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Tauri Shell

The desktop shell is built on Tauri 2. It owns the native window, launches the backend, and guarantees that the two shut down together.

The Shell's Job​

The shell does three things:

  1. Spawns the sidecar — it starts the self-contained Node.js backend process and waits until the local API is ready before opening the webview. You never see a half-loaded window pointing at a dead server.
  2. Hosts the webview — the production web app runs inside the Tauri webview and talks to the backend over 127.0.0.1 on a random free port.
  3. Owns the lifecycle — window events and process events are wired so that backend and shell always exit as one unit.

Window Lifecycle​

  • Close — closing the window triggers a graceful shutdown of the sidecar. The backend is asked to stop cleanly, and the app waits for it before exiting. No orphan Node.js process is left behind.
  • Backend crash — if the sidecar exits unexpectedly, the shell terminates with an error instead of showing a window that cannot do anything. Normal exits are marked separately so a clean shutdown is never mistaken for a crash.
  • Restart — starting the app again re-spawns the sidecar from scratch. State lives in the data directory, not in the process, so restarts are lossless.

The Window Is the API​

Because the shell waits for the API before showing content, first launch feels immediate: the window opens on a ready application. The backend listens only on 127.0.0.1 on an ephemeral port, so nothing is exposed to the network.

Updater Integration​

Release builds integrate the Tauri updater. The shell can check for core updates, verify the manifest and minisign signature, install the platform artifact, and restart. The updater replaces the core separately from the user's data directory, and unsigned downgrades are rejected. Builds made without an update endpoint and public key are fully functional but report that updates are not configured.

Development Builds​

For development, the same shell can run against a dev server and a locally started backend. The production guarantee — sidecar exits with the window — applies to packaged builds; pnpm desktop:dev wires the shell to your running dev processes instead.

For how the sidecar is bundled and managed, see Node Sidecar.