Lumidexx Phonebook is a minimal, self-contained contact management app designed for fast deployment on any standard PHP/Apache hosting environment. The entire system runs from two files — index.php and db.json — with no external dependencies, frameworks, or database server required.

On first run, the app walks the user through a simple license activation screen: enter your license key, and the app automatically detects the domain, generates a unique installation ID, and activates against the Lumidexx Remote License API. From then on, the license is silently re-validated on a schedule (not on every page load), with a built-in offline grace period so a temporary API outage doesn't lock users out unfairly.

A persistent status widget at the top of the app always shows the current license state — Active, Grace Period, or Invalid — along with license type, activation usage, support status, and the last time it was checked, plus a manual re-check button.

If the license ever becomes invalid, the phonebook interface is fully hidden and all add/edit/delete actions are blocked server-side, not just visually — so there's no way to bypass the check from the client. Once valid, users get a clean, dark-themed interface to add, edit, and delete contacts (name, phone, email, notes), all stored in a single flat JSON file.

Key features:

• Two-file architecture — no database, no build tools, no dependencies
• Auto-installer with one-time license activation
• Scheduled license re-validation with configurable interval
• Offline grace period to avoid false lockouts during API downtime
• Server-side enforcement of license state on every write action
• Always-visible license status widget
• Optional HMAC signature verification support
• Clean, dark glassmorphism UI
• One-click installation deactivation for license transfer

Ideal as a starter template, a Digital Shop demo product, or a lightweight internal tool for teams that want licensing enforcement without the overhead of a full framework.