Private by default.

On Novastart nothing leaves your machine until you share a canvas. When you do, only the people you invite can see it, the windows stream from your machine to theirs, and only editors can write.

Sharing is one of the best things about the canvas, and it is also where people rightly ask what leaves their computer. Here is the answer: what stays put, what moves when you share, who can see it, and who can change it.

Nothing leaves until you say so.

Your canvas is on your machine. The apps on it, where they sit, which page each browser window is on, the labels and the files on the board: all of it lives on the computer you are using. There is no step where a canvas is sent somewhere so that it can be shown to you.

Sharing is the one thing that changes that, and it is a thing you do on purpose. Until you pick a board and send an invite, the board is yours alone. Does my canvas go to a server? No. It stays on your machine until you share it.

You choose exactly what to share.

Sharing works on one canvas or one folder, never on everything. Pick one canvas and that canvas is shared. Pick a folder and every canvas inside it comes along. Everything on a shared canvas comes with it: every app at its spot, every label, every file.

And nothing else. A teammate you invite to the trip canvas sees the trip canvas. They do not see the work folder beside it, the canvases in it, or anything you did not name. Can they see my other canvases? No. They see only the canvas or folder you shared.

Only the people you invite.

You share by email. Type an address and that person is a member of the board. Two roles say what a member can do: Owner and Editor. Nobody who was not invited is a member, and members are the only people who can see the board.

That rule is enforced underneath, not just in the interface. Row-level security covers every table and every live connection. Only members of a board can listen to it, and only editors can write to it. Someone without an invite cannot see the board, its windows, its cursors or its files.

Once people are on the board you can see them. Presence avatars show who is on this canvas right now, and each teammate's cursor moves in the colour they chose. Presence is per canvas, so each board has its own roster, and so are conversations: message a teammate from their avatar and it belongs to that canvas.

Machine to machine.

A shared window is a live window. The app keeps running on its owner's machine, and everyone else sees it at its spot on the board and can click and type into it. That picture streams peer to peer over WebRTC, from the owner's machine to each teammate's. Your clicks go straight into the window on the other machine, and the window streams straight back. Nothing passes through a server in the middle.

Files are different, because a file has to be opened. Open a PDF, an office document or an image on a shared canvas, up to 100 MB, and it is mirrored so that everyone can open the real file rather than a picture of it. That happens on a shared canvas only. A file on a canvas you have not shared stays where it is.

Keep a window to yourself.

Sharing a canvas does not mean every window on it is open to everyone. Hide a window with one click and teammates see a placeholder where it was. The window keeps running for you; they see that something is there and nothing more.

You can also lock a window against moves, so a teammate cannot drag it out of place. And undo on a shared board takes back only your own mistake, never a teammate's work.

Only editors can write.

Seeing a board and changing it are two different things. Every member can look. Editors can change the board: move windows, open apps, type into shared windows. That is the second half of the rule: only members can listen, only editors can write.

Two editors changing the same window at once is fine. Sync is a CRDT, using Yjs technology, so edits from everyone always converge. Move a window while a teammate changes its URL and both changes survive. Lose the connection and your moves wait, then merge when you are back.

Handing over, not sharing.

Sometimes you do not want a live shared board; you want to give someone a copy. Save a whole workspace as one .novastart file and pass that on. It is a file, and it goes where you send it and nowhere else.

The short version.

Your canvas stays on your machine. You share one canvas or one folder, by email, and teammates see only that. Only members can listen, only editors can write, and windows stream from machine to machine. Sharing is something you do, never something that happens to you.

The team collaboration page shows two machines on one canvas, including the offline board where moves merge when you are back. For what a shared canvas feels like to work on, read one canvas instead of a screen share. The install page has the app and Novastart OS.