SongMirror

Overview

SongMirror keeps the playlists you curate on one service mirrored across all the others. Spotify, TIDAL, Qobuz, Deezer, Amazon Music, Apple Music, YouTube Music, and a local, Jellyfin-ready download folder stay identical without manual re-adding, one-by-one copying, or a paid cloud service holding your library. It can run one-way with a chosen source of truth, use an authoritative group where two or more services jointly define the playlist, or reconcile every selected service in bidirectional (N-way) mode. I built it as a free, open-source alternative to Soundiiz and TuneMyMusic that you own and host yourself.

I wrote up the engineering behind it in a dedicated post: A Self-Hosted Playlist Mirror for Seven Music Services.

What I Built

It started as a headless Python engine and grew into a browser app on the same core:

• Sync engine in Python: ISRC-first matching with Unicode-aware fuzzy fallbacks (RapidFuzz plus anyascii romanization, anchored by track duration), oldest-first date-added ordering, and a paranoid removal path guarded by a dry-run default, per-pass caps, and net-loss and empty-snapshot protection.
• Web app with a FastAPI backend and a React single-page UI: connect each service, build any number of named syncs, choose one-way, authoritative-group, or N-way reconciliation, run one-off transfers, and watch every match, add, and removal stream live over server-sent events. A services layer drives the engine so the web layer never touches it directly.
• Seven music-service connectors behind one MirrorTarget interface: Spotify, TIDAL, Qobuz, Deezer, Amazon Music, Apple Music, and YouTube Music. A separate Jellyfin integration keeps a local download mirror organized and playlist-ready.
• Docker deployment: one docker compose up -d serves the UI and runs your syncs on schedule. Everything is configured in the browser and saved to a local data folder, so no credentials ever leave the machine.

Highlights

• Cross-catalog matching that survives multi-artist credit drift, remaster and "Official Music Video" suffixes, and non-Latin scripts, never guessing when nothing clears the bar.
• Authoritative groups for playlists curated across two or more services, plus bidirectional N-way sync with echo suppression via a per-provider canonical snapshot, add-wins conflict resolution, and a read-collapse guard against transient API hiccups.
• One-off transfers with pause, resume, and stop, plus manual resolution of tracks that could not be matched automatically.
• A Jellyfin-ready local audio mirror through spotDL, with per-playlist folders, real playlist covers, and an auto-updated .m3u8.

Screenshots

The source is on GitHub, MIT-licensed, and the default run is a dry run that prints every add and removal it would make before touching a single playlist.