Two Markdown memories for your AIs. What changes is who can get in, and what it costs.
Hjarni and Cobrain do the same basic thing: Markdown notes on a server that Claude, ChatGPT and other AIs read and write over MCP. The differences are in the plan limits, in how you give one folder to another person, and in the price of a team.
Let us start with what is the same
And it is more than you would expect.
Both keep notes in Markdown, in folders, and expose them to AIs through an MCP server: you paste an address, you authorise, and Claude, ChatGPT, Claude Code or Cursor read and write. Both keep a history of who changed what, both have a 30-day trash, neither uses your notes to train models, and both let you export everything whenever you like.
So the question is not «which one works»: both do. It is how many notes you need before you pay, who you need to share them with, and how many of you there are.
Where they differ
Three things, and all three show up on the bill.
The free plan. Hjarni gives 25 notes, with 20 MB of attachments. Cobrain gives 1,000 notes, without attachments. With 25 notes you try the tool; with 1,000 you work in it for months, and you pay when you need attachments or someone writing alongside you.
Giving one folder to a person. In Cobrain you share a branch (a folder and everything under it) with an email address, read or write, and whoever receives it gets in free: their AI sees that branch and nothing else. Hjarni shares with a public link, view or edit, and on Pro with up to two collaborators.
The team. Hjarni Teams costs €18 per person a month. Cobrain's Team costs $7 a seat, from three seats: for three people that is €21 a month instead of €54. And the clients you give a branch to do not take a seat.
Line by line
The first rows are the same for both: that is where an honest comparison starts.
| Hjarni | Cobrain | |
|---|---|---|
| Note format | Markdown in folders | Markdown in folders |
| How an AI connects | MCP server, one address and one authorisation | MCP server, one address and one authorisation |
| History, with who changed what | yes, with restore | yes, with restore, on the free plan too |
| Trash | 30 days | 30 days |
| Export | Markdown, in a ZIP | folders of Markdown files, in a ZIP |
| Free plan | 25 notes, 20 MB of attachments | 1,000 notes, no attachments |
| Pro | €11 ($12) a month | $9 a month |
| Giving one folder to a person | a public link, view or edit; on Pro up to 2 collaborators | one branch, by email, read or write; on Pro unlimited readers and up to 3 people who write |
| Whoever receives a folder | — | gets in free, always |
| Team | €18 ($20) per seat a month | $7 per seat a month, from 3 seats |
| Encryption | in transit and full-disk | in transit, and every note encrypted with its brain's own key |
| Where the data lives | Germany | Ireland |
| Apps | iPhone, iPad, Android, Mac, a Chrome extension | in the browser, on the phone too |
| Notes by email | yes, on Pro | no |
Hjarni figures taken from hjarni.com on 13 October 2026 (pricing, FAQ, security, teams). In both cases the server opens the note to hand it to your AI: neither one is end-to-end encrypted.
When Hjarni suits you better
We would rather say it than have you find out later.
- You want a native app on iPhone, Android or Mac, and an extension to clip web pages.
- You want to send notes by email.
- A few notes are enough, but you need attachments without paying.
- You want the data in Germany.
When Cobrain suits you better
Usually when another person joins.
- You have more than 25 notes and do not want to pay just to keep trying.
- You work with clients or collaborators: each gets their own folder, by email, and pays nothing.
- You are a team: the Team plan costs less than half per person.
- You want every note encrypted with its brain's own key, not just the disk.
Questions
Can I move my notes from Hjarni to Cobrain?
Yes, and your AI does it. Connect it to both, or give it the folder from Hjarni's export, and ask it to move the notes one by one, keeping the same folders. The guide has the text to paste.
Which AIs connect?
The same ones: Claude, ChatGPT, Claude Code, Codex, Cursor, Antigravity and any MCP client. The guides connect them one by one.
Do my notes sit on your server?
Yes, as with Hjarni: that is the price of making them reachable from every AI. Here every note is encrypted with one key per brain, and permissions are applied by the database. The details are in permissions and privacy.
If I stop paying, do I lose everything?
No, with either. Here going back to free limits, it does not delete, and the full export is there on every plan.
A thousand notes free, and a folder for whoever works with you.
Connect your first AI in two minutes and see whether it changes your day. We do not ask for a card, and what goes in comes back out unchanged.
