added desktop parity multi artist metadata

modules/astra-library-scanner/android/src/androidTest/java/expo/modules/astralibraryscanner/data/ArtistCreditMetadataReaderTest.kt

@@ -0,0 +1,62 @@
+package expo.modules.astralibraryscanner.data
+
+import android.content.Context
+import android.net.Uri
+import android.util.Base64
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import java.io.File
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ArtistCreditMetadataReaderTest {
+  private lateinit var fixture: File
+  private lateinit var invalidFixture: File
+
+  @Before
+  fun writeFixtures() {
+    val context = ApplicationProvider.getApplicationContext<Context>()
+    fixture = File(context.cacheDir, "repeated-artists.opus").apply {
+      writeBytes(Base64.decode(OPUS_FIXTURE_BASE64, Base64.DEFAULT))
+    }
+    invalidFixture = File(context.cacheDir, "invalid-artists.opus").apply {
+      writeBytes(byteArrayOf(0x00, 0x01, 0x02))
+    }
+  }
+
+  @After
+  fun removeFixtures() {
+    fixture.delete()
+    invalidFixture.delete()
+  }
+
+  @Test
+  fun exoMetadataStackReturnsEveryRepeatedOpusCredit() {
+    val context = ApplicationProvider.getApplicationContext<Context>()
+
+    val credits = ArtistCreditMetadataReader.read(context, Uri.fromFile(fixture), 12_000)
+
+    assertEquals(listOf("Earth, Wind & Fire", "The Emotions"), credits.artists)
+    assertEquals(listOf("Curator One", "Curator Two"), credits.albumArtists)
+  }
+
+  @Test
+  fun unreadableContainerFallsBackToEmptyCredits() {
+    val context = ApplicationProvider.getApplicationContext<Context>()
+
+    assertEquals(
+      ArtistCreditNames(),
+      ArtistCreditMetadataReader.read(context, Uri.fromFile(invalidFixture), 1_000),
+    )
+  }
+
+  private companion object {
+    // 80 ms of silent Opus audio with two ARTIST and two ALBUMARTIST comments.
+    const val OPUS_FIXTURE_BASE64 =
+      "T2dnUwACAAAAAAAAAACRB/HqAAAAANqihuMBE09wdXNIZWFkAQE4AYC7AAAAAABPZ2dTAAAAAAAAAAAAAJEH8eoBAAAArQRGQgGoT3B1c1RhZ3MNAAAAQXN0cmEgZml4dHVyZQUAAAAZAAAAQVJUSVNUPUVhcnRoLCBXaW5kICYgRmlyZRMAAABBUlRJU1Q9VGhlIEVtb3Rpb25zFwAAAEFMQlVNQVJUSVNUPUN1cmF0b3IgT25lFwAAAEFMQlVNQVJUSVNUPUN1cmF0b3IgVHdvHQAAAFRJVExFPVJlcGVhdGVkIEFydGlzdCBGaXh0dXJlT2dnUwAEOBAAAAAAAACRB/HqAgAAAGOKDDAFBwYGBgYIC+S5oLyECAfGsw7GCAfGsw7GCAfGsw7GCAfGsw7G"
+  }
+}

modules/astra-library-scanner/android/src/androidTest/java/expo/modules/astralibraryscanner/data/CatalogMigrationTest.kt

@@ -0,0 +1,77 @@
+package expo.modules.astralibraryscanner.data
+
+import androidx.room.testing.MigrationTestHelper
+import androidx.sqlite.db.SupportSQLiteDatabase
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class CatalogMigrationTest {
+  @get:Rule
+  val helper = MigrationTestHelper(
+    InstrumentationRegistry.getInstrumentation(),
+    AstraCatalogDatabase::class.java,
+  )
+
+  @After
+  fun cleanUp() {
+    InstrumentationRegistry.getInstrumentation().targetContext.deleteDatabase(TEST_DATABASE)
+  }
+
+  @Test
+  fun migrationAddsCreditColumnsAndMarksOnlyLocalSourcesStale() {
+    helper.createDatabase(TEST_DATABASE, 1).apply {
+      insertSource("local:1", "local", 1)
+      insertSource("jellyfin:2", "jellyfin", 2)
+      close()
+    }
+
+    val database = helper.runMigrationsAndValidate(
+      TEST_DATABASE,
+      2,
+      true,
+      CATALOG_MIGRATION_1_2,
+    )
+
+    database.query(
+      "SELECT source_key, artist_credit_version FROM catalog_sources ORDER BY source_key",
+    ).use { cursor ->
+      assertTrue(cursor.moveToFirst())
+      assertEquals("jellyfin:2", cursor.getString(0))
+      assertEquals(CURRENT_ARTIST_CREDIT_VERSION, cursor.getInt(1))
+      assertTrue(cursor.moveToNext())
+      assertEquals("local:1", cursor.getString(0))
+      assertEquals(LEGACY_ARTIST_CREDIT_VERSION, cursor.getInt(1))
+    }
+
+    database.query("PRAGMA table_info(tracks)").use { cursor ->
+      val columnNames = buildSet {
+        val nameIndex = cursor.getColumnIndexOrThrow("name")
+        while (cursor.moveToNext()) add(cursor.getString(nameIndex))
+      }
+      assertTrue("artist_names_json" in columnNames)
+      assertTrue("album_artist_names_json" in columnNames)
+    }
+  }
+
+  private fun SupportSQLiteDatabase.insertSource(key: String, type: String, id: Long) {
+    execSQL(
+      """
+        INSERT INTO catalog_sources
+          (source_key, source_type, source_id, active_generation_id, updated_at)
+        VALUES (?, ?, ?, NULL, 0)
+      """.trimIndent(),
+      arrayOf<Any>(key, type, id),
+    )
+  }
+
+  private companion object {
+    const val TEST_DATABASE = "artist-credit-migration-test"
+  }
+}

modules/astra-library-scanner/android/src/androidTest/java/expo/modules/astralibraryscanner/data/RoomLibraryRepositoryTest.kt

@@ -495,6 +495,76 @@ class RoomLibraryRepositoryTest {
     )
   }
 
+  @Test
+  fun structuredArtistCreditsPreserveNamesContainingPunctuation() = runBlocking {
+    val artistNames = listOf("Earth, Wind & Fire", "The Emotions")
+    val display = formatArtistNames(artistNames)
+    publish(
+      "credits",
+      listOf(
+        track("credits", 0, "Best of My Love").copy(
+          artist = display,
+          artistNamesJson = serializeArtistNames(artistNames),
+          artistSortKey = SortKeys.forText(display),
+        ),
+      ),
+    )
+    val dao = catalog.catalogDao()
+    val revision = dao.getRevision()
+
+    val astraArtists = dao.getAllArtistSummaries(revision, "astra")
+    assertEquals(setOf("Earth, Wind & Fire", "The Emotions"), astraArtists.map { it.artist }.toSet())
+    assertEquals(
+      1,
+      dao.countArtistTracks(revision, "astra", "earth, wind & fire", "songs"),
+    )
+    assertEquals(
+      1,
+      dao.countArtistTracks(revision, "astra", "the emotions", "appearances"),
+    )
+    assertEquals(
+      listOf(display),
+      dao.getAllArtistSummaries(revision, "fileTags").map { it.artist },
+    )
+  }
+
+  @Test
+  fun staleArtistCreditVersionAdvancesOnlyWhenGenerationPublishes() = runBlocking {
+    val dao = catalog.catalogDao()
+    dao.insertMeta(CatalogMetaEntity(collationVersion = COLLATION_VERSION, updatedAt = 0))
+    dao.putSource(
+      CatalogSourceEntity(
+        sourceKey = "local:1",
+        sourceType = "local",
+        sourceId = 1,
+        activeGenerationId = null,
+        updatedAt = 0,
+        artistCreditVersion = LEGACY_ARTIST_CREDIT_VERSION,
+      ),
+    )
+
+    dao.insertGeneration(ScanGenerationEntity("cancelled", "local:1", "staging", 1))
+    dao.deleteGenerationTracks("cancelled")
+    dao.deleteGeneration("cancelled")
+    assertEquals(LEGACY_ARTIST_CREDIT_VERSION, dao.getSource("local:1")?.artistCreditVersion)
+
+    dao.insertGeneration(ScanGenerationEntity("complete", "local:1", "staging", 2))
+    dao.publishGeneration(
+      sourceKey = "local:1",
+      generationId = "complete",
+      previousGenerationId = null,
+      now = 2,
+      albumIdentityUpdates = emptyList(),
+      albums = emptyList(),
+      artists = emptyList(),
+      artistTrackIndex = emptyList(),
+      directories = emptyList(),
+      ftsRows = emptyList(),
+      artistCreditVersion = CURRENT_ARTIST_CREDIT_VERSION,
+    )
+    assertEquals(CURRENT_ARTIST_CREDIT_VERSION, dao.getSource("local:1")?.artistCreditVersion)
+  }
+
   /** 10 tracks under each of A-Z, so every section has rows above and below it. */
   private fun seedAlphabet(): List<TrackEntity> =
     (0 until ALPHABET_SEED_SIZE).map { index ->

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/AstraLibraryScannerModule.kt

@@ -39,9 +39,11 @@ import expo.modules.kotlin.modules.ModuleDefinition
 import expo.modules.kotlin.records.Field
 import expo.modules.kotlin.records.Record
 import expo.modules.astralibraryscanner.data.AstraLibraryRepository
+import expo.modules.astralibraryscanner.data.ArtistCreditMetadataReader
 import expo.modules.astralibraryscanner.data.LocalAudioFile
 import expo.modules.astralibraryscanner.data.LocalAudioMetadata
 import expo.modules.astralibraryscanner.data.ScanCancelledException
+import expo.modules.astralibraryscanner.data.formatArtistNames
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.async
@@ -651,6 +653,22 @@ class AstraLibraryScannerModule : Module() {
       } catch (_: Throwable) {}
     }
 
+    val credits = ArtistCreditMetadataReader.read(context, uri, metadataTimeoutMs)
+    val artistNames = credits.artists.takeIf { it.size > 1 }.orEmpty()
+    val albumArtistNames = credits.albumArtists.takeIf { it.size > 1 }.orEmpty()
+    result["artistNames"] = artistNames
+    result["albumArtistNames"] = albumArtistNames
+    if (artistNames.isNotEmpty()) {
+      result["artist"] = formatArtistNames(artistNames)
+    } else if (result["artist"] == null && credits.artists.size == 1) {
+      result["artist"] = credits.artists[0]
+    }
+    if (albumArtistNames.isNotEmpty()) {
+      result["albumArtist"] = formatArtistNames(albumArtistNames)
+    } else if (result["albumArtist"] == null && credits.albumArtists.size == 1) {
+      result["albumArtist"] = credits.albumArtists[0]
+    }
+
     // Header-level facts MMR can't provide (channels, bit depth) or only on
     // API 31+ (sample rate). Failure here is non-fatal — keep the tag data.
     val extractor = MediaExtractor()
@@ -693,8 +711,11 @@ class AstraLibraryScannerModule : Module() {
       ok = this["ok"] as? Boolean ?: false,
       title = this["title"] as? String,
       artist = this["artist"] as? String,
+      artistNames = (this["artistNames"] as? List<*>)?.filterIsInstance<String>().orEmpty(),
       album = this["album"] as? String,
       albumArtist = this["albumArtist"] as? String,
+      albumArtistNames =
+        (this["albumArtistNames"] as? List<*>)?.filterIsInstance<String>().orEmpty(),
       genre = this["genre"] as? String,
       mimeType = this["mimeType"] as? String,
       durationMs = (this["durationMs"] as? Number)?.toLong(),

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/ArtistCredits.kt

@@ -0,0 +1,115 @@
+package expo.modules.astralibraryscanner.data
+
+import android.content.Context
+import android.net.Uri
+import com.google.android.exoplayer2.MediaItem
+import com.google.android.exoplayer2.MetadataRetriever
+import com.google.android.exoplayer2.metadata.flac.VorbisComment
+import com.google.android.exoplayer2.metadata.id3.InternalFrame
+import com.google.android.exoplayer2.metadata.id3.TextInformationFrame
+import java.util.concurrent.TimeUnit
+import org.json.JSONArray
+
+internal const val CURRENT_ARTIST_CREDIT_VERSION = 2
+internal const val LEGACY_ARTIST_CREDIT_VERSION = 1
+
+internal data class ArtistCreditNames(
+  val artists: List<String> = emptyList(),
+  val albumArtists: List<String> = emptyList(),
+)
+
+internal fun normalizeArtistNames(values: Iterable<String?>): List<String> {
+  val result = LinkedHashMap<String, String>()
+  for (value in values) {
+    val display = MediaTagCleanup.clean(value)
+      ?.replace(Regex("\\s+"), " ")
+      ?.trim()
+      ?.takeIf(String::isNotEmpty)
+      ?: continue
+    val key = display.lowercase()
+    result.putIfAbsent(key, display)
+  }
+  return result.values.toList()
+}
+
+internal fun formatArtistNames(values: Iterable<String?>): String {
+  val names = normalizeArtistNames(values)
+  return when (names.size) {
+    0 -> ""
+    1 -> names[0]
+    2 -> "${names[0]} & ${names[1]}"
+    else -> "${names.dropLast(1).joinToString(", ")} & ${names.last()}"
+  }
+}
+
+internal fun serializeArtistNames(values: Iterable<String?>): String? {
+  val names = normalizeArtistNames(values)
+  return if (names.size > 1) JSONArray(names).toString() else null
+}
+
+internal fun deserializeArtistNames(value: String?): List<String> {
+  if (value.isNullOrBlank()) return emptyList()
+  return runCatching {
+    val json = JSONArray(value)
+    normalizeArtistNames((0 until json.length()).map { index -> json.optString(index, null) })
+  }.getOrDefault(emptyList())
+}
+
+/**
+ * Order-preserving collector for multi-value artist tags. Container-specific
+ * metadata walkers feed raw key/value pairs here; normalization is kept pure so
+ * repeated Vorbis comments and repeated ID3 frames share identical behavior.
+ */
+internal class ArtistCreditCollector {
+  private val artists = mutableListOf<String?>()
+  private val albumArtists = mutableListOf<String?>()
+
+  fun consider(rawKey: String?, rawValue: String?) {
+    if (rawKey == null || rawValue == null) return
+    val key = rawKey.trim().uppercase().replace(Regex("[\\s_-]+"), "")
+    val target = when (key) {
+      "ARTIST", "ARTISTS", "TPE1" -> artists
+      "ALBUMARTIST", "ALBUMARTISTS", "TPE2" -> albumArtists
+      else -> null
+    } ?: return
+
+    // ID3 text frames may expose multiple values joined with NUL even when the
+    // decoder returns a single string. Do not split punctuation: commas and
+    // ampersands are valid parts of an individual artist name.
+    rawValue.split('\u0000').forEach(target::add)
+  }
+
+  fun build(): ArtistCreditNames = ArtistCreditNames(
+    artists = normalizeArtistNames(artists),
+    albumArtists = normalizeArtistNames(albumArtists),
+  )
+}
+
+internal object ArtistCreditMetadataReader {
+  fun read(context: Context, uri: Uri, timeoutMs: Long): ArtistCreditNames {
+    return try {
+      val trackGroups = MetadataRetriever.retrieveMetadata(context, MediaItem.fromUri(uri))
+        .get(timeoutMs, TimeUnit.MILLISECONDS)
+      val collector = ArtistCreditCollector()
+
+      for (groupIndex in 0 until trackGroups.length) {
+        val group = trackGroups.get(groupIndex)
+        for (formatIndex in 0 until group.length) {
+          val metadata = group.getFormat(formatIndex).metadata ?: continue
+          for (entryIndex in 0 until metadata.length()) {
+            when (val entry = metadata.get(entryIndex)) {
+              is VorbisComment -> collector.consider(entry.key, entry.value)
+              is TextInformationFrame ->
+                entry.values.forEach { value -> collector.consider(entry.id, value) }
+              is InternalFrame -> collector.consider(entry.description, entry.text)
+            }
+          }
+        }
+      }
+      collector.build()
+    } catch (_: Throwable) {
+      // Unsupported container, malformed tags, I/O failure, or timeout.
+      ArtistCreditNames()
+    }
+  }
+}

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/AstraLibraryRepository.kt

@@ -257,6 +257,7 @@ class AstraLibraryRepository private constructor(
       .mapTo(hashSetOf()) { it.uri.toString() }
     val catalogDao = requireCatalog().catalogDao()
     return requireUser().userDao().getFolders().map { folder ->
+      val source = catalogDao.getSource(localSourceKey(folder.id))
       mapOf(
         "id" to folder.id.toDouble(),
         "tree_uri" to folder.treeUri,
@@ -267,6 +268,10 @@ class AstraLibraryRepository private constructor(
         "scan_status" to folder.lastScanStatus,
         "scan_error" to folder.lastScanError,
         "track_count" to catalogDao.countActiveTracksForFolder(folder.id).toDouble(),
+        "needs_metadata_reindex" to (
+          source != null &&
+            source.artistCreditVersion < CURRENT_ARTIST_CREDIT_VERSION
+          ),
       )
     }
   }
@@ -370,6 +375,9 @@ class AstraLibraryRepository private constructor(
       val dao = database.catalogDao()
       val sourceKey = localSourceKey(folderId)
       val previousSource = dao.getSource(sourceKey)
+      val effectiveFull = full ||
+        (previousSource != null &&
+          previousSource.artistCreditVersion < CURRENT_ARTIST_CREDIT_VERSION)
       val generationId = UUID.randomUUID().toString()
       val startedAt = System.currentTimeMillis()
 
@@ -415,7 +423,7 @@ class AstraLibraryRepository private constructor(
               async(Dispatchers.IO) {
                 throwIfScanCancelled(isCancelled)
                 val old = existingByPath[file.uri]
-                val unchanged = !full &&
+                val unchanged = !effectiveFull &&
                   old != null &&
                   old.mtime == file.lastModified &&
                   old.size == file.size
@@ -491,6 +499,7 @@ class AstraLibraryRepository private constructor(
           artistTrackIndex = readModels.artistTrackIndex,
           directories = readModels.directories,
           ftsRows = readModels.ftsRows,
+          artistCreditVersion = CURRENT_ARTIST_CREDIT_VERSION,
         )
         userDao.updateFolderScanState(folderId, System.currentTimeMillis(), "ready", null)
         scheduleSnapshot()
@@ -2502,10 +2511,27 @@ class AstraLibraryRepository private constructor(
     val extension = file.name.substringAfterLast('.', "")
     val title = clean(metadata.title)
       ?: file.name.removeSuffix(if (extension.isEmpty()) "" else ".$extension")
-    val artist = clean(metadata.artist) ?: "Unknown Artist"
+    val artistNames = normalizeArtistNames(metadata.artistNames)
+    val albumArtistNames = normalizeArtistNames(metadata.albumArtistNames)
+    val artist = if (artistNames.size > 1) {
+      formatArtistNames(artistNames)
+    } else {
+      clean(metadata.artist) ?: artistNames.firstOrNull() ?: "Unknown Artist"
+    }
     val album = clean(metadata.album) ?: "Unknown Album"
-    val albumArtist = clean(metadata.albumArtist)
-    val provisional = CatalogReadModelBuilder.provisionalIdentity(album, artist, albumArtist)
+    val albumArtist = if (albumArtistNames.size > 1) {
+      formatArtistNames(albumArtistNames)
+    } else {
+      clean(metadata.albumArtist) ?: albumArtistNames.firstOrNull()
+    }
+    val artistNamesJson = serializeArtistNames(artistNames)
+    val albumArtistNamesJson = serializeArtistNames(albumArtistNames)
+    val provisional = CatalogReadModelBuilder.provisionalIdentity(
+      album,
+      artist,
+      albumArtist,
+      artistNamesJson,
+    )
     val now = System.currentTimeMillis()
     return TrackEntity(
       generationId = generationId,
@@ -2514,8 +2540,10 @@ class AstraLibraryRepository private constructor(
       folderId = folderId,
       title = title,
       artist = artist,
+      artistNamesJson = artistNamesJson,
       album = album,
       albumArtist = albumArtist,
+      albumArtistNamesJson = albumArtistNamesJson,
       albumIdentityKey = provisional.first,
       albumDisplayArtist = provisional.second,
       duration = (metadata.durationMs ?: 0L) / 1_000.0,
@@ -2739,6 +2767,7 @@ class AstraLibraryRepository private constructor(
   private fun buildCatalogDatabase(): AstraCatalogDatabase =
     Room.databaseBuilder(applicationContext, AstraCatalogDatabase::class.java, CATALOG_DB_NAME)
       .setJournalMode(RoomDatabase.JournalMode.WRITE_AHEAD_LOGGING)
+      .addMigrations(CATALOG_MIGRATION_1_2)
       .fallbackToDestructiveMigration(true)
       .build()
 

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/CatalogDatabase.kt

@@ -9,7 +9,9 @@ import androidx.room.RawQuery
 import androidx.room.RoomDatabase
 import androidx.room.Transaction
 import androidx.room.Upsert
+import androidx.room.migration.Migration
 import androidx.sqlite.db.SupportSQLiteQuery
+import androidx.sqlite.db.SupportSQLiteDatabase
 
 data class TrackSyncRow(
   val path: String,
@@ -87,6 +89,7 @@ interface CatalogDao {
     """
       UPDATE catalog_sources
       SET active_generation_id = :generationId,
+          artist_credit_version = COALESCE(:artistCreditVersion, artist_credit_version),
           updated_at = :updatedAt
       WHERE source_key = :sourceKey
     """,
@@ -95,6 +98,7 @@ interface CatalogDao {
     sourceKey: String,
     generationId: String,
     updatedAt: Long,
+    artistCreditVersion: Int? = null,
   )
 
   @Insert(onConflict = OnConflictStrategy.ABORT)
@@ -1206,11 +1210,12 @@ interface CatalogDao {
     artistTrackIndex: List<ArtistTrackIndexEntity>,
     directories: List<DirectorySummaryEntity>,
     ftsRows: List<TrackFtsEntity>,
+    artistCreditVersion: Int? = null,
   ): Long {
     for (update in albumIdentityUpdates) {
       updateAlbumIdentity(update.trackId, update.identityKey, update.displayArtist)
     }
-    setActiveGeneration(sourceKey, generationId, now)
+    setActiveGeneration(sourceKey, generationId, now, artistCreditVersion)
     setGenerationState(generationId, "active", now, null)
     incrementRevision(now)
     val revision = getRevision()
@@ -1283,9 +1288,24 @@ interface CatalogDao {
     TrackFtsEntity::class,
   ],
   views = [ActiveTrackView::class],
-  version = 1,
+  version = 2,
   exportSchema = true,
 )
 abstract class AstraCatalogDatabase : RoomDatabase() {
   abstract fun catalogDao(): CatalogDao
 }
+
+internal val CATALOG_MIGRATION_1_2 = object : Migration(1, 2) {
+  override fun migrate(database: SupportSQLiteDatabase) {
+    database.execSQL("ALTER TABLE tracks ADD COLUMN artist_names_json TEXT")
+    database.execSQL("ALTER TABLE tracks ADD COLUMN album_artist_names_json TEXT")
+    database.execSQL(
+      "ALTER TABLE catalog_sources ADD COLUMN artist_credit_version INTEGER NOT NULL DEFAULT 2",
+    )
+    // Existing local generations used the singular Android metadata fields and
+    // require a complete extraction pass. Remote rows need no forced network sync.
+    database.execSQL(
+      "UPDATE catalog_sources SET artist_credit_version = 1 WHERE source_type = 'local'",
+    )
+  }
+}

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/CatalogEntities.kt

@@ -25,6 +25,8 @@ data class CatalogSourceEntity(
   @ColumnInfo(name = "source_id") val sourceId: Long,
   @ColumnInfo(name = "active_generation_id") val activeGenerationId: String? = null,
   @ColumnInfo(name = "updated_at") val updatedAt: Long,
+  @ColumnInfo(name = "artist_credit_version", defaultValue = "2")
+  val artistCreditVersion: Int = CURRENT_ARTIST_CREDIT_VERSION,
 )
 
 @Entity(
@@ -60,8 +62,10 @@ data class TrackEntity(
   @ColumnInfo(name = "folder_id") val folderId: Long? = null,
   val title: String,
   val artist: String,
+  @ColumnInfo(name = "artist_names_json") val artistNamesJson: String? = null,
   val album: String,
   @ColumnInfo(name = "album_artist") val albumArtist: String? = null,
+  @ColumnInfo(name = "album_artist_names_json") val albumArtistNamesJson: String? = null,
   @ColumnInfo(name = "album_identity_key") val albumIdentityKey: String,
   @ColumnInfo(name = "album_display_artist") val albumDisplayArtist: String? = null,
   val duration: Double = 0.0,
@@ -123,8 +127,10 @@ data class ActiveTrackView(
   @ColumnInfo(name = "folder_id") val folderId: Long?,
   val title: String,
   val artist: String,
+  @ColumnInfo(name = "artist_names_json") val artistNamesJson: String?,
   val album: String,
   @ColumnInfo(name = "album_artist") val albumArtist: String?,
+  @ColumnInfo(name = "album_artist_names_json") val albumArtistNamesJson: String?,
   @ColumnInfo(name = "album_identity_key") val albumIdentityKey: String,
   @ColumnInfo(name = "album_display_artist") val albumDisplayArtist: String?,
   val duration: Double,

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/CatalogReadModelBuilder.kt

@@ -33,8 +33,10 @@ data class LocalAudioMetadata(
   val ok: Boolean,
   val title: String? = null,
   val artist: String? = null,
+  val artistNames: List<String> = emptyList(),
   val album: String? = null,
   val albumArtist: String? = null,
+  val albumArtistNames: List<String> = emptyList(),
   val genre: String? = null,
   val mimeType: String? = null,
   val durationMs: Long? = null,
@@ -128,13 +130,14 @@ object CatalogReadModelBuilder {
     album: String,
     artist: String,
     albumArtist: String?,
+    artistNamesJson: String? = null,
   ): Pair<String, String> {
     val albumKey = normalizeKey(normalizeAlbum(album))
     val explicit = normalizeDisplay(albumArtist.orEmpty())
     if (explicit.isNotEmpty()) {
       return identity(albumKey, "aa:${normalizeKey(explicit).ifEmpty { normalizeKey(UNKNOWN_ARTIST) }}") to explicit
     }
-    val primary = primaryArtist(artist)
+    val primary = primaryArtist(artist, artistNamesJson)
     return identity(albumKey, "ta:${normalizeKey(primary)}") to primary
   }
 
@@ -145,7 +148,7 @@ object CatalogReadModelBuilder {
     for (track in tracks) {
       val albumKey = normalizeKey(normalizeAlbum(track.album))
       val explicit = normalizeDisplay(track.albumArtist.orEmpty())
-      val primary = primaryArtist(track.artist)
+      val primary = primaryArtist(track.artist, track.artistNamesJson)
       val prepared = PreparedAlbumTrack(
         track = track,
         albumKey = albumKey,
@@ -408,9 +411,11 @@ object CatalogReadModelBuilder {
   private fun canonicalPrimary(track: TrackEntity): String {
     val albumArtist = normalizeDisplay(track.albumArtist.orEmpty())
     if (albumArtist.isNotEmpty()) {
+      val parsedAlbumArtists = deserializeArtistNames(track.albumArtistNamesJson)
+      if (parsedAlbumArtists.isNotEmpty()) return parsedAlbumArtists[0]
       return splitAlbumArtists(albumArtist).firstOrNull() ?: albumArtist
     }
-    return splitTrackArtists(track.artist).firstOrNull() ?: UNKNOWN_ARTIST
+    return primaryArtist(track.artist, track.artistNamesJson)
   }
 
   private fun canonicalArtistNames(track: TrackEntity): List<String> {
@@ -421,9 +426,21 @@ object CatalogReadModelBuilder {
       if (key.isNotEmpty()) result.putIfAbsent(key, display)
     }
     add(canonicalPrimary(track))
-    val trackArtists = splitTrackArtists(track.artist)
+    val parsedTrackArtists = deserializeArtistNames(track.artistNamesJson)
+    val trackArtists = if (parsedTrackArtists.isNotEmpty()) {
+      parsedTrackArtists
+    } else {
+      splitTrackArtists(track.artist)
+    }
     trackArtists.forEach(::add)
-    if (trackArtists.isEmpty()) splitAlbumArtists(track.albumArtist.orEmpty()).forEach(::add)
+    if (trackArtists.isEmpty()) {
+      val parsedAlbumArtists = deserializeArtistNames(track.albumArtistNamesJson)
+      if (parsedAlbumArtists.isNotEmpty()) {
+        parsedAlbumArtists.forEach(::add)
+      } else {
+        splitAlbumArtists(track.albumArtist.orEmpty()).forEach(::add)
+      }
+    }
     return result.values.toList()
   }
 
@@ -480,8 +497,10 @@ object CatalogReadModelBuilder {
   private fun normalizeAlbum(value: String): String =
     normalizeDisplay(value).ifEmpty { UNKNOWN_ALBUM }
 
-  private fun primaryArtist(value: String): String =
-    splitTrackArtists(value).firstOrNull() ?: UNKNOWN_ARTIST
+  private fun primaryArtist(value: String, artistNamesJson: String? = null): String =
+    deserializeArtistNames(artistNamesJson).firstOrNull()
+      ?: splitTrackArtists(value).firstOrNull()
+      ?: UNKNOWN_ARTIST
 
   private fun identity(albumKey: String, discriminator: String): String =
     "album:$albumKey::$discriminator"

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/LibraryModels.kt

@@ -133,8 +133,10 @@ fun ActiveTrackView.toBridgeMap(): Map<String, Any?> = mapOf(
   "folder_id" to folderId?.toDouble(),
   "title" to title,
   "artist" to artist,
+  "artist_names" to deserializeArtistNames(artistNamesJson),
   "album" to album,
   "album_artist" to albumArtist,
+  "album_artist_names" to deserializeArtistNames(albumArtistNamesJson),
   "album_identity_key" to albumIdentityKey,
   "album_display_artist" to albumDisplayArtist,
   "duration" to duration,

modules/astra-library-scanner/android/src/test/java/expo/modules/astralibraryscanner/data/ArtistCreditsTest.kt

@@ -0,0 +1,47 @@
+package expo.modules.astralibraryscanner.data
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ArtistCreditsTest {
+  @Test
+  fun repeatedVorbisCreditsPreserveOrderAndPunctuation() {
+    val collector = ArtistCreditCollector()
+    collector.consider("ARTIST", " Earth, Wind & Fire ")
+    collector.consider("artist", "The Emotions")
+    collector.consider("ALBUMARTIST", "Curator One")
+    collector.consider("album_artist", "Curator Two")
+
+    val credits = collector.build()
+
+    assertEquals(listOf("Earth, Wind & Fire", "The Emotions"), credits.artists)
+    assertEquals(listOf("Curator One", "Curator Two"), credits.albumArtists)
+    assertEquals("Earth, Wind & Fire & The Emotions", formatArtistNames(credits.artists))
+    assertEquals("Curator One & Curator Two", formatArtistNames(credits.albumArtists))
+  }
+
+  @Test
+  fun duplicateCreditsAreRemovedCaseInsensitivelyWithoutReordering() {
+    val collector = ArtistCreditCollector()
+    collector.consider("TPE1", "Artist One")
+    collector.consider("ARTIST", " artist   one ")
+    collector.consider("ARTISTS", "Artist Two")
+    collector.consider("TPE2", "Album Artist\u0000Guest Curator")
+
+    val credits = collector.build()
+
+    assertEquals(listOf("Artist One", "Artist Two"), credits.artists)
+    assertEquals(listOf("Album Artist", "Guest Curator"), credits.albumArtists)
+  }
+
+  @Test
+  fun unrelatedOrMissingMetadataProducesEmptyCredits() {
+    val collector = ArtistCreditCollector()
+    collector.consider("TITLE", "Song")
+    collector.consider(null, "Artist")
+    collector.consider("ARTIST", null)
+
+    assertEquals(ArtistCreditNames(), collector.build())
+  }
+
+}

modules/astra-library-scanner/index.ts

@@ -24,8 +24,12 @@ export interface ExtractedMetadata {
   error?: string;
   title?: string | null;
   artist?: string | null;
+  /** Ordered repeated ARTIST tag values; empty when the file has no multi-value credit. */
+  artistNames?: string[];
   album?: string | null;
   albumArtist?: string | null;
+  /** Ordered repeated ALBUMARTIST tag values; empty when not multi-valued. */
+  albumArtistNames?: string[];
   genre?: string | null;
   /** Container mime type reported by MediaMetadataRetriever. */
   mimeType?: string | null;

package.json

@@ -68,7 +68,7 @@
     "test:desktop-remote": "node --experimental-strip-types --test src/services/desktopRemotePairing.test.mts",
     "test:dynamic-playlists": "node --experimental-strip-types --experimental-specifier-resolution=node --test src/shared/playlists/dynamicPlaylist.test.mts",
     "test:album-grouping": "node --experimental-strip-types --experimental-specifier-resolution=node --test src/shared/library/albumGrouping.test.mts src/shared/library/albumEligibility.test.mts src/library/albumIdentity.test.mts src/library/albumSummary.test.mts",
-    "test:artist-grouping": "node --experimental-strip-types --test src/library/artistGrouping.test.mts",
+    "test:artist-grouping": "node --experimental-strip-types --test src/library/artistGrouping.test.mts src/audio/artistCreditTransport.test.mts",
     "test:waveform-math": "node --experimental-strip-types --test src/scope/waveformMath.test.mts",
     "test:desktop-sync": "node --experimental-strip-types --experimental-specifier-resolution=node --test src/library/importMatching.test.mts src/services/desktopSyncPlaylistMerge.test.mts src/services/desktopSyncPolicy.test.mts src/shared/sync/conflictPreview.test.mts",
     "test:eq-share": "node --experimental-strip-types --experimental-specifier-resolution=node --test src/audio/eqShare.test.mts",

src/audio/artistCreditTransport.test.mts

@@ -0,0 +1,20 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  parseArtistCreditTransport,
+  serializeArtistCreditTransport,
+} from './artistCreditTransport.ts';
+
+test('artist credits survive the string-only player transport', () => {
+  const names = ['Earth, Wind & Fire', 'The Emotions'];
+  assert.deepEqual(
+    parseArtistCreditTransport(serializeArtistCreditTransport(names)),
+    names
+  );
+});
+
+test('artist credit transport rejects malformed or empty values', () => {
+  assert.equal(parseArtistCreditTransport('{bad json'), undefined);
+  assert.equal(parseArtistCreditTransport('[]'), undefined);
+  assert.equal(serializeArtistCreditTransport([]), undefined);
+});

src/audio/artistCreditTransport.ts

@@ -0,0 +1,20 @@
+import { normalizeArtistNames } from '../shared/library/artistCredits.ts';
+
+export function serializeArtistCreditTransport(
+  names: readonly unknown[] | null | undefined
+): string | undefined {
+  const normalized = normalizeArtistNames(names);
+  return normalized.length > 0 ? JSON.stringify(normalized) : undefined;
+}
+
+export function parseArtistCreditTransport(value: unknown): string[] | undefined {
+  if (typeof value !== 'string' || value.trim().length === 0) return undefined;
+  try {
+    const parsed = JSON.parse(value) as unknown;
+    if (!Array.isArray(parsed)) return undefined;
+    const names = normalizeArtistNames(parsed);
+    return names.length > 0 ? names : undefined;
+  } catch {
+    return undefined;
+  }
+}

src/audio/sampleTracks.ts

@@ -2,6 +2,10 @@ import type { Track as RntpTrack } from 'react-native-track-player';
 import type { Track } from '@/types/audio';
 import { streamUrlForTrack } from '@/services/remoteUrls';
 import { artworkThumbFromSource, playerBackdropArtworkSource } from '@/library/artwork';
+import {
+  parseArtistCreditTransport,
+  serializeArtistCreditTransport,
+} from './artistCreditTransport';
 
 /**
  * M0 verification tracks. Streamed from a public royalty-free source so playback
@@ -64,6 +68,10 @@ export function toRntpTrack(track: Track): RntpTrack {
     sampleRate: track.sampleRate,
     bitDepth: track.bitDepth,
     bitrate: track.bitrate,
+    astraArtistNamesJson: serializeArtistCreditTransport(track.artistNames),
+    astraAlbumArtist: track.albumArtist,
+    astraAlbumArtistNamesJson: serializeArtistCreditTransport(track.albumArtistNames),
+    astraAlbumIdentityKey: track.albumIdentityKey,
     astraPath: track.path,
     sourceType: track.sourceType,
     sourceId: track.sourceId,
@@ -81,7 +89,13 @@ export function rntpToTrack(rt: RntpTrack): Track {
     path: astraPath ?? String(rt.url),
     title: rt.title ?? 'Unknown title',
     artist: rt.artist ?? 'Unknown artist',
+    artistNames: parseArtistCreditTransport(rt.astraArtistNamesJson),
     album: rt.album ?? '',
+    albumArtist:
+      typeof rt.astraAlbumArtist === 'string' ? rt.astraAlbumArtist : undefined,
+    albumArtistNames: parseArtistCreditTransport(rt.astraAlbumArtistNamesJson),
+    albumIdentityKey:
+      typeof rt.astraAlbumIdentityKey === 'string' ? rt.astraAlbumIdentityKey : undefined,
     duration: typeof rt.duration === 'number' ? rt.duration : 0,
     artworkData:
       typeof rt.astraArtworkData === 'string'

src/components/player/NowPlayingOverlay.tsx

@@ -262,20 +262,23 @@ export function NowPlayingOverlay() {
     [libraryTracks, track]
   );
   const artistName = track
-    ? resolveNavigationArtist(
-        libraryTrack ?? { artist: track.artist, album_artist: track.albumArtist ?? null },
+      ? resolveNavigationArtist(
+        libraryTrack ?? {
+          artist: track.artist,
+          artist_names: track.artistNames,
+          album_artist: track.albumArtist ?? null,
+          album_artist_names: track.albumArtistNames,
+        },
         artistGroupingMode
       )
     : '';
   const artistCreditTokens = useMemo(() => {
     if (!track) return [];
-    const collaborators = splitCollaborators(track.artist);
-    return buildArtistNameTokens(
-      collaborators.length > 0 ? collaborators : [track.artist]
-    ).map((token) => ({
-      ...token,
-      separator: token.separator ? ', ' : null,
-    }));
+    const collaborators =
+      track.artistNames && track.artistNames.length > 0
+        ? track.artistNames
+        : splitCollaborators(track.artist);
+    return buildArtistNameTokens(collaborators.length > 0 ? collaborators : [track.artist]);
   }, [track]);
   const albumKey = track?.albumIdentityKey ?? libraryTrack?.album_identity_key;
 

src/components/player/nowPlayingPreferences.test.mts

@@ -24,3 +24,10 @@ test('builds separate clickable credits for collaborative track artists', () =>
     { artist: 'ValkyR', separator: null },
   ]);
 });
+
+test('structured credits preserve commas and ampersands inside one artist name', () => {
+  assert.deepEqual(buildArtistNameTokens(['Earth, Wind & Fire', 'The Emotions']), [
+    { artist: 'Earth, Wind & Fire', separator: ' & ' },
+    { artist: 'The Emotions', separator: null },
+  ]);
+});

src/library/albumIdentity.test.mts

@@ -16,7 +16,9 @@ function createRow(
     id: overrides.id ?? nextId++,
     album: overrides.album,
     artist: overrides.artist,
+    artist_names: overrides.artist_names ?? [],
     album_artist: overrides.album_artist ?? null,
+    album_artist_names: overrides.album_artist_names ?? [],
     artwork_hash: overrides.artwork_hash ?? null,
     source_type: overrides.source_type ?? 'local',
     artwork_source_id: overrides.artwork_source_id ?? null,
@@ -41,6 +43,17 @@ test('provisional identity uses the primary collaborator when album artist is mi
   assert.equal(provisional.displayArtist, 'Jane Remover');
 });
 
+test('provisional identity prefers the first structured artist credit', () => {
+  const provisional = buildProvisionalAlbumIdentity(
+    null,
+    'Earth, Wind & Fire & The Emotions',
+    'duets',
+    ['Earth, Wind & Fire', 'The Emotions']
+  );
+  assert.equal(provisional.key, 'album:duets::ta:earth, wind & fire');
+  assert.equal(provisional.displayArtist, 'Earth, Wind & Fire');
+});
+
 test('recompute merges shared-cover multi-artist albums into a Various Artists group', () => {
   const rows = [
     createRow({ id: 1, album: 'Split Release', artist: 'Artist A', artwork_hash: 'shared' }),

src/library/albumIdentity.ts

@@ -17,6 +17,7 @@ import {
   groupTracksByAlbumIdentity,
   normalizeDisplay,
 } from '../shared/library/albumGrouping.ts';
+import { formatArtistNames, normalizeArtistNames } from '../shared/library/artistCredits.ts';
 
 export interface ProvisionalAlbumIdentity {
   key: string;
@@ -32,11 +33,23 @@ export interface ProvisionalAlbumIdentity {
 export function buildProvisionalAlbumIdentity(
   albumArtist: string | null,
   artist: string,
-  album: string
+  album: string,
+  artistNames?: readonly string[] | null,
+  albumArtistNames?: readonly string[] | null
 ): ProvisionalAlbumIdentity {
-  const key = buildAlbumIdentityKeyFromTrack({ album, artist, album_artist: albumArtist });
-  const normalizedAlbumArtist = normalizeDisplay(albumArtist ?? '');
-  const displayArtist = normalizedAlbumArtist || getPrimaryArtistFromTrackArtist(artist);
+  const key = buildAlbumIdentityKeyFromTrack({
+    album,
+    artist,
+    artist_names: artistNames,
+    album_artist: albumArtist,
+    album_artist_names: albumArtistNames,
+  });
+  const normalizedAlbumArtist =
+    normalizeDisplay(albumArtist ?? '') || formatArtistNames(albumArtistNames);
+  const displayArtist =
+    normalizedAlbumArtist ||
+    normalizeArtistNames(artistNames)[0] ||
+    getPrimaryArtistFromTrackArtist(artist);
   return { key, displayArtist };
 }
 
@@ -45,7 +58,9 @@ export interface AlbumIdentityRow {
   id: number;
   album: string;
   artist: string;
+  artist_names: string[];
   album_artist: string | null;
+  album_artist_names: string[];
   artwork_hash: string | null;
   source_type: string;
   artwork_source_id: string | null;
@@ -72,7 +87,9 @@ export function computeAlbumIdentityUpdates(
     row,
     album: row.album,
     artist: row.artist,
+    artist_names: row.artist_names,
     album_artist: row.album_artist,
+    album_artist_names: row.album_artist_names,
     base_artwork_hash:
       row.artwork_hash ?? (row.source_type !== 'local' ? row.artwork_source_id : null),
   }));

src/library/artistGrouping.test.mts

@@ -14,7 +14,9 @@ function createTrack(
   const timestamp = nextTimestamp++;
   return {
     artist: overrides.artist,
+    artist_names: overrides.artist_names ?? null,
     album_artist: overrides.album_artist ?? null,
+    album_artist_names: overrides.album_artist_names ?? null,
     artwork_hash: overrides.artwork_hash ?? null,
     year: overrides.year ?? null,
     added_at: overrides.added_at ?? timestamp,
@@ -40,6 +42,37 @@ test('canonical artist records distinguish primary and collaborator-only artists
   assert.equal(guest.primary_track_count, 0);
 });
 
+test('structured credits keep punctuation inside an artist name', () => {
+  const artists = buildArtistList([
+    createTrack({
+      artist: 'Earth, Wind & Fire & The Emotions',
+      artist_names: ['Earth, Wind & Fire', 'The Emotions'],
+    }),
+  ], 'astra');
+
+  assert.deepEqual(
+    artists.map((artist) => [artist.artist, artist.primary_track_count]),
+    [
+      ['Earth, Wind & Fire', 1],
+      ['The Emotions', 0],
+    ]
+  );
+  assert.ok(!artists.some((artist) => artist.artist === 'Earth'));
+  assert.ok(!artists.some((artist) => artist.artist === 'Wind'));
+});
+
+test('file-tags mode keeps a structured collaboration as one display group', () => {
+  const display = 'Earth, Wind & Fire & The Emotions';
+  const artists = buildArtistList([
+    createTrack({
+      artist: display,
+      artist_names: ['Earth, Wind & Fire', 'The Emotions'],
+    }),
+  ], 'fileTags');
+
+  assert.deepEqual(artists.map((artist) => artist.artist), [display]);
+});
+
 test('file-tags artist records count every indexed track as primary', () => {
   const artists = buildArtistList([
     createTrack({ artist: 'Primary Artist feat. Guest Artist' }),

src/library/artistGrouping.ts

@@ -5,12 +5,13 @@
 //              every collaborator so featured artists are browsable.
 //   'fileTags' (desktop "strict"): use the tag verbatim (album_artist || artist).
 //
-// Mobile has no parsed `artist_names_json` columns (MMR yields one artist string),
-// so desktop's parsed-array paths collapse to splitCollaborators(artist) — which is
-// the parsing heuristic. Everything here is derivable from artist + album_artist.
+// Structured artist arrays are preferred when present so punctuation inside an
+// individual name is never mistaken for a collaboration boundary. Legacy and
+// remote rows still fall back to the original display-string heuristics.
 
 // Runtime imports stay relative so this module can run under plain `node --test`.
 import { normalizeDisplay, normalizeKey, splitCollaborators } from '../shared/library/albumGrouping.ts';
+import { normalizeArtistNames } from '../shared/library/artistCredits.ts';
 import type { Artist, DbTrack } from '../types/library';
 
 // Shared with the album-identity port so artist and album grouping can never
@@ -23,9 +24,16 @@ const UNKNOWN_ARTIST = 'Unknown Artist';
 const VARIOUS_ARTISTS_KEY = 'various artists';
 
 /** Track fields the grouping logic reads (subset of DbTrack, for testability). */
-export type ArtistTrackLike = Pick<
+export interface ArtistCreditTrackLike {
+  artist: string;
+  artist_names?: readonly string[] | null;
+  album_artist: string | null;
+  album_artist_names?: readonly string[] | null;
+}
+
+export type ArtistTrackLike = ArtistCreditTrackLike & Pick<
   DbTrack,
-  'artist' | 'album_artist' | 'artwork_hash' | 'year' | 'added_at' | 'modified_at' | 'album_identity_key'
+  'artwork_hash' | 'year' | 'added_at' | 'modified_at' | 'album_identity_key'
 >;
 
 /** Like splitCollaborators but keeps "&" (e.g. "Earth, Wind & Fire" stays whole). */
@@ -54,23 +62,27 @@ function dedupeByKey(parts: string[]): string[] {
 }
 
 /** File-tags artist: album_artist if present, else the raw track artist. */
-export function resolveStrictBrowseArtist(track: Pick<DbTrack, 'artist' | 'album_artist'>): string {
+export function resolveStrictBrowseArtist(track: ArtistCreditTrackLike): string {
   const albumArtist = normalizeDisplay(track.album_artist ?? '');
   if (albumArtist) return albumArtist;
   return normalizeDisplay(track.artist) || UNKNOWN_ARTIST;
 }
 
 /** Astra-grouping primary: album_artist's first collaborator, else artist's first. */
-export function resolveCanonicalBrowseArtist(track: Pick<DbTrack, 'artist' | 'album_artist'>): string {
+export function resolveCanonicalBrowseArtist(track: ArtistCreditTrackLike): string {
   const albumArtist = normalizeDisplay(track.album_artist ?? '');
   if (albumArtist) {
+    const parsedAlbumArtists = normalizeArtistNames(track.album_artist_names);
+    if (parsedAlbumArtists.length > 0) return parsedAlbumArtists[0];
     return splitAlbumArtistCollaborators(albumArtist)[0] ?? albumArtist;
   }
+  const parsedTrackArtists = normalizeArtistNames(track.artist_names);
+  if (parsedTrackArtists.length > 0) return parsedTrackArtists[0];
   return splitCollaborators(track.artist)[0] ?? UNKNOWN_ARTIST;
 }
 
 /** Every artist a track is indexed under in astra mode: primary + all collaborators. */
-export function getCanonicalArtistIndexNames(track: Pick<DbTrack, 'artist' | 'album_artist'>): string[] {
+export function getCanonicalArtistIndexNames(track: ArtistCreditTrackLike): string[] {
   const unique = new Map<string, string>();
   const add = (name: string) => {
     const display = normalizeDisplay(name);
@@ -81,10 +93,17 @@ export function getCanonicalArtistIndexNames(track: Pick<DbTrack, 'artist' | 'al
 
   add(resolveCanonicalBrowseArtist(track));
 
-  const trackArtists = splitCollaborators(track.artist);
+  const parsedTrackArtists = normalizeArtistNames(track.artist_names);
+  const trackArtists =
+    parsedTrackArtists.length > 0 ? parsedTrackArtists : splitCollaborators(track.artist);
   for (const name of trackArtists) add(name);
   if (trackArtists.length === 0) {
-    for (const name of splitAlbumArtistCollaborators(track.album_artist ?? '')) add(name);
+    const parsedAlbumArtists = normalizeArtistNames(track.album_artist_names);
+    const albumArtists =
+      parsedAlbumArtists.length > 0
+        ? parsedAlbumArtists
+        : splitAlbumArtistCollaborators(track.album_artist ?? '');
+    for (const name of albumArtists) add(name);
   }
 
   return Array.from(unique.values());
@@ -98,18 +117,18 @@ export function getCanonicalArtistIndexNames(track: Pick<DbTrack, 'artist' | 'al
  * bucket is the only artist page that lists those tracks in that mode.
  */
 export function resolveNavigationArtist(
-  track: Pick<DbTrack, 'artist' | 'album_artist'>,
+  track: ArtistCreditTrackLike,
   mode: ArtistGroupingMode
 ): string {
   if (mode === 'fileTags') return resolveStrictBrowseArtist(track);
   const canonical = resolveCanonicalBrowseArtist(track);
   if (normalizeKey(canonical) !== VARIOUS_ARTISTS_KEY) return canonical;
-  return splitCollaborators(track.artist)[0] ?? canonical;
+  return normalizeArtistNames(track.artist_names)[0] ?? splitCollaborators(track.artist)[0] ?? canonical;
 }
 
 /** Whether a track belongs to the given artist key under the active browse mode. */
 export function trackMatchesBrowseArtist(
-  track: Pick<DbTrack, 'artist' | 'album_artist'>,
+  track: ArtistCreditTrackLike,
   targetArtistKey: string,
   mode: ArtistGroupingMode
 ): boolean {
@@ -125,9 +144,15 @@ export function trackMatchesBrowseArtist(
   const trackArtistKey = normalizeKey(track.artist);
   if (trackArtistKey && trackArtistKey === targetArtistKey) return true;
 
+  if (normalizeArtistNames(track.album_artist_names).some((n) => normalizeKey(n) === targetArtistKey)) {
+    return true;
+  }
   if (splitAlbumArtistCollaborators(track.album_artist ?? '').some((n) => normalizeKey(n) === targetArtistKey)) {
     return true;
   }
+  if (normalizeArtistNames(track.artist_names).some((n) => normalizeKey(n) === targetArtistKey)) {
+    return true;
+  }
   return splitCollaborators(track.artist).some((n) => normalizeKey(n) === targetArtistKey);
 }
 

src/library/scanner.ts

@@ -34,6 +34,7 @@ type NativeFolder = LibraryFolder & {
   track_count: number;
   scan_status?: string;
   scan_error?: string | null;
+  needs_metadata_reindex?: boolean;
 };
 
 function displayNameFromTreeUri(treeUri: string): string {

src/library/trackAdapter.ts

@@ -25,8 +25,11 @@ export function dbTrackToTrack(track: DbTrack): Track {
     origin: 'library',
     title: track.title,
     artist: track.artist,
+    artistNames: track.artist_names?.length > 0 ? track.artist_names : undefined,
     album: track.album,
     albumArtist: track.album_artist ?? undefined,
+    albumArtistNames:
+      track.album_artist_names?.length > 0 ? track.album_artist_names : undefined,
     albumIdentityKey: track.album_identity_key,
     duration: track.duration,
     trackNumber: track.track_number ?? undefined,

src/shared/library/albumGrouping.ts

@@ -1,8 +1,7 @@
 // Port of desktop astra/src/shared/library/albumGrouping.ts — keep semantically
-// identical so album identities match the desktop app. Mobile has no
-// artist_names/*_names_json columns; those inputs stay undefined and the module
-// falls through to the string-splitting paths, exactly like desktop does for
-// files without multi-value tags.
+// identical so album identities match the desktop app. Structured artist
+// arrays are preferred; legacy and remote rows without them fall through to
+// the same string-splitting paths desktop uses for single-value tags.
 
 // Explicit .ts extension so the module resolves under plain `node --test`
 // (Metro and tsc accept it via allowImportingTsExtensions).

src/stores/libraryStore.ts

@@ -53,7 +53,10 @@ function persistSetting(key: string, value: string) {
   void AstraLibraryData.setSettings({ [key]: value });
 }
 
-export type FolderWithCount = LibraryFolder & { track_count: number };
+export type FolderWithCount = LibraryFolder & {
+  track_count: number;
+  needs_metadata_reindex?: boolean;
+};
 
 interface ScanProgressState {
   phase: 'idle' | 'discovering' | 'extracting' | 'analyzing';
@@ -487,7 +490,10 @@ export const useLibraryStore = create<LibraryStore>((set, get) => {
 
           await get().refresh();
           set({ initialized: true });
-          if (status.status === 'rebuilding' && !get().isScanning) {
+          const needsMetadataReindex = get().folders.some(
+            (folder) => folder.available && folder.needs_metadata_reindex === true
+          );
+          if ((status.status === 'rebuilding' || needsMetadataReindex) && !get().isScanning) {
             void get().rebuildLocalIndex();
           }
         })().catch((error) => {

src/types/library.ts

@@ -9,8 +9,12 @@ export interface DbTrack {
   folder_id: number | null; // NULL for remote tracks (no SAF folder)
   title: string;
   artist: string;
+  /** Ordered repeated ARTIST tag values; empty for legacy/single-value rows. */
+  artist_names: string[];
   album: string;
   album_artist: string | null;
+  /** Ordered repeated ALBUMARTIST values; empty for legacy/single-value rows. */
+  album_artist_names: string[];
   album_identity_key: string;
   /** Settled group artist ("Various Artists" for shared-artwork compilations);
    *  written by the album-identity recompute pass, NULL until it first runs. */