12 min read·
Build a Spiritual OS on One API: Astrology to Human Design
Build a Spiritual OS on one API: one OpenAPI spec, one key, one engine across 12+ distinct domains from astrology to human design, numerology, and tarot.
Brett Calloway
Developer Advocate & AI Integration Specialist
United States
Brett Calloway has 12 years of experience building APIs and developer tooling, including three years focused on AI-native infrastructure for spiritual and wellness applications. He writes on building context-rich AI agents using Model Context Protocol, drawing on a developer relations background. His coverage spans API integration patterns, AI agent architecture, and rapid prototyping with astrology, tarot, and numerology data.
12 years in API developmentDeveloper relations backgroundWriting on AI agents and MCP
API integrationAI agentsModel Context ProtocolDeveloper toolsAstrology APIMCP
46 articles published
Articles by Brett Calloway
15 min read·
Best Astrology APIs for Developers: 2026 Buyer Guide
Compare the best astrology APIs for developers in 2026: domain coverage, MCP transport, accuracy, and pricing across RoxyAPI, AstrologyAPI, and Prokerala.
12 min read·
RoxyAPI for Advanced Use Cases: Simple Surface, Deep Control
RoxyAPI gives serious builders clean commercial licensing with no AGPL, twelve domains under one contract, KP sub-sub-lords, and primitives you own by RoxyAPI.
8 min read·
Cache Astrology API Calls to Cut Costs at Scale
Your astrology API bill should not grow one to one with users. Cache deterministic results in your own store and the cost flattens as you scale.
12 min read·
API Key Security: Revocation, Rotation, Scraping Defense
Evaluate API key security: revocation latency, rotation policy, scraping defense, rate limiting, and credential leakage controls. By RoxyAPI.
9 min read·
Ship AI Prompt Files for Cursor, Claude Code, Copilot
Compare CLAUDE.md, Cursor rules, Copilot instructions, and Windsurf rules. What goes in each prompt file for API consumers. By RoxyAPI.
13 min read·
Add Tarot Readings to a Shopify Store with App Proxy
Add a tarot card of the day, daily horoscope, kundli, and post-checkout numerology to a Shopify store via App Proxy. One pattern for all 10 domains.
12 min read·
Astrology Widget for WordPress: Shortcode and Block Tutorial
Add a daily horoscope, natal chart, kundli, and Life Path widget to WordPress with one shortcode pattern, transient caching, and a custom REST proxy.
11 min read·
AGENTS.md vs llms.txt vs ai-plugin.json vs agent-card.json
Four agent-discovery files, four different consumers. Compare AGENTS.md, llms.txt, ai-plugin.json, and agent-card.json with byte sizes and shipping rules.
12 min read·
Build a Voice Astrology Agent with Vapi and Remote MCP
Wire a Vapi voice assistant to a Remote MCP astrology server in under 30 minutes. Step-by-step setup, web SDK embed, cost breakdown by RoxyAPI.
17 min read·
How to Add Numerology Features to Your Dating App (Complete API Guide)
Add numerology-powered matchmaking to a dating app with three endpoints: chart, compatibility, and personal year. Working code, caching, multi-language, MCP shortcut.
9 min read·
Astrology API Accuracy Benchmark vs NASA JPL Horizons DE441
Open MIT-licensed reproducible benchmark for any astrology API. 210 planet positions across 21 charts vs NASA JPL Horizons DE441 reference.
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