# OpenEphemeris API

> Auto-generated from openapi.json v1.0.0 on 2026-03-02T19:47:57Z
> Do not edit manually — run `go run ./cmd/tooling generate-llms`

**OpenEphemeris Engine** - Professional Astrological Calculations

## Quick Facts

- **Base URL**: `https://api.openephemeris.com`
- **Auth**: Bearer token or `X-Meridian-API-Key` header
- **Public Endpoints**: 95
- **Agent Output Mode**: `?format=llm`
- **OpenAPI Spec**: https://api.openephemeris.com/openapi.json

## Endpoint Groups

- **ACG** (12 endpoints, GET, POST): Cyclocartography Time-Series (Go Engine); ACG Line Crossing Points (Go Engine); Available ACG Datasets
- **Human Design** (6 endpoints, POST): Create Human Design Chart Alias; Create Human Design Chart; Human Design Composite
- **Time Conversion** (6 endpoints, GET, POST): Delta T (TT-UT1) calculation; Equation of Time; Calendar conversion to Julian Day Number
- **agricultural** (3 endpoints, GET): Biodynamic monthly calendar; Biodynamic daily profile; Void of Course Moon
- **api-metadata** (8 endpoints, GET): API Root; Get Supported House Systems; Get Natal Chart Request Schema
- **calendar** (3 endpoints, GET): Wheel of the Year — True Astronomical Dates; Lunar Standstill — 18.6-Year Nodal Cycle Status; 8-Phase Lunar Classification + Next Principal Phases
- **chinese** (2 endpoints, GET, POST): Calculate Four Pillars of Destiny (BaZi); Chinese zodiac animal and element for a year
- **comparative** (6 endpoints, POST): Calculate Composite; Calculate Composite Midpoint; Calculate Natal Transits
- **eclipse** (6 endpoints, GET): Raw Besselian Elements; Lunar Eclipse Global Circumstances; Next Visible Eclipse
- **ephemeris** (14 endpoints, POST): Calculate angles + points (granular); Check aspects between two longitudes; Calculate essential dignities (granular)
- **health** (3 endpoints, GET): Health Check; Global Health Check; Detailed Health Check
- **location-timezone** (4 endpoints, GET, POST): Search for locations by name; Reverse geocode coordinates to location name; Resolve IANA timezone from coordinates
- **lunar** (4 endpoints, GET): Get current Moon aspects; Get Moon sign ingresses for date range; Get lunar phase
- **predictive** (9 endpoints, POST): Calculate secondary (Naibod) progressed chart; Calculate Predictive Events (Unified Endpoint); Calculate Planetary Return Timing
- **tidal** (2 endpoints, GET): Astronomical Tidal Forcing; Astronomical Tidal Forcing (Deep Time)
- **vedic** (1 endpoints, POST): Generate a Vedic (sidereal) natal chart
- **venus-cycles** (6 endpoints, POST): Compute Venus Star Points; Range-based Venus conjunctions; Venus 8-year star pattern

## Documentation

- **Interactive API Reference**: https://openephemeris.com/docs
- **OpenAPI Spec (JSON)**: https://api.openephemeris.com/openapi.json
- **Full Agent Manifest**: https://openephemeris.com/llms-full.txt
- **MCP Tooling**: `npx -y @openephemeris/mcp-server` for direct AI agent integration