miniSCP

A cross-platform, dual-panel SFTP/local file manager — a small WinSCP-style commander built on Bun, Electrobun, and Angular.

Each of the two panels independently shows either the local filesystem or a remote server over SSH/SFTP, so you can move files local↔remote, remote↔remote, or local↔local through one symmetric engine.

Name & icon are placeholders. See Rebranding — it's a one-file change.

Developer docs

Dense reference material lives in docs/: architecture (processes, windows, RPC, every module/service), build & release (Build-n versioning, per-target release pipeline, CI), platform notes (macOS/Windows/Linux matrix, runtime deps + smoke tests), and gotchas (known landmines).

Features

• Dual-panel commander UI; either panel can be Local or any saved connection.
• Session tabs: each tab is an independent left/right workspace; remote sessions stay connected and transfers keep running in background tabs.
• Per-panel action toolbar with a direction-explicit send button, plus a VSCode-style status bar showing live transfer progress (click to expand the transfer queue with per-file speed and ETA).
• Overwrite confirmation on name collisions, with a source-vs-destination comparison (size, modified date, which is newer) and batch replace-all / skip-all.
• Settings (gear, top-right): light / dark / system theme and speed units (MB/s or Mbps), persisted across restarts.
• On macOS the tab bar is fused with the window titlebar; other platforms keep a standard titlebar.
• Menu-bar (tray) icon: template icon that adapts to light/dark; click it to bring the app to the front.
• Edit files (F4 / toolbar / File menu): a built-in editor works on local and remote files directly; or pick an external app (Settings → Editor → Custom → Choose…). External edits of remote files download to a temp folder, are watched, and every save auto-uploads (visible in the transfer list) until the session disconnects. Leftover temp files from a crash are offered for cleanup at the next start.
• Browse, sort (name/size/modified, folders first), keyboard navigation.
• Create folder / file, rename, delete (recursive), change permissions (chmod).
• Upload, download, and remote→remote send — files and whole folders — with a transfer queue, per-job progress, and cancel.
• Connection manager: saved connections organised into folders, password or private-key auth (with passphrase).

Stack

Layer	Choice
Runtime	Bun (main process, all SSH/SFTP + file IO)
Desktop	Electrobun 2.0 via Hutch (native webview, typed RPC bridge)
Frontend	Angular 22 (standalone, signals, zoneless) in ui/
Styling	Tailwind CSS v4, Oxide-derived tokens (no component library)
Icons	@ng-icons/tdesign-icons
SSH/SFTP	ssh2 (pure-JS under Bun)

The repo is a Bun workspace: the Electrobun app at the root, the Angular app in ui/. Shared types and the RPC contract live in src/shared/ and are imported by both sides.

src/shared/     types.ts, rpc.ts (wire contract), branding.ts
src/bun/        Electrobun main process
  fs/           FileSystemProvider + LocalProvider + SftpProvider + registry
  transfers/    engine.ts (queue/stream copy) + walk.ts (recursive helpers)
  store/        connections.json persistence
ui/src/app/     Angular components + signal services

Prerequisites

• Bun ≥ 1.3 (bun --version).
• macOS: Xcode Command Line Tools (for the app build).
• Linux: AppIndicator — the app links it for the tray and will not start without it (ERR_DLOPEN_FAILED). libayatana-appindicator (Arch), libayatana-appindicator3-1 (Debian/Ubuntu), libayatana-appindicator-gtk3 (Fedora), plus system webkit2gtk. Details and diagnostics in platform notes.
• No Node install required — a preload shim (scripts/node-version-shim.ts) satisfies the Angular CLI's Node version check while running under Bun.
• Network on the first bun install: Electrobun 2.x's npm package is a bootstrap that downloads its build tool (Hutch), the Electrobun core and the pinned Bun runtime into ~/.hutch (~200 MB), and projects the SDK into the gitignored .hutch/devkit/.

Setup

bun install          # installs root + ui workspace deps

Develop

bun run dev

This starts the Angular dev server (hot reload for UI code) and launches the Electrobun app pointed at it. Edits under ui/ reload instantly; edits to the Bun main process (src/bun/**, RPC schema) trigger an app relaunch.

Releases

Versioning is Sublime-style: Build n, where n is the commit count (git rev-list --count HEAD), regenerated into the gitignored src/shared/version.gen.ts by every build script (and postinstall).

One artifact per invocation, on the matching host — electrobun cannot cross-compile (Hutch builds for its own OS and arch):

bun run release -- --target mac-arm64   # on an Apple Silicon Mac
bun run release -- --target win-x64     # on a Windows 11 x64 machine
bun run release -- --target linux-x64   # on a Linux x64 machine

Artifacts land in release/<target>/miniSCP-Build<n>-<target>.* — a .dmg on the Mac; on Windows a -Setup.zip installer and a -portable.zip (unzip anywhere and run); on Linux Electrobun's -Setup.tar.gz installer. There is no Intel Mac build: Electrobun 2.x publishes no macOS x64 core. CI: .gitea/workflows/release.yml runs the same script on a macos + windows runner matrix once act_runners are registered; trigger by pushing a build-<n> tag.

Build a packaged app

bun run build        # ng build (ui/dist) + electrobun build -> build/*/miniSCP*.app

The Angular bundle is copied into the app under views://app. The macOS icon is compiled from assets/icon.iconset into AppIcon.icns automatically.

For a distributable (optimized, with auto-update channel) build, use bunx electrobun build --env=stable (see the Electrobun docs for signing, notarization, and release hosting).

Rebranding

Everything user-facing reads from src/shared/branding.ts:

export const BRANDING = {
  appName: "miniSCP",          // window title, bundle name, app-data folder
  identifier: "es.teknes.miniscp",
  legacyNames: [],             // previous names; their data dirs migrate on boot
  version: "0.1.0",
  icon: "assets/icon.iconset",
} as const;

To change the icon: edit assets/logo.svg (app icon) and assets/tray/tray-glyph.svg (menu-bar glyph), then run bun scripts/gen-icons.ts — it regenerates the macOS iconset, icon.png, the tray template image, and the tray progress frames from the SVGs (@resvg/resvg-js, dev-only dependency).

Renaming appName changes the app-data directory. Add the old name to legacyNames and the app moves the previous folder (connections, settings, edit temp files) into place on the next boot.

Where connections are stored

Saved connections live in a plain JSON file in the OS app-data directory (macOS: ~/Library/Application Support/miniSCP/connections.json), written with 0600 permissions.

⚠️ Passwords are stored in plaintext in this file (a deliberate v1 simplicity choice). Anyone who can read the file can read the passwords. If that isn't acceptable for your use, use key-based auth or don't save the password (connect ad-hoc). OS-keychain storage is a natural future addition.

Keyboard shortcuts

Tab switch panel · ↑/↓/PgUp/PgDn/Home/End move cursor · Space select · Enter open folder · Backspace parent · Ctrl/Cmd+A select all · F5 send to other panel · F2 rename · F7 new folder · F8/Delete delete · Cmd/Ctrl+T new tab · Cmd/Ctrl+W close tab · Ctrl+Tab next tab · Cmd/Ctrl+, settings · Cmd/Ctrl+=/-/0 interface bigger / smaller / 100%.

(On Macs, function keys may need fn — every action also has a toolbar button.)

Same-file protection

Copying a file or folder onto itself would truncate it to zero bytes (the destination is opened for writing before the source is read). miniSCP blocks this at several layers:

• Same session / same host: every connection carries a filesystem identity (local, or resolvedIP:port — the hostname is DNS-resolved, so myserver.lan and its IP compare equal even across two panels/tabs holding separate SSH sessions to the same server). Equal identity + equal or nested paths ⇒ the transfer is refused before anything is opened.
• Hidden aliases (two different addresses that reach the same machine — NAT, split DNS): when identities differ but source and destination paths collide anyway, a probe file is written through one connection and looked up through the other; if it's visible on both, they're the same machine and the copy is refused. (SFTP offers no device/inode identity — the mechanism cp/rsync use locally — so probing is the only deterministic test.)
• The overwrite dialog never offers to "Replace" a file with itself — such items are auto-skipped with a notice.

Known residual limitation: the same filesystem mounted at different paths on two connections (bind mounts, NFS exported twice, shared container volumes) cannot be detected — the paths differ, so no guard or probe triggers. Be careful when two panels reach the same data through different mount points.

Portability notes

Platform seams are isolated behind process.platform / PLATFORM branches marked with PORTABILITY: comments: editor launch (open / cmd /c start / xdg-open), app pickers, owner/group lookups, tray images, window chrome, shell-integration wording, drive listing, and the connections-file ACL. The application menu (src/bun/menu.ts) is macOS-only for now; the in-app UI covers every menu action.

Right-click menus are HTML, on every platform (ui/src/app/core/context-menu.service.ts) rather than native — electrobun's native context menu is a documented no-op on Linux, and one menu implementation beats two that drift. Only reveal / open-with-default / copy-path cross to the backend, through the shellItemAction RPC.

Windows (beta)

Windows 11+ x64 is supported as a beta target (win-arm64 deferred). All electrobun APIs the app uses are implemented on Windows; known issues are upstream:

• HiDPI blur (electrobun#324): WebView2 rendered at 1x on scaled displays on Electrobun 1.18; 2.x ships per-monitor DPI setup — to re-check on the first 2.x Windows build.
• Notifications use legacy balloon style, not Windows toast.
• Unsigned binaries: both the Setup.exe installer and the portable exe trigger SmartScreen/Mark-of-the-Web warnings on first run. The installer unpacks to %LOCALAPPDATA% and, since Electrobun 2.x, ships an uninstaller.
• connections.json is protected with an icacls current-user ACL instead of POSIX 0600 (which is meaningless on Windows).

First-Windows-boot smoke test: drives dropdown lists C:\ etc.; navigate to a drive root ('..' disappears); local↔remote transfers; external editor launch (cmd /c start) and the .exe picker; Show in Explorer / Recycle Bin; tray icon renders colored; Permissions absent on local panels; Ctrl+labels in tooltips; portable zip runs from any folder.

Linux (beta)

Linux x64 is supported as a beta target and ships Electrobun's own installer (-Setup.tar.gz). One hard requirement: the AppIndicator library listed under Prerequisites — electrobun links it for the tray, so without it the app aborts at startup with ERR_DLOPEN_FAILED rather than merely losing its tray icon.

• No native menus at all upstream (both the app menubar and context menus are no-ops). The menubar was already macOS-only and the context menus are now HTML, so nothing is missing in practice.
• Tray visibility depends on the desktop: KDE, XFCE, MATE and Cinnamon show it; GNOME 3.26+ needs the AppIndicator extension. The app works either way.
• Unsigned, and no AppImage or .deb — unpack the -Setup.tar.gz and run its installer.
• NVIDIA GPUs need WEBKIT_DISABLE_DMABUF_RENDERER=1 or the window renders black. The dev scripts set it automatically when an NVIDIA driver is detected; an installed build needs it set by hand (e.g. in its desktop entry) — see gotchas.

Full dependency table, diagnostics and the first-boot smoke test: platform notes.

Known issues

• Rare native crash under load. A long-running session (multiple remote connections, extended uptime) could hit a Bun panic — a segfault inside Bun 1.3.13's FFI thread-safe callbacks executing Electrobun's native→worker bridge (FFI_Callback_threadsafe_call → web_worker.spin in the decoded crash report). This is an upstream Bun × Electrobun bug, not app code; a restart recovers cleanly and in-flight work isn't corrupted. Electrobun 2.0.2 pins Bun 1.4.0, which may have fixed it — not yet confirmed under load. Bun's own crash reporter link is printed to the console on panic.

Not in v1

Drag-and-drop, file preview/edit, transfer resume, symlink following (symlinks are listed but skipped by transfers), OS keychain, tab persistence across restarts, Linux AppImage/.deb packages (the release is Electrobun's Setup installer).