Emby is Jellyfin's upstream ancestor and speaks a near-identical MediaBrowser
API, so the existing Jellyfin stack is parameterised by a `MediaBrowserDialect`
rather than forked. `JellyfinClient`, its auth service, endpoint discovery, LAN
discovery, and the add/edit connection screens all take the dialect and keep one
implementation; `MediaBackend.emby` and `ConnectionKind.emby` carry it through
the neutral models, the Drift `kind` discriminator, downloads, and caches.
Every divergence below was measured against a live Emby 4.9.5 server, not
inferred from documentation, and each is documented at its capability getter.
Jellyfin's request strings stay byte-identical so nothing about its behaviour
changes.
Routes and auth
- Emby only accepts the pre-10.9 user-scoped item routes (`/Users/{id}/Items/…`,
`/Users/{id}/PlayedItems/…`, `/Users/{id}/FavoriteItems/…`); the unprefixed
forms Jellyfin 10.11 added return 404.
- The API is also served under a legacy `/emby` prefix, and both dialects accept
the token as `X-Emby-Token` or `api_key=`.
- Emby answers only its own LAN discovery datagram ("who is EmbyServer?") and
ignores Jellyfin's; its default HTTPS port is 8920.
- No `/QuickConnect` route exists, so Quick Connect stays Jellyfin-only.
Row fields Emby withholds
- `ProductionYear`, `OfficialRating`, `PremiereDate` and `DateCreated` are absent
from list rows unless named in `Fields`, which would otherwise strip the year
and age-rating badge from every card in the app.
- `UserData.LastPlayedDate` never appears on a list row under `Fields=UserData`,
`EnableUserData=true` or the user-scoped `Ids=` form — only on the single-item
detail route, or when the Emby-specific `UserDataLastPlayedDate` token is
requested. Without it every recency-ordered surface silently degrades to
library-add time, and `JellyfinApiCache.applyWatchState` stamps
`DateTime.now()` on watched rows, so an offline watch-state pull would rewrite
the cached play time of everything it walked.
Continue Watching and Next Up
- Emby computes Next Up per series only: the library-wide `/Shows/NextUp` query
returns nothing under every parameter combination tried. The shelf is
therefore reconstructed from a played-episode recency scan plus one
`/Shows/NextUp?SeriesId=` per distinct series, bounded by a shared wall clock
that covers the scan as well — per-request timeouts cannot bound the pass
because `MediaServerHttpClient` times the connect and receive phases
independently. Rows are stamped with their series' newest play from the same
response that ordered them, so no per-series enrichment request is needed.
- `/Shows/NextUp` ignores `NextUpDateCutoff`, and no server-side played-date
filter exists to delegate to (`MinDatePlayed` and `MinDateLastPlayed` are
ignored; `MinDateLastSaved`, `MinDateCreated` and `MinPremiereDate` filter
unrelated dates), so the 365-day window is applied to the scanned dates.
- The resume route returns items with no saved position, including plain next
episodes, so the Emby resume leg reads from `/Items?Filters=IsResumable`.
- Emby is ahead of Jellyfin in one place: `/Users/{id}/Items/{id}/HideFromResume`
makes Continue Watching removal a real capability.
Everything else
- `/Sessions/Playing` and `/Sessions/Playing/Progress` reject a body with no
`PlaySessionId` (HTTP 400), so playback reporting always sends one.
- Passing any `MediaTypes` value to the playlist query returns an empty list.
- There is no aggregate `/Items/Filters` route; the four filter facets are
reassembled from `/Genres`, `/OfficialRatings`, `/Studios` and `/Tags`.
- Metadata writes take name-pair lists (`Genres: [{'Name': 'Action'}]`); the
plain string array is accepted and then silently discarded.
- Custom artwork uploads must be base64 text, not raw bytes — which was broken
for Jellyfin too and is fixed for both.
- Trickplay, media segments and lyrics 404 on Emby, so scrub previews are absent
and intro/credit markers fall back to chapter names.
Verified against a local Emby 4.9.5 and a Jellyfin 10.11.11 control server:
onboarding, browse, detail, playable stream URLs serving real bytes, subtitle
sidecars, watch-state write and restore, hubs, cross-server aggregation and
search across both backends simultaneously.
Trakt was the one service outside the tracker abstraction. TraktScrobbleService
re-implemented the whole playback lifecycle beside TrackerCoordinator, and
TraktSyncService pushed watched state from its own WatchStateNotifier
subscription, so the player called two objects at every lifecycle point and one
watch could be written twice. TraktTracker now implements RealtimeScrobbleTracker
like Simkl; the duplicated player call sites collapse to one each, and Trakt
shares the coordinator's ID resolver instead of re-fetching show ids every
episode.
Capabilities are split so a tracker declares what it is rather than being
special-cased: ScrobblePolicy carries each service's own resend/seek rules,
EpisodeHistoryTracker names the remote row a per-item history write targets, and
SeriesProgressTracker covers one-counter-per-series services. Writes from all
four trackers go through a shared TrackerWriteQueue, generalised from the
Trakt-only queue, with the legacy Trakt payload migrated on load. Trakt becomes
the fourth TrackersProvider slot and TraktAccountProvider is deleted, so one
object owns the active session per profile.
Two failure paths found while consolidating are fixed here too.
The queue's retries only ran on profile bind, connect and app foreground, so a
network blip mid-session left queued watches waiting for the next foreground.
OfflineModeProvider now notifies on connectivity changes, not just offline-state
or WiFi-flag changes, and main.dart flushes the queue when the network returns.
The queue also counted every failure toward the five attempts that permanently
drop an item, so a rate limit or a service having a bad hour could discard a
pending watch - the loss the queue exists to prevent. Only an answer about the
write itself now spends an attempt: 4xx counts, while rate limits, 5xx,
recoverable token-refresh failures and requests that never arrived do not. A
back-off answer also defers that service for the rest of the flush, so a queue
holding many rows does not fire all of them at a service that just asked for
quiet.
edde746