Download Zylch Desktop

Alpha installers for macOS and Windows. Everything runs locally — your email, contacts, and credentials stay in ~/.zylch/.

First public release coming soon. Links below point to the latest build on GitHub — if you see a 404, star the repo to be notified when it drops.
macOS Apple Silicon · .dmg macOS Intel · .dmg Windows x64 · .exe installer

Install on macOS

  1. Double-click the .dmg and drag Zylch into Applications.
  2. Open Applications, right-click (or Ctrl-click) on Zylch.app and pick Open.
  3. macOS will say "cannot verify the developer of Zylch". Click Open.
  4. From then on you can launch Zylch normally from Dock, Spotlight, or Launchpad.

If you just double-click the first time, macOS only offers a Cancel button — the right-click → Open path is the one that lets you through.

Install on Windows

  1. Double-click Zylch-Setup-<version>.exe.
  2. Windows SmartScreen will say "Windows protected your PC". Click the small More info link, then Run anyway.
  3. Follow the installer prompts — you can pick the install directory.
  4. Launch Zylch from the Start menu.

The installer is not yet code-signed. SmartScreen flags any unsigned new app by default; once enough users have run it, the warning goes away automatically.

First launch

The very first time you run Zylch there's no profile configured, so the app opens a Welcome to Zylch window instead of the main interface. Fill in:

  • Email address — identifies your profile.
  • LLM provider + API key — Anthropic or OpenAI. You bring your own.
  • Email app password — generated from your provider's account settings (not your login password). Zylch speaks IMAP directly; no OAuth dance.
  • IMAP / SMTP host + port — auto-filled for Gmail, Outlook, iCloud, Yahoo. Override if you're on a custom host.
  • Telegram bot token — optional, for the proactive morning / evening digest.

On Create profile and continue, Zylch writes ~/.zylch/profiles/<email>/.env (file perms 600, dir perms 700) and opens the main window. Everything else — MrCall credentials, personal notes — is editable from Settings afterwards.

Prefer the terminal? Grab the CLI on GitHub. Same engine, same data directory.