Moon Phases & Lunar Positions

What is the Moon Phases endpoint?

You need both the lunar phase at birth and the Moon's natal position in one call. The Moon Phases endpoint takes birth data and returns which of the eight lunar phases the Moon was in (Waxing Crescent, First Quarter, Full Moon, etc.), the natal Moon's exact ecliptic position, sign and house placement, plus an interpretive reading for that phase.

This endpoint is part of the Natal Chart API.

Why does this endpoint exist?

You are surfacing lunar content in your product and you want both the phase calculation and the natal Moon placement bundled together. Computing the Sun-Moon angular distance to determine the phase is one ephemeris query; locating the Moon's sign and house is another. This endpoint runs both at once and returns a structured bundle ready to render.

What inputs does it need?

You pass standard birth data: API key, full name, date components, time components, gender, place, decimal latitude and longitude, and timezone offset from UTC. The Moon's phase changes meaningfully every few hours, so birth time precision matters. Authentication uses a Bearer token in the Authorization header.

What does the response data look like?

You get a data object that bundles the phase, the natal Moon position, and an interpretive reading. The phase_no and phase_name identify which of the eight lunar phases applies. The natal_moon object covers the Moon's ecliptic position. The content object provides a one-line feature summary plus a details array of paragraphs.

What does a real response look like?

Below is the response for a sample birth (24 May 2023, 14:40:43 IST, New Delhi). The Moon was in Waxing Crescent at 54° from the Sun, sitting at 27° Cancer in the 10th house.

{
  "success": 1,
  "data": {
    "phase_no": 2,
    "phase_name": "Waxing Crescent Moon",
    "phase_degree": "54.3334317",
    "natal_moon": {
      "full_degree": "117.3008709",
      "longitude": "27:18:3",
      "sign": "Cancer",
      "house": 10
    },
    "content": {
      "feature": "Growth, Expansion, Building momentum",
      "details": [
        "The Waxing Crescent phase is associated with growth, expansion, and building momentum. Astrologically, this phase reflects the early stages of development, both personally and professionally. Those born during the Waxing Crescent may be perceived as proactive individuals, keen on pursuing growth opportunities and building a foundation for future endeavors.",
        "Individuals in this phase of the lunar cycle may possess a natural inclination to explore new ideas, meet challenges head-on, and cultivate a sense of adventure. They are seen as builders, laying the groundwork for their aspirations, and demonstrating resilience in the face of challenges."
      ]
    }
  }
}

What can you build with this endpoint?

You use the Moon Phases endpoint whenever your product surfaces "Moon-at-birth" content, lunar-cycle personality features, or natal Moon details with reader-facing prose. The bundled response means a single call covers both the phase classification and the Moon's sign and house, so you do not need to combine results from multiple endpoints.

1. Lunar personality cards. Show "You were born under a Waxing Crescent Moon" with the feature line as the subtitle and details as the body copy.
2. Natal Moon detail panels. Render the natal_moon object as a sign-and-house mini-card alongside the phase reading.
3. Phase-themed content engines. Group users by phase_no to deliver phase-specific newsletters, daily prompts, or community features.
4. Moon-aware onboarding. Surface lunar phase + Moon sign as part of the first profile setup flow alongside Sun sign and Ascendant.

How accurate is the calculation?

You are computing both an angular relationship (Sun-Moon distance for the phase) and a precise ecliptic position (the natal Moon). Both come from Swiss Ephemeris with NASA JPL ephemeris data. The phase_degree is arc-second accurate, and the natal Moon's position uses the same ephemeris as Planetary Positions.

The Moon moves about 13 degrees per day, faster than any other body. A 30-minute birth-time error rarely changes the phase but can shift house placement. Treat house-based interpretations as approximate for unknown birth times.

How does this relate to the parent API?

You are layering lunar content on top of the standard birth chart. This endpoint complements the Natal Chart API by providing the lunar phase classification plus the Moon's natal placement and interpretation in one call.

Planetary Positions also returns the Moon's position, but without phase classification or interpretive prose. Use this endpoint when your UI specifically surfaces lunar-themed content. For day-by-day lunar tracking across a month, see the Moon Phase Calendar endpoint.

Summary

The Moon Phases endpoint returns the lunar phase at birth (one of eight named phases), the Moon's natal ecliptic position with sign and house, and an interpretive reading for the phase. It runs on Swiss Ephemeris with NASA JPL ephemeris data and supports twelve languages. Use it whenever your product surfaces lunar-themed content on top of a standard birth chart.