A tiny, self-contained Subsonic-compatible music server written in Rust. Point it at a folder of music, give it a username and a password in a TOML file, and any Subsonic client can browse and stream your library.

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                a tiny Subsonic server in Rust

Features

• One binary, one TOML file, one SQLite database. No external services.
• Built on actix-web 4 with sqlx (SQLite) for storage.
• Library scanner powered by lofty — extracts ID3/Vorbis/MP4/etc. tags and embedded cover art from mp3, flac, ogg, opus, m4a, wav, and more.
• Falls back to cover.jpg / folder.jpg / front.jpg next to the audio file if there's no embedded picture.
• Stable IDs (ar-… / al-… / so-…) derived from tag content, so re-scans are idempotent and clients don't lose their bookmarks.
• HTTP Range support for proper seeking.
• Subsonic token auth (t = md5(password + salt)) and plaintext (p=… or p=enc:<hex>) both supported.
• CORS is permissive — works directly from web clients.

Install

Homebrew (macOS / Linux):

brew install tsirysndr/tap/smolsonic

Or build from source:

Quick start

# 1. Create a config
cp smolsonic.example.toml smolsonic.toml
$EDITOR smolsonic.toml      # set music_dir, username, password

# 2. Run
smolsonic --config smolsonic.toml

On first launch smolsonic scans music_dir, creates the SQLite database, and starts the HTTP server. Point any Subsonic client at http://<host>:<port>/rest/… using the credentials from your TOML file.

Configuration

smolsonic.toml (all keys shown):

music_dir     = "/path/to/your/music"   # required
username      = "admin"                  # required
password      = "changeme"               # required

# Optional — defaults shown
port          = 4533
host          = "0.0.0.0"
database_path = "smolsonic.db"
covers_dir    = "covers"

CLI

Usage: smolsonic [OPTIONS]

Options:
  -c, --config <CONFIG>  Path to the TOML config file [default: smolsonic.toml]
      --no-scan          Skip the startup library scan
  -h, --help             Print help
  -V, --version          Print version

Trigger a rescan from a running server with the standard Subsonic endpoint:

GET /rest/startScan.view?u=…&t=…&s=…
GET /rest/getScanStatus.view?u=…&t=…&s=…

Supported endpoints

Full navidrome-style endpoint coverage. Both .view-suffixed and plain paths are accepted, on both GET and POST. Responses are JSON with the Subsonic envelope ({"subsonic-response": …}).

System — ping, getUser, getMusicFolders, getScanStatus, startScan

Library (ID3 tag browsing) — getArtists, getArtist, getAlbum, getSong, getAlbumList2, getAlbumList (alias)

Library (folder browsing) — getIndexes, getMusicDirectory

Genres — getGenres, getSongsByGenre

Lists — getRandomSongs, getStarred2, getStarred (alias)

Playback — stream, download, getCoverArt, scrobble, getNowPlaying, updateNowPlaying

Search — search3, search2 (alias)

Playlists — getPlaylists, getPlaylist, createPlaylist, updatePlaylist, deletePlaylist

Starring — star, unstar

Artist / album info — getArtistInfo, getArtistInfo2, getAlbumInfo, getAlbumInfo2, getSimilarSongs, getSimilarSongs2, getTopSongs, getLyrics. These return minimal stub shapes (no Last.fm or external lookups).

GET / returns a plain-text index of every endpoint and its query params.

Tested clients

Anything that speaks Subsonic API 1.16.x and prefers tag-based browsing should work, including Substreamer, play:sub, Symfonium, Tempo, and Sonixd.

How auth works

Subsonic clients send credentials as query parameters:

• Token auth (preferred): u=<user>&t=<token>&s=<salt> where token = md5(password + salt).
• Plaintext: u=<user>&p=<password> or p=enc:<hex-encoded password>.

smolsonic accepts both. The single user/password come from the TOML config. There's no user database.

Development

cargo run -- --config smolsonic.toml
RUST_LOG=debug cargo run -- --config smolsonic.toml

Project layout:

src/
  main.rs            entry point
  cli.rs             clap CLI + neon styling + ASCII banner
  config.rs          TOML loader
  db.rs              SqlitePool + schema migrations
  models.rs          Artist / Album / Song row types
  scanner.rs         walkdir + lofty + cover art extraction
  server/
    mod.rs           actix App + routing
    auth.rs          Subsonic token / plaintext auth
    response.rs      JSON envelope helpers
    repo.rs          sqlx queries
    handlers.rs      Subsonic endpoint handlers

License

MIT.