GenesisCore Astrology Guide
JAStart free analysis

Free astrology API and embeddable widget

An embeddable Moon, Sun, Venus, Mars and Mercury sign widget for your site, and a JSON API that returns tropical and sidereal planet signs plus the Ascendant for a date, time and place. No signup, no API key.

1. Embeddable widget

Visitors enter a birth date and see the sign with a link to its meaning. If the sign changed that day and no time is given, both signs are shown. Live preview:

Paste as an iframe (recommended)

<iframe src="https://genesis-astro-guide-r2owtywexa-an.a.run.app/widget/sign.html?planet=moon&lang=en" title="Moon sign calculator" loading="lazy" style="width:100%;max-width:440px;height:340px;border:0;border-radius:12px"></iframe>
<p><a href="https://genesis-astro-guide-r2owtywexa-an.a.run.app/en/guides/moon">Moon sign meanings (GenesisCore Astrology Guide)</a></p>

Paste as a script

<script src="https://genesis-astro-guide-r2owtywexa-an.a.run.app/widget/embed.js" data-planet="moon" data-lang="en" async></script>
<p><a href="https://genesis-astro-guide-r2owtywexa-an.a.run.app/en/guides/moon">Moon sign meanings (GenesisCore Astrology Guide)</a></p>

planet= takes moon, sun, venus, mars or mercury; lang= ja or en; theme=light gives a white background.

2. JSON API

GET https://genesis-astro-guide-r2owtywexa-an.a.run.app/api/v1/chart?date=YYYY-MM-DD&time=HH:MM&offset=9[&lat=..&lon=..][&lang=ja|en]
  • date：required, 1900–2100
  • time：defaults to 12:00
  • offset：hours from UTC (9 for Japan); defaults to 0
  • lat / lon：add these to get the Ascendant, MC and Lagna (Lahiri); east positive

Returns: longitude and sign of the Sun through Pluto (tropical and sidereal/Lahiri), retrograde flags, the ayanamsa, and links to each sign's meaning page. CORS enabled, no key.

Example: 1 May 1990 12:30 Tokyo →

3. Bulk data downloads

Moon (tropical and sidereal) and Venus, Mars and Mercury sign ingress times for 1940–2030 are available as CSV and JSON. Go to the data page →

4. MCP server for AI assistants

A free remote MCP server so AI assistants (Claude, ChatGPT, Cursor and others) can answer "what is my moon sign?", "what is my Vedic rashi?" or "when is the next Mercury retrograde?". No auth, Streamable HTTP with JSON responses.

https://genesis-astro-guide-r2owtywexa-an.a.run.app/mcp
claude mcp add --transport http genesis-astro https://genesis-astro-guide-r2owtywexa-an.a.run.app/mcp
{
  "mcpServers": {
    "genesis-astro": { "type": "http", "url": "https://genesis-astro-guide-r2owtywexa-an.a.run.app/mcp" }
  }
}
  • calculate_birth_chart_signs：Sun to Pluto in tropical and sidereal (Lahiri) signs, Moon nakshatra, Ascendant / Lagna
  • get_retrograde_periods：Mercury, Venus, Mars, Jupiter and Saturn retrogrades 2025–2027
  • get_sign_ingresses：Mercury, Venus and Mars sign ingress times 1940–2030
  • get_current_sky：planet positions right now

OpenAPI spec: /openapi.json · /llms.txt · GitHub ↗

5. Terms of use

Free, no signup, fine for commercial sites. Please keep a link to "GenesisCore Astrology Guide" where results are shown, and avoid bursts of heavy traffic. Calculations use Astronomy Engine 2.1.19; the code is on GitHub. GitHub ↗

Free Astrology API and Embeddable Widget (Moon Sign, Ascendant, Planet Signs)