fd377a7446
Fourth and final step of ADR-008's server half. When nothing the client declared can direct-play a file and this host can re-encode, resolve now answers playable with engine "transcode". The client sees a string it already understands, so the frozen JSON contract did not change. The ordering is the whole point and is asserted directly: transcoding sits after the direct-play loop, so a file that plays directly never pays for it. Re-encoding something a client could already decode would burn the GPU and lose quality for nothing, which is the failure mode ADR-008 rejects by choosing direct play first. Verified red-green - hoisting the check above the loop fails with "direct play must always win". The capability is resolved once at boot and passed in, not read inside a request: detection spawns ffmpeg to prove the encoder works, and that must never happen on the request path. It is also passed rather than read from the transcode package so the tests can drive both answers without hardware. TranscodeID is deliberately not a registry entry. Every other engine is something a client declares; this one is the server's own capability, so it is not advertised in /playback/engines and a client must not name it. On a host with no usable encoder canTranscode is false and every answer is byte-identical to what it was before any of this existed - which is this deployment, and is why ADR-002 still holds for it. |
||
|---|---|---|
| cmd/vellum | ||
| docs | ||
| internal | ||
| migrations | ||
| scripts | ||
| web | ||
| .dockerignore | ||
| .gitignore | ||
| compose.yml | ||
| DEPLOY.md | ||
| Dockerfile | ||
| entrypoint.sh | ||
| go.mod | ||
| go.sum | ||
| LICENSE | ||
| Makefile | ||
| README.md | ||
Vellum
One application, one process, one database for every media type — ebooks, comics, audiobooks, music, photos, games, and video — behind a single account system with real per-user progress and per-library permissions.
A modular monolith. One Go binary, one SQLite file, one web frontend.
The full plan lives in ~/.opencode/plan/vellum.md.
Status
| Phase | Scope | State |
|---|---|---|
| 0 | Repo, config, migrations, health, Docker | done |
| 1 | Users, sessions, library grants | done |
| 2 | Scanner, items, assets | done |
| 2b | FTS5 search | done |
| 3 | EPUB reader + progress | done |
| 4 | CBZ comic reader | done |
| PDF reading (pdf.js) | done | |
| 5 | Job queue, metadata (Open Library, Google Books, MusicBrainz, ComicVine, IGDB, TMDB) | done |
| 6a | Audiobooks + music playback | done |
| 6c | Photos + thumbnails | done |
| 7 | Games: ROM scanning, platforms, cloud saves, EmulatorJS | done |
| UI | Svelte app: home, browse, item pages, readers | done |
| 6b | Music smart playlists | not started |
| — | Video (stays on Jellyfin) | deferred |
What works today: an administrator adds libraries pointing at server folders, scans them, and optionally enriches metadata. Users sign in and read EPUBs and PDFs, read CBZ comics, listen to audiobooks track-by-track, browse photos, and play emulated games in the browser with their own cloud saves — with position saved per account, per file.
Six media types work: ebooks, comics, audiobooks, music, photos, games. Video is the only one not implemented, and it stays on Jellyfin on purpose.
Of the services in the existing stack, this covers Stump, Kavita, Audiobookshelf, Navidrome, and RomM. Only Jellyfin (video) is left.
Quick start
sudo dnf install golang # once; Go is not in the base image here
make build
make run
curl localhost:7788/healthz # {"database":"ok","status":"ok",...}
Run with media roots configured:
VELLUM_MEDIA_DIRS=/mnt/storage/media/ebooks:/mnt/storage/media/comics make run
Configuration
All configuration is environment variables. Every one has a default, so the binary runs with no configuration at all.
| Variable | Default | Meaning |
|---|---|---|
VELLUM_LISTEN |
:7788 |
Bind address |
VELLUM_DATA_DIR |
./data |
SQLite database lives here |
VELLUM_CONFIG_DIR |
./config |
Regenerable cache (covers, pages) |
VELLUM_MEDIA_DIRS |
(none) | Read-only library roots, colon-separated |
VELLUM_ADMIN_USER |
(none) | Creates the first admin, only on an empty database |
VELLUM_ADMIN_PASSWORD |
(none) | Password for that first admin (min 8 chars) |
VELLUM_COOKIE_SECURE |
false |
Set true when serving over TLS |
VELLUM_COMICVINE_API_KEY |
(none) | Enables comic metadata via ComicVine |
VELLUM_DISCOVERY |
on |
Set off to stop advertising over mDNS on the LAN |
VELLUM_IGDB_CLIENT_ID |
(none) | Enables game metadata via IGDB |
VELLUM_IGDB_CLIENT_SECRET |
(none) | IGDB client secret (both required) |
VELLUM_TMDB_API_KEY |
(none) | Enables movie and TV metadata via TMDB |
VELLUM_LOG_LEVEL |
info |
debug, info, warn, error |
VELLUM_LOG_FORMAT |
text |
text or json |
VELLUM_SESSION_TTL |
720h |
Login session lifetime |
VELLUM_SHUTDOWN_GRACE |
15s |
Graceful shutdown timeout |
The first admin is created only when no users exist, so setting these on an established install does nothing. If the database is empty and they are unset, the server logs a warning and refuses to invent a default password.
Layout
cmd/vellum/ main — wiring and lifecycle only, the one place packages meet
internal/
core/ config, logging, database, migrations, timestamps
httpx/ shared JSON helpers
httpapi/ router, middleware, security headers, static SPA serving
auth/ argon2id, sessions, grants, bootstrap
apitoken/ credentials for non-browser clients (Jellyfin, Subsonic)
catalog/ THE data seam: read an item, and check you may
library/ library CRUD and the media-type registry
scanner/ walk the filesystem and reconcile with the database
probe/ ffprobe wrapper — codec facts (optional dependency)
media/ generic item/file/cover/progress endpoints
home/ the five home shelves
search/ FTS5 queries
metadata/ the enrichment job and its matching policy
providers/ Open Library, Google Books, MusicBrainz, ComicVine, IGDB, TMDB
playback/ playback engine selection endpoint
engine/ playback engine registry (html5, mpv, vlc, mdk)
progress/ the polymorphic per-user progress store
stream/ range-capable file serving
jobs/ table-backed job queue
natsort/ natural ordering for pages and tracks
jellyfin/ Jellyfin protocol adapter (+ dto/)
subsonic/ Subsonic protocol adapter (+ dto/)
discovery/ mDNS advertisement on the LAN
arch/ import-rule tests; holds no code
modules/
ebooks/ EPUB parsing and cover extraction
comics/ CBZ page listing and extraction
games/ platforms, IGDB, cloud saves, EmulatorJS
photos/ thumbnail generation
web/ Svelte app; dist/ is embedded via web/embed.go
migrations/ embedded SQL, applied in order at boot
docs/ architecture guide and decision records
Module rule: the core never imports a feature module; modules import the core and mount their own routes, tables, and scanner rules. Adding a media type is a new package plus a migration, never a core edit.
Layer rule: packages are arranged in six layers and a package may never
import from a higher one. This is enforced by tests in internal/arch, not by
convention — see docs/ARCHITECTURE.md.
Schema rule: media items are global; everything user-specific is a join. Nothing may hold per-user state on a media row.
Documentation
- docs/ARCHITECTURE.md — how the pieces fit and why.
- docs/decisions/ — the decisions that were expensive to reverse, with the alternatives that were rejected.
Database
SQLite in WAL mode, opened through modernc.org/sqlite — a pure-Go driver, so
the binary builds with CGO_ENABLED=0 and cross-compiles without a toolchain
per target.
Migrations are embedded and applied in filename order; applied files are
recorded only by number in PRAGMA user_version, so never edit an applied
migration — add a new one.
Back up by copying the database (or its directory); VACUUM INTO 'backup.db'
takes a consistent snapshot while running.
Deploy
make docker # podman build
podman compose up -d # see compose.yml
The container mounts /data (database), /config (cache), and /media
(read-only). On SELinux hosts every bind mount needs :z — compose.yml
already has it.
The application never writes to /media.
Development
make dev # backend + Vite dev server together, with hot reload
make build # builds the frontend, then the Go binary with it embedded
make build-go # Go only, when the frontend is unchanged
make check # gofmt + vet + test
make run # run the server on :7788
cd web && pnpm dev # frontend only; needs the backend running on :7788
make dev is the one to reach for while developing: it builds and starts the
backend, waits for it to answer, then starts Vite. Vite proxies /api to the
backend so the browser sees a single origin and sessions behave exactly as in
production. Ctrl-C stops both.
If you run Vite on its own, the backend must already be running, or every
request fails with ECONNREFUSED on :7788.