cosm

Install guide

Installing Cosm

The install is one drag. The only real decision comes the first time you open it — so this page tells you exactly what it is before you get there.

Download for Mac

Requires a Mac running macOS 15 (Sequoia) or later — Apple silicon or Intel. Cosm is signed with a Developer ID and notarized by Apple.

Install

  1. Drag Cosm into Applications. The disk image has an Applications folder next to the app — drop it there before you open it.

    Opened straight from the disk image, Cosm may run from a temporary, read-only copy of itself, where it can’t keep its Accessibility permission or install its own updates. Cosm notices and asks you to move it, but doing it now saves the round trip.

  2. Open Cosm from your Applications folder. There’s no Dock icon — Cosm lives in the menu bar, and the sidebar appears at the left edge of your screen.

The first time you open it

  1. “Help improve Cosm.” A one-time notice that Cosm sends anonymous usage statistics and crash reports to help fix bugs and guide development, and that it never collects window titles, other app names, or window contents. It’s on by default: OK keeps it on, Turn Off opts out. Cosm works the same either way.
  2. The macOS Accessibility prompt. Only if you haven’t granted it already. This is the one that matters — it’s worth knowing what you’re granting.
  3. “Choose a display for Cosm.” Only if you have more than one display connected. The sidebar opens on the display you pick and stays on its current Space.

There’s nothing else — no account, no sign-in. After that, Cosm checks for its own updates and tells you when one is ready; you decide when to install it.

What Cosm can and can’t see

Listing your open windows takes no permission at all — macOS hands that list to any app that asks, along with the name of the app each window belongs to. What macOS puts behind Accessibility is the next step: reading what a window is called, and moving focus from one window to another. That’s the only permission Cosm ever asks for. It never asks for Screen Recording — what’s inside a window isn’t something Cosm can see, only what it’s called.

Decline, and Cosm still opens and still lists your windows — each row labelled with its app instead of its window. You get Cursor, Cursor, Cursor where you should see the three files you actually have open, and clicking a row won’t bring that window forward, because bringing a window forward is the same permission. Switching windows is what Cosm is for, so this is the permission it runs on. We’d rather say that than call it optional. You can grant it later from the sidebar’s Request access button; it takes effect immediately, with no restart.

The titles Cosm reads stay on your Mac. A pinned row keeps its last title — and, for a document, the file’s path — in a plain file under Application Support, so the row is still there tomorrow; unpin it and that goes with it. The usage statistics Cosm sends are a short, fixed list of counted events — things like that Cosm launched, whether you granted Accessibility, which placement mode you picked, how many displays and spaces you use rounded off to “1”, “2-3”, or “4+”. Every value in them is either a word from that list or one of those buckets. There’s no free-text field anywhere in it, which is why a window title can’t end up there, even by accident. That isn’t a policy we’re promising to keep. It’s a shape the code can’t take.

Reads
Each window’s title, which app it belongs to, its size and position, and — for document apps — the path of the file open in it. Enough to draw a row and put a window where you want it.
Stores
On your Mac only, in a plain file under Application Support: a pinned row keeps its last window title and file path until you unpin it; a claimed row drops its own 24 hours after you last used it.
Doesn’t read
Anything inside a window. That would need Screen Recording, which Cosm never asks for.
Doesn’t send
No usage-statistics event has a field that could carry a title, an app name, or a file path.