Cygtree
An offline Windows mind map any AI can work on
Simply a note board that respects you and your wallet.
Start planning, stop subscribing.
Cygtree is a mind-mapping and whiteboard app for Windows 10 and 11. It costs $20 once — not a month, once — and it runs fully offline, with no account. Your boards are ordinary files on your own disk.
Your licence key is emailed here, so it has to be one you can actually open.
Windows 10 & 11 · 64-bit
- macOS coming soon
- Linux coming soon
What is Cygtree, exactly?
No outline, no rows, no tree view pretending to be a canvas. You put a card down, you drag another next to it, and the line between them is the thought.
Cards you can actually push around
Arrange, connect, nest and collapse. Colour a branch so you can find it again. Fold a finished section away without deleting it.
Images, PDFs and audio live on the board
Not attachments in a sidebar — the page you are quoting sits next to the card that argues with it, at the size you dropped it.
- Every edit is undoable, and the history is a panel you can read, not a mystery.
- Search and a command palette, so a board with hundreds of cards stays navigable.
- Dictation and read-aloud built in, running on your machine.
- Export the board as an image or a copy, whenever you want, with no account.
Does it work offline? Yes — completely
Cygtree never phones home. There is no cloud, no sync, no server and no account to sign into. Your boards are ordinary files sitting in a folder you chose, which you can copy, back up, email, or open in ten years when nobody is running this company any more.
- No telemetry in the app. It checks your licence once per computer and is otherwise silent. The privacy page says exactly what leaves your machine, including the awkward parts.
- No account. You never make one. There is no password to lose and no login to expire.
- Your files stay yours. Nothing is stored anywhere we control, so nothing goes away if we do.
Does it run on Mac or Linux?
Not today. Cygtree is Windows 10 and 11, 64-bit, and that is the only thing it is. macOS and Linux are things I want to do, not things I am promising — do not buy it expecting them.
Does it come with AI? No — you bring your own
Cygtree does not sell you tokens and does not hold an API key. It drives the AI tools you have already installed and already paid for — and they edit the board itself, not a chat window sitting beside it.
The CLI you already use
Claude Code, Codex and Cursor run as themselves, signed into your own account, at your own plan's rates.
Any ACP agent
Cygtree speaks the Agent Client Protocol, so an agent nobody has written yet can drive a board the day it ships.
Model of the week, welcome
The model list is read off your machine, not shipped in the app. A model released this morning is selectable this morning.
Cygtree charges you nothing for AI and takes no cut of it. If you have no AI tool installed, the board still works — it is a mind map first.
How much does Cygtree cost? $20, once
It is a small tool that runs on your computer and writes files to your disk. That should not be a monthly bill, so it isn't one.
- No card required
- Every feature, not a crippled demo
- Licence key arrives by email
- One computer per trial key
- No subscription, no seats, no renewal
- No cloud account to sign into
- Your boards are files on your disk
- Two computers per licence key