Download the desktop app

Fleece AI Brain runs on your computer — your knowledge stays local. Pick your operating system, install, then sign in with this same account.

Version 0.2.3 · unsigned beta

macOS

Universal — works on both Apple Silicon (M1–M4) and Intel Macs.

Download for macOS
First launch — macOSmay warn it can't verify the app
  1. Open the .dmg and drag Fleece AI Brain into your Applications folder (don't run it from the disk image).
  2. Double-click it once. You'll see “Apple could not verify… is free of malware.” Click Done (not “Move to Trash”).
  3. Open menu → System Settings → Privacy & Security, and scroll down to the Security section.
  4. Next to “Fleece AI Brain was blocked…”, click Open Anyway, authenticate, then click Open Anyway once more. macOS remembers it — future launches are normal.
  5. Note: that button only appears for about an hour after you tried to open the app. If it's missing, double-click the app again first.

Prefer Terminal? Paste this and press Return — it clears the download flag so the app opens straight away:

xattr -dr com.apple.quarantine "/Applications/Fleece AI Brain.app"

Windows

Windows 10 / 11, 64-bit. Standard installer.

Download for Windows
MSI installer
First launch — Windowsmay warn it can't verify the app
  1. Run the installer. If a blue “Windows protected your PC” box appears, click the More info link, then the Run anyway button.
  2. Alternatively: right-click the downloaded file → Properties → tick Unblock at the bottom → OK, then run it.

Linux

Portable — runs on any distro.

Download AppImage
.deb (Debian / Ubuntu).rpm (Fedora / RHEL)
First launch — Linuxmay warn it can't verify the app
  1. AppImage: make it executable (chmod +x the file) then double-click to run.
  2. .deb / .rpm: install with your package manager; the app lands in your applications menu.
Why the warning?This beta isn't yet signed with a paid Apple/Microsoft developer certificate, so the OS shows an “unverified developer” prompt on first launch. The app is safe — the steps above are a one-time approval, and code signing is on the way to remove the prompt entirely.

After installing

  1. Open Fleece AI Brain.
  2. Go to Sources → Sign in to Fleece — a browser window authorizes this computer.
  3. Connect a source (Gmail, Notion, Slack…) and sync.