Cozy 0.1.0

Watch something at the same time as someone far away.

Cozy puts the people you're watching with in a small window that floats over everything else, and lets any of you share a screen or a single app — with its sound, in stereo — straight to the others. Their voices sit above the film, and the film ducks out of the way when someone speaks.

There is nothing to set up. No account, no sign-up, no server to run, and nothing to pay. Install it, press Start something, read the seven characters to whoever you're watching with. After the first time, it's one button with their name on it.

Getting it

• macOS — Cozy-0.1.0-universal.dmg (Apple silicon and Intel). Right-click → Open the first time; the build isn't signed.
• Windows — Cozy-0.1.0-x64.exe for most machines, -arm64 for an ARM device, or the plain
  Cozy-0.1.0.exe if you want one installer that covers both. SmartScreen will warn once, for the
  same reason.
• Linux — the .deb if your distribution takes one (it registers cozy:// invite links and sets up the sandbox for Ubuntu 24.04+), otherwise the .AppImage.

macOS needs one permission it will ask for: Screen & System Audio Recording. Grant it and reopen Cozy — macOS only applies it on a fresh launch. Without it the film arrives silent with no error, which is a nasty way to spend an evening.

What's actually been tested

macOS: verified. Every feature below was measured on real hardware — 127 automated checks driving real windows, including a four-person call, stereo audio end to end, and the overlay staying out of a shared screen.

Windows and Linux: built and reviewed, never run on real hardware. The code paths are checked against Electron's own platform documentation and the Linux fallbacks are exercised in CI, but nobody has opened these binaries on a real machine. If you do, tell us how it went — it's the most useful thing anyone could contribute right now.

Known limits, honestly

• Netflix, Disney+ and Prime come through black. They blank themselves for any screen recorder. Not fixable without defeating DRM, which this project won't do. Local files, YouTube, Twitch, DVD/Blu-ray players and most things that aren't a paid subscription service all work.
• About 5–10% of network pairs can't make a direct connection — office Wi-Fi, some mobile carriers. Cozy notices after twelve seconds and suggests what usually helps, all free.
• On Wayland the overlays can't float. The compositor decides, not the app, and every API this needs is a no-op there — so Cozy draws them inside its own window instead. X11 behaves like macOS and Windows.
• On Linux the overlays appear in a whole-screen share. There's no way to exclude a window from capture there. Share a single window instead.

Full detail in LIMITATIONS.md.

Privacy

Video and audio go straight from one computer to the other and never touch a server. The one server involved introduces the two of you and then gets out of the way — it can't read what it relays, because the room id is derived from a secret it's never given and every message is sealed. No accounts, no telemetry, no crash reporting, no analytics. The only thing that ever phones home is the update check, and Settings → Updates turns it off.

PRIVACY.md explains it properly, including what it does not protect against.