diff --git a/internal/audiobooks/abs/libraries_handler.go b/internal/audiobooks/abs/libraries_handler.go
index 3e36497c..127921ad 100644
--- a/internal/audiobooks/abs/libraries_handler.go
+++ b/internal/audiobooks/abs/libraries_handler.go
@@ -571,6 +571,7 @@ func siloItemToLibraryItem(item *models.MediaItem, lib AudiobookLibrary, baseURL
 			Tracks:     []AudioTrack{},
 			Chapters:   []ChapterABS{},
 			NumTracks:  0, // populated by item-detail handler
+			Tags:       []string{},
 		},
 		AddedAt:   addedAtMs,
 		UpdatedAt: updatedAtMs,
diff --git a/internal/audiobooks/abs/types.go b/internal/audiobooks/abs/types.go
index f5ee26b3..363a7e20 100644
--- a/internal/audiobooks/abs/types.go
+++ b/internal/audiobooks/abs/types.go
@@ -121,6 +121,13 @@ type LibraryItemMedia struct {
 	Tracks     []AudioTrack `json:"tracks"`
 	Chapters   []ChapterABS `json:"chapters"`
 	NumTracks  int          `json:"numTracks"`
+	// Tags is a book-level tag list. NEVER null on the wire — the ABS
+	// Android client's Kotlin `Book.tags: List<String>` is non-nullable,
+	// so Jackson throws MissingKotlinParameterException when the field
+	// is absent (or null) and the entire LibraryItem fails to parse —
+	// which silently breaks downloads (the downloader's apiHandler
+	// callback receives null and gives up). Always emit []  in v1.
+	Tags []string `json:"tags"`
 }
 
 // CollapsedSeriesV1 is the per-item annotation real ABS attaches when