Features

Search and requests

Search covers tracks, albums, artists, and playlists from the connected music catalog. It understands more than exact titles: a query like “workout energy” or “chill sunday” is routed to genre and mood browsing rather than plain-text search.

Every request opens a window where you can set, per request:

These choices are stored on the request itself, so a retry weeks later still honours what you originally asked for.

The requests screen

Requests are grouped by album and playlist, with a sidebar of groups and a detail panel for the selected one. The list is ordered by most recent activity, so anything you just asked for, or that just changed, is at the top. Each row shows when it was requested and when it last moved.

From here you can retry a failed track, retry a whole group, cancel anything in flight, delete a request, prioritise it, or pause it.

The download queue

Downloads run one album or playlist at a time, in order. Every track in a group finishes before the next group starts, so you never end up with five half-finished albums.

• Jump the queue. Move any track, album, or playlist to the front from its actions menu. A badge shows it took effect. Retried tracks are prioritised automatically.
• Pause and resume. Pause an individual album or playlist, or the entire queue, from the toolbar. A paused album or playlist stays parked until you resume it, including across a restart. Pausing the whole queue lasts until you resume it or the container restarts.
• Restart recovery. If Synthseek restarts mid-queue, it rebuilds the queue from the database on boot and picks up where it left off. Paused work stays paused, and work already handed to Lidarr is left alone.

Verified imports

Synthseek checks what arrived before it goes into your library.

• The file’s tags are checked against what you asked for, and a file that does not match closely enough is refused.
• With an AcoustID key configured, the audio itself is fingerprinted and identified, so a file whose tags look right but whose contents are something else is refused. An identification that comes back inconclusive does not block anything; only positive evidence against the file does.
• A file whose tags cannot be read at all is refused rather than waved through.

A refused file is not thrown away.

The review queue

Anything that failed verification waits in a review queue. For each held file you can see exactly why it was rejected, listen to it, and then approve or discard it. Approving imports it immediately. Discarding removes the file and leaves the rejection on record.

Held files are kept for a configurable retention period, fourteen days by default.

Source quarantine

When a source repeatedly delivers the wrong thing, that exact source and file pairing is quarantined and excluded from future searches. Other files from the same peer stay eligible; quarantine is deliberately narrow. You can see which sources have been set aside and why, and lift a quarantine at any time.

Separately, and off by default, peers can be automatically banned after a configurable number of failed attempts.

Automatic retries

Anything Synthseek could not find can be watched. A background sweep re-searches watched tracks on a cadence that spaces attempts out as a track stays missing, so a brand new release is retried sooner than something that has been unavailable for months.

Under a failed track you can see when the next attempt is due, how many attempts there have been, and start one immediately.

A track that failed because of a problem on your own machine, a full disk or an unwritable folder, does not spend any of its retry budget. That is not something another peer can fix, so Synthseek keeps waiting for you rather than quietly giving up.

This is off by default.

Quality upgrades

Already have a song in poor quality? Ask for a better copy and Synthseek replaces it in place.

• The decision reads the actual files, not search result metadata, so a claimed bitrate cannot fool it.
• The old file is moved to a recycle bin rather than deleted, and the move is verified before anything else happens.
• If the replacement cannot be completed, the original is restored where possible, and otherwise stays recoverable in the recycle bin, with the log naming exactly where it is.
• The recycle bin empties itself after a retention period, thirty days by default.

You can upgrade a single track, or select several tracks in your library and upgrade them in one action. Synthseek reports back honestly on each one.

Bring in music you already have

Drag your own files into Synthseek, including zip archives. Each track is identified, tagged, and filed into your library the same way a download would be. If a file matches something you had already requested, that request is closed out for you.

Uploads are streamed rather than buffered, so large archives work. Archive contents are validated before extraction.

Your library

A full library section to browse everything you have.

• Tracks is a table, with sorting, per-column filters, and a requested-at column.
• Albums, Artists, and Playlists are card grids with artwork.
• Faceted filtering across all views, with counts that respect the other active filters.
• Search, sorting, and smooth infinite scrolling.
• Views refresh on their own as downloads finish. No manual reload.
• Select several tracks at once to retry, upgrade, or add them to a playlist.

Track status sorting follows the real download pipeline order rather than alphabetical order, so active work sorts above resolved work, which sorts above unresolved work.

Content detail

Click any artist, album, or playlist and a rich detail view opens in place, without losing your spot. Navigation stacks, so you can go from an artist to one of their albums to a related artist and back out again.

Each view pulls from several metadata sources at once and streams the sections in as they arrive:

• Artwork, a biography, and factual details.
• For an artist: a discography, top tracks, similar artists, and links to their presence elsewhere.
• For an album or playlist: a full tracklist with live per-track status.
• An overlay showing what you already have in your library.
• Actions to request anything you are missing, individually or in bulk.

When a metadata source is unavailable, Synthseek says so, and says how long it has been unavailable, rather than quietly showing you an incomplete page.

Playlists

Full playlist management inside your library.

• Create a playlist from tracks you already have.
• Rename and delete your own playlists.
• Add and remove tracks, several at a time.
• Request a playlist from the catalog and Synthseek downloads every track, preserving the original order.

Playlist import and export

• Import from JSPF, XSPF, and Exportify CSV. The flow is a dry run first, showing you exactly what matched and what did not, then a commit of the selection you approve.
• Export to JSPF, round-trippable back into Synthseek.
• Duplicate tracks within an imported playlist are collapsed, with a count of how many were skipped.

Sync to a media server

Any eligible playlist can be pushed to Plex, one at a time or all at once, from either the requests screen or your library. A background job keeps synced playlists named correctly and topped up with tracks they are missing.

Renames flow both ways. Rename in Synthseek and Plex follows within seconds; rename in Plex and Synthseek picks it up on the next pass.

Currently, playlist sync only ever adds tracks to the remote playlist. It never removes them.

Discovery

A dedicated Discover page with a trending hero, browsable genres, an artist spotlight, a leaderboard of what is most represented in your library, and your recent requests.

Connect your listening history

• ListenBrainz provides discovery mixes: collaborative filtering recommendations, weekly exploration, weekly jams, and daily jams. Choose which mixes you want, name them, and optionally have Synthseek request their tracks automatically as they refresh. A mix can be kept as a single playlist that updates in place, rather than creating a new dated playlist every time.
• Last.fm surfaces your recent scrobbles and top tracks, with real artwork, and powers similar-artist recommendations across the application.

Discovery integrations are per user. Each member connects their own accounts and gets their own mixes.

Import your existing library

Connect a library source and bring your existing collection across.

Spotify is supported today. Browse your saved albums, saved tracks, and playlists in a table with bulk selection, pick what you want, and import it. Imported playlists can be kept in sync, so new additions on the source side flow through automatically.

Each member connects their own account and imports into their own library.

Multi-user

Synthseek is built for more than one person.

• Local accounts, or sign in with Plex.
• Import members straight from your Plex server.
• Three roles: administrator, trusted, and member.
• Administrator-only settings are hidden from everyone else, not merely disabled.
• Requests are scoped to their owner and show who made them.
• Each member has their own profile, their own connected accounts, and their own language preference.
• Optionally require administrator approval before a plain member’s requests download anything.

Interface

• Modern and responsive, with a bottom navigation bar on phones.
• Three themes: Synthseek, Midnight, and Ocean.
• Four languages: English, Español, Deutsch, and Français.
• Live progress everywhere, driven by server-sent events rather than polling.
• A progress dock that follows long-running work such as playlist population, library imports, and media server sync.
• In-app update notifications when a newer version is published, with the patch notes for it.

AI assistants

Synthseek ships an MCP server, so an assistant such as Claude can search, request, organise, and report on your library in plain language. Around forty tools cover search, downloads, requests, playlists, library, listening history, settings, and operations.

Every connection is scoped to one member. An assistant sees and acts on that member’s account and library only, shaped by their role.

See the AI Assistants page.

Operations

• A jobs section listing every background job relevant to your setup, with what each one does, when it last ran, when it runs next, and a run-now button.
• A log viewer with level filtering, auto-refresh, and export.
• A live health view for each connected service.
• Automatic database backups before any schema change, and, where there is room, a copy-validated upgrade that proves the migration on a copy before touching your live database.