiri), whole-sign houses, mean lunar nodes.
• Ayanamsa and house systems will become user-configurable options.
• Yoni/Vashya kootas use the standard simplified compatibility model.
• Set ANTHROPIC_API_KEY in .env.local to enable AI readings (model claude-sonnet-5); otherwise the classical analysis is shown.

Engine validation

npx tsx lib/astro/selftest.ts     # core positions + dasha
npx tsx lib/astro/vargatest.ts    # divisional chart rules
npx tsx lib/astro/avtest.ts       # Ashtakavarga bindu totals
npx tsx lib/astro/compattest.ts   # Guna Milan + transits