Several people. One note. A server that cannot read it.
Culma is an end-to-end encrypted knowledge base. Your notes stay Markdown files in a folder you chose, several people write in the same note at the same time, and our node holds only ciphertext — titles, folders and who is a member included.
You, here
The live demo loads here.
Another person, in the same note
The live demo loads here.
What our node stores for this vault, right now
The live demo loads here.
Every byte in the right-hand column was sealed on the left-hand device. The key never reached us. This is not a visualization — it is the node's own listing for the vault you are typing into.
Linux · Windows · macOS · Android · iOS · Browser
Free on one device, forever. No account to start.
Your notes are files.
Markdown in a folder you chose, with real subfolders. A whiteboard is an SVG. There is nothing to export, because nothing was taken — and in ten years they open in any editor, including none at all.
Everybody writes at once.
Live cursors, per-note history, a trash, folder roles and groups. Two people editing the same sentence converge instead of overwriting each other.
The intelligence runs on your machine.
Search, semantic search and dictation compute on the device. That is why they still work on a vault we cannot read — and why nothing you write is uploaded to be understood.
Nobody pays to be invited.
The license belongs to whoever pays for it. The people they invite need nothing of their own: no account to buy, no subscription, no seat to find.
What our server sees
| We store | We can read | |
|---|---|---|
| Your notes, titles, folder names, whiteboards, attachments | sealed bytes | nothing |
| Who is a member of which vault | sealed bytes | nothing |
| How large each change was, and when it arrived | yes | that something changed |
| Which device connected, and from which address | yes | that a device synced |
The full table — every surface, what is kept, for how long, and what we cannot know even if we wanted to — is on one page.
Who it is for
For yourself.
A complete notes and whiteboard app that runs offline, on one device, free, with no account. Pay only when a second device or another person appears.
For a practice with a duty of secrecy.
Lawyers, tax advisors, physicians, works councils. Built so the provider does not know the content — technically, not contractually. Processing agreement and TOM documentation on request.
For an organization.
Folder roles, groups, directory sync, a node in Germany or one you run yourself. Buy the license outright or subscribe.
Pricing
- Free — one device, everything local, no end.
- Personal — your own devices, a cloud copy, share links.
- Team — shared folders, roles and groups, per person.
- Perpetual licenses and self-hosting start at €79 per seat.
What Culma does not do yet
We would rather you read this here than find it in week three.
No inline comments or @mentions.
You edit the draft together instead, which for two or three people is genuinely better. For ten it is not. It is the next thing being built.
No importer from Confluence or Notion.
Bring a folder of Markdown files and it just works. Bring a Confluence space and today that is a manual job.
No tables or database views.
Notes, whiteboards, tasks, backlinks and PDFs — not a database.
No SSO yet.
Directory sync from CSV and Nextcloud today; Entra ID and LDAP later.
The encryption has not been independently reviewed.
The key model and the protocol are published and you can read them. A review is commissioned as soon as first sales clear an agreed threshold, and the report will be published with its findings, not with a summary.
The client source is not published.
The specification is. The builds are reproducible. We are not calling this open source, because it is not.
As of 18 October 2026.
Culma on your machine
Linux, Windows, macOS, Android, iOS and the browser. Free on one device, forever, with no account.