Desktop app

The desktop build is a Tauri 2 shell: a Rust process owns the window, tray and updater, starts the packaged backend as a sidecar, and renders the frontend in a WebView.

Installation

Channel	Artifact	Dependency
`fat`	`Hetu_x.y.z_x64-setup.exe` / `.msi`	None (bundles the .NET runtime)
`slim`	`Hetu.Slim._x.y.z_x64-setup.exe` / `.msi`	Requires the .NET 10 runtime
Linux	`.AppImage` / `.deb`	AppImage needs no installation

From tag to update: CI produces installers and manifests for both channels; the client fetches manifests in GitHub → mirror order and verifies signatures.

Auto-update

Endpoint order: GitHub primary, then three mirrors (ghproxy.net / gh-proxy.com / ghfast.top).
Each channel has its own manifest: latest.json (fat) and latest-slim.json (slim); they never overwrite each other.
Installers are signed; a signature mismatch aborts the install. Install mode is passive.
An update badge appears next to the version; opening it shows the release notes.

Installers embed a preinstall hook that terminates leftover backend processes (taskkill /F /IM Hetu.Api.exe) before overwriting files, so a locked sqlite-vec\vec0.dll can no longer break an upgrade.

Tray and process lifecycle

Behaviour	Details
Close window	Minimizes to the tray by default; the backend keeps running so background jobs continue. Disable in Settings → App
Quit	Tray menu “Quit Hetu” terminates the backend child process first
Hard kill	The backend remembers the shell PID (`HETU_PARENT_PID`); if the shell disappears it exits by itself, leaving no orphan holding the port
Dev reuse	In development, if `HETU_API_DEV_PORT` already has a backend, the shell reuses it

Install and data directories

Path (Windows example)	Content
`<install>\Hetu (Slim).exe`	Shell executable (the fat channel ships `Hetu.exe`)
`<install>\Hetu.Api.exe`	Backend sidecar — the install hook makes sure it is not running
`<install>\wwwroot\`	Frontend assets served by the backend
`<install>\sqlite-vec\vec0.dll`	SQLite vector extension (locked by a leftover backend when installs fail)
`%LOCALAPPDATA%\Hetu\hetu.db`	Database (plus `-wal` / `-shm`)
`%LOCALAPPDATA%\Hetu\logs\`	Logs

Install hook

src-tauri/nsis-hooks.nsh runs before files are copied (NSIS_HOOK_PREINSTALL):

!macro NSIS_HOOK_PREINSTALL
  DetailPrint "Stopping leftover Hetu backend..."
  nsExec::Exec '"$SYSDIR\taskkill.exe" /F /IM Hetu.Api.exe /T'
  Pop $0
  Sleep 500
!macroend

Worktree root and cleanup

Item	Default / options
Root	`.hetu-worktrees/<repo>/<worktree>` next to the repository
Custom root	Settings → Workspace: absolute path, validated to be outside every repository
Cleanup criteria	Changes merged (or remote branch deleted) + clean working tree + idle past the threshold
Interval	1 / 6 / 12 / 24 hours, or automatic cleanup off
Branch deletion	Off by default (directory only); can be enabled
Manual run	“Clean now” in settings returns checked / removed / kept counts

Data location

The shell passes the data directory to the backend via HETU_DATA_DIR: on Windows that is %LOCALAPPDATA%\Hetu (hetu.db plus WAL, and logs/). Copy that directory to migrate machines.

Packaging it yourself

# 1) build the backend sidecar (fat or slim)
pwsh ./scripts/publish-backend.ps1 -Mode SelfContained      -Rid win-x64
pwsh ./scripts/publish-backend.ps1 -Mode FrameworkDependent -Rid win-x64

# 2) build the installer
cd shell/hetu-desktop
npm run tauri:build                                            # fat
npm run tauri:build -- --config src-tauri/tauri.slim.conf.json  # slim

Sidecar naming must follow the Tauri convention: binaries/Hetu.Api-<rust-target-triple>(.exe).

Troubleshooting

Symptom	Fix
`Error opening file for writing` during install	A leftover backend holds the file: end all `Hetu.Api.exe` in Task Manager and retry. Newer installers handle this automatically
`Could not fetch a valid release JSON`	The manifest could not be fetched. Open `releases/latest/download/latest.json` (slim: `latest-slim.json`) in a browser to confirm, then upgrade to the latest build
Window is gone but the app still runs	Click the tray icon to restore it; the backend intentionally keeps running