SwipeFi

Self-hosted music player with a Tinder-like swipe interface for curating your collection. Plays bitperfect via DLNA/UPnP to any compatible renderer. Runs as a Docker container on a Synology NAS.

Swipe right to keep a track. Swipe left to move it to a to_delete folder. That's it.

Features

• Bitperfect DLNA playback to any UPnP/DLNA renderer (WiiM, TV, Sonos, etc.)
• Tinder-like swipe UI — keep or discard tracks
• Spotify-style bottom tab navigation (Folders, Now Playing, Settings)
• Mini-player bar showing current track when browsing folders
• Folder browser with one-tap playback
• Reorderable queue with drag-to-reorder, skip-to, and sort-aware metadata column (play count or date added) with consistent icon and accent color styling
• Queue context display showing source folder and sort order in the queue header
• Swipe gestures in queue: swipe left to reject (delete), swipe right to remove from queue
• Play count tracking (counts after 60 seconds of listening)
• Live play count updates on the Now Playing screen via WebSocket
• Audio format info on the now-playing card (sample rate, bit depth, bitrate) for FLAC files
• Transcode detection — flags FLAC files transcoded from lossy sources (powered by flacalyzer, warning badge on album art, toggle in Settings, runs on rescan)
• Spotify-style full-width progress bar with elapsed/remaining times below
• Smart +15s skip — advances to the next track when 15 seconds or less remain (no more disabled button at end-of-track)
• Sort by date added, play count, or last played with ascending/descending toggle
• Cover art display (embedded, MusicBrainz/Cover Art Archive fallback)
• Deletion management — restore or permanently delete rejected files from Settings
• Orphan folder cleanup after permanent deletion — when the last audio file in a folder is purged, the folder is removed entirely (including leftover cover art, .cue, .log, etc.); walks up the directory tree removing newly-empty ancestors
• Cached cover art cleanup on permanent delete
• External device takeover detection (transitions to idle when another app takes over)
• Resilient device disconnection detection (time-based 30-second threshold tolerates network hiccups during track changes)
• Automatic reconnection with exponential backoff when a device becomes unreachable (preserves queue for seamless recovery)
• Reconnect state recovery (picks up the playing track and rebuilds the queue with original sort order on reconnect)
• Stable device connection display on refresh (no flicker)
• Persisted device name (Settings always shows the friendly name, never a raw UUID)
• Background delete/restore processing (survives page refresh, shows progress)
• Navigation guard during delete/restore (blocks back button and tab changes while processing)
• Browser back button support with in-tab navigation
• Optimistic loading state when starting folder playback (no "No track playing" flash)
• Auto-refresh player state when returning from background
• Directional lock on swipe card (prevents wiggle during vertical scroll)
• Instant progress bar reset on track skip (no stale position flash)
• Loading indicator while DLNA renderer buffers a new track
• Graceful track transitions (stops current before starting next)
• DLNA connection retry on transient failures
• Fast library scanning (single-pass, optimized for network shares)
• Automatic partial rescan after rejecting tracks
• Scan cancellation when music directory changes
• Play counts and deletion state preserved when switching music directories
• Configurable music directory via in-app settings
• Single Docker container, single binary
• Auto-updates via Watchtower

Tech Stack

• Backend: Go (chi, goupnp, modernc.org/sqlite, gorilla/websocket)
• Frontend: Svelte 5 + TypeScript + Vite (client-side SPA, embedded in Go binary)
• Icons: Lucide (via lucide-svelte)
• Database: SQLite
• CI/CD: GitHub Actions → ghcr.io → Watchtower

Deploy on Synology NAS

Prerequisites

• Synology NAS with DSM 7.2+
• Container Manager installed (Package Center → search "Container Manager")

Step 1 — Create folders

In File Station, navigate to the docker shared folder:

docker/
├── swipefi/
│   └── data/
└── watchtower/

Step 2 — Create the SwipeFi project

1. Open Container Manager → Project → Create
2. Project name: swipefi
3. Path: /docker/swipefi
4. Source: "Create docker-compose.yml", paste:

services:
  swipefi:
    image: ghcr.io/hancohogenbirk/swipefi:latest
    container_name: swipefi
    pull_policy: always
    network_mode: host
    volumes:
      - /volume1/Audio:/audio
      - /volume1/docker/swipefi/data:/data
    environment:
      - SWIPEFI_PORT=8080
      - SWIPEFI_DATA_DIR=/data
    restart: unless-stopped

5. Click Next → skip Web Portal → Done

Adjust /volume1/Audio to match your audio shared folder name.

Step 3 — Create Watchtower (auto-updates)

1. Container Manager → Project → Create
2. Project name: watchtower
3. Path: /docker/watchtower
4. Source: "Create docker-compose.yml", paste:

services:
  watchtower:
    image: nickfedor/watchtower:latest
    container_name: watchtower
    environment:
      - TZ=Europe/Brussels
      - WATCHTOWER_CLEANUP=true
      - WATCHTOWER_SCHEDULE=0 0 3 * * *
      - WATCHTOWER_INCLUDE_STOPPED=true
      - WATCHTOWER_REVIVE_STOPPED=false
      - DOCKER_API_VERSION=1.43
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    command: swipefi
    restart: unless-stopped

5. Click Next → Done

Step 4 — Configure

1. Open http://your-nas:8080
2. Select your DLNA renderer (auto-discovered)
3. Go to the Settings tab → navigate to your music folder → tap the green button
4. Switch to the Folders tab → browse → play → swipe

Usage

Navigation

The app uses a bottom tab bar with three tabs:

• Folders — browse your music library, tap play on any folder
• Now Playing — swipe card interface, transport controls, queue access
• Settings — music directory picker, deletion management

Swiping

On the Now Playing screen:

• Swipe right — keep the track, advance to next
• Swipe left — move track to to_delete folder, advance to next

Deletion Management

Rejected files are moved to <music_dir>/to_delete/. To manage them:

1. Go to Settings tab → Marked for Deletion
2. Select files with checkboxes (or "Select All")
3. Restore — moves files back to their original location
4. Delete Forever — permanently removes files and cached art. If a folder's last audio file is purged, the whole folder (including non-audio leftovers like cover art, .cue or .log files) is removed and empty parent folders are cleaned up

Back Button

The browser back button navigates within the current tab (e.g., subfolder → parent folder, queue → now playing). At a tab root, it shows a "Leave SwipeFi?" confirmation.

Local Development

Prerequisites

• Go 1.26+
• Node.js 22+

Run

# Terminal 1 — backend
SWIPEFI_MUSIC_DIR=/path/to/music SWIPEFI_DATA_DIR=./data go run ./cmd/swipefi

# Terminal 2 — frontend (with hot reload)
cd web && npm install && npm run dev

Open http://localhost:5173. The Vite dev server proxies API calls to the Go backend on port 8080.

Build single binary

cd web && npm run build && cd ..
go build -ldflags="-s -w" -o swipefi ./cmd/swipefi

The binary embeds the frontend and serves everything on port 8080.

Build Docker image

docker build -t swipefi .

The multi-stage Dockerfile builds the frontend, compiles a stripped Go binary, and compresses it with UPX for a minimal image.

Run tests

# Go
go vet ./...
go test ./...

# Frontend type check
cd web && npx svelte-check

# E2E (requires backend running with music dir)
cd web && npx playwright test

Configuration

If SWIPEFI_MUSIC_DIR is not set, the app prompts you to pick a directory in the Settings UI. The choice is saved to SQLite and persists across restarts.

Rejected files are always moved to <music_dir>/to_delete/.

Architecture

Phone/Browser (Svelte SPA)
     ↕ REST + WebSocket
Go Backend (chi router)
     ↕ UPnP AV commands
DLNA Renderer ← pulls audio from Go's HTTP file server (bitperfect)

The backend acts as a UPnP control point — it discovers DLNA renderers on the network, sends playback commands, and serves raw audio files. No transcoding, no resampling. Works with any UPnP/DLNA compatible renderer.