Metadata

Build metadata providers that power search, artist pages, and album views in Nuclear.

Metadata Providers

Metadata providers supply Nuclear with information about artists, albums, and tracks. When a user searches for music or opens an artist page, Nuclear delegates to whatever metadata provider is active. Without one, there's nothing to search and nothing to display.

Plugins can either add new providers, or use data from existing providers.

Most plugins will add a new provider. Check out the Discogs plugin for a good reference implementation.

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Implementing a provider

Minimal example

A metadata provider is an object that you register with api.Providers.register(). At minimum, it needs an id, kind: 'metadata', a name, and at least one search method:

import type { MetadataProvider, NuclearPlugin, NuclearPluginAPI } from '@nuclearplayer/plugin-sdk';

const provider: MetadataProvider = {
  id: 'my-metadata',
  kind: 'metadata',
  name: 'My Metadata Source',

  searchCapabilities: ['artists', 'albums'],

  async searchArtists(params) {
    // Call your API, return ArtistRef[]
  },
  async searchAlbums(params) {
    // Call your API, return AlbumRef[]
  },
};

const plugin: NuclearPlugin = {
  onEnable(api: NuclearPluginAPI) {
    api.Providers.register(provider);
  },
  onDisable(api: NuclearPluginAPI) {
    api.Providers.unregister('my-metadata');
  },
};

export default plugin;

Always unregister your provider in onDisable. If you don't, it stays registered and Nuclear may still route queries to it after the plugin is disabled.

Capabilities

Capabilities tell Nuclear which methods your provider supports. Nuclear will never call a method you haven't declared a capability for.

Search capabilities

Declared via searchCapabilities. Controls which search methods Nuclear calls:

Capability	Method called	Returns
'artists'	searchArtists(params)	ArtistRef[]
'albums'	searchAlbums(params)	AlbumRef[]
'tracks'	searchTracks(params)	Track[]
'playlists'	searchPlaylists(params)	PlaylistRef[]
'unified'	search(params)	SearchResults

The search params for individual methods (searchArtists, searchAlbums, etc.) contain query and limit. For search (unified), there's an additional types array so you know which categories were requested.

Most providers should implement individual search methods (searchArtists, searchAlbums, etc.). Use 'unified' only if your API has a single endpoint that returns all types at once.

Artist metadata capabilities

Declared via artistMetadataCapabilities. Controls artist detail pages:

Capability	Method called	Returns
'artistDetails'	fetchArtistDetails(artistId)	Artist
'artistAlbums'	fetchArtistAlbums(artistId)	AlbumRef[]
'artistTopTracks'	fetchArtistTopTracks(artistId)	TrackRef[]
'artistRelatedArtists'	fetchArtistRelatedArtists(artistId)	ArtistRef[]

Album metadata capabilities

Declared via albumMetadataCapabilities:

Capability	Method called	Returns
'albumDetails'	fetchAlbumDetails(albumId)	Album

You don't have to support everything. Declare only what your source can provide. Nuclear adapts the UI based on what's available - for example, if you don't declare 'artistTopTracks', the top tracks section won't appear on artist pages.

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Return types

Your provider methods must return objects matching types from @nuclearplayer/model (also exported from @nuclearplayer/plugin-sdk). Every entity has a source field (ProviderRef) that identifies where it came from.

Thumbnails and artwork

Nuclear picks the best artwork for each context. These include thumbnails, cover art, background images, or artist profile pictures. Provide multiple sizes when you can.

ProviderRef

Every entity needs a source that ties it back to your provider. This is how Nuclear navigates between search results and detail pages.

type ProviderRef = {
  provider: string;  // Must match your provider's id
  id: string;        // Your provider's identifier for this entity
  url?: string;      // Optional link to the source page
};

Compound IDs

The id can be anything your provider understands. You'll receive it back in fetchArtistDetails(id), fetchAlbumDetails(id), etc.

Example: The Discogs plugin uses compound IDs like master:12345 to encode both the release type (release/master) and ID in a single string.

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Using metadata

Plugins can also query the active metadata provider. Use api.Metadata.* to search and fetch details without knowing which provider is registered.

export default {
  async onEnable(api: NuclearPluginAPI) {
    const results = await api.Metadata.search({
      query: 'Radiohead',
      types: ['artists', 'albums'],
      limit: 10,
    });

    if (results.artists?.length) {
      const artistId = results.artists[0].source.id;
      const providerId = results.artists[0].source.provider;

      // Fetch full details (routes to the same provider that returned the search result)
      const artist = await api.Metadata.fetchArtistDetails(artistId, providerId);
      const albums = await api.Metadata.fetchArtistAlbums(artistId, providerId);
    }
  },
};

Consumer reference

api.Metadata.search(params: SearchParams, providerId?: string): Promise<SearchResults>
api.Metadata.fetchArtistDetails(artistId: string, providerId?: string): Promise<Artist>
api.Metadata.fetchArtistAlbums(artistId: string, providerId?: string): Promise<AlbumRef[]>
api.Metadata.fetchArtistTopTracks(artistId: string, providerId?: string): Promise<TrackRef[]>
api.Metadata.fetchArtistRelatedArtists(artistId: string, providerId?: string): Promise<ArtistRef[]>
api.Metadata.fetchAlbumDetails(albumId: string, providerId?: string): Promise<Album>

All methods accept an optional providerId. If omitted, Nuclear uses the first registered metadata provider.

The artistId and albumId values are provider-specific. Always pass the providerId from the same ProviderRef that gave you the ID. Mixing IDs from one provider with a different providerId will produce errors or wrong results.