12 min read·
Whole Sign Fallback at Polar Latitudes for Birth Chart APIs
Placidus and Koch fail above 66 degrees north. Here is what RoxyAPI returns at the cutoff and how to override to Whole Sign for traditional charts.
Torsten Brinkmann
Astrologer & Developer Advocate
Germany
Torsten Brinkmann combines 16 years of Western astrology practice with a software engineering background, specializing in astrological calculation tools, birth chart APIs, and planetary aspect analysis. His Computer Science training shapes writing that addresses both the astronomical mathematics behind natal charts and the developer integration patterns for astrology APIs. He is currently writing a technical guide to birth chart calculation for developers.
Computer Science background16 years of practiceWriting a technical astrology guide
Western astrologyBirth chart analysisPlanetary aspectsSynastryAPI integrationAstrology software
41 articles published
Articles by Torsten Brinkmann
10 min read·
Retrograde Station Detection: Stationary Point Edge Cases
Why naive day-step retrograde detection misses planetary stations, and how to detect zero crossings of longitude velocity for the astrology API.
15 min read·
Timezone Bugs in Astrology: A Complete Developer Guide
Timezone bugs silently corrupt natal charts. DST ambiguity, historical offsets, IANA vs decimal inputs, and how to debug chart mismatches.
9 min read·
Build a Biorhythm App with Cursor and RoxyAPI in 30 Minutes
Build a working biorhythm app using Cursor and the RoxyAPI Biorhythm API. 10 cycles, editorial interpretations, zero domain knowledge required.
10 min read·
How Biorhythm Energy Ratings Work: The 1-10 Scale Explained
The biorhythm energy rating condenses three primary cycles into a 1-10 score. Learn how the scale works and how to display it.
10 min read·
VSOP87 vs JPL DE440: Which Planetary Ephemeris to Use
Compare VSOP87 and JPL DE440 planetary ephemeris models for accuracy, speed, and file size. Find out which fits your astrology app or astronomy project.
10 min read·
Planetary Aspect Calculation for Developers: Orbs and Edge Cases
How to calculate planetary aspects correctly. Covers orb systems, the 360 degree wrap-around bug, applying vs separating detection, and a working API example.
12 min read·
Placidus House Calculation for Developers: The Math
How Placidus house calculation works, the iterative algorithm behind house cusps, and why it breaks at extreme latitudes. Developer guide with working API example.
11 min read·
Birth Chart Calculation From Scratch: The Full Algorithm
Every step of a birth chart calculation explained for developers. From UTC conversion to aspect orbs, with a working API example.
11 min read·
MCP Astrology Server: 12 Spiritual Domains, 145+ AI Tools [2026]
Set up 12 MCP servers with 145+ spiritual data tools for AI agents: astrology, Human Design, tarot, numerology, I-Ching, dreams, crystals, and more. One API key.
9 min read·
Daily Horoscope API with Unique Forecasts Per Sign [2026]
Most horoscope APIs return identical text for 11 of 12 signs. Learn how whole-sign house positions produce unique daily content per zodiac sign with transit metadata.
11 min read·
How We Test Astrology API Accuracy: 828 Gold Standard Tests Explained
828 gold standard tests verify astrology API accuracy against DrikPanchang, onlinejyotish.com, and JyotishApp. Full testing methodology explained.