Cookie & Local Storage Policy

Effective Date: 19 March 2026 — Last Updated: 19 March 2026

This policy explains how Trefnus CMMS uses browser storage technologies on your device. Unlike many web applications, Trefnus CMMS does not use traditional cookies for tracking or advertising. Instead, we use browser-native storage APIs (localStorage, sessionStorage, and IndexedDB) essential to the Application's functionality.

1. Technologies Used

The Application uses the following browser storage technologies:

1.1 localStorage

Persistent key-value storage that remains until explicitly cleared. Used for essential application functionality.

1.2 sessionStorage

Temporary key-value storage that is cleared when the browser tab is closed. Used for session-level authentication.

1.3 IndexedDB

A larger-capacity structured database in the browser. Used for storing application data and file attachments.

1.4 Service Worker Cache

A browser cache managed by a service worker for offline functionality. Stores application files (HTML, CSS, JavaScript, icons) to enable the Application to work without an internet connection.

2. What We Store — localStorage

Key	Purpose	Category
`licence_activated`	Records whether the licence has been activated on this device	Essential
`licence_user_id`	Stores the authenticated user ID for licence association	Essential
`licence_activated_at`	Timestamp of licence activation	Essential
`licence_last_verified`	Timestamp of last successful licence verification	Essential
`licence_device_hash`	Unique device identifier (randomly generated UUID)	Essential
`cmmsAuth`	Stores hashed local password and setup completion status	Essential
`pwaInstallBannerDismissed`	Records if the user dismissed the PWA install banner (sessionStorage)	Functional

Additionally, the Supabase authentication library may store authentication tokens and session data in localStorage under keys prefixed with sb-.

3. What We Store — sessionStorage

Key	Purpose	Category
`cmms_session_authenticated`	Records whether the user has entered the correct local password for this browser session	Essential
`pwaInstallBannerDismissed`	Prevents the PWA install banner from reappearing within the same session after dismissal	Functional

4. What We Store — IndexedDB

Database	Store	Purpose	Category
`CMMS_FileStorage`	`files`	Stores uploaded file attachments (images, documents) associated with assets and work orders	Essential
`CMMS_FileStorage`	`appData`	Stores all application data including assets, work orders, contracts, to-do items, settings, and maintenance history	Essential

5. What We Store — Service Worker Cache

The service worker caches the Application's static files (HTML, CSS, JavaScript, icons, fonts) to enable offline access. This cache:

Contains only application code and assets, not user data;
Is automatically updated when new versions are available;
Can be cleared through your browser settings.

6. Categories Explained

Essential: Required for the Application to function. Without these, the Application cannot operate. These cannot be disabled.
Functional: Enhance user experience but are not strictly necessary. The Application will function without them.

7. What We Do NOT Use

Tracking Cookies: We do not use any cookies for tracking, analytics, or advertising;
Third-Party Cookies: We do not set or allow third-party cookies;
Analytics: We do not use Google Analytics or any other analytics platform;
Advertising: We do not use any advertising or remarketing technologies;
Fingerprinting: We do not use browser fingerprinting beyond the randomly generated device UUID.

8. Managing Stored Data

You can manage or delete stored data through your browser settings:

Clear All Data: Use your browser's "Clear browsing data" or "Clear site data" feature. Note: this will delete all your maintenance data and require re-activation;
View Stored Data: Use your browser's Developer Tools (usually F12) > Application tab to inspect localStorage, sessionStorage, and IndexedDB;
Clear Service Worker Cache: Unregister the service worker through Developer Tools > Application > Service Workers.

Warning: Clearing browser storage will permanently delete all your maintenance data (assets, work orders, contracts, etc.) and may require you to re-activate your licence. This action cannot be undone. Always export or backup your data before clearing browser storage.

9. Legal Basis

We rely on the following legal bases for using browser storage:

Essential storage: Necessary for the performance of the contract (providing the Application to you) and for legitimate interests (licence verification, security);
Functional storage: Based on legitimate interest (improving user experience).

Because we only use essential and functional storage (no tracking or advertising), separate cookie consent is not required under most privacy regulations. However, this policy serves as transparent disclosure of our storage practices.

10. Changes to This Policy

We may update this policy to reflect changes in the Application's storage practices. Updates will be posted on this page with an updated date.

11. Contact

For questions about this Cookie & Local Storage Policy, contact:

Trefnus
Email: privacy@trefnus.com