The payoff slice. Until now a candidate's only claim on a slot was "some
artist you play is adjacent to it in a similarity graph" — a fact that says
nothing about whether the music sounds like anything you like. Now the
candidate's own folksonomy tags (cached by slice 5) are compared against
the user's taste-profile tags, so the deck ranks on taste and can say WHY.
The blend is MULTIPLICATIVE — score × (1 + weight × overlap) — and that
choice carries the whole safety argument:
- An untagged candidate has overlap 0, so its score is EXACTLY unchanged.
Tag coverage is permanently partial (#2376); it must cost a candidate
nothing, not sink it (rule #131).
- Nothing can leapfrog on tags alone. An additive term with a large
weight would let a near-zero-similarity artist outrank a strong match
for sharing one popular tag, which reads as noise.
- Weight 0 restores pure similarity order bit-for-bit, so the operator's
knob has a real off position.
overlap = Σ(shared) candWeight × normalizedTasteWeight ÷ Σ(all) candWeight.
Normalizing the taste side by the user's strongest tag makes the score
comparable across users (taste weights accumulate with listening, so a
heavy listener's raw numbers dwarf a new user's while meaning the same
thing). Dividing by the candidate's own mass makes it comparable across
candidates, so a densely-tagged artist can't win on tag count alone.
Applied to the whole over-fetched pool BEFORE selectSuggestions, so the
rotation and diversity rules operate on blended scores — boosting only the
twelve already chosen by similarity would leave the re-ranking undone.
A query failure is returned, NOT degraded past. Graceful degradation is
for expected absence (no taste profile, no cached tags) and both are
handled explicitly as empty inputs; swallowing a real error would hide a
broken DB behind a subtly worse ranking that nothing reports.
Migration 0051 adds a FOURTH tuning scope rather than columns on
taste_tuning, because snooze_days lives here too and a snooze must never
be read as taste signal (#2374) — filing it under 'taste' would put it one
careless join from the leak that design forbids. Expanding
recommendation_tuning_audit's CHECK is in the same migration per rule #36,
and a test asserts the audit row lands, which is what would catch its
absence.
snooze_days moves out of a Go constant onto the tuning card (rule #25),
closing the deferral from #2374.
Tag-overlap tests use deliberately SKEWED fixtures: an evenly-matching pool
cannot exercise a re-ranking, since every candidate gets the same
multiplier and the order is unchanged whether the blend works or not.
Admin UI + client attribution follow in this batch — rule #27.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Minstrel
A self-hosted music server that thinks for you. Smart shuffle, contextual likes, ListenBrainz-aware radio, and Lidarr automation — server-side, so every client (web, mobile, Subsonic third-party) gets the same intelligence.
State and intelligence belong on the server, not the client.
Highlights
- OpenSubsonic-compatible. Existing Subsonic clients (DSub, Symfonium, play:Sub, etc.) connect with no special configuration.
- Server-side smart shuffle. Track-similarity vectors, dual-like model (general + contextual), and session memory keep mixes coherent across devices.
- ListenBrainz radio. Session-aware "more like this" pulls from ListenBrainz similarity data, not a static genre tag.
- Lidarr integration. Triggered scans, request-driven album imports, and a quarantine flow when something doesn't fit.
- Built-in web SPA. Full-feature library, search, queue, playlists, and admin — no separate frontend container to deploy.
- Native Android client, shipped with the server. The signed APK is bundled into every image and attached to each release — sideload it once, then the app self-updates straight from your own server (no app store, no separate download to track).
Quickstart
# compose.yaml
services:
minstrel:
image: git.fabledsword.com/bvandeusen/minstrel:latest
ports: ['4533:4533']
volumes:
# Your music library. Point ./music at wherever your audio files
# live. Mounted read-only — Minstrel never writes to your library.
- ./music:/music:ro
# Generated data: playlist cover collages, artist art, caches.
# The path must match MINSTREL_STORAGE_DATA_DIR, which the image
# sets to /app/data — keep this mount on /app/data or your cache
# won't survive a container recreate.
- minstrel-data:/app/data
environment:
MINSTREL_DATABASE_URL: postgres://minstrel:minstrel@db:5432/minstrel?sslmode=disable
# Colon-separated library roots to scan; must match the container
# path of the read-only music mount above (/music here).
MINSTREL_LIBRARY_SCAN_PATHS: /music
depends_on: [db]
db:
image: postgres:17
environment:
POSTGRES_USER: minstrel
POSTGRES_PASSWORD: minstrel
POSTGRES_DB: minstrel
# Postgres data dir — users, likes, play history, sessions, settings.
# The one volume you must never lose; back it up with pg_dump.
volumes: [pgdata:/var/lib/postgresql/data]
volumes:
minstrel-data:
pgdata:
docker compose up -d
First run
With the stack up, a handful of in-app steps get you to a working library. Use your own host in place of localhost if you're reaching the server over a LAN/VPN address (plain http:// is fine — no TLS required).
1. Create your admin account. Visit http://localhost:4533/register. The first account on a fresh instance is automatically the administrator; later users join through the same form or an invite token (step 5).
2. Let the first library scan finish. scan_on_startup is on by default, so Minstrel walks your mounted library on boot and imports artists, albums, and tracks — no button to press. Watch progress (and re-scan any time) on the Admin page (/admin); the scan runs in stages and is incremental, so later restarts only pick up what changed.
3. (Optional) Name the instance and wire up integrations. In admin Settings → Integrations (/admin/integrations), add a ListenBrainz token (scrobbling + similarity radio) and/or a Lidarr URL + API key (the request flow). These live in the UI and apply without a restart; the display name can also be set via MINSTREL_BRANDING_APP_NAME.
4. Install the Android app. Open Settings (/settings) and use the Install the Android app card to download the APK that ships inside this server image, then sign in with the same account. From then on the app self-updates straight from your server.
5. Invite the rest of the household. From admin Users (/admin/users), generate an invite token (or enable open registration). Each person gets their own account, so likes, play history, and recommendations stay per-user.
For the full configuration surface, see config.example.yaml.
Configuration
Most operators only need the env vars in the quickstart above. A few extras worth knowing:
MINSTREL_BRANDING_APP_NAME— rename the instance ("Family Jukebox", "Office Music"). Surfaces in the header, browser tab, and OG share previews.MINSTREL_STORAGE_DATA_DIR— where generated artefacts (playlist cover collages, artist art, caches) are written. The container image sets this to/app/data, which is why the quickstart mounts theminstrel-datavolume there.MINSTREL_LIBRARY_SCAN_PATHS— colon-separated list of music library roots to scan. Supports multiple roots (/music:/podcasts).
ListenBrainz integration (per-user scrobble + similarity tokens) and Lidarr integration (URL + API key) are configured through the admin Settings UI rather than env vars or yaml — per Minstrel's "config in UI" rule, integration settings live where operators can edit them without restarting.
Most operational keys have a MINSTREL_<SECTION>_<FIELD> env override. Recommendation and events tuning are yaml-only. See config.example.yaml for the authoritative surface.
Updating
Image tags (git.fabledsword.com/bvandeusen/minstrel:<tag>):
:latest— the newest blessed image. Moves on everymainpush and every release. Recommended for most operators.:vYYYY.MM.DD— immutable per-day release tags. Pin one of these for a deployment you don't want moving under you. (Per-day CalVer — no trailing patch digit; a same-day re-cut moves the tag forward.):main— the rolling post-merge tip. Same image as:latestat push time; choose it if you want to trackmainexplicitly rather than the release line.
Every :latest and every :vYYYY.MM.DD bundles the current signed Android APK, so the in-app update channel is always live. Database migrations run automatically at startup; rollbacks require restoring a Postgres dump.
Specs
Authoritative scope lives under docs/:
- Server spec — current implementation focus.
- Client spec — Flutter companion app.
Development
Two concurrent dev processes:
- Backend:
docker compose up— Postgres + Minstrel on:4533. - Frontend:
cd web && npm install && npm run dev— Vite dev server on:5173with HMR. The Vite server proxies/api/*and/rest/*to:4533so session cookies work.
Testing
- Unit + race (no DB):
make test-short. - Full suite incl. integration tests:
make test-integration. This runs against a dedicatedminstrel_testdatabase so a test run never truncates your devminstreldata (admin user, library, likes). It brings up the compose Postgres and creates the test DB if missing. - CI runs both: a fast
go test -short -racegate plus an integration job with its own ephemeral Postgres (.gitea/workflows/test-go.yml).
Production build
docker build -t minstrel . runs the SvelteKit build inside a node stage, copies the output into the golang stage, and //go:embeds it into the final binary. The container serves the SPA from / alongside the API surfaces; no separate static-file server is required.
Branches
- Day-to-day work happens on
dev(or feature branches merged intodev). mainis protected — changes land via PR fromdev.- Releases are cut by tagging
v*offmain; the release workflow builds and pushes the container image to the Gitea registry.
Task and milestone tracking: Fable (Minstrel project, id 12).
License
See LICENSE.





