Siphon

A self-hosted web UI for rclone. Browse a remote server from any browser (laptop or phone) and download files straight onto your home server's drives, with fast parallel transfers. Siphon is a small, password-protected front end; rclone does the heavy lifting.

Quick start

Docker

docker compose up -d --build
# then open http://<server-ip>:8080

Files download into ./downloads; saved connections live in ./data. rclone is bundled in the image, so there's nothing else to install.

Single-file app (Windows / macOS / Linux)

1. Download the binary for your OS from the Releases page (siphon-win-x64.exe, siphon-macos-arm64, siphon-macos-x64, or siphon-linux-x64).
2. Run it once. It creates a config.json next to itself.
3. Open http://localhost:8080 (or http://<pc-ip>:8080 from another device) and finish first-run setup in the browser.

On macOS/Linux, make it executable first: chmod +x siphon-*. The binaries are unsigned, so Windows SmartScreen or macOS Gatekeeper may warn once. rclone is fetched automatically on first run if it isn't already installed.

Configuration

Set these as environment variables (Docker) or as keys in config.json (single-file app). Environment variables win if both are set.

Setting	config.json key	Default	What it does
APP_USERNAME	appUsername	admin when auth is enabled	Login username. Change this from admin.
APP_PASSWORD	appPassword	none	Plaintext password for login.
APP_PASSWORD_HASH	appPasswordHash	none	Scrypt password hash from --hash-password. Takes precedence over APP_PASSWORD.
LOGIN_MAX_ATTEMPTS	loginMaxAttempts	10	Failed login attempts before lockout. Set 0 to disable lockout.
LOGIN_LOCKOUT_MINUTES	loginLockoutMinutes	15	Lockout duration after too many failed attempts.
SESSION_TTL_HOURS	sessionTtlHours	72	Session lifetime before re-login is required.
TRUST_PROXY	trustProxy	false	Trust reverse-proxy headers for client IP and protocol.
SECURE_COOKIES	secureCookies	auto	Cookie security mode: auto, true, false.
DOWNLOAD_DIRS	downloadDirs	/downloads	Where files can be saved. Label=path pairs, comma-separated.
PORT	port	8080	Web UI port.
DATA_DIR	dataDir	./data	Where saved connections are stored.

DOWNLOAD_DIRS powers the in-app folder picker. List each drive or folder you want to save into, for example Movies=/mnt/movies,Backup=/mnt/backup. In Docker, mount each of those paths as a volume. The same folders scope which local files can be uploaded, since uploads read from the server's local disk into the remote folder you are browsing.

SFTP uploads run single-stream per file (rclone can't multi-thread a single-file SFTP upload). Overall upload throughput across multiple files comes from the Concurrent setting in the transfer queue.

First-run setup

On first launch with no configured credentials (no APP_PASSWORD / APP_PASSWORD_HASH environment variables and no appPassword / appPasswordHash in config.json), Siphon starts in setup mode. Only setup APIs are available until setup is completed.

Open the app in a browser and choose one of these:

• Create an admin username and password.
• Run without a password (open mode), only for trusted networks.

Setup mode should be completed before exposing Siphon beyond loopback or a trusted LAN.

If APP_PASSWORD / APP_PASSWORD_HASH or appPassword / appPasswordHash is configured, those credentials override stored auth state and setup is skipped.

Features

• Connect over SFTP with a password or private key.
• Browse remote folders with current-folder filtering, sorting, multi-select, and right-click download.
• Fast parallel downloads (1 to 16 streams) with live progress and speed.
• Upload files and folders that already exist on the Siphon server's local disk into the remote folder you are browsing.
• Downloads keep running on the server even if you close the tab or your phone.
• Save connections so you don't retype credentials, and pick a save folder per download.

Keep it running on boot

• Docker: already handled (restart: unless-stopped in docker-compose.yml).
• Windows: run npm run service:install from an Administrator PowerShell (or right-click windows-service/Install-SiphonService.ps1 > "Run with PowerShell"). It wraps the packaged dist-bin/siphon-win-x64.exe in WinSW as an auto-start service that restarts on failure and rolls its logs - no system Node.js needed at runtime. For a first-time build of the exe, add -Build. See windows-service/ for details.
• Linux: point a systemd unit at the binary with Restart=always.

Authentication and security

• Username + password login is supported. The default username is admin when auth is enabled, change it with APP_USERNAME or appUsername.
• You can configure the password as plaintext (APP_PASSWORD or appPassword) or as a scrypt hash (APP_PASSWORD_HASH or appPasswordHash). Generate hashes with:

./siphon --hash-password

Hashed passwords take precedence over plaintext values.

• Login lockout is enabled by default, loginMaxAttempts=10 and loginLockoutMinutes=15. Set loginMaxAttempts=0 to disable lockout.
• Sessions expire automatically, sessionTtlHours=72 by default.
• For HTTPS behind VPN or reverse proxy, set trustProxy=true and secureCookies=true.
• Password changes are available in-app for store-managed credentials. Env-managed credentials are read-only and skip the setup wizard.
• Forgot your password, if a hash is configured (APP_PASSWORD_HASH or appPasswordHash), replace or remove that hash first (or regenerate it with --hash-password) because hash settings take precedence over plaintext. Then set a new password or hash and restart Siphon.
• Siphon runs rclone privately on localhost with random credentials, browsers only talk to Siphon's API, never to rclone directly.
• Saved passwords are stored by rclone (obscured in its config), not by Siphon. Downloads are restricted to folders you configure.
• This version does not verify SFTP host keys, run it on a network you trust.

Breaking change: passwordless upgrades now enter setup mode

Existing installs that previously ran with no password and no env credentials now start in setup mode and block operational APIs until setup is completed. This is intentional and fail-closed.

Offline recovery:

1. Stop Siphon.
2. Delete auth.json from dataDir.
   • macOS default: ~/Library/Application Support/Siphon/auth.json
   • Linux default: ~/.local/share/siphon/auth.json
   • Windows default: %APPDATA%\Siphon\auth.json
3. Start Siphon again and complete setup.

Deleting auth.json is also how you leave open mode.

Development

npm install
npm run web:server   # API on :8080 (needs rclone on PATH or set RCLONE_PATH)
npm run web:dev      # UI on :5174 with hot reload
npm test             # run the tests
npm run typecheck    # type-check server + web
npm run lint         # lint with oxlint
npm run format       # format with Prettier

To build the single-file binaries yourself: npm run package:all (outputs to dist-bin/).

Project layout

src/
  server/        Fastify API: auth, config, sessions, request handling
    routes/      HTTP route handlers (auth, browse, downloads, uploads, ...)
    rclone/      rclone process supervisor, client, and download manager
  ui/            React UI built with Primer (components + hooks in lib/)
  web/           Vite entry point that mounts the UI
  shared/        Types and the API contract shared between server and UI
test/            Vitest unit tests
windows-service/ WinSW-based Windows service install/uninstall (PowerShell)
Dockerfile       Container image (bundles rclone)
docker-compose.yml

Contributing

Contributions are welcome. Please read CONTRIBUTING.md for setup, coding style, and the checks CI runs. By participating you agree to the Code of Conduct.

• Found a security issue? Follow the security policy and report it privately.
• Curious what changed between releases? See the changelog.

License

Siphon is released under the MIT License.