Why KetBook?

There's a simple principle at the heart of KetBook: your thoughts, your notes, your knowledge should belong to you and only you.

Not to a cloud service provider. Not to a corporation analyzing your data for "better recommendations." Not to a third party you have to trust.

Just you.

The Problem with Modern Note-Taking

Most note-taking apps today follow the same pattern:

1. You write notes
2. They're uploaded to someone else's server
3. You trust that company won't:
4. Read your notes
5. Analyze your data
6. Get breached
7. Go out of business
8. Change their terms
9. Raise prices indefinitely

This isn't a sustainable model for your most valuable asset: your knowledge.

The KetBook Approach

KetBook takes a radically different approach:

Zero-Trust Architecture

Your notes live in your own iCloud account. Not on our servers. Not in a shared database. In your personal iCloud Private Database and iCloud Drive.

We literally cannot access your data even if we wanted to. There's no central server to breach. No database to leak. No third party to trust.

End-to-End Privacy

Apple encrypts your iCloud data. We never see it. We never touch it. Your notes sync across your Macs through your iCloud account, not through our infrastructure.

AI Without Compromise

Want AI features? Bring your own API key. Your notes are processed by the AI service you choose and control, not by our servers (because we don't have servers).

The AI features happen client-side or with your own API credentials. Your data stays yours.

Native macOS. No Web Dependencies.

Built with Swift 6 and SwiftUI. Runs entirely on your Mac. No internet connection required (except for iCloud sync, which is optional).

Menu bar access. Keyboard shortcuts. Instant search. Markdown editing. Everything you need, nothing you don't.

One-Time Purchase

No subscriptions. No recurring fees. No "freemium" tiers with locked features.

Buy once. Own forever.

Your tool, your data, your control.

The Trade-Off

There's a trade-off to this approach: we can't offer collaboration features. We can't provide web access. We can't do anything that requires a central server.

But for many people, that's not a trade-off. It's the point.

If you want privacy-first, zero-trust knowledge management, KetBook is built for you.

Ready to own your knowledge? Download KetBook on the Mac App Store.