Privacy Policy

Sổ Bản Mệnh – Lunar Calendar, Tarot, Tử Vi · Updated 11 October 2026

In short: the personal details you enter stay on your device (except feedback you choose to send, questions you ask Hỏi Vận and what you save while signed in, see sections 4, 5 and 6). Accounts are optional, we do not sell data, and the app currently shows no ads.

1. Information you enter

To build a Tử Vi chart you may enter your birth date, birth hour, gender and, optionally, your name; for numerology, your birth date and full name at birth. These are stored only on your device (app storage, or browser storage for the web version), and all lunar calendar, chart, numerology and tarot calculations run on the device. They are not sent to our servers unless you use Hỏi Vận (section 5) or save them to an account (section 6).

2. Random device identifier

The app creates a random identifier, stored on your device, so that the daily tarot card stays the same for the whole day. It contains no personal information and is never sent anywhere.

3. Technical data for the web version

The web version is hosted on Google Cloud. Like any website, the server keeps basic technical logs (IP address, browser type, time of request) to operate and secure the service. We do not use them to identify or track you.

The web version uses Google Analytics to count visits: which pages are viewed, device and browser type, approximate region, and where visitors come from (for example Google or Facebook). Google Analytics uses cookies and may use this data under Google's policy. Your birth date and time, name and anything you enter for a chart are not sent to Google Analytics. You can block it with an ad / tracker blocker or the Google Analytics opt-out add-on. The phone app does not use Google Analytics.

4. Feedback you send

When you send feedback from "Góp ý", we store its text, its type (feedback, bug, idea), the page you sent it from, the platform (web, iOS, Android), the time, and any contact details you chose to add, in Google Cloud Firestore, only to read and answer it. Your IP address is not stored with it (the server keeps it in memory briefly to stop mass sending). Email us to have your feedback deleted.

5. Hỏi Vận (AI assistant)

When you use "Hỏi Vận" on the Tử Vi or Tarot page, the app sends your question, the earlier messages of that conversation, the character you picked to answer, and a summary of the chart (birth date and time, gender, the stars in the 12 palaces and the app's reading; not your name) or of the spread (the cards, their positions and meanings) to Sổ Bản Mệnh's server and on to Google Gemini, which writes the answer. Data is sent only when you ask; if you don't use Hỏi Vận, nothing is sent.

While you are not signed in, Sổ Bản Mệnh's server does not store the questions or answers; while signed in, the conversation is kept in your account (section 6). Otherwise the server only counts questions and processing per day to cap costs, and keeps your IP address in memory briefly to stop mass sending. Sổ Bản Mệnh uses the paid Gemini API; under Google's terms this content is not used to improve Google's products and may be kept for a limited time to detect abuse. Answers are written by AI and may be inaccurate.

Questions and wallet code. Each device gets 3 free questions. To count them, the app creates a random wallet code stored on the device; the server keeps only, under that code, the number of free questions used and of questions bought, with no personal information. You can enter the wallet code on another device to keep using questions you bought.

Buying questions (web version). You pay by bank transfer (a VietQR code) with the order code as the transfer message. SePay receives the transaction notice from the receiving bank and tells our server the amount and the order code so the questions are added. We store the order code, pack, amount, time and status; we do not store the payer's name or account number (the banks and SePay hold these under their own policies). Bought questions do not expire and are not refundable; if a transfer had the wrong message or was not credited, email us with the order code or wallet code.

Own portrait (web version). When you press "Vẽ chân dung riêng" on the Tử Vi page, the app sends the chart's gender and the names of the stars around its Mệnh palace, with your photo if you choose to send one (shrunk on your device), to Sổ Bản Mệnh's server and on to Google Gemini, which draws it. The server stores neither the photo nor the portrait: the portrait comes back and is kept only on your device. Google handles the photo under the Gemini API terms above. Only send a photo of yourself or of someone who agreed.

6. Accounts (optional, web version)

Every feature works without an account. If you want to keep things to see on another device, you can sign in with Google or with an email and password. Sign-in is handled by Google's Firebase Authentication, which keeps your email, name and profile photo (when signing in with Google), your password in hashed form, and when the account was created and last used. We never see your password.

While you are signed in we store in Google Cloud Firestore, under your account: the charts you choose to save (name if given, birth date and time, gender), the Tarot and Oracle spreads you draw (cards, topic, time), and your Hỏi Vận conversations (questions, answers, the answering character), saved after each answer. Each keeps at most the latest 100 items (charts: 50). They are used only to show them back to you: not for ads, not analysed, not shared. Questions and wallet codes (section 5) stay separate and are not tied to the account.

On the account page you can delete single items, or press "Xoá tài khoản" (Delete account) to permanently delete the account and everything saved in it at once.

7. What we don't do

• Accounts are optional; we only get an email address when you sign up or sign in (section 6) or add one to your feedback.
• We do not sell, rent or share your personal information with third parties (other than sending it to Google Gemini to answer you when you use Hỏi Vận, as in section 5, and using Google Firebase for sign-in, as in section 6).
• There are currently no ads; we do not sell or share visit statistics for advertising.

8. Future changes

If we add advertising, in-app purchases or a new feature that sends your data anywhere, we will update this policy before turning them on, stating what data is sent, to whom and why.

9. Deleting your data

You can edit your details at any time with "Sửa thông tin". To delete everything, uninstall the app or, for the web version, clear this site's data in your browser settings. If you have an account, press "Xoá tài khoản" on the account page to delete it and everything saved at once (section 6). Otherwise our servers keep only feedback you sent, the question counts per wallet code and question orders (sections 4 and 5); email us to delete them.

10. Children

The app is not directed to children under 13 and we do not knowingly collect their information.

11. For reference only

The lunar calendar is computed astronomically. Tarot and Tử Vi content is for reference and entertainment only and is not a substitute for professional medical, legal, financial or psychological advice.

12. Contact

For any privacy question, email xemvan68@gmail.com.