A minimal note‑taking web app demonstrating how premium features can be unlocked at runtime using the Keymint licensing API.
Free tier: create, edit, delete notes. Premium (unlocked with valid license):
- Export note (Markdown placeholder for PDF)
- Dark mode toggle
Frontend (Vite + React + Tailwind) → Backend (Express proxy) → Keymint API.
Backend holds KEYMINT_ACCESS_TOKEN and validates a user‑supplied license key via /activate-key (proxied by /api/enter-license). On success it stores an in‑memory activeLicense (tier PRO) and exposes entitlements.
- Edit
server/.env:
KEYMINT_ACCESS_TOKEN=at_real_value
KEYMINT_PRODUCT_ID=prod_real_value
PORT=4000
- Install deps (first time):
cd server && npm install
cd ../client && npm install
- Start servers (in two terminals):
cd server && npm run dev
cd client && npm run dev
- App loads: tier is FREE, premium buttons disabled.
- Enter a fake key → error toast.
- Enter a real Keymint key → tier PRO, features unlock.
- Create a note → Export (downloads markdown file) & toggle Dark Mode.
POST /api/enter-license→ activates supplied licenseKey against product.GET /api/license-state→ returns{ tier, features, hostId? }.GET /api/feature/exportPDF/GET /api/feature/darkMode(authorization check only).
Removed legacy endpoints from earlier prototype (/api/create-key, etc.).
Any valid activation -> tier PRO -> features: exportPDF, darkMode.
Invalid / not activated -> tier FREE.
- In‑memory only (restart resets license + notes).
- Export uses a simple Markdown blob instead of real PDF to keep minimal.
- For production: add persistence, real PDF (e.g. jsPDF), offline grace, better error UI.
Keep the Keymint access token server‑side only. Never embed in frontend.
- Persist notes & license (SQLite)
- Real PDF generation
- License tier differentiation (PRO vs ENTERPRISE feature sets)
- Offline cached validation with revalidate interval
- CI + Docker demo container