API Reference

API Reference

Every endpoint Moonbase exposes on the server. Paths are absolute and served by both the Jellyfin and Emby plugins unless noted.

Auth column:

• Yes requires any valid Jellyfin or Emby session.
• Admin requires an elevated (administrator) session.
• Session uses a stored Seerr session rather than the platform token.
• No is anonymous (used for web assets, discovery, and the inbound Seerr webhook, which has its own shared secret).

Some areas are gated by config: the Settings and public Themes endpoints return 503 when settings sync is disabled, and the Games endpoints return empty results or 404 when the game library feature is turned off.

Seerr rename: the primary prefix is /Moonfin/Seerr. The old /Moonfin/Jellyseerr prefix still works as a legacy alias for every Seerr endpoint, and some responses still include legacy jellyseerr* fields for older clients.

Status and settings

Method	Path	Auth	Description
GET	/Moonfin/Ping	Yes	Plugin status: version, whether sync is enabled, Seerr/MDBList/TMDB availability, and admin defaults
GET	/Moonfin/Defaults	Yes	The admin-configured default settings profile
GET	/Moonfin/Settings	Yes	The current user's full settings envelope
POST	/Moonfin/Settings	Yes	Save the current user's settings (merge or replace via body)
DELETE	/Moonfin/Settings	Yes	Delete all of the current user's settings
HEAD	/Moonfin/Settings	Yes	Check whether the current user has stored settings (200 or 404)
GET	/Moonfin/Settings/Stream	Yes	Server-sent events stream of settings changes, theme changes, and admin messages
GET, POST	/Moonfin/Settings/{userId}	Admin	Get or save another user's settings
GET	/Moonfin/Settings/Resolved/{profile}	Yes	The resolved flat values for a profile (global, desktop, mobile, tv)
POST, DELETE	/Moonfin/Settings/Profile/{profile}	Yes	Save or delete one device profile's overrides (global cant be deleted)
GET, POST	/Moonfin/Settings/detailsScreenBlur and /detailsScreenBlur/{profile}	Yes	Get or save the details-screen backdrop blur
GET, POST	/Moonfin/Settings/detailsScreenOpacity and /detailsScreenOpacity/{profile}	Yes	Get or save the details-screen backdrop opacity

See Settings Sync for the envelope shape and the full list of synced settings.

Admin

Method	Path	Auth	Description
POST	/Moonfin/Admin/PushDefaults	Admin	Apply admin defaults to all users (overwrite=true resets everyone, otherwise merges)
POST	/Moonfin/Admin/PushDefaults/{userId}	Admin	Apply admin defaults to a single user
POST	/Moonfin/Broadcast	Admin	Send an announcement to all users, over the SSE stream for connected clients and as a push to registered devices
GET	/Moonfin/Libraries/CheckWriteAccess	Admin	Test whether the server can write metadata to each library, and report failing paths

Media bar, genres, and themes

Method	Path	Auth	Description
GET	/Moonfin/MediaBar	Yes	The resolved media bar items for the current user (profile query, default global)
GET	/Moonfin/Genres	Yes	All genre names and ids across the user's movie and series libraries
GET	/Moonfin/Themes	Yes	List uploaded custom themes
GET	/Moonfin/Themes/{themeId}	Yes	Get one custom theme by id
GET	/Moonfin/Admin/Themes	Admin	Theme metadata index for the admin panel
POST	/Moonfin/Admin/Themes	Admin	Upload or replace a theme payload
DELETE	/Moonfin/Admin/Themes/{themeId}	Admin	Delete a theme

See Themes for the editor and upload flow.

Ratings (MDBList and TMDB)

Method	Path	Auth	Description
GET	/Moonfin/MdbList/Ratings	Yes	MDBList ratings for a title (type = movie or show, tmdbId), filtered to the user's chosen sources. An optional profile query (desktop, mobile, or tv) resolves the sources against that device profile, anything else falls back to global
GET	/Moonfin/MdbList/KeyInfo	Admin	Validate an MDBList API key and return the account's plan and remaining quota (backs the Test Key button, optional key query tests an unsaved key, otherwise the server-wide key is used)
POST	/Moonfin/MdbList/ClearCache	Admin	Drop every cached MDBList rating so lookups refetch from the API
GET	/Moonfin/MdbList/Lists	Yes	The cached catalog of MDBList official lists
GET	/Moonfin/MdbList/Lists/{slug}/Items	Yes	Cached items for one official list (optional mediatype)
GET	/Moonfin/Tmdb/EpisodeRating	Yes	TMDB rating for one episode (tmdbId, season, episode)
GET	/Moonfin/Tmdb/SeasonRatings	Yes	TMDB ratings for every episode in a season (tmdbId, season)
GET	/Moonfin/Tmdb/ProductionCompanies	Yes	TMDB studios for a title (tmdbId, type), each flagged for logo availability
GET	/Moonfin/Tmdb/StudioImage/{companyId}	Yes	A cached studio logo PNG (re-downloaded from TMDB if evicted)
GET	/Moonfin/Assets/{fileName}	No	Bundled rating provider icons
GET	/Moonfin/UserRatings/Mine	Yes	Every personal rating the calling user has set, in one response, so a client can sort a library by My Rating and filter it by liked or disliked. Neither server has a user rating sort of its own

Custom rows and collections

Method	Path	Auth	Description
GET	/Moonfin/CustomRows/Items	Yes	Resolve an external home row (source, type, params) into items, cached server-side for 24 hours
GET	/Moonfin/Collections/{collectionId}/Order	Yes	The current user's saved item order for a collection
POST	/Moonfin/Collections/{collectionId}/Order	Yes	Save the user's item order for a collection (empty array clears it)

Audiobook bookmarks and notes

Method	Path	Auth	Description
GET	/Moonfin/Bookmarks	Yes	Every bookmark the calling user has, across items
GET	/Moonfin/Bookmarks/{itemId}	Yes	One item's bookmarks and notes for the calling user
POST	/Moonfin/Bookmarks/{itemId}	Yes	Save the item's bookmarks for the calling user
POST	/Moonfin/Bookmarks/{itemId}/Notes	Yes	Save the item's notes for the calling user

Clients work from local storage first and reconcile with these, so nothing waits on the network to open a book.

Retro games

All game endpoints require the game library feature to be enabled. See Retro Games for the full guide.

Method	Path	Auth	Description
GET	/Moonfin/Games/Libraries	Yes	Libraries treated as game (ROM) libraries
GET	/Moonfin/Games/{libraryId}/Systems	Yes	Top-level system folders in a game library
GET	/Moonfin/Games/{libraryId}/Games	Yes	Games in a library, optionally filtered by system
GET	/Moonfin/Games/{libraryId}/Games/{gameId}	Yes	One game's full detail (ROM, core, BIOS)
GET	/Moonfin/Games/{libraryId}/Thumb/{gameId}	Yes	Stream a game's box art or screenshot (type query), downloaded and cached on first request
GET	/Moonfin/Games/{libraryId}/Rom/{token}	Yes	Stream a ROM file, auto-extracting archives, with range support
GET	/Moonfin/Games/{libraryId}/Rom/{token}/{fileName}	Yes	The same stream with an explicit file name, which some cores need to identify the ROM
GET	/Moonfin/Games/{libraryId}/Bios/{token}	Yes	Stream a BIOS file a core needs
GET	/Moonfin/Games/Cores/Status	Yes	Whether the self-hosted emulator cores are installed or downloading
POST	/Moonfin/Games/Cores/Install	Admin	Download and install the cores bundle in the background
POST	/Moonfin/Games/Cores/Upload	Admin	Install cores from an uploaded zip
GET	/Moonfin/Games/Saves/{gameId}	Yes	Download a saved game blob for the current user (kind, default state)
PUT	/Moonfin/Games/Saves/{gameId}	Yes	Upload or overwrite a saved game blob (max 32 MB)
GET	/Moonfin/EmulatorJS/player.html	No	The in-browser player shell
GET	/Moonfin/EmulatorJS/data/{**path}	No	Self-hosted EmulatorJS runtime files, with a CDN fallback when not installed
GET	/Moonfin/Games/Debug	Admin	Diagnostics for game library detection
PUT	/Moonfin/Games/{libraryId}/Games/{gameId}/Core	Yes	Pin one game to a specific core
PUT	/Moonfin/Games/{libraryId}/Games/{gameId}/Backend	Yes	Pin one game to the native or EmulatorJS backend

Artwork

Method	Path	Auth	Description
GET	/Moonfin/Games/ArtworkCapabilities	Yes	Advertises the manifest-driven artwork protocol, so older clients keep the old path
GET	/Moonfin/Games/{libraryId}/ArtworkManifest	Yes	The cataloged artwork state for one system, without scheduling any provider work. Returns 304 when nothing changed
POST	/Moonfin/Games/{libraryId}/ArtworkPriority	Yes	Promotes already cataloged artwork into the order the client actually needs it
GET	/Moonfin/Games/{libraryId}/Artwork/{gameId}/{role}/{revision}	Yes	One versioned artwork file, served locally
POST	/Moonfin/Games/{libraryId}/Artwork/{gameId}/Refresh	Admin	Repair path that reopens and reschedules one artifact

Arcade compatibility

Method	Path	Auth	Description
GET	/Moonfin/Games/ArcadeCompatibility/Status	Admin	Whether the FBNeo and MAME data files are installed, and what they cover
PUT	/Moonfin/Games/ArcadeCompatibility/{core}/Dat	Admin	Replace one core's data file with an uploaded XML, up to 512 MB

Active downloads

Method	Path	Auth	Description
GET	/Moonfin/Transcodes/Active	Admin	Active transcode and download jobs with progress and session info (includePlayback adds HLS playback jobs)
DELETE	/Moonfin/Transcodes/Active/{jobId}	Admin	Cancel an active job
GET	/Moonfin/Transcodes/Mine	Yes	The caller's own transcode jobs, scoped by the device id on its token, so a client can show progress and an ETA for a download it started

Seerr

Method	Path	Auth	Description
GET	/Moonfin/Seerr/Config	Yes	Seerr config for the client (see the response shape below)
POST	/Moonfin/Seerr/Login	Yes	Sign in to Seerr with Jellyfin/Emby or local credentials and store the session
GET	/Moonfin/Seerr/Status	Yes	Whether Seerr is enabled and the current user's session status
GET	/Moonfin/Seerr/Validate	Yes	Confirm the stored session is still valid
DELETE	/Moonfin/Seerr/Logout	Yes	Log out and clear the stored session
GET, POST, PUT, DELETE	/Moonfin/Seerr/Api/{**path}	Session	Authenticated proxy to the Seerr API using the stored session

The /Moonfin/Jellyseerr/... prefix mirrors all of the above. See Reverse Proxy and Seerr for proxy and single sign-on notes.

Seerr config response

{
  "enabled": true,
  "url": "https://seerr.example.com",
  "displayName": "Seerr",
  "variant": "seerr",
  "userEnabled": true
}

Field	Type	Description
enabled	bool	Whether Seerr is enabled by the admin
url	string	The Seerr server URL used for proxying
displayName	string	The name shown in the client (admin override, defaults to Seerr)
variant	string	Always seerr on current versions
userEnabled	bool	Whether the user has Seerr enabled in their own settings

Notifications (Seerr and new media)

Method	Path	Auth	Description
GET, POST	/Moonfin/Notifications/Prefs	Yes	Get or save the caller's notification preferences, including the new media opt-in (notifyOnNewMedia)
POST, DELETE	/Moonfin/Notifications/Register	Yes	Register or remove a push token for the caller's device
GET	/Moonfin/Notifications/WebhookInfo	Admin	The Seerr webhook URL, secret, supported types, and provisioning status
POST	/Moonfin/Notifications/Reprovision	Admin	Re-register Moonfin's webhook in Seerr immediately
POST	/Moonfin/Seerr/Webhook	No (shared secret)	Inbound Seerr webhook, authenticated by the secret query or X-Moonfin-Webhook-Secret header

Web hosting and discovery

Method	Path	Auth	Description
GET	/Moonfin/Web/{**path}	No	Serve the Moonfin web app static files with SPA fallback
GET	/Moonfin/Web/config.json	No	Runtime config for web plugin mode
GET	/Moonfin/Web/loader.js	No	The loader bridge script for the stock Jellyfin header button
GET	/Moonfin/Discovery and /Moonfin/Discovery/discover	No	Same-origin server metadata for web discovery