Purple Tome

Zi Wei Dou Shu · Purple Star Astrology

An astrology app you live in, not one you check.

Write down your days — a line at 11:40pm about what the day actually turned out to be about. A thousand-year-old chart reads them back, says what it expects before it happens, and keeps the score where you can see it.

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Your life, on the record

Everything it called, and everything you wrote — on one thread.

The chart writes down what it expects before the days it is talking about, and seals it. You write down what actually happened. Both land on the same line, in date order, and neither one can be quietly edited afterwards.

When a window closes it comes back and asks what really happened. Your answer goes into a record it shows you — including the stretches it reads badly.

02Sep
SealedOpens Sep 9

Written and closed. Not a word of it shows until the window is over — so nobody, including us, can read it backwards into what happened.

04Sep
11:40 PM

Said the thing I had been rehearsing for a week. It took four seconds and nobody flinched. All that dread was about me, not them.

06Sep
People72% sure

Between noon and sunset you will have to repeat yourself at least twice in a routine exchange, because the other person missed the point the first time.

贪狼 keeps pulling in your Partnership palace this week

Before it happens — does this sound like it will?

Sounds likelyDoubt it
09Sep
PeopleWindow closed

Did anything happen with the people around you?

YesSort ofNo
09Sep
Our record with you

14 of 21 landed. Every one of them was written down before it happened, and you said what actually came true.

The chart underneath

Zi Wei Dou Shu —— the astrology Chinese emperors kept for themselves.

It is named after the Purple Enclosure, the still point the whole night sky turns around, understood as the emperor’s seat in heaven. The Ming named their palace after the same stars — we know it as the Forbidden City.

For most of a thousand years it stayed inside the court: private study of the sky was restricted by law, because a method that can time a succession can also time a rebellion. Your chart is a ring of twelve palaces, cast once from your birth moment and never recast. What moves is time across it.

FRAP

One page every morning

What today is made of — and what it will cost you.

Not a horoscope for a twelfth of the planet. This page is read off your own chart and the transformations in play today: what runs easy, the one thing that runs harder, and a line about what you are actually carrying.

Every claim on it can be opened up to show the palace it came from. Nothing is asserted that the chart cannot be checked against.

Purple TomeDay 3
November 24
Today’s fortune
Read off your partner

The weight of the day sits on your living space and your sense of ease there, and it runs quiet there.

Easier

Moving through daily logistics flows without needing extra push.

Handling communications with people outside your immediate circle feels straightforward.

Harder

Close relationships demand more of your patience than usual, as unspoken friction sits right at the center.

For you

“You are carrying a quiet exhaustion that has no name yet, holding it alone because there is simply no one to hand it to.”

It asks tomorrow morning65% sure

“Between noon and sunset, you will have to repeat yourself at least twice during a routine domestic exchange because the other person simply missed the point the first time.”

Why it lands

The chart is computed. Only the words are written.

Cast properly, not generated

Your chart comes out of a deterministic engine — true solar time for your exact birthplace, the twelve palaces, the fourteen majors, the four transformations. No model touches the arithmetic. Two people born the same day in different cities get different charts, because they have them.

Every call points back at a star

A call is never floated on its own. It carries the configuration it came from — “Tian Tong turns to Adversity in your Wealth palace this month” — so you can go look at the chart and see the thing it was reading.

The words are written by AI, under rules

Turning a computed chart into English is the one job a purpose-built, constrained AI does here. It is not allowed to invent a chart, to diagnose you, to give financial or medical advice, or to write anything that cannot be answered “no”. Nobody is pretending a human astrologer is on the other end.

The Ming-dynasty 紫微斗数全書, the source the system is read from. Drag to unroll it.

Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 18Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 17Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 16Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 15Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 14Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 13Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 12Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 11Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 10Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 9Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 8Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 7Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 6Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 5Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 4Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 3Zi Wei Dou Shu Quan Shu (紫微斗数全书), Ming-dynasty edition — leaf 2

What it costs

Your chart, a reading every day and your journal are free. Premium is $7.99 a month.

Or $79.99 a year, which works out at $6.67 a month. Premium opens the in-depth readings on every palace, the yearly and decade cycles, compatibility with the people you invite, and lets you open a sealed call before its window is over. Subscriptions are handled by the App Store and Google Play, and can be cancelled there any time. What’s in each tier →

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COMMON QUESTIONS

Zi Wei Dou Shu, answered

Can I use it on the web, or do I need the app?

It is an app, on iPhone and Android. The website used to cast charts too; it no longer does, because the daily reading, the journal and the ledger only make sense on the device you carry. Everything you read here about the twelve palaces, the stars and the transformations stays free to read on the site.

What is Zi Wei Dou Shu (Purple Star Astrology)?

Zi Wei Dou Shu (紫微斗数), or Purple Star Astrology, is a Chinese astrology system roughly a thousand years old. From your exact birth moment it casts a chart of 12 houses and 100+ stars that maps your personality, love, career, wealth and health.

How is Purple Star Astrology different from Western astrology and BaZi?

Western sun-sign astrology sorts everyone into 12 signs. Zi Wei Dou Shu builds a far more detailed chart — 12 houses, 100+ stars and four transformations — so two people born the same day usually differ. Unlike BaZi (Four Pillars), it lays your life out as a 12-room map and also shows when each area comes into play.

Do I need my exact birth time?

Your birth time matters — it is cast to a two-hour period (shichen), and a different hour can change the chart. If you do not know it, you can still get a meaningful reading; a known time simply makes it more precise.

What do the 12 houses (palaces) mean?

Your chart is divided into 12 palaces — Self, Siblings, Partner, Children, Wealth, Health, Travel, Friends, Career, Property, Wellbeing and Parents. Each one covers a fixed area of life, and the stars that land in it describe how that area tends to unfold.

Is my birth chart reading free?

Yes. Casting your Purple Star birth chart, reading the overview, getting a reading each day and keeping a journal are all free in the app. A subscription unlocks unlimited in-depth readings across every palace, plus the decade, annual and daily cycles.

Can Zi Wei Dou Shu show timing — which year or decade matters?

Yes. Beyond who you are, Zi Wei Dou Shu shows when — which decade favors your career, which year tests your relationships, and which area of life is active for you right now.

Are the readings written by AI?

Yes — and the chart isn’t. The chart is computed by a deterministic engine (no AI involved); the written reading is generated by a purpose-built AI that only translates the computed chart, following rules grounded in the classical texts. It never invents a star, a palace, or a transformation.

How is this different from asking ChatGPT?

A general chatbot has no charting engine. Ask it for your Zi Wei chart and it will confidently produce one — with no true solar time conversion, no verified transformation tables, and no way for you to tell which parts it made up. Purple Tome computes first, then reads. The AI is only allowed to describe what the engine calculated.

Can the chart be wrong?

The engine is deterministic and covered by tests against the classical tables, and we publish fixes openly in our changelog. Interpretation is a different matter: classical schools genuinely differ on some points, and we follow one school consistently. If anything in your chart looks off, report it — chart accuracy comes before everything else here.

Is there a human astrologer reviewing my reading?

No, and we won’t pretend otherwise. Purple Tome is a charting engine plus a constrained AI translator, built by a developer who reads the classical sources. It’s a tool for reflection — not a substitute for a human practitioner, and not medical, financial, or legal advice.