Who We Are
Nu Stack is operated by Daniel Archie Skemp, doing business as Nu Stack ("we," "us," or "our"). We operate nustack.app, a precious metals calculator and portfolio management platform. We are based in the United States.
What We Collect and Why
Account data: When you create an account we collect your email address and password (stored and hashed by Firebase Authentication). This is required to provide the service.
Portfolio and transaction data: All transaction entries, coin portfolio records, prospecting trips, batch lots, and sell records you create are stored in Google Firebase Firestore under your user ID. This data belongs to you and is used solely to power your account.
Usage data: Firebase and Google Analytics collect your IP address, device type, browser, and in-app activity for performance monitoring and analytics. We use this to understand how the app is used and to fix problems.
Payment data: Subscription payments are processed by a third-party payment provider. We do not store your credit card information.
Location data: The prospecting and dealer map features use your device's GPS when you explicitly enable them. Location data from active sessions is stored in your account. We do not track your location in the background.
Voice data: The "Hey Stack" voice mode processes speech locally on your device using your browser's Web Speech API. Audio is not transmitted to or stored on our servers.
How We Use Your Data
We use your data to: provide and improve the app, authenticate your account, process your subscription, display live and historical spot prices, and send price alerts you have configured. We do not sell your data. We do not use your transaction or portfolio data for advertising.
Third-Party Services
Nu Stack uses the following third-party services that may process your data:
- Google Firebase — Authentication, database, cloud functions, hosting
- Google Analytics for Firebase — Usage analytics
- Google Gemini AI — Coin identification (photos you submit are sent to Google's AI API for analysis; we do not store these images beyond the identification session)
- Metals price API — Live spot price data (no personal data shared)
- Payment processor — Subscription billing
Firebase Service Data is used by Google in accordance with their privacy policy. You can review Google's data practices at firebase.google.com/support/privacy.
Cookies & Local Storage
Nu Stack uses browser local storage to save your preferences (currency selection, UI settings). Firebase Authentication uses cookies/tokens for session management. We do not use advertising or tracking cookies. See our Cookie Policy for full details.
Your Rights
You may request access to, correction of, or deletion of your personal data at any time by emailing support@nustack.com. California residents have additional rights under CCPA/CPRA including the right to know what data is collected and the right to opt out of its sale (we do not sell data). EU and UK residents have rights under GDPR including data portability and the right to restrict processing.
Data Retention
Your account data is retained for as long as your account is active. If you delete your account, your data is deleted from our systems within 30 days, except where we are required by law to retain it.
Children
Nu Stack is not directed at children under 13. We do not knowingly collect data from anyone under 13.
Changes
We will notify you of material changes to this policy via email or an in-app notice.
Contact
If you have questions about this privacy policy, please contact us at support@nustack.com.