TezStudio KO
PRIVACY POLICY

SajuAI

Last updated · 2026-05-08

1. Overview

TezStudio ("the Studio") respects user privacy in SajuAI ("the App") and handles personal data in accordance with applicable laws including South Korea's Personal Information Protection Act and GDPR.

SajuAI is a learning and self-reflection platform for traditional Korean Saju Myeongnihak (Four Pillars of Destiny). We collect only the minimum personal data necessary to derive a user's chart and provide AI-powered consultation.

2. Information We Collect

2-1. Saju analysis data

  • Name (optional, nickname accepted) — for displaying analysis results
  • Date and time of birth — required to compute the chart
  • Gender — used in interpretation
  • Birthplace (optional) — used for precise solar-term correction
  • Lunar/solar calendar selection
  • Relationship profiles — Saju information of partners or family members the user voluntarily registers, used for compatibility analysis

2-2. Account data

  • Apple/Google ID or anonymous guest identifier — Firebase Authentication
  • Email address — automatically provided by Apple/Google sign-in
  • Display name — automatically provided by social sign-in

2-3. Purchase data

  • Purchase receipts and transaction IDs — Apple App Store / Google Play in-app purchases
  • The App never accesses card details directly; payments are processed by Apple/Google.

2-4. Usage data

  • Analysis results, chat history, ticket balance (Firestore)
  • Anonymized app usage events (Firebase Analytics)

3. AI Services (Important)

SajuAI uses OpenAI's GPT-4o-mini and GPT-4o Vision APIs to power Saju analysis, AI fortune teller chat, and image-based face/palm reading.

  • At analysis time, the user's chart, question text, and (when applicable) submitted images are transmitted to OpenAI servers.
  • OpenAI does not use API data to train models and deletes API data within 30 days. See the OpenAI Privacy Policy.
  • Face and palm photos are used only for the single analysis request and are not retained.

4. Data Storage and Location

  • Google Firebase (Firestore, Authentication) — hosted on Google Cloud (US / AS regions)
  • Google Cloud Functions — for IAP receipt validation and other server logic (asia-northeast3 / Seoul region)
  • All transport encrypted via HTTPS/TLS

5. Camera and Photo Access

Camera and photo library access are requested only when the user explicitly invokes the face or palm reading feature. The captured or selected image is sent once to the OpenAI Vision API and discarded immediately afterward; it is not retained on the App or our servers.

6. Third Parties and Sub-Processors

We do not share personal data with third parties except for the following sub-processors:

  • Google LLC — Firebase Authentication, Firestore, Analytics, Cloud Functions
  • OpenAI, L.L.C. — GPT-based analysis and consultation
  • Apple Inc. — Sign in with Apple, App Store payments

7. Retention and Deletion

  • Account data, Saju profile, and chat history are deleted immediately upon account deletion.
  • Purchase receipts and transaction IDs are retained for 5 years per Korea's e-commerce law.
  • Uninstalling the App does not automatically delete server data — use in-app account deletion or email us.

8. User Rights

You may request access, correction, deletion, restriction of processing, or withdrawal of consent at any time.

  • Edit or delete profiles directly in My Page → Profile Management.
  • Delete all your data in Settings → Account Deletion.
  • Email requests: supports@tez.kr

9. Children's Privacy

SajuAI is not directed to children under 14. We do not knowingly collect personal data from children. If we discover that a user under 14 has registered, we will promptly delete the associated data.

10. Security

  • TLS 1.2+ encryption in transit
  • Per-user data isolation enforced by Firebase Security Rules
  • API keys and other secrets stored as server environment variables only — never exposed to clients

11. Policy Changes

We will provide advance notice via the App or this page before any material change to this policy. Significant changes may also be communicated via push notification or email.

12. Disclaimer

Saju analysis and AI fortune teller consultations are educational and self-reflective content based on traditional Korean Myeongnihak theory. They do not substitute for professional medical, legal, financial, or other advice.

13. Contact

For privacy inquiries or to exercise your rights, contact supports@tez.kr.