Welcome to Huyền Cơ Mệnh Lý (also known as Mystic Metaphysics, Tinix Tử Vi & Bát Tự). We respect your privacy and are committed to protecting your personal data. This document outlines how our application operates, how data is processed, and the terms governing the use of our services and in-app subscriptions.
Part 1: Privacy Policy
1.1 Core Principles: Guest-First & Privacy by Design
Huyền Cơ Mệnh Lý is built with a guest-first, local-first, privacy-by-design architecture:
- No Account Required: You do not need to register, create an account, or provide personal details such as your phone number, email address, or social media profile to explore astrological charts and use our core features.
- On-Device Data Storage: All your saved astrological profiles (Hồ sơ lá số), birth charts, personal reflections, and questions are stored locally on your device via secure on-device storage. We do not store or synchronize your private charts on any central database.
1.2 Information We Process
A. Astrological Input Data & Ephemeral Calculations
When you generate an astrological chart (Tử Vi Đẩu Số, Bát Tự Tứ Trụ, Kinh Dịch Quẻ Mệnh, Chọn Ngày Lành) or request an in-depth reading, the required parameters (solar/lunar birth date, birth hour, gender, and query context) are transmitted over an encrypted TLS connection (HTTPS) to our computational engine and language processing service:
- This data is used strictly in real-time to compute astronomical positions, stems and branches (Can Chi), palace arrangements, and generate the textual interpretation.
- Birth data and reading queries are ephemeral and are never sold to data brokers, never shared with unauthorized third parties, and never used for advertising profiling.
B. Subscriptions & In-App Purchases
Huyền Cơ Mệnh Lý offers optional subscription tiers (Basic and Pro) to unlock higher monthly consultation limits:
- Payment Security: All financial transactions, billing instruments, and payment details are handled exclusively and securely by Google Play Billing (Google LLC) on Android and Apple App Store In-App Purchase (Apple Inc.) on iOS.
- No Financial Data Collection: We never receive, process, or store credit card numbers, billing addresses, or bank account details.
- Cryptographic Store Tokens: When you purchase or restore a subscription, the store platform provides an anonymous cryptographic token (
purchaseToken or receipt data). Our backend validates this token directly with official developer APIs solely to activate your plan and allocate consultation quotas.
C. Anonymous Installation ID & Fair-Usage Limiting
- To enforce monthly quota limits (Free: 15 consultations/month, Basic: 50 consultations/month, Pro: 300 consultations/month) and protect backend servers against automated spam attacks, the app generates an anonymous random installation identifier (
X-Install-Id) kept on your device.
- This identifier contains no personal information and cannot identify you personally.
D. Minimal Device Permissions
- Internet Access (
android.permission.INTERNET): Required to connect to our secure server for solar-lunar calendar synchronization, generating in-depth interpretations, and verifying subscription receipts.
- Photo / Storage Access: Requested strictly when you choose to export your chart image or PDF report to your device. We do not inspect, collect, or access your other photos or files.
E. Technical Logs & Diagnostics
Anonymous crash logs, operating system versions, and performance diagnostics may be collected via standard store developer services to help us identify technical bugs and enhance stability.
1.3 Third-Party Services
We work with trusted industry providers for infrastructure and billing:
- Google Play Billing & Services (Google LLC) — For app distribution and secure subscription checkout.
- Apple App Store & In-App Purchase (Apple Inc.) — For iOS app distribution and payment processing.
- Cloudflare (Cloudflare, Inc.) & Cloud Infrastructure — For secure API gateway routing, TLS encryption, and anti-DDoS security.
- Natural Language & Metaphysics Interpretation Engine — Cloud-based automated engine for generating context-aware interpretations and answers based on classical Eastern metaphysics traditions.
1.4 Data Retention, Deletion, and User Rights
- Immediate Local Deletion: You can wipe all saved chart profiles, reading history, and local preferences at any time simply by clearing application data or uninstalling the app.
- Data Requests: You may reach out to us at baka3k@gmail.com for any inquiries regarding subscription records or privacy questions.
1.5 Children’s Privacy
Huyền Cơ Mệnh Lý is not directed toward children under 13 years of age (or under 16 in the European Economic Area). We do not knowingly collect personal information from children.
Part 2: Terms of Service & Subscription Conditions
2.1 Disclaimer: Cultural Reflection & Entertainment
Important Notice: Eastern Metaphysics (Tử Vi, Bát Tự, Kinh Dịch, Phong Thủy) is an ancient cultural and philosophical system. All calculations, chart layouts, interpretations, and consultations provided in this app are intended strictly for cultural reflection, personal insight, philosophical exploration, and entertainment purposes.
- No Professional Advice: Readings and consultations do not substitute professional medical, psychiatric, legal, tax, or financial/investment advice. Always consult qualified professionals for critical life choices.
- No Outcome Guarantee: We do not make claims or warranties regarding future predictions or the deterministic nature of chart interpretations.
2.2 In-App Subscriptions & Billing Rules
| Plan |
Monthly Limit |
Standard Price (USD) |
Key Features |
| Free Tier |
15 consultations / month |
Free ($0.00) |
Unlimited Tử Vi & Bát Tự chart plotting, I Ching divination, Auspicious date selection, local profile management. |
| Basic Plan |
50 consultations / month |
$5.99 / month* |
Expanded consultation quota, in-depth lifetime analysis, marriage compatibility (Hợp Hồn), Hexagram inquiries. |
| Pro Plan (Best Value) |
300 consultations / month |
$11.99 / month* |
High-volume consultation capacity, priority server processing, high-resolution PDF and image export. |
*Prices in local currencies (such as VND, JPY, EUR) are converted and displayed by Google Play and Apple App Store according to applicable regional pricing and tax matrices.
Auto-Renewal & Billing
- Subscriptions automatically renew at the end of each monthly period unless canceled at least 24 hours before the end of the current billing cycle.
- Your Google Play or Apple account is charged upon confirmation of purchase.
Cancellation Instructions
You can manage, pause, or cancel your subscription at any time without penalty:
- On Android (Google Play): Open Google Play Store > tap your profile icon (top right) > Payments & subscriptions > Subscriptions > select Huyền Cơ Mệnh Lý > tap Cancel subscription. (Or visit play.google.com/store/account/subscriptions).
- On iOS (Apple App Store): Open Settings on your device > tap your Apple ID > Subscriptions > select Huyền Cơ Mệnh Lý > tap Cancel Subscription.
Following cancellation, your subscription remains active until the end of the paid billing period.
Restoring Purchases & Refunds
- Restore: If you switch devices or reinstall the app, tap "Khôi phục gói mua" (Restore Purchases) in the Subscription screen or Settings to restore your tier.
- Refunds: All refund requests are governed by Google Play’s and Apple’s official refund policies through order history.
2.3 Intellectual Property & User Conduct
You agree not to reverse-engineer, decompile, scrape, or flood the API services supporting the application. All chart graphics, algorithms, character artwork, UI designs, and texts are the intellectual property of Baka Team and protected under international copyright treaties.
2.4 Contact Us
For any inquiries, feedback, or support regarding this policy or our application, please contact: