Several people. One note. A server that cannot read it.

Culma is an end-to-end encrypted knowledge base. Several people write in the same note at the same time, and our server holds only ciphertext — the text, the titles, the folder names and who is a member included.

Everybody writes at once
Live cursors, version history per note, a trash, folder roles and groups. Two people editing the same sentence converge instead of overwriting each other.

It works offline
The vault is on your phone. The server is a copy, and a copy nobody can read. Nothing waits for a network.

The intelligence runs on your device
Search, semantic search and dictation compute on the phone. That is why they still work on a vault we cannot read — and why nothing you write is uploaded to be understood. Both models are free on every plan.

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
Your notes, titles, folder names, whiteboards and attachments: sealed bytes we cannot read. How large each change was and when it arrived: yes. Which device connected, and from which address: yes. The whole table is on culma.eu.

Also in the app
Whiteboards on an infinite canvas. Tasks collected from every note. Backlinks and wikilinks. Daily notes. A trash you can restore from. One hue that colors the entire app, in light and in dark. Pair this phone with your desktop by scanning a code.

What Culma does not do yet
No inline comments or @mentions. No importer from Confluence or Notion. No tables or database views. No single sign-on; directory sync from CSV and Nextcloud today. Two things are on the desktop today and not on the phone yet: taking everything out in one archive, and bringing a PDF in. The encryption has not been reviewed by anyone outside the project: the key model and the protocol are published and you can read them. The client source is not published, so we do not call this open source.

As of 20 October 2026.

Free on one device, forever, with no account. Paid plans for syncing and sharing are at culma.eu.