Introducing KetBook

Today, we're launching KetBook – a privacy-first knowledge management app for macOS that fundamentally rethinks how note-taking apps should work.

The Core Principle

We literally cannot access your data.

Not "we promise not to." Not "we have good security." We cannot access your notes because we don't store them. They live in your own iCloud account, encrypted by Apple, synced across your devices.

How It Works

Your iCloud Account

All your notes are stored in:
- CloudKit Private Database for structured data
- iCloud Drive for note content

Both are part of your personal iCloud account. Not a shared database. Not our servers. Your account.

Apple Sign In

Authentication happens through Apple Sign In. We never see your password. We never store credentials. Apple handles authentication, we just verify the token.

iCloud Sync

Notes sync automatically across all your Macs signed into the same Apple ID. No manual sync. No third-party service. Just iCloud doing what it does best.

What This Means

For Security:
- No central server to breach
- No database to leak
- No credentials to steal
- End-to-end encryption by Apple

For Privacy:
- We don't have analytics
- We don't track usage
- We don't "improve recommendations"
- We literally don't know what you write

For Longevity:
- No startup that might fail
- No subscription that might be canceled
- No service that might be acquired
- Your data in your iCloud account, forever

Built for macOS

Native Swift 6 application with SwiftUI interface. Menu bar access. Keyboard shortcuts. Markdown editing. Full-text search.

Designed for developers and power users who care about:
- Type safety (Swift 6)
- Performance (native code)
- Transparency (Action Log shows everything)
- Privacy (zero-trust architecture)

AI Features (Optional)

Want AI-powered search and organization? Bring your own Ollama Cloud API key.

Your notes are processed by your AI service with your credentials. Not by our servers (because we don't have servers).

Pricing

$9.99 per month. Cancel anytime.

Your notes stay in your iCloud account even if you cancel. We don't hold your data hostage. The subscription is for the app, not for access to your own data.

Get KetBook

Available now on the Mac App Store.

Download KetBook and take back ownership of your knowledge.

Questions? Check out our Documentation or Contact Support.