fix(jellyfin): resolve library-view ids in getItem so clients can load the library

server/jellyfin/items.go

@@ -3,6 +3,7 @@ package jellyfin
 import (
 	"context"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"github.com/Masterminds/squirrel"
@@ -233,13 +234,30 @@ func (api *Router) listPlaylists(ctx context.Context, opts model.QueryOptions, f
 	return result(slice.Map(playlists, dto.PlaylistToBaseItem), int(total), opts.Offset), nil
 }
 
-// getItem fetches a single entity by id, trying album, artist and song in turn. For albums
-// and songs (which each belong to exactly one library) it 404s if the current user lacks
-// access to that library, so an id can't be used to probe content outside the user's libraries.
+// getItem fetches a single entity by id, trying library view, album, artist and song in turn.
+// For albums and songs (which each belong to exactly one library) it 404s if the current user
+// lacks access to that library, so an id can't be used to probe content outside the user's
+// libraries.
 func (api *Router) getItem(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 	id := chi.URLParam(r, "itemId")
 	u, _ := request.UserFrom(ctx)
+	// Finamp resolves a /UserViews entry (Id=library id) by fetching it as a plain item; without
+	// this, the home screen and every library tab 404 trying to probe it as an album/artist/song.
+	if libID, err := strconv.Atoi(id); err == nil && u.HasLibraryAccess(libID) {
+		for _, lib := range u.Libraries {
+			if lib.ID == libID {
+				api.ok(w, r, libraryView(lib))
+				return
+			}
+		}
+		// Admin bypass: Libraries is empty but access is granted to every library, so fetch the
+		// real one instead of returning a placeholder.
+		if lib, err := api.ds.Library(ctx).Get(libID); err == nil {
+			api.ok(w, r, libraryView(*lib))
+			return
+		}
+	}
 	if al, err := api.ds.Album(ctx).Get(id); err == nil {
 		if !u.HasLibraryAccess(al.LibraryID) {
 			http.Error(w, "Not Found", http.StatusNotFound)

server/jellyfin/items_test.go

@@ -400,6 +400,47 @@ var _ = Describe("Items", func() {
 			Expect(json.Unmarshal(w.Body.Bytes(), &item)).To(Succeed())
 			Expect(item.Id).To(Equal("a1"))
 		})
+
+		// Finamp fetches a /UserViews entry (Id=library id) as a plain item to resolve the
+		// library node before it can load the home screen or any library tab.
+		It("resolves a library-view id (from /UserViews) as a CollectionFolder item", func() {
+			w := httptest.NewRecorder()
+			libs := model.Libraries{{ID: 1, Name: "Music Library"}}
+			r := httptest.NewRequest("GET", "/Items/1", nil).WithContext(ctxUserWithLibraries(libs))
+			r = withChiURLParam(r, "itemId", "1")
+			api.getItem(w, r)
+			Expect(w.Code).To(Equal(http.StatusOK))
+			var item dto.BaseItemDto
+			Expect(json.Unmarshal(w.Body.Bytes(), &item)).To(Succeed())
+			Expect(item.Id).To(Equal("1"))
+			Expect(item.Name).To(Equal("Music Library"))
+			Expect(item.Type).To(Equal("CollectionFolder"))
+			Expect(item.CollectionType).To(Equal("music"))
+			Expect(item.IsFolder).To(BeTrue())
+		})
+
+		It("does not resolve a library-view id the user has no access to", func() {
+			w := httptest.NewRecorder()
+			libs := model.Libraries{{ID: 2, Name: "Other"}} // no access to library 1
+			r := httptest.NewRequest("GET", "/Items/1", nil).WithContext(ctxUserWithLibraries(libs))
+			r = withChiURLParam(r, "itemId", "1")
+			api.getItem(w, r)
+			Expect(w.Code).To(Equal(http.StatusNotFound))
+		})
+
+		It("resolves a library-view id for an admin even though their Libraries slice is empty", func() {
+			ds.Library(context.Background()).(*tests.MockLibraryRepo).SetData(model.Libraries{{ID: 1, Name: "Music Library"}})
+			w := httptest.NewRecorder()
+			r := httptest.NewRequest("GET", "/Items/1", nil).WithContext(ctxAdmin())
+			r = withChiURLParam(r, "itemId", "1")
+			api.getItem(w, r)
+			Expect(w.Code).To(Equal(http.StatusOK))
+			var item dto.BaseItemDto
+			Expect(json.Unmarshal(w.Body.Bytes(), &item)).To(Succeed())
+			Expect(item.Id).To(Equal("1"))
+			Expect(item.Name).To(Equal("Music Library"))
+			Expect(item.Type).To(Equal("CollectionFolder"))
+		})
 	})
 
 	Describe("getLatest", func() {

server/jellyfin/library.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"strconv"
 
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/server/jellyfin/dto"
 )
 
 // accessibleLibraryIDs returns the ids of the libraries the current user can access. An
@@ -30,3 +32,18 @@ func resolveLibraryScope(ctx context.Context, parentId string) (scopeIDs []int,
 	}
 	return accessibleLibraryIDs(ctx), false
 }
+
+// libraryView builds the CollectionFolder BaseItemDto Jellyfin clients use to represent a
+// library as a top-level browsing node. It's shared by getUserViews (which lists every
+// accessible library) and getItem (which resolves a single one), since Finamp fetches a
+// UserView's id as a plain item to load the library.
+func libraryView(lib model.Library) dto.BaseItemDto {
+	return dto.BaseItemDto{
+		Id:                strconv.Itoa(lib.ID),
+		Name:              lib.Name,
+		Type:              "CollectionFolder",
+		CollectionType:    "music",
+		IsFolder:          true,
+		BackdropImageTags: []string{},
+	}
+}

server/jellyfin/users.go

@@ -2,7 +2,6 @@ package jellyfin
 
 import (
 	"net/http"
-	"strconv"
 
 	"github.com/navidrome/navidrome/model/request"
 	"github.com/navidrome/navidrome/server/jellyfin/dto"
@@ -15,14 +14,7 @@ func (api *Router) getUserViews(w http.ResponseWriter, r *http.Request) {
 	u, _ := request.UserFrom(r.Context())
 	views := make([]dto.BaseItemDto, 0, len(u.Libraries))
 	for _, lib := range u.Libraries {
-		views = append(views, dto.BaseItemDto{
-			Id:                strconv.Itoa(lib.ID),
-			Name:              lib.Name,
-			Type:              "CollectionFolder",
-			CollectionType:    "music",
-			IsFolder:          true,
-			BackdropImageTags: []string{},
-		})
+		views = append(views, libraryView(lib))
 	}
 	api.ok(w, r, dto.QueryResult{Items: views, TotalRecordCount: len(views), StartIndex: 0})
 }