Questions, answered.
Where your library lives, how to leave with it, and what's coming next.
Is Cairn free?
Yes — free for everyone. No account, no card, no item limit. The web app, the Chrome extension and agent access are all included.
Do I need an account?
No. Open the app and start saving. There's nothing to sign up for and nothing to sign into.
Where is my data?
On your device. The web app keeps your library in this browser's storage. Nothing is uploaded anywhere.
How do voice notes work?
Press V in the app (or open Capture and choose Record a voice note), allow the microphone, and talk. Press Stop & save and the recording joins your library with its waveform; play it on the card or open it to jump around and change the speed. Recordings stay on your device, in this browser's storage, which holds a few megabytes in all: roughly fifteen minutes of voice alongside your other saves. If you connect a library folder, each note is also written there as an ordinary audio file. Recording stops by itself at five minutes.
What's the demo library?
A full sample library with a one-minute tour, so you can see Cairn at work before adding your own things. It's kept apart from your own library — nothing you do there touches it.
Can I leave?
Yes. The export button at the bottom of the sidebar writes your whole library to a JSON file in one click. No lock-in, no account to close.
Can AI agents use my library?
Yes, on your computer. In Cairn, open Connect agents: choose a folder for your library, and Cairn copies a small program into it that Claude, Cursor, Codex, Gemini and other MCP clients can start. Agents can always search and read; adding, organizing and moving to the Trash are separate switches, off by default. Nothing is ever deleted for good. It needs Chrome or Edge (to save to a folder) and Node.js 18 or newer.
Does it use AI?
Not yet. Ask answers questions by searching your own saves on your device and shows the sources. Summaries and connecting your own model are coming later.
Which browsers can capture?
The Cairn extension works in Chrome, Edge, Brave and Arc. Firefox is next. In any browser you can also paste a link, type a note or drop an image straight into the app.
Will it work on my phone?
The app opens in a phone browser, but it's built for a computer first. A phone-friendly capture view is on the list.
Terms in one line
Use it for your own things, and we'll never sell or read your library.