10 min read
Synastry Calculation for Developers: Comparing Two Charts
Learn how synastry calculation works, from inter-chart aspects and orb systems to composite charts. Build relationship compatibility features with a working API.
Blog
Insights, tutorials, and updates from the RoxyAPI team
Recent Posts
15 min read
Swiss Ephemeris AGPL Licensing for SaaS Developers
Swiss Ephemeris AGPL license requires SaaS apps to open source their entire codebase. Learn your options and AGPL-free alternatives for astrology APIs.
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.
10 min read
Numerology Calculation Algorithms: Pythagorean vs Chaldean
How Pythagorean and Chaldean numerology calculations differ in letter mapping, digit reduction, and master number handling. A developer reference.
10 min read
Horoscope Generation for Developers: Transit Forecasts
How transit based horoscope generation works, from planetary positions to daily forecasts. Real API examples for developers building zodiac apps.
11 min read
Gun Milan Scoring Algorithm: How Kundli Matching Works
How the 36-point Gun Milan algorithm scores compatibility across 8 kootas. Covers Nadi dosha cancellation, Bhakoot exceptions, and API integration.
13 min read
How to Evaluate a Tarot API: Developer Checklist 2026
A 10-point checklist to evaluate tarot APIs on card coverage, spread support, reproducibility, AI readiness, and pricing before you commit.
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.
9 min read
Ayanamsa Explained for Developers: Lahiri vs Raman vs KP
Ayanamsa is the offset between tropical and sidereal zodiacs. Learn how Lahiri, Raman, and KP systems differ and how to implement them in code.
15 min read
AI Agents Calling Real APIs: How Tool Calling and MCP Work in Practice
See how AI agents actually call APIs in production. Real examples of OpenAI function calling, Claude tool use, Gemini ADK, and MCP with request/response flows and code you can run today.
15 min read
AI Astrology API vs Calculation Infrastructure: 375x Gap
AI wrapper astrology APIs charge $0.15 per query. GPT-4o-mini costs $0.0004 for the same result. 375x markup exposed with full pricing math. By RoxyAPI.
Featured Posts
13 min read
Best Tarot APIs for Developers 2026: Features and Pricing
Compare the best tarot APIs for developers: 78-card decks, spreads, seeded draws, card images, MCP, and flat pricing reviewed by RoxyAPI.
12 min read
Best Vedic Astrology API for Kundli and Panchang 2026
Compare RoxyAPI, AstrologyAPI, and Prokerala for kundli, panchang, dasha, and KP: fact-checked features, pricing, and real cost math.