Astronomical calculation

A precision astronomical calculation engine

Psychomantic calculates planetary positions, transits, and lunar cycles from the NASA JPL DE442Q ephemeris. A proprietary calculation engine built for precision and the analysis of astronomical data applied to astrology.

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Free plan • Developer API • GDPR-compliant data

< 1 arcmin
Planetary precision
~< 5 µs
Latency per calculation
DE442Q
NASA JPL ephemeris
100%
Proprietary engine
Multi-system

An astronomical calculation engine

Planetary positions, transits, lunar cycles: precise, verifiable calculations.

Detailed Natal Chart

Planetary positions, houses, aspects, and dominants calculated with NASA JPL DE442Q ephemerides.

Real-time Transits

Track current planetary movements and their interactions with your natal chart.

Astrocartography

Visualize your planetary lines on a world map and discover where your configurations resonate strongest.

Asteroids

Chiron, Vesta, Juno, Pallas and more, interpolated at 1-day steps for high precision.

Developer API

REST API with API key authentication, quotas and integrated billing. Published surface and sample call: psychomantic.com/api.

Data Sovereignty

100% proprietary engine, no dependency on Swiss Ephemeris. Complete account deletion compliant with GDPR.

How does it work?

Three steps, zero jargon.

1

Your information

Enter your date, time, and place of birth. The engine calculates your planetary positions with precision.

2

Your chart

Planetary positions calculated to less than 1 arcminute on the NASA JPL DE442Q ephemeris.

3

Your reading

A structured analysis of your configurations translated into clear language.

Developer API

A complete API, from astronomy to symbolic systems

Astronomical calculations, complementary systems, AI interpretation: a single REST API, ~< 5 µs per calculation, authenticated by API key. The published surface and a sample call are on psychomantic.com/api.

curl 
curl -X POST https://api.psychomantic.com/v1/astro/natal \
  -H "X-API-Key: ish_..." \
  -H "Content-Type: application/json" \
  -d '{"date":"1990-06-15","time":"14:30","latitude":48.8566,"longitude":2.3522}'
Astronomy & calculations

Natal charts, transits, synastry, compatibility, solar return, astrocartography, asteroids, moon phase, ephemerides, retrogrades.

Complementary systems

Yi King (HLLS), Chinese zodiac, Matrix of Destiny (22 arcana + karmic program), mirror hours.

AI interpretation

Chart interpretation and life guide generated from calculated data.

Accounts & platform

Auth, profiles, saved charts, API keys, usage tracking, Stripe, PNG export, geocoding.

Read the documentation
Freemium model

Free essentials, options to go further

Most modules are free: natal chart, transits, synastry, solar return, astrocartography, asteroids. Some advanced sections and heavy API usage will be offered as a paid option.

Essential calculations: free
Advanced modules: free
Premium options: paid

Frequently Asked Questions

What you should know about Psychomantic.

What is Psychomantic?
Psychomantic is a high-precision astrology engine that calculates planetary positions, transits, astrocartography, and asteroid influences from NASA JPL DE442Q astronomical ephemerides.
How accurate are the calculations?
Planetary positions are calculated with sub-arcminute precision using NASA JPL DE442Q ephemerides. Asteroids are interpolated at 1-day steps to minimize error.
Will Psychomantic be free?
Most modules are free. Some advanced sections and heavy API usage will be offered as a paid option.
How is my data protected?
Your data is stored securely. You can request account deletion at any time, in compliance with GDPR. Psychomantic does not use Swiss Ephemeris: the engine is 100% proprietary.
What makes Psychomantic different from other astrology tools?
Unlike many tools that depend on third-party libraries like Swiss Ephemeris, Psychomantic uses a custom astronomical engine based on NASA JPL DE442Q data. This guarantees precision, technological sovereignty, and flexibility for future development.

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