Privacy Policy
Last updated: February 2026
Our Core Principle
CellSentry is designed with privacy as a fundamental principle. Your spreadsheet data never leaves your computer. All formula analysis — both the rule engine and AI-powered detection — runs entirely on your local machine.
What We Don't Collect
- We do not collect, transmit, or store your spreadsheet data
- We do not use telemetry or analytics
- We do not track your usage patterns
- We do not send your formulas to any external server
- The AI model runs locally — no cloud API calls are made during analysis
What We Do Process
- License validation: When you activate a Pro license, CellSentry contacts the Lemon Squeezy API to verify your license key. This transmits only your license key and a hardware fingerprint (a hash — not your actual hardware details). License validation results are cached locally for offline use (7-day grace period).
- Model download: On first launch, CellSentry downloads the AI model (~1 GB) from GitHub Releases. This is a one-time download. No personal data is transmitted.
Payment Processing
Pro subscriptions are processed by Lemon Squeezy, which acts as our Merchant of Record. Lemon Squeezy handles all payment information, billing, and tax compliance. CellSentry never sees or stores your payment details. Please refer to Lemon Squeezy's Privacy Policy for details on how they handle payment data.
Local Data Storage
CellSentry stores the following data locally on your machine:
- License cache (encrypted, machine-bound)
- Application settings and preferences
- Usage statistics (scan counts, stored locally only)
- AI model files
All local data is stored in your system's standard application data directory and can be fully removed by uninstalling CellSentry.
Open Source
CellSentry's source code is available on GitHub. You can inspect exactly what the software does and verify our privacy claims.
Contact
If you have questions about this privacy policy, please open an issue on our GitHub repository.