AI answers you can actually check.
Altretta is your private second brain: your notes and your code in one signed graph on your own disk. Ask anything, and every answer cites the exact source it came from — the decision, the note, or the function — 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
Knowledge deserves something better.
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 its word — 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.
Understand your whole project — what you write and what you code.
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.
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.
From 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.
We have no idea you are using this.
That is not a policy we could change, it is how the app is built. There is no analytics library inside it, no crash reporter, nothing fetched from a server to draw the interface, and a fresh install never works out which machine it is on.
No analytics, of any kind
There is no analytics or product-usage library 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.
The interface loads nothing from anywhere
Fonts and assets ship inside the app; the chrome never calls out to a server in order to draw itself. Your own notes are the exception, and only because you would want them to be: a note containing an image at a web address makes the app fetch that image, exactly as any reader would.
A fresh install stays anonymous
Your machine is described to us at one moment and one only: when you start a trial or activate a licence, which sends the host name, OS and architecture so the licence can be bound to a device. Never open the app's account panel and that moment never arrives.
Where content does leave the machine, stated plainly
Everything below is something you switch on. None of it happens to someone who installs the app and writes notes. Naming all of it is the only way the sentence above stays true, so this list is meant to be complete rather than reassuring.
- The AI you connect. Altretta hands your AI client the passages an answer is built from. There is no model inside the app, so if that client talks to a cloud provider those passages reach it under your own account and their terms, not ours. Retrieval, embedding and the grounding verdict are local either way; point the client at a model running on your own machine and nothing leaves at all.
- Publishing a site. Choosing to publish uploads the pages you selected — rendered as HTML, with the images they reference — to our server, so other people can open them at a public address. That is the whole point of the feature and it is the one place note content sits on our infrastructure. The selection starts empty, a note marked private is dropped even if you picked it, and there is a local export that writes the same site to a folder you host yourself.
- Encrypted sync. What lands in your Dropbox, OneDrive, network share or USB stick is ciphertext with hashed file names, and our servers are not in the path at all — the folder is yours and you chose it.
- Notion and Confluence import. Reading from those accounts means talking to them, with credentials you supplied.
- Signing in and licensing. Activating a licence, checking whether it is still valid once per app launch, and signing in through Google, Microsoft or GitHub if you choose to.
Do not take our word for it
The app reaches the network in a small, boring set of places and you can watch every one: a check for updates against a static file on our download CDN, and — only if you use them — your own AI provider, your Notion or Confluence account, our licence and account server, the plugin hub, and whichever identity provider you sign in with. Point a network monitor at it and see.
Common questions.
Do I truly own my notes?
Yes. Every note is a standard Markdown file on your disk. Open it with any editor, back it up, or leave Altretta whenever you want: your knowledge stays with you.
Why pay if the app is free?
The desktop app, answers grounded in your notes, and one synced folder are free forever. Paid plans add unlimited synced folders, publishing pages others can verify, reach further back through your history, and the encrypted team vault. If a single synced folder covers how you work, Free is genuinely all you need.
How can I trust the AI's answers?
Every answer quotes the exact notes it came from, with citations and a verdict of grounded, weak or ungrounded. If a claim isn't backed by your notes, the question is refused rather than answered.
Do I need to be technical to connect my AI?
No. Altretta detects the AI apps you already have — like Claude, Cursor or VS Code — and connects them in one click. No config files, no keys to paste, and you choose which folders the AI can see.
Do I need to pay for AI separately?
Altretta is a pure memory layer: it doesn't include its own LLM. You connect your preferred model over MCP with your own subscription, so you use the AI you already pay for and keep control of your keys.
Can I bring my existing notes?
Yes. Altretta reads ordinary Markdown, so your current notes folder 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, so nobody outside the team can read what a note says — not us, not whoever hosts the folder. Access is per person and revocable: remove someone and the key is rotated, so they can no longer read anything. One limit we would rather state than have you discover: in the team vault, filenames and folder structure are not encrypted, so the host still sees the shape of the vault and every note's name.
Which platforms does it support?
Altretta is available today for macOS (Apple Silicon and Intel), Windows, and Linux. Downloads always point to the latest published version.
Take control of your knowledge.
Private, offline, and verifiable. Your notes, your AI, your rules.