license-impl

License Implementation Skill

Always read docs/LICENSE_PLAN.md before writing any code. It is the authoritative source for schemas, IPC contracts, phase scope, and security decisions.

Quick Reference

New files for this feature

IPC channels to add in main/main.js and main/preload.js

'license:status'     // → { status, tier, daysLeft, features, customerName, expiresAt }
'license:activate'   // payload: { key } → { success, data: licenseState }
'license:deactivate' // → { success }
'license:openPortal' // → opens shell.openExternal to purchase URL

state.license shape (init in state object)

license: {
  status: 'trial',        // 'trial'|'licensed'|'expired'|'invalid'|'grace'
  tier: 'trial',          // 'trial'|'personal'|'pro'|'team'
  daysLeft: 14,
  features: [],           // ['ai','backup','encryption','unlimited']
  customerName: '',
  expiresAt: null,
  licenseId: null,
}

Feature gate pattern

function licenseGate(feature) {
  return state.license.features.includes(feature);
}
// Usage: if (!licenseGate('ai')) { showUpgradePrompt('ai'); return; }

Dependency

npm install @noble/ed25519

@noble/ed25519 — audited pure-JS Ed25519 implementation. Works in Node (main process) and browser (renderer for client-side pre-validation). No native bindings needed.

Phase Checklist

Phase 1 — Offline skeleton

• cortex-keygen/keygen.js — generate-keypair and issue commands
• main/machine-id.js — fingerprint function exported
• main/license-validator.js — validateLicense(), getTrialState(), loadLicenseFile()
• main/main.js — add license:status, license:activate handlers
• main/preload.js — expose window.noteflow.license.*
• renderer/app.js — state.license init, load on startup, openActivationModal()
• renderer/index.html — #license-modal, #trial-banner
• renderer/styles.css — modal + banner styles
• Settings tab: License section

Phase 2 — Feature gating

• licenseGate(feature) in renderer
• AI Chat gated behind ai
• Backup gated behind backup
• Encryption (note lock) gated behind encryption
• 50-note cap on Trial (gate unlimited)
• Feature-lock overlay component

Phase 3 — Online activation

• Activation server deployed (Cloudflare Workers / Vercel)
• license:activate wired to POST /api/v1/activate
• Background heartbeat (non-blocking, setInterval in main process)
• license:deactivate wired to POST /api/v1/deactivate
• Grace period countdown written to license.json

Phase 4 — Polish

• Key input auto-format (dashes + uppercase)
• Windows URI handler cortex://activate?key=...
• In-app purchase link
• Deep-link handler in main/main.js

Security Rules (Non-Negotiable)

1. Private key never leaves the keygen tool. Never embed it in the app.
2. license.json is AES-256-GCM encrypted using machineId as the key — never plaintext.
3. Always verify the Ed25519 signature before trusting any payload field.
4. Never trust status from renderer state alone for security decisions — re-read from validator in main process.
5. Atomic write for license.json — .tmp → fs.renameSync pattern (same as all other data files).

Key Format

CORTEX-A1B2C-D3E4F-G5H6I-J7K8L

Decodes to: base64url(payload_json) + '.' + base64url(ed25519_signature)

Payload required fields: id, product, version, type, seats, issued_at, features[], customer.email

Machine Fingerprint

// main/machine-id.js
const inputs = [
  os.hostname(),
  os.cpus()[0]?.model ?? '',
  firstNonLoopbackMAC(),  // os.networkInterfaces()
  process.env.USERPROFILE ?? process.env.HOME ?? '',
].join('|');
return crypto.createHash('sha256').update(inputs).digest('hex');

Hamming-distance tolerance of 1 character handles minor hardware changes (RAM upgrade, NIC change) without requiring re-activation.

Trial State

Stored in settings.json under trial key (backward-compatible addition):

{
  "trial": {
    "startedAt": "ISO8601",
    "notesCreated": 0
  }
}

Trial expires 14 days after startedAt. Note cap is 50 (notesCreated >= 50 blocks new note creation with upgrade prompt).