Your second brain, with receipts.
Notes that stay yours, an AI you can check, and a signed history that proves both. Ask anything — every answer cites the note, the decision or the function it came from, so you can open it and see for yourself.
When was the migration approved?
The migration was approved on March 12, with a budget of €48.000
Every answer, with its proof
In brief
Altretta is a private, local-first notes app: your notes and your code are your own Markdown files, and every AI answer cites the exact source it came from, with a signed history.
- Your files
- Markdown on your machine, no silo
- Your own AI
- Connect your model over MCP
- Everything leaves proof
- Signed, reversible history
- Available on
- macOS · Windows · Linux · free
Every other tool makes you choose.
Your notes are trapped in someone else's app
Proprietary databases, closed formats, and syncs that disappear one day. Your knowledge should be yours, forever.
AI answers without proof
Assistants hallucinate, mix sources, and you can't verify where each claim came from. Without evidence, there's no trust.
Team knowledge stays siloed
Fragmented wikis, permissions impossible to revoke, and sensitive data exposed to third parties. Sharing shouldn't mean losing control.
Don't trust it. Check it.
Trust is something you extend. Verification is something you do. Altretta is built so you never have to take anyone's word — ours or your AI's — for anything that matters.
A checkmark that had to earn it
The badge appears only when two things hold at once: the signature actually checks out, and the note still matches what that signature covers. If either check fails there is no badge — it fails closed rather than giving itself the benefit of the doubt.
It tells you when something changed
If a note was signed and then edited, you are told exactly that — not quietly downgraded to "unsigned". A signature that no longer covers what you are reading is worth saying out loud.
An assistant that will say it does not know
Ask about something your notes do not cover and it tells you so — no answer is produced at all. Getting one anyway is a separate choice you have to make on purpose.
Answers point at the page, not the file
PDFs, Word files, presentations and spreadsheets are read in with their structure intact — page numbers, slide numbers, even the article numbers in a regulation — so a grounded answer cites the exact place it came from instead of just a filename.
Your notes stay yours
Every note is an ordinary file on your computer. No lock-in, no format you can't open. Move it, back it up, or leave Altretta anytime — your knowledge comes with you.
It connects the dots you'd miss
Altretta links related notes automatically, surfacing the idea from months ago you forgot you wrote — all on your machine, nothing uploaded.
See the shape of everything you know
One click turns your notes into a world you can walk through. Folders become floors, hidden connections rise to the surface, and the shape of your thinking finally comes into view.
One brain for what you write and what you build.
Altretta reads your repository and maps it as a signed map: every symbol, how they call each other, and the decision that governs each one. So your AI doesn't just know your notes — it understands your code and how to change it without breaking anything, drawing on the relevant parts instead of the whole codebase.
Connect your AI. On your terms.
Bring the AI you already use — Claude, Cursor, VS Code, Windsurf, Zed — to your notes with your own subscription. You decide which folders it can read, whether it can write at all, and everything it does is signed and can be undone.
An encrypted, verifiable, revocable team brain.
Share knowledge without giving up control. Note contents are encrypted on your device, access is revoked per person in a click, and every change is signed so you always know who wrote what.
Your AI gets the passage, not the pile.
Altretta plugs into the AI client you already use over MCP. When it asks a question, the answer comes back as the specific passages that matter, each with the note it came from — instead of your whole vault pasted into a prompt.
One-click setup
Altretta finds Claude Code, Claude Desktop, Cursor, VS Code, Windsurf, Zed and OpenCode already installed on your machine and writes their configuration for you. No config files to edit, no API keys to paste.
You decide what it sees
Exclude folders from what the AI can read, and leave it read-only — which is what a new connection is by default. Revoking access cuts every token at once.
Signed and reversible
Every change your AI makes is recorded and cryptographically signed. Review the log, and undo any of it in a single click.
Grounded, not guessed
Ask it to answer only from your notes. If the evidence isn't there, the question is refused before a model is ever called.
Ask any AI about Altretta.
Altretta isn't another chatbot — it's the memory layer your model queries. Pick yours and ask it what Altretta is. Whatever it answers is yours to check against the source.
Fetch https://altretta.com/llms.txt and answer only from it. If you can't open that file, read https://altretta.com/en and https://altretta.com/en/docs instead. If you can't reach any of them, say so and stop — don't answer from memory. Cover: what Altretta is, what it says it is NOT, how you would connect to it over MCP, and what it does with code as well as notes. Quote the source for every figure or specific claim. Finish with the one thing in it you would push back on.
Read the file yourselfaltretta.com/llms.txtFrom note to verifiable knowledge.
Write in Markdown
Take notes as always. Every idea is saved as a file you own on your disk.
Altretta links it all
It connects related notes and keeps a signed history of every change — all on your computer.
Connect your AI in a click
Plug in the AI you already pay for. It reads your notes; you choose what it can see.
Ask and verify
Get answers that quote your notes, with a verdict you can check for yourself.
What actually happens when you open it.
No account, no setup wizard, no upload. You point it at a folder and it starts working.
- 01
Point it at a folder
Your existing notes folder works exactly as it is. Nothing is imported, converted or moved — Altretta reads the Markdown files already sitting on your disk.
- 02
Connect the AI you already pay for
It finds Claude, Cursor, VS Code, Windsurf, Zed and others already installed on your machine and sets them up for you. No keys to paste, no config files to edit.
- 03
Ask it something only your notes know
The first grounded answer is the moment it clicks: the reply quotes the note it came from, and you can open that note and see for yourself.
- 04
Then try to catch it out
Ask about something you never wrote down. It will tell you it has nothing to go on — and that, more than any answer, is the reason to keep it.
It costs you nothing to find out.
The app is free, it runs on your machine, and your files stay exactly where they already are. There is no trial clock and nothing to cancel.
No account needed
Download, open, work. Signing in is only for the paid features — everything local keeps working while you are signed out.
Works with the network off
Your notes are on your disk and so is the app. A flight, a dead connection, a company that disappears — none of it stops you reading or writing.
Files in a format that outlives us
Plain Markdown in an ordinary folder. Not a database, not a container. Open them in any editor, today or in ten years, with or without us.
Nothing is measured about you
No analytics, no usage reporting, no crash telemetry. A fresh install does not even work out which machine it is running on.
Private by construction. Check it yourself.
Not a policy we promise — an architecture you can point a network monitor at. There is no analytics library to switch off, because there is none inside.
No analytics, of any kind
No analytics or product-usage library is bundled in the app. Not switched off by default — not there at all.
No crash or error reporting
When something goes wrong it goes wrong on your machine, and it stays on your machine.
Nothing fetched to draw the interface
Fonts and assets ship inside the app; the interface never calls a server to render itself. The one exception is your own notes — an image at a web address is fetched exactly as any reader would.
A fresh install stays anonymous
Your machine is described to us at one moment only: when you start a trial or activate a licence. Never open the account panel, and that moment never arrives.
Content leaves your machine only when you switch something on — your own AI, publishing, sync, imports, sign-in. Every one of those paths, and every network call the app can make, is named on one page.
Every network call, listedYour AI gets the passage, not the pile.
Pasting your whole vault into a prompt burns tokens. Altretta hands the model only the cited passages that matter — 94.3% fewer input tokens than pasting everything, measured on 24 pre-registered questions.
The measured savings
94.3%
Your AI gets the passage, not the pile.
Fair questions, straight answers.
Do I truly own my notes?
Yes — and not as a promise, as a file format. Every note is plain Markdown on your disk. Open it in any editor, back it up, or walk away whenever you want: your knowledge was never anywhere else.
How can I trust the AI's answers?
You don't have to — that is the point. Every answer quotes the exact notes it came from, with a verdict: grounded, weak or ungrounded. And when your notes don't back an answer, Altretta refuses to invent one.
Do you train AI on my notes?
We could not if we wanted to. Altretta ships no AI model and your notes never reach our servers, so there is nothing to train and nowhere to train it. The only model that sees your notes is the one you connect — under your account and their terms, or running entirely on your machine.
What happens to my notes if Altretta disappears?
Nothing. The app runs on your machine and keeps opening, reading, writing, searching and answering with our servers gone. Your notes are plain Markdown files in a folder you chose — they would not even notice.
Why pay if the app is free?
The desktop app, grounded answers and one synced folder are free forever — no trial clock, nothing to cancel. Paying adds unlimited synced folders, publishing pages anyone can verify, deeper history, and the encrypted team vault. If one synced folder covers how you work, Free is genuinely all you need.
Do I need to pay for AI separately?
There is no new subscription hiding here. Altretta is the memory layer; the model is whichever one you already pay for, connected over MCP — or one running free on your own machine. Your keys stay yours.
Do I need to be technical to connect my AI?
No. Altretta finds the AI apps you already have — Claude, Cursor, VS Code and others — and connects them in one click. No config files, no keys to paste, and you choose which folders the AI can see.
Can I bring my existing notes?
Yes, and there is no import step, because there is nothing to import into. Point Altretta at your existing Markdown folder and it works as-is. Pro adds one-click import from Notion and Confluence.
How does the encrypted team brain work?
You share a vault whose note contents are encrypted on your device — not us, not whoever hosts the folder, nobody outside the team can read a note. Remove someone and the key rotates: their access actually ends. One limit we state rather than let you discover: filenames and folder structure are not encrypted, so the host still sees the shape of the vault and every note's name.
Why should I believe the signatures?
You shouldn't — you should check them. The engine’s source is public, the byte layout of the history is published as a spec, and every published page carries a verifier that checks its signature in your browser, offline, without an account. Change one byte and watch it refuse.
Which platforms does it support?
macOS (Apple Silicon and Intel), Windows and Linux, today. No mobile yet — we would rather tell you that here than after you download.
Own your second brain. All of it.
Private, offline, verifiable — and free to find out. Your notes, your AI, your rules.