Your birth chart, inside your AI assistant
AI assistants explain a birth chart well and calculate one badly: asked for a rising sign, a chatbot often guesses. Connect Lunonis and ChatGPT or Claude gets real positions from an ephemeris, then does what it is good at, putting them in plain words.
Why connect a calculator
A birth chart is arithmetic before it is interpretation. The Sun sign needs a date, the Moon sign sometimes needs the hour, and the rising sign needs the exact time and the birth city, because it changes sign about every two hours. A language model with no calculator in reach has to recall or invent those numbers.
With Lunonis connected, the assistant calls our chart engine instead. The planets come from an ephemeris with the tropical zodiac and Placidus houses, the same engine that powers the free birth chart calculator on this site. The assistant then explains what came back, and is told to use only those values.
What your assistant can do with it
Birth chart: Sun, Moon and rising sign, every planet with its sign, degree and house, the five tightest aspects and the dominant element and modality. Without a birth time you still get the planets in signs, and the assistant says plainly that the rising sign and houses need the time.
Compatibility: two sets of birth details give the tone of the connection, whether the Suns share an element, the Venus, Mars, Sun and Moon pairings and the tightest contacts between the charts. It counts aspects and gives no score.
Places: if your city name matches several places (Paris in France and in Texas), the assistant is given the candidates and asks you which one you mean, instead of guessing.
In ChatGPT
The Lunonis GPT is being published in the GPT Store. Until then, the connector below works in ChatGPT and Claude.
- Connector: in ChatGPT, open the settings for apps and connectors, turn on developer mode if your plan offers it, add a custom connector and paste the server URL below. No sign-in is needed.
- Ask: "What is my birth chart? I was born on 24 February 1994 at 08:12 in Lviv."
Server URLhttps://lunonis.com/mcpIn Claude
Claude supports remote MCP servers as custom connectors.
- Open Settings, then Connectors, and choose Add custom connector.
- Name it Lunonis and paste the server URL below. There is no sign-in to configure.
- Start a chat, enable the Lunonis connector, and ask for your chart or for a comparison with someone else.
Server URLhttps://lunonis.com/mcpOther assistants and tools
Any tool that speaks the Model Context Protocol over HTTP can use the same URL, including Cursor, VS Code and other editors. The developer page lists the three tools, their inputs and a ready-made configuration.
What happens to your birth details
Lunonis calculates the chart and returns it. It does not store the birth details the connector sends and keeps no request log of its own. Your conversation stays with ChatGPT or Claude, under their privacy terms, so share only what you are comfortable sharing there.
The chart link your assistant gives you opens the free chart on lunonis.com. It carries the birth details in the address, as every chart link on this site does, so treat it as personal. Astrology here is for reflection: it is not prediction, medical, legal or financial advice.
Lunonis in AI assistants
Is it free?
Yes. The connector and the custom GPT are free and need no account. The links they give you open the free birth chart on lunonis.com. Personal books and forecasts are optional paid products and are mentioned only when relevant.
Do I need to log in or share an API key?
No. The server is public and read-only, so you add one URL and nothing else. It cannot change anything in your accounts.
How accurate is the chart?
Positions come from an ephemeris, not from the language model, using the tropical zodiac and Placidus houses. The same engine runs the free calculators on lunonis.com. The wording of the interpretation is the assistant's own.
What if I do not know my birth time?
You still get the Sun sign, the planets in signs and most aspects. The rising sign, houses and Midheaven need the time and are left out rather than guessed. The Moon sign can differ if the Moon changed sign that day, and the answer says so.
Is my birth data stored?
Lunonis does not store what the connector sends and keeps no request log of its own. ChatGPT or Claude keep your conversation under their own terms.
Which languages does it work in?
You talk to the assistant in any language it supports. The links it returns can point to the Lunonis page in any of our eleven site languages.