feat(scanner): implement selective folder scanning and file system watcher improvements (#4674)

* feat: Add selective folder scanning capability

Implement targeted scanning of specific library/folder pairs without
full recursion. This enables efficient rescanning of individual folders
when changes are detected, significantly reducing scan time for large
libraries.

Key changes:
- Add ScanTarget struct and ScanFolders API to Scanner interface
- Implement CLI flag --targets for specifying libraryID:folderPath pairs
- Add FolderRepository.GetByPaths() for batch folder info retrieval
- Create loadSpecificFolders() for non-recursive directory loading
- Scope GC operations to affected libraries only (with TODO for full impl)
- Add comprehensive tests for selective scanning behavior

The selective scan:
- Only processes specified folders (no subdirectory recursion)
- Maintains library isolation
- Runs full maintenance pipeline scoped to affected libraries
- Supports both full and quick scan modes

Examples:
  navidrome scan --targets "1:Music/Rock,1:Music/Jazz"
  navidrome scan --full --targets "2:Classical"

* feat(folder): replace GetByPaths with GetFolderUpdateInfo for improved folder updates retrieval

Signed-off-by: Deluan <deluan@navidrome.org>

* test: update parseTargets test to handle folder names with spaces

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(folder): remove unused LibraryPath struct and update GC logging message

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(folder): enhance external scanner to support target-specific scanning

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): simplify scanner methods

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(watcher): implement folder scanning notifications with deduplication

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(watcher): add resolveFolderPath function for testability

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(watcher): implement path ignoring based on .ndignore patterns

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): implement IgnoreChecker for managing .ndignore patterns

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(ignore_checker): rename scanner to lineScanner for clarity

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): enhance ScanTarget struct with String method for better target representation

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(scanner): validate library ID to prevent negative values

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): simplify GC method by removing library ID parameter

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(scanner): update folder scanning to include all descendants of specified folders

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(subsonic): allow selective scan in the /startScan endpoint

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): update CallScan to handle specific library/folder pairs

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): streamline scanning logic by removing scanAll method

Signed-off-by: Deluan <deluan@navidrome.org>

* test: enhance mockScanner for thread safety and improve test reliability

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): move scanner.ScanTarget to model.ScanTarget

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor: move scanner types to model,implement MockScanner

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): update scanner interface and implementations to use model.Scanner

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(folder_repository): normalize target path handling by using filepath.Clean

Signed-off-by: Deluan <deluan@navidrome.org>

* test(folder_repository): add comprehensive tests for folder retrieval and child exclusion

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): simplify selective scan logic using slice.Filter

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): streamline phase folder and album creation by removing unnecessary library parameter

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): move initialization logic from phase_1 to the scanner itself

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(tests): rename selective scan test file to scanner_selective_test.go

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(configuration): add DevSelectiveWatcher configuration option

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(watcher): enhance .ndignore handling for folder deletions and file changes

Signed-off-by: Deluan <deluan@navidrome.org>

* docs(scanner): comments

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(scanner): enhance walkDirTree to support target folder scanning

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(scanner, watcher): handle errors when pushing ignore patterns for folders

Signed-off-by: Deluan <deluan@navidrome.org>

* Update scanner/phase_1_folders.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* refactor(scanner): replace parseTargets function with direct call to scanner.ParseTargets

Signed-off-by: Deluan <deluan@navidrome.org>

* test(scanner): add tests for ScanBegin and ScanEnd functionality

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(library): update PRAGMA optimize to check table sizes without ANALYZE

Signed-off-by: Deluan <deluan@navidrome.org>

* test(scanner): refactor tests

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(ui): add selective scan options and update translations

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(ui): add quick and full scan options for individual libraries

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(ui): add Scan buttonsto the LibraryList

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(scan): update scanning parameters from 'path' to 'target' for selective scans.

* refactor(scan): move ParseTargets function to model package

* test(scan): suppress unused return value from SetUserLibraries in tests

* feat(gc): enhance garbage collection to support selective library purging

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(scanner): prevent race condition when scanning deleted folders

When the watcher detects changes in a folder that gets deleted before
the scanner runs (due to the 10-second delay), the scanner was
prematurely removing these folders from the tracking map, preventing
them from being marked as missing.

The issue occurred because `newFolderEntry` was calling `popLastUpdate`
before verifying the folder actually exists on the filesystem.

Changes:
- Move fs.Stat check before newFolderEntry creation in loadDir to
  ensure deleted folders remain in lastUpdates for finalize() to handle
- Add early existence check in walkDirTree to skip non-existent target
  folders with a warning log
- Add unit test verifying non-existent folders aren't removed from
  lastUpdates prematurely
- Add integration test for deleted folder scenario with ScanFolders

Fixes the issue where deleting entire folders (e.g., /music/AC_DC)
wouldn't mark tracks as missing when using selective folder scanning.

* refactor(scan): streamline folder entry creation and update handling

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(scan): add '@Recycle' (QNAP) to ignored directories list

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(log): improve thread safety in logging level management

* test(scan): move unit tests for ParseTargets function

Signed-off-by: Deluan <deluan@navidrome.org>

* review

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: deluan <deluan.quintao@mechanical-orchard.com>

cmd/scan.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"encoding/gob"
 	"os"
+	"strings"
 
 	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/utils/pl"
@@ -17,11 +19,13 @@ import (
 var (
 	fullScan   bool
 	subprocess bool
+	targets    string
 )
 
 func init() {
 	scanCmd.Flags().BoolVarP(&fullScan, "full", "f", false, "check all subfolders, ignoring timestamps")
 	scanCmd.Flags().BoolVarP(&subprocess, "subprocess", "", false, "run as subprocess (internal use)")
+	scanCmd.Flags().StringVarP(&targets, "targets", "t", "", "comma-separated list of libraryID:folderPath pairs (e.g., \"1:Music/Rock,1:Music/Jazz,2:Classical\")")
 	rootCmd.AddCommand(scanCmd)
 }
 
@@ -68,7 +72,18 @@ func runScanner(ctx context.Context) {
 	ds := persistence.New(sqlDB)
 	pls := core.NewPlaylists(ds)
 
-	progress, err := scanner.CallScan(ctx, ds, pls, fullScan)
+	// Parse targets if provided
+	var scanTargets []model.ScanTarget
+	if targets != "" {
+		var err error
+		scanTargets, err = model.ParseTargets(strings.Split(targets, ","))
+		if err != nil {
+			log.Fatal(ctx, "Failed to parse targets", err)
+		}
+		log.Info(ctx, "Scanning specific folders", "numTargets", len(scanTargets))
+	}
+
+	progress, err := scanner.CallScan(ctx, ds, pls, fullScan, scanTargets)
 	if err != nil {
 		log.Fatal(ctx, "Failed to scan", err)
 	}

cmd/wire_gen.go

@@ -69,9 +69,9 @@ func CreateNativeAPIRouter(ctx context.Context) *nativeapi.Router {
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	watcher := scanner.GetWatcher(dataStore, scannerScanner)
+	watcher := scanner.GetWatcher(dataStore, modelScanner)
-	library := core.NewLibrary(dataStore, scannerScanner, watcher, broker)
+	library := core.NewLibrary(dataStore, modelScanner, watcher, broker)
 	maintenance := core.NewMaintenance(dataStore)
 	router := nativeapi.New(dataStore, share, playlists, insights, library, maintenance)
 	return router
@@ -95,10 +95,10 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
 	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
 	playbackServer := playback.GetInstance(dataStore)
-	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, scannerScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics)
+	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, modelScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics)
 	return router
 }
 
@@ -150,7 +150,7 @@ func CreatePrometheus() metrics.Metrics {
 	return metricsMetrics
 }
 
-func CreateScanner(ctx context.Context) scanner.Scanner {
+func CreateScanner(ctx context.Context) model.Scanner {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
@@ -163,8 +163,8 @@ func CreateScanner(ctx context.Context) scanner.Scanner {
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	return scannerScanner
+	return modelScanner
 }
 
 func CreateScanWatcher(ctx context.Context) scanner.Watcher {
@@ -180,8 +180,8 @@ func CreateScanWatcher(ctx context.Context) scanner.Watcher {
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
 	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	watcher := scanner.GetWatcher(dataStore, scannerScanner)
+	watcher := scanner.GetWatcher(dataStore, modelScanner)
 	return watcher
 }
 
@@ -202,7 +202,7 @@ func getPluginManager() plugins.Manager {
 
 // wire_injectors.go:
 
-var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.GetWatcher, plugins.GetManager, metrics.GetPrometheusInstance, db.Db, wire.Bind(new(agents.PluginLoader), new(plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(plugins.Manager)), wire.Bind(new(metrics.PluginLoader), new(plugins.Manager)), wire.Bind(new(core.Scanner), new(scanner.Scanner)), wire.Bind(new(core.Watcher), new(scanner.Watcher)))
+var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.GetWatcher, plugins.GetManager, metrics.GetPrometheusInstance, db.Db, wire.Bind(new(agents.PluginLoader), new(plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(plugins.Manager)), wire.Bind(new(metrics.PluginLoader), new(plugins.Manager)), wire.Bind(new(core.Watcher), new(scanner.Watcher)))
 
 func GetPluginManager(ctx context.Context) plugins.Manager {
 	manager := getPluginManager()

cmd/wire_injectors.go

@@ -45,7 +45,6 @@ var allProviders = wire.NewSet(
 	wire.Bind(new(agents.PluginLoader), new(plugins.Manager)),
 	wire.Bind(new(scrobbler.PluginLoader), new(plugins.Manager)),
 	wire.Bind(new(metrics.PluginLoader), new(plugins.Manager)),
-	wire.Bind(new(core.Scanner), new(scanner.Scanner)),
 	wire.Bind(new(core.Watcher), new(scanner.Watcher)),
 )
 
@@ -103,7 +102,7 @@ func CreatePrometheus() metrics.Metrics {
 	))
 }
 
-func CreateScanner(ctx context.Context) scanner.Scanner {
+func CreateScanner(ctx context.Context) model.Scanner {
 	panic(wire.Build(
 		allProviders,
 	))

conf/configuration.go

@@ -125,6 +125,7 @@ type configOptions struct {
 	DevAlbumInfoTimeToLive           time.Duration
 	DevExternalScanner               bool
 	DevScannerThreads                uint
+	DevSelectiveWatcher              bool
 	DevInsightsInitialDelay          time.Duration
 	DevEnablePlayerInsights          bool
 	DevEnablePluginsInsights         bool
@@ -600,6 +601,7 @@ func setViperDefaults() {
 	viper.SetDefault("devalbuminfotimetolive", consts.AlbumInfoTimeToLive)
 	viper.SetDefault("devexternalscanner", true)
 	viper.SetDefault("devscannerthreads", 5)
+	viper.SetDefault("devselectivewatcher", true)
 	viper.SetDefault("devinsightsinitialdelay", consts.InsightsInitialDelay)
 	viper.SetDefault("devenableplayerinsights", true)
 	viper.SetDefault("devenablepluginsinsights", true)

core/library.go

@@ -21,11 +21,6 @@ import (
 	"github.com/navidrome/navidrome/utils/slice"
 )
 
-// Scanner interface for triggering scans
-type Scanner interface {
-	ScanAll(ctx context.Context, fullScan bool) (warnings []string, err error)
-}
-
 // Watcher interface for managing file system watchers
 type Watcher interface {
 	Watch(ctx context.Context, lib *model.Library) error
@@ -43,13 +38,13 @@ type Library interface {
 
 type libraryService struct {
 	ds      model.DataStore
-	scanner Scanner
+	scanner model.Scanner
 	watcher Watcher
 	broker  events.Broker
 }
 
 // NewLibrary creates a new Library service
-func NewLibrary(ds model.DataStore, scanner Scanner, watcher Watcher, broker events.Broker) Library {
+func NewLibrary(ds model.DataStore, scanner model.Scanner, watcher Watcher, broker events.Broker) Library {
 	return &libraryService{
 		ds:      ds,
 		scanner: scanner,
@@ -155,7 +150,7 @@ type libraryRepositoryWrapper struct {
 	model.LibraryRepository
 	ctx     context.Context
 	ds      model.DataStore
-	scanner Scanner
+	scanner model.Scanner
 	watcher Watcher
 	broker  events.Broker
 }
@@ -192,7 +187,7 @@ func (r *libraryRepositoryWrapper) Save(entity interface{}) (string, error) {
 	return strconv.Itoa(lib.ID), nil
 }
 
-func (r *libraryRepositoryWrapper) Update(id string, entity interface{}, cols ...string) error {
+func (r *libraryRepositoryWrapper) Update(id string, entity interface{}, _ ...string) error {
 	lib := entity.(*model.Library)
 	libID, err := strconv.Atoi(id)
 	if err != nil {

core/library_test.go

@@ -29,7 +29,7 @@ var _ = Describe("Library Service", func() {
 	var userRepo *tests.MockedUserRepo
 	var ctx context.Context
 	var tempDir string
-	var scanner *mockScanner
+	var scanner *tests.MockScanner
 	var watcherManager *mockWatcherManager
 	var broker *mockEventBroker
 
@@ -43,7 +43,7 @@ var _ = Describe("Library Service", func() {
 		ds.MockedUser = userRepo
 
 		// Create a mock scanner that tracks calls
-		scanner = &mockScanner{}
+		scanner = tests.NewMockScanner()
 		// Create a mock watcher manager
 		watcherManager = &mockWatcherManager{
 			libraryStates: make(map[int]model.Library),
@@ -616,11 +616,12 @@ var _ = Describe("Library Service", func() {
 
 			// Wait briefly for the goroutine to complete
 			Eventually(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "1s", "10ms").Should(Equal(1))
 
 			// Verify scan was called with correct parameters
-			Expect(scanner.ScanCalls[0].FullScan).To(BeFalse()) // Should be quick scan
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
 		})
 
 		It("triggers scan when updating library path", func() {
@@ -641,11 +642,12 @@ var _ = Describe("Library Service", func() {
 
 			// Wait briefly for the goroutine to complete
 			Eventually(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "1s", "10ms").Should(Equal(1))
 
 			// Verify scan was called with correct parameters
-			Expect(scanner.ScanCalls[0].FullScan).To(BeFalse()) // Should be quick scan
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
 		})
 
 		It("does not trigger scan when updating library without path change", func() {
@@ -661,7 +663,7 @@ var _ = Describe("Library Service", func() {
 
 			// Wait a bit to ensure no scan was triggered
 			Consistently(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "100ms", "10ms").Should(Equal(0))
 		})
 
@@ -674,7 +676,7 @@ var _ = Describe("Library Service", func() {
 
 			// Ensure no scan was triggered since creation failed
 			Consistently(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "100ms", "10ms").Should(Equal(0))
 		})
 
@@ -691,7 +693,7 @@ var _ = Describe("Library Service", func() {
 
 			// Ensure no scan was triggered since update failed
 			Consistently(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "100ms", "10ms").Should(Equal(0))
 		})
 
@@ -707,11 +709,12 @@ var _ = Describe("Library Service", func() {
 
 			// Wait briefly for the goroutine to complete
 			Eventually(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "1s", "10ms").Should(Equal(1))
 
 			// Verify scan was called with correct parameters
-			Expect(scanner.ScanCalls[0].FullScan).To(BeFalse()) // Should be quick scan
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
 		})
 
 		It("does not trigger scan when library deletion fails", func() {
@@ -721,7 +724,7 @@ var _ = Describe("Library Service", func() {
 
 			// Ensure no scan was triggered since deletion failed
 			Consistently(func() int {
-				return scanner.len()
+				return scanner.GetScanAllCallCount()
 			}, "100ms", "10ms").Should(Equal(0))
 		})
 
@@ -868,31 +871,6 @@ var _ = Describe("Library Service", func() {
 	})
 })
 
-// mockScanner provides a simple mock implementation of core.Scanner for testing
-type mockScanner struct {
-	ScanCalls []ScanCall
-	mu        sync.RWMutex
-}
-
-type ScanCall struct {
-	FullScan bool
-}
-
-func (m *mockScanner) ScanAll(ctx context.Context, fullScan bool) (warnings []string, err error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	m.ScanCalls = append(m.ScanCalls, ScanCall{
-		FullScan: fullScan,
-	})
-	return []string{}, nil
-}
-
-func (m *mockScanner) len() int {
-	m.mu.RLock()
-	defer m.mu.RUnlock()
-	return len(m.ScanCalls)
-}
-
 // mockWatcherManager provides a simple mock implementation of core.Watcher for testing
 type mockWatcherManager struct {
 	StartedWatchers   []model.Library

core/maintenance_test.go

@@ -14,7 +14,7 @@ import (
 )
 
 var _ = Describe("Maintenance", func() {
-	var ds *extendedDataStore
+	var ds *tests.MockDataStore
 	var mfRepo *extendedMediaFileRepo
 	var service Maintenance
 	var ctx context.Context
@@ -42,7 +42,7 @@ var _ = Describe("Maintenance", func() {
 				Expect(err).ToNot(HaveOccurred())
 				Expect(mfRepo.deleteMissingCalled).To(BeTrue())
 				Expect(mfRepo.deletedIDs).To(Equal([]string{"mf1", "mf2"}))
-				Expect(ds.gcCalled).To(BeTrue(), "GC should be called after deletion")
+				Expect(ds.GCCalled).To(BeTrue(), "GC should be called after deletion")
 			})
 
 			It("triggers artist stats refresh and album refresh after deletion", func() {
@@ -97,7 +97,7 @@ var _ = Describe("Maintenance", func() {
 				})
 
 				// Set GC to return error
-				ds.gcError = errors.New("gc failed")
+				ds.GCError = errors.New("gc failed")
 
 				err := service.DeleteMissingFiles(ctx, []string{"mf1"})
 
@@ -143,7 +143,7 @@ var _ = Describe("Maintenance", func() {
 			err := service.DeleteAllMissingFiles(ctx)
 
 			Expect(err).ToNot(HaveOccurred())
-			Expect(ds.gcCalled).To(BeTrue(), "GC should be called after deletion")
+			Expect(ds.GCCalled).To(BeTrue(), "GC should be called after deletion")
 		})
 
 		It("returns error if deletion fails", func() {
@@ -253,11 +253,8 @@ var _ = Describe("Maintenance", func() {
 })
 
 // Test helper to create a mock DataStore with controllable behavior
-func createTestDataStore() *extendedDataStore {
+func createTestDataStore() *tests.MockDataStore {
-	// Create extended datastore with GC tracking
+	ds := &tests.MockDataStore{}
-	ds := &extendedDataStore{
-		MockDataStore: &tests.MockDataStore{},
-	}
 
 	// Create extended album repo with Put tracking
 	albumRepo := &extendedAlbumRepo{
@@ -365,18 +362,3 @@ func (m *extendedArtistRepo) IsRefreshStatsCalled() bool {
 	defer m.mu.RUnlock()
 	return m.refreshStatsCalled
 }
-
-// Extension of MockDataStore to track GC calls
-type extendedDataStore struct {
-	*tests.MockDataStore
-	gcCalled bool
-	gcError  error
-}
-
-func (ds *extendedDataStore) GC(ctx context.Context) error {
-	ds.gcCalled = true
-	if ds.gcError != nil {
-		return ds.gcError
-	}
-	return ds.MockDataStore.GC(ctx)
-}

log/log.go

@@ -80,8 +80,8 @@ var (
 
 // SetLevel sets the global log level used by the simple logger.
 func SetLevel(l Level) {
-	currentLevel = l
 	loggerMu.Lock()
+	currentLevel = l
 	defaultLogger.Level = logrus.TraceLevel
 	loggerMu.Unlock()
 	logrus.SetLevel(logrus.Level(l))
@@ -114,6 +114,8 @@ func levelFromString(l string) Level {
 
 // SetLogLevels sets the log levels for specific paths in the codebase.
 func SetLogLevels(levels map[string]string) {
+	loggerMu.Lock()
+	defer loggerMu.Unlock()
 	logLevels = nil
 	for k, v := range levels {
 		logLevels = append(logLevels, levelPath{path: k, level: levelFromString(v)})
@@ -172,6 +174,8 @@ func SetDefaultLogger(l *logrus.Logger) {
 }
 
 func CurrentLevel() Level {
+	loggerMu.RLock()
+	defer loggerMu.RUnlock()
 	return currentLevel
 }
 
@@ -220,10 +224,15 @@ func Writer() io.Writer {
 }
 
 func shouldLog(requiredLevel Level, skip int) bool {
-	if currentLevel >= requiredLevel {
+	loggerMu.RLock()
+	level := currentLevel
+	levels := logLevels
+	loggerMu.RUnlock()
+
+	if level >= requiredLevel {
 		return true
 	}
-	if len(logLevels) == 0 {
+	if len(levels) == 0 {
 		return false
 	}
 
@@ -233,7 +242,7 @@ func shouldLog(requiredLevel Level, skip int) bool {
 	}
 
 	file = strings.TrimPrefix(file, rootPath)
-	for _, lp := range logLevels {
+	for _, lp := range levels {
 		if strings.HasPrefix(file, lp.path) {
 			return lp.level >= requiredLevel
 		}

model/datastore.go

@@ -43,5 +43,5 @@ type DataStore interface {
 
 	WithTx(block func(tx DataStore) error, scope ...string) error
 	WithTxImmediate(block func(tx DataStore) error, scope ...string) error
-	GC(ctx context.Context) error
+	GC(ctx context.Context, libraryIDs ...int) error
 }

model/folder.go

@@ -85,7 +85,7 @@ type FolderRepository interface {
 	GetByPath(lib Library, path string) (*Folder, error)
 	GetAll(...QueryOptions) ([]Folder, error)
 	CountAll(...QueryOptions) (int64, error)
-	GetLastUpdates(lib Library) (map[string]FolderUpdateInfo, error)
+	GetFolderUpdateInfo(lib Library, targetPaths ...string) (map[string]FolderUpdateInfo, error)
 	Put(*Folder) error
 	MarkMissing(missing bool, ids ...string) error
 	GetTouchedWithPlaylists() (FolderCursor, error)

model/scanner.go

@@ -0,0 +1,81 @@
+package model
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ScanTarget represents a specific folder within a library to be scanned.
+// NOTE: This struct is used as a map key, so it should only contain comparable types.
+type ScanTarget struct {
+	LibraryID  int
+	FolderPath string // Relative path within the library, or "" for entire library
+}
+
+func (st ScanTarget) String() string {
+	return fmt.Sprintf("%d:%s", st.LibraryID, st.FolderPath)
+}
+
+// ScannerStatus holds information about the current scan status
+type ScannerStatus struct {
+	Scanning    bool
+	LastScan    time.Time
+	Count       uint32
+	FolderCount uint32
+	LastError   string
+	ScanType    string
+	ElapsedTime time.Duration
+}
+
+type Scanner interface {
+	// ScanAll starts a scan of all libraries. This is a blocking operation.
+	ScanAll(ctx context.Context, fullScan bool) (warnings []string, err error)
+	// ScanFolders scans specific library/folder pairs, recursing into subdirectories.
+	// If targets is nil, it scans all libraries. This is a blocking operation.
+	ScanFolders(ctx context.Context, fullScan bool, targets []ScanTarget) (warnings []string, err error)
+	Status(context.Context) (*ScannerStatus, error)
+}
+
+// ParseTargets parses scan targets strings into ScanTarget structs.
+// Example: []string{"1:Music/Rock", "2:Classical"}
+func ParseTargets(libFolders []string) ([]ScanTarget, error) {
+	targets := make([]ScanTarget, 0, len(libFolders))
+
+	for _, part := range libFolders {
+		part = strings.TrimSpace(part)
+		if part == "" {
+			continue
+		}
+
+		// Split by the first colon
+		colonIdx := strings.Index(part, ":")
+		if colonIdx == -1 {
+			return nil, fmt.Errorf("invalid target format: %q (expected libraryID:folderPath)", part)
+		}
+
+		libIDStr := part[:colonIdx]
+		folderPath := part[colonIdx+1:]
+
+		libID, err := strconv.Atoi(libIDStr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid library ID %q: %w", libIDStr, err)
+		}
+		if libID <= 0 {
+			return nil, fmt.Errorf("invalid library ID %q", libIDStr)
+		}
+
+		targets = append(targets, ScanTarget{
+			LibraryID:  libID,
+			FolderPath: folderPath,
+		})
+	}
+
+	if len(targets) == 0 {
+		return nil, fmt.Errorf("no valid targets found")
+	}
+
+	return targets, nil
+}

model/scanner_test.go

@@ -0,0 +1,89 @@
+package model_test
+
+import (
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("ParseTargets", func() {
+	It("parses multiple entries in slice", func() {
+		targets, err := model.ParseTargets([]string{"1:Music/Rock", "1:Music/Jazz", "2:Classical"})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(3))
+		Expect(targets[0].LibraryID).To(Equal(1))
+		Expect(targets[0].FolderPath).To(Equal("Music/Rock"))
+		Expect(targets[1].LibraryID).To(Equal(1))
+		Expect(targets[1].FolderPath).To(Equal("Music/Jazz"))
+		Expect(targets[2].LibraryID).To(Equal(2))
+		Expect(targets[2].FolderPath).To(Equal("Classical"))
+	})
+
+	It("handles empty folder paths", func() {
+		targets, err := model.ParseTargets([]string{"1:", "2:"})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+		Expect(targets[0].FolderPath).To(Equal(""))
+		Expect(targets[1].FolderPath).To(Equal(""))
+	})
+
+	It("trims whitespace from entries", func() {
+		targets, err := model.ParseTargets([]string{"  1:Music/Rock", " 2:Classical "})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+		Expect(targets[0].LibraryID).To(Equal(1))
+		Expect(targets[0].FolderPath).To(Equal("Music/Rock"))
+		Expect(targets[1].LibraryID).To(Equal(2))
+		Expect(targets[1].FolderPath).To(Equal("Classical"))
+	})
+
+	It("skips empty strings", func() {
+		targets, err := model.ParseTargets([]string{"1:Music/Rock", "", "2:Classical"})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+	})
+
+	It("handles paths with colons", func() {
+		targets, err := model.ParseTargets([]string{"1:C:/Music/Rock", "2:/path:with:colons"})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+		Expect(targets[0].FolderPath).To(Equal("C:/Music/Rock"))
+		Expect(targets[1].FolderPath).To(Equal("/path:with:colons"))
+	})
+
+	It("returns error for invalid format without colon", func() {
+		_, err := model.ParseTargets([]string{"1Music/Rock"})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("invalid target format"))
+	})
+
+	It("returns error for non-numeric library ID", func() {
+		_, err := model.ParseTargets([]string{"abc:Music/Rock"})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("invalid library ID"))
+	})
+
+	It("returns error for negative library ID", func() {
+		_, err := model.ParseTargets([]string{"-1:Music/Rock"})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("invalid library ID"))
+	})
+
+	It("returns error for zero library ID", func() {
+		_, err := model.ParseTargets([]string{"0:Music/Rock"})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("invalid library ID"))
+	})
+
+	It("returns error for empty input", func() {
+		_, err := model.ParseTargets([]string{})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("no valid targets found"))
+	})
+
+	It("returns error for all empty strings", func() {
+		_, err := model.ParseTargets([]string{"", "  ", ""})
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("no valid targets found"))
+	})
+})

persistence/album_repository.go

@@ -337,8 +337,12 @@ on conflict (user_id, item_id, item_type) do update
 	return r.executeSQL(query)
 }
 
-func (r *albumRepository) purgeEmpty() error {
+func (r *albumRepository) purgeEmpty(libraryIDs ...int) error {
 	del := Delete(r.tableName).Where("id not in (select distinct(album_id) from media_file)")
+	// If libraryIDs are specified, only purge albums from those libraries
+	if len(libraryIDs) > 0 {
+		del = del.Where(Eq{"library_id": libraryIDs})
+	}
 	c, err := r.executeSQL(del)
 	if err != nil {
 		return fmt.Errorf("purging empty albums: %w", err)

persistence/folder_repository.go

@@ -4,7 +4,10 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"os"
+	"path/filepath"
 	"slices"
+	"strings"
 	"time"
 
 	. "github.com/Masterminds/squirrel"
@@ -91,8 +94,47 @@ func (r folderRepository) CountAll(opt ...model.QueryOptions) (int64, error) {
 	return r.count(query)
 }
 
-func (r folderRepository) GetLastUpdates(lib model.Library) (map[string]model.FolderUpdateInfo, error) {
+func (r folderRepository) GetFolderUpdateInfo(lib model.Library, targetPaths ...string) (map[string]model.FolderUpdateInfo, error) {
-	sq := r.newSelect().Columns("id", "updated_at", "hash").Where(Eq{"library_id": lib.ID, "missing": false})
+	where := And{
+		Eq{"library_id": lib.ID},
+		Eq{"missing": false},
+	}
+
+	// If specific paths are requested, include those folders and all their descendants
+	if len(targetPaths) > 0 {
+		// Collect folder IDs for exact target folders and path conditions for descendants
+		folderIDs := make([]string, 0, len(targetPaths))
+		pathConditions := make(Or, 0, len(targetPaths)*2)
+
+		for _, targetPath := range targetPaths {
+			if targetPath == "" || targetPath == "." {
+				// Root path - include everything in this library
+				pathConditions = Or{}
+				folderIDs = nil
+				break
+			}
+			// Clean the path to normalize it. Paths stored in the folder table do not have leading/trailing slashes.
+			cleanPath := strings.TrimPrefix(targetPath, string(os.PathSeparator))
+			cleanPath = filepath.Clean(cleanPath)
+
+			// Include the target folder itself by ID
+			folderIDs = append(folderIDs, model.FolderID(lib, cleanPath))
+
+			// Include all descendants: folders whose path field equals or starts with the target path
+			// Note: Folder.Path is the directory path, so children have path = targetPath
+			pathConditions = append(pathConditions, Eq{"path": cleanPath})
+			pathConditions = append(pathConditions, Like{"path": cleanPath + "/%"})
+		}
+
+		// Combine conditions: exact folder IDs OR descendant path patterns
+		if len(folderIDs) > 0 {
+			where = append(where, Or{Eq{"id": folderIDs}, pathConditions})
+		} else if len(pathConditions) > 0 {
+			where = append(where, pathConditions)
+		}
+	}
+
+	sq := r.newSelect().Columns("id", "updated_at", "hash").Where(where)
 	var res []struct {
 		ID        string
 		UpdatedAt time.Time
@@ -149,7 +191,7 @@ func (r folderRepository) GetTouchedWithPlaylists() (model.FolderCursor, error)
 	}, nil
 }
 
-func (r folderRepository) purgeEmpty() error {
+func (r folderRepository) purgeEmpty(libraryIDs ...int) error {
 	sq := Delete(r.tableName).Where(And{
 		Eq{"num_audio_files": 0},
 		Eq{"num_playlists": 0},
@@ -157,6 +199,10 @@ func (r folderRepository) purgeEmpty() error {
 		ConcatExpr("id not in (select parent_id from folder)"),
 		ConcatExpr("id not in (select folder_id from media_file)"),
 	})
+	// If libraryIDs are specified, only purge folders from those libraries
+	if len(libraryIDs) > 0 {
+		sq = sq.Where(Eq{"library_id": libraryIDs})
+	}
 	c, err := r.executeSQL(sq)
 	if err != nil {
 		return fmt.Errorf("purging empty folders: %w", err)

persistence/folder_repository_test.go

@@ -0,0 +1,213 @@
+package persistence
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/pocketbase/dbx"
+)
+
+var _ = Describe("FolderRepository", func() {
+	var repo model.FolderRepository
+	var ctx context.Context
+	var conn *dbx.DB
+	var testLib, otherLib model.Library
+
+	BeforeEach(func() {
+		ctx = request.WithUser(log.NewContext(context.TODO()), model.User{ID: "userid"})
+		conn = GetDBXBuilder()
+		repo = newFolderRepository(ctx, conn)
+
+		// Use existing library ID 1 from test fixtures
+		libRepo := NewLibraryRepository(ctx, conn)
+		lib, err := libRepo.Get(1)
+		Expect(err).ToNot(HaveOccurred())
+		testLib = *lib
+
+		// Create a second library with its own folder to verify isolation
+		otherLib = model.Library{Name: "Other Library", Path: "/other/path"}
+		Expect(libRepo.Put(&otherLib)).To(Succeed())
+	})
+
+	AfterEach(func() {
+		// Clean up only test folders created by our tests (paths starting with "Test")
+		// This prevents interference with fixture data needed by other tests
+		_, _ = conn.NewQuery("DELETE FROM folder WHERE library_id = 1 AND path LIKE 'Test%'").Execute()
+		_, _ = conn.NewQuery(fmt.Sprintf("DELETE FROM library WHERE id = %d", otherLib.ID)).Execute()
+	})
+
+	Describe("GetFolderUpdateInfo", func() {
+		Context("with no target paths", func() {
+			It("returns all folders in the library", func() {
+				// Create test folders with unique names to avoid conflicts
+				folder1 := model.NewFolder(testLib, "TestGetLastUpdates/Folder1")
+				folder2 := model.NewFolder(testLib, "TestGetLastUpdates/Folder2")
+
+				err := repo.Put(folder1)
+				Expect(err).ToNot(HaveOccurred())
+				err = repo.Put(folder2)
+				Expect(err).ToNot(HaveOccurred())
+
+				otherFolder := model.NewFolder(otherLib, "TestOtherLib/Folder")
+				err = repo.Put(otherFolder)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Query all folders (no target paths) - should only return folders from testLib
+				results, err := repo.GetFolderUpdateInfo(testLib)
+				Expect(err).ToNot(HaveOccurred())
+				// Should include folders from testLib
+				Expect(results).To(HaveKey(folder1.ID))
+				Expect(results).To(HaveKey(folder2.ID))
+				// Should NOT include folders from other library
+				Expect(results).ToNot(HaveKey(otherFolder.ID))
+			})
+		})
+
+		Context("with specific target paths", func() {
+			It("returns folder info for existing folders", func() {
+				// Create test folders with unique names
+				folder1 := model.NewFolder(testLib, "TestSpecific/Rock")
+				folder2 := model.NewFolder(testLib, "TestSpecific/Jazz")
+				folder3 := model.NewFolder(testLib, "TestSpecific/Classical")
+
+				err := repo.Put(folder1)
+				Expect(err).ToNot(HaveOccurred())
+				err = repo.Put(folder2)
+				Expect(err).ToNot(HaveOccurred())
+				err = repo.Put(folder3)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Query specific paths
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestSpecific/Rock", "TestSpecific/Classical")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(HaveLen(2))
+
+				// Verify folder IDs are in results
+				Expect(results).To(HaveKey(folder1.ID))
+				Expect(results).To(HaveKey(folder3.ID))
+				Expect(results).ToNot(HaveKey(folder2.ID))
+
+				// Verify update info is populated
+				Expect(results[folder1.ID].UpdatedAt).ToNot(BeZero())
+				Expect(results[folder1.ID].Hash).To(Equal(folder1.Hash))
+			})
+
+			It("includes all child folders when querying parent", func() {
+				// Create a parent folder with multiple children
+				parent := model.NewFolder(testLib, "TestParent/Music")
+				child1 := model.NewFolder(testLib, "TestParent/Music/Rock/Queen")
+				child2 := model.NewFolder(testLib, "TestParent/Music/Jazz")
+				otherParent := model.NewFolder(testLib, "TestParent2/Music/Jazz")
+
+				Expect(repo.Put(parent)).To(Succeed())
+				Expect(repo.Put(child1)).To(Succeed())
+				Expect(repo.Put(child2)).To(Succeed())
+
+				// Query the parent folder - should return parent and all children
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestParent/Music")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(HaveLen(3))
+				Expect(results).To(HaveKey(parent.ID))
+				Expect(results).To(HaveKey(child1.ID))
+				Expect(results).To(HaveKey(child2.ID))
+				Expect(results).ToNot(HaveKey(otherParent.ID))
+			})
+
+			It("excludes children from other libraries", func() {
+				// Create parent in testLib
+				parent := model.NewFolder(testLib, "TestIsolation/Parent")
+				child := model.NewFolder(testLib, "TestIsolation/Parent/Child")
+
+				Expect(repo.Put(parent)).To(Succeed())
+				Expect(repo.Put(child)).To(Succeed())
+
+				// Create similar path in other library
+				otherParent := model.NewFolder(otherLib, "TestIsolation/Parent")
+				otherChild := model.NewFolder(otherLib, "TestIsolation/Parent/Child")
+
+				Expect(repo.Put(otherParent)).To(Succeed())
+				Expect(repo.Put(otherChild)).To(Succeed())
+
+				// Query should only return folders from testLib
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestIsolation/Parent")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(HaveLen(2))
+				Expect(results).To(HaveKey(parent.ID))
+				Expect(results).To(HaveKey(child.ID))
+				Expect(results).ToNot(HaveKey(otherParent.ID))
+				Expect(results).ToNot(HaveKey(otherChild.ID))
+			})
+
+			It("excludes missing children when querying parent", func() {
+				// Create parent and children, mark one as missing
+				parent := model.NewFolder(testLib, "TestMissingChild/Parent")
+				child1 := model.NewFolder(testLib, "TestMissingChild/Parent/Child1")
+				child2 := model.NewFolder(testLib, "TestMissingChild/Parent/Child2")
+				child2.Missing = true
+
+				Expect(repo.Put(parent)).To(Succeed())
+				Expect(repo.Put(child1)).To(Succeed())
+				Expect(repo.Put(child2)).To(Succeed())
+
+				// Query parent - should only return parent and non-missing child
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestMissingChild/Parent")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(HaveLen(2))
+				Expect(results).To(HaveKey(parent.ID))
+				Expect(results).To(HaveKey(child1.ID))
+				Expect(results).ToNot(HaveKey(child2.ID))
+			})
+
+			It("handles mix of existing and non-existing target paths", func() {
+				// Create folders for one path but not the other
+				existingParent := model.NewFolder(testLib, "TestMixed/Exists")
+				existingChild := model.NewFolder(testLib, "TestMixed/Exists/Child")
+
+				Expect(repo.Put(existingParent)).To(Succeed())
+				Expect(repo.Put(existingChild)).To(Succeed())
+
+				// Query both existing and non-existing paths
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestMixed/Exists", "TestMixed/DoesNotExist")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(HaveLen(2))
+				Expect(results).To(HaveKey(existingParent.ID))
+				Expect(results).To(HaveKey(existingChild.ID))
+			})
+
+			It("handles empty folder path as root", func() {
+				// Test querying for root folder without creating it (fixtures should have one)
+				rootFolderID := model.FolderID(testLib, ".")
+
+				results, err := repo.GetFolderUpdateInfo(testLib, "")
+				Expect(err).ToNot(HaveOccurred())
+				// Should return the root folder if it exists
+				if len(results) > 0 {
+					Expect(results).To(HaveKey(rootFolderID))
+				}
+			})
+
+			It("returns empty map for non-existent folders", func() {
+				results, err := repo.GetFolderUpdateInfo(testLib, "NonExistent/Path")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(BeEmpty())
+			})
+
+			It("skips missing folders", func() {
+				// Create a folder and mark it as missing
+				folder := model.NewFolder(testLib, "TestMissing/Folder")
+				folder.Missing = true
+				err := repo.Put(folder)
+				Expect(err).ToNot(HaveOccurred())
+
+				results, err := repo.GetFolderUpdateInfo(testLib, "TestMissing/Folder")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(results).To(BeEmpty())
+			})
+		})
+	})
+})

persistence/library_repository.go

@@ -177,7 +177,9 @@ func (r *libraryRepository) ScanEnd(id int) error {
 		return err
 	}
 	// https://www.sqlite.org/pragma.html#pragma_optimize
-	_, err = r.executeSQL(Expr("PRAGMA optimize=0x10012;"))
+	// Use mask 0x10000 to check table sizes without running ANALYZE
+	// Running ANALYZE can cause query planner issues with expression-based collation indexes
+	_, err = r.executeSQL(Expr("PRAGMA optimize=0x10000;"))
 	return err
 }
 

persistence/library_repository_test.go

@@ -142,4 +142,62 @@ var _ = Describe("LibraryRepository", func() {
 		Expect(libAfter.TotalSize).To(Equal(sizeRes.Sum))
 		Expect(libAfter.TotalDuration).To(Equal(durationRes.Sum))
 	})
+
+	Describe("ScanBegin and ScanEnd", func() {
+		var lib *model.Library
+
+		BeforeEach(func() {
+			lib = &model.Library{
+				ID:   0,
+				Name: "Test Scan Library",
+				Path: "/music/test-scan",
+			}
+			err := repo.Put(lib)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		DescribeTable("ScanBegin",
+			func(fullScan bool, expectedFullScanInProgress bool) {
+				err := repo.ScanBegin(lib.ID, fullScan)
+				Expect(err).ToNot(HaveOccurred())
+
+				updatedLib, err := repo.Get(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(updatedLib.LastScanStartedAt).ToNot(BeZero())
+				Expect(updatedLib.FullScanInProgress).To(Equal(expectedFullScanInProgress))
+			},
+			Entry("sets FullScanInProgress to true for full scan", true, true),
+			Entry("sets FullScanInProgress to false for quick scan", false, false),
+		)
+
+		Context("ScanEnd", func() {
+			BeforeEach(func() {
+				err := repo.ScanBegin(lib.ID, true)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("sets LastScanAt and clears FullScanInProgress and LastScanStartedAt", func() {
+				err := repo.ScanEnd(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+
+				updatedLib, err := repo.Get(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(updatedLib.LastScanAt).ToNot(BeZero())
+				Expect(updatedLib.FullScanInProgress).To(BeFalse())
+				Expect(updatedLib.LastScanStartedAt).To(BeZero())
+			})
+
+			It("sets LastScanAt to be after LastScanStartedAt", func() {
+				libBefore, err := repo.Get(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+
+				err = repo.ScanEnd(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+
+				libAfter, err := repo.Get(lib.ID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(libAfter.LastScanAt).To(BeTemporally(">=", libBefore.LastScanStartedAt))
+			})
+		})
+	})
 })

persistence/persistence.go

@@ -157,7 +157,7 @@ func (s *SQLStore) WithTxImmediate(block func(tx model.DataStore) error, scope .
 	}, scope...)
 }
 
-func (s *SQLStore) GC(ctx context.Context) error {
+func (s *SQLStore) GC(ctx context.Context, libraryIDs ...int) error {
 	trace := func(ctx context.Context, msg string, f func() error) func() error {
 		return func() error {
 			start := time.Now()
@@ -167,11 +167,17 @@ func (s *SQLStore) GC(ctx context.Context) error {
 		}
 	}
 
+	// If libraryIDs are provided, scope operations to those libraries where possible
+	scoped := len(libraryIDs) > 0
+	if scoped {
+		log.Debug(ctx, "GC: Running selective garbage collection", "libraryIDs", libraryIDs)
+	}
+
 	err := run.Sequentially(
-		trace(ctx, "purge empty albums", func() error { return s.Album(ctx).(*albumRepository).purgeEmpty() }),
+		trace(ctx, "purge empty albums", func() error { return s.Album(ctx).(*albumRepository).purgeEmpty(libraryIDs...) }),
 		trace(ctx, "purge empty artists", func() error { return s.Artist(ctx).(*artistRepository).purgeEmpty() }),
 		trace(ctx, "mark missing artists", func() error { return s.Artist(ctx).(*artistRepository).markMissing() }),
-		trace(ctx, "purge empty folders", func() error { return s.Folder(ctx).(*folderRepository).purgeEmpty() }),
+		trace(ctx, "purge empty folders", func() error { return s.Folder(ctx).(*folderRepository).purgeEmpty(libraryIDs...) }),
 		trace(ctx, "clean album annotations", func() error { return s.Album(ctx).(*albumRepository).cleanAnnotations() }),
 		trace(ctx, "clean artist annotations", func() error { return s.Artist(ctx).(*artistRepository).cleanAnnotations() }),
 		trace(ctx, "clean media file annotations", func() error { return s.MediaFile(ctx).(*mediaFileRepository).cleanAnnotations() }),

resources/i18n/pt-br.json

@@ -300,6 +300,8 @@
       },
       "actions": {
         "scan": "Scanear Biblioteca",
+        "quickScan": "Scan Rápido",
+        "fullScan": "Scan Completo",
         "manageUsers": "Gerenciar Acesso do Usuário",
         "viewDetails": "Ver Detalhes"
       },
@@ -308,6 +310,9 @@
         "updated": "Biblioteca atualizada com sucesso",
         "deleted": "Biblioteca excluída com sucesso",
         "scanStarted": "Scan da biblioteca iniciada",
+        "quickScanStarted": "Scan rápido iniciado",
+        "fullScanStarted": "Scan completo iniciado",
+        "scanError": "Erro ao iniciar o scan. Verifique os logs",
         "scanCompleted": "Scan da biblioteca concluída"
       },
       "validation": {
@@ -598,11 +603,12 @@
   "activity": {
     "title": "Atividade",
     "totalScanned": "Total de pastas scaneadas",
-    "quickScan": "Scan rápido",
+    "quickScan": "Rápido",
-    "fullScan": "Scan completo",
+    "fullScan": "Completo",
+    "selectiveScan": "Seletivo",
     "serverUptime": "Uptime do servidor",
     "serverDown": "DESCONECTADO",
-    "scanType": "Tipo",
+    "scanType": "Último Scan",
     "status": "Erro",
     "elapsedTime": "Duração"
   },

scanner/controller.go

@@ -26,24 +26,8 @@ var (
 	ErrAlreadyScanning = errors.New("already scanning")
 )
 
-type Scanner interface {
-	// ScanAll starts a full scan of the music library. This is a blocking operation.
-	ScanAll(ctx context.Context, fullScan bool) (warnings []string, err error)
-	Status(context.Context) (*StatusInfo, error)
-}
-
-type StatusInfo struct {
-	Scanning    bool
-	LastScan    time.Time
-	Count       uint32
-	FolderCount uint32
-	LastError   string
-	ScanType    string
-	ElapsedTime time.Duration
-}
-
 func New(rootCtx context.Context, ds model.DataStore, cw artwork.CacheWarmer, broker events.Broker,
-	pls core.Playlists, m metrics.Metrics) Scanner {
+	pls core.Playlists, m metrics.Metrics) model.Scanner {
 	c := &controller{
 		rootCtx: rootCtx,
 		ds:      ds,
@@ -65,9 +49,10 @@ func (s *controller) getScanner() scanner {
 	return &scannerImpl{ds: s.ds, cw: s.cw, pls: s.pls}
 }
 
-// CallScan starts an in-process scan of the music library.
+// CallScan starts an in-process scan of specific library/folder pairs.
+// If targets is empty, it scans all libraries.
 // This is meant to be called from the command line (see cmd/scan.go).
-func CallScan(ctx context.Context, ds model.DataStore, pls core.Playlists, fullScan bool) (<-chan *ProgressInfo, error) {
+func CallScan(ctx context.Context, ds model.DataStore, pls core.Playlists, fullScan bool, targets []model.ScanTarget) (<-chan *ProgressInfo, error) {
 	release, err := lockScan(ctx)
 	if err != nil {
 		return nil, err
@@ -79,7 +64,7 @@ func CallScan(ctx context.Context, ds model.DataStore, pls core.Playlists, fullS
 	go func() {
 		defer close(progress)
 		scanner := &scannerImpl{ds: ds, cw: artwork.NoopCacheWarmer(), pls: pls}
-		scanner.scanAll(ctx, fullScan, progress)
+		scanner.scanFolders(ctx, fullScan, targets, progress)
 	}()
 	return progress, nil
 }
@@ -99,8 +84,11 @@ type ProgressInfo struct {
 	ForceUpdate     bool
 }
 
+// scanner defines the interface for different scanner implementations.
+// This allows for swapping between in-process and external scanners.
 type scanner interface {
-	scanAll(ctx context.Context, fullScan bool, progress chan<- *ProgressInfo)
+	// scanFolders performs the actual scanning of folders. If targets is nil, it scans all libraries.
+	scanFolders(ctx context.Context, fullScan bool, targets []model.ScanTarget, progress chan<- *ProgressInfo)
 }
 
 type controller struct {
@@ -158,7 +146,7 @@ func (s *controller) getScanInfo(ctx context.Context) (scanType string, elapsed
 	return scanType, elapsed, lastErr
 }
 
-func (s *controller) Status(ctx context.Context) (*StatusInfo, error) {
+func (s *controller) Status(ctx context.Context) (*model.ScannerStatus, error) {
 	lastScanTime, err := s.getLastScanTime(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("getting last scan time: %w", err)
@@ -167,7 +155,7 @@ func (s *controller) Status(ctx context.Context) (*StatusInfo, error) {
 	scanType, elapsed, lastErr := s.getScanInfo(ctx)
 
 	if running.Load() {
-		status := &StatusInfo{
+		status := &model.ScannerStatus{
 			Scanning:    true,
 			LastScan:    lastScanTime,
 			Count:       s.count.Load(),
@@ -183,7 +171,7 @@ func (s *controller) Status(ctx context.Context) (*StatusInfo, error) {
 	if err != nil {
 		return nil, fmt.Errorf("getting library stats: %w", err)
 	}
-	return &StatusInfo{
+	return &model.ScannerStatus{
 		Scanning:    false,
 		LastScan:    lastScanTime,
 		Count:       uint32(count),
@@ -208,6 +196,10 @@ func (s *controller) getCounters(ctx context.Context) (int64, int64, error) {
 }
 
 func (s *controller) ScanAll(requestCtx context.Context, fullScan bool) ([]string, error) {
+	return s.ScanFolders(requestCtx, fullScan, nil)
+}
+
+func (s *controller) ScanFolders(requestCtx context.Context, fullScan bool, targets []model.ScanTarget) ([]string, error) {
 	release, err := lockScan(requestCtx)
 	if err != nil {
 		return nil, err
@@ -224,7 +216,7 @@ func (s *controller) ScanAll(requestCtx context.Context, fullScan bool) ([]strin
 	go func() {
 		defer close(progress)
 		scanner := s.getScanner()
-		scanner.scanAll(ctx, fullScan, progress)
+		scanner.scanFolders(ctx, fullScan, targets, progress)
 	}()
 
 	// Wait for the scan to finish, sending progress events to all connected clients

scanner/controller_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/server/events"
@@ -20,7 +21,7 @@ import (
 var _ = Describe("Controller", func() {
 	var ctx context.Context
 	var ds *tests.MockDataStore
-	var ctrl scanner.Scanner
+	var ctrl model.Scanner
 
 	Describe("Status", func() {
 		BeforeEach(func() {

scanner/external.go

@@ -8,10 +8,12 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"strings"
 
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/log"
-	. "github.com/navidrome/navidrome/utils/gg"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/slice"
 )
 
 // scannerExternal is a scanner that runs an external process to do the scanning. It is used to avoid
@@ -23,19 +25,41 @@ import (
 // process will forward them to the caller.
 type scannerExternal struct{}
 
-func (s *scannerExternal) scanAll(ctx context.Context, fullScan bool, progress chan<- *ProgressInfo) {
+func (s *scannerExternal) scanFolders(ctx context.Context, fullScan bool, targets []model.ScanTarget, progress chan<- *ProgressInfo) {
+	s.scan(ctx, fullScan, targets, progress)
+}
+
+func (s *scannerExternal) scan(ctx context.Context, fullScan bool, targets []model.ScanTarget, progress chan<- *ProgressInfo) {
 	exe, err := os.Executable()
 	if err != nil {
 		progress <- &ProgressInfo{Error: fmt.Sprintf("failed to get executable path: %s", err)}
 		return
 	}
-	log.Debug(ctx, "Spawning external scanner process", "fullScan", fullScan, "path", exe)
+
-	cmd := exec.CommandContext(ctx, exe, "scan",
+	// Build command arguments
+	args := []string{
+		"scan",
 		"--nobanner", "--subprocess",
 		"--configfile", conf.Server.ConfigFile,
 		"--datafolder", conf.Server.DataFolder,
 		"--cachefolder", conf.Server.CacheFolder,
-		If(fullScan, "--full", ""))
+	}
+
+	// Add targets if provided
+	if len(targets) > 0 {
+		targetsStr := strings.Join(slice.Map(targets, func(t model.ScanTarget) string { return t.String() }), ",")
+		args = append(args, "--targets", targetsStr)
+		log.Debug(ctx, "Spawning external scanner process with targets", "fullScan", fullScan, "path", exe, "targets", targetsStr)
+	} else {
+		log.Debug(ctx, "Spawning external scanner process", "fullScan", fullScan, "path", exe)
+	}
+
+	// Add full scan flag if needed
+	if fullScan {
+		args = append(args, "--full")
+	}
+
+	cmd := exec.CommandContext(ctx, exe, args...)
 
 	in, out := io.Pipe()
 	defer in.Close()

scanner/folder_entry.go

@@ -15,9 +15,7 @@ import (
 	"github.com/navidrome/navidrome/utils/chrono"
 )
 
-func newFolderEntry(job *scanJob, path string) *folderEntry {
+func newFolderEntry(job *scanJob, id, path string, updTime time.Time, hash string) *folderEntry {
-	id := model.FolderID(job.lib, path)
-	info := job.popLastUpdate(id)
 	f := &folderEntry{
 		id:         id,
 		job:        job,
@@ -25,8 +23,8 @@ func newFolderEntry(job *scanJob, path string) *folderEntry {
 		audioFiles: make(map[string]fs.DirEntry),
 		imageFiles: make(map[string]fs.DirEntry),
 		albumIDMap: make(map[string]string),
-		updTime:    info.UpdatedAt,
+		updTime:    updTime,
-		prevHash:   info.Hash,
+		prevHash:   hash,
 	}
 	return f
 }

scanner/folder_entry_test.go

@@ -40,9 +40,8 @@ var _ = Describe("folder_entry", func() {
 				UpdatedAt: time.Now().Add(-30 * time.Minute),
 				Hash:      "previous-hash",
 			}
-			job.lastUpdates[folderID] = updateInfo
 
-			entry := newFolderEntry(job, path)
+			entry := newFolderEntry(job, folderID, path, updateInfo.UpdatedAt, updateInfo.Hash)
 
 			Expect(entry.id).To(Equal(folderID))
 			Expect(entry.job).To(Equal(job))
@@ -53,15 +52,10 @@ var _ = Describe("folder_entry", func() {
 			Expect(entry.updTime).To(Equal(updateInfo.UpdatedAt))
 			Expect(entry.prevHash).To(Equal(updateInfo.Hash))
 		})
+	})
 
-		It("creates a new folder entry with zero time when no previous update exists", func() {
+	Describe("createFolderEntry", func() {
-			entry := newFolderEntry(job, path)
+		It("removes the lastUpdate from the job after creation", func() {
-
-			Expect(entry.updTime).To(BeZero())
-			Expect(entry.prevHash).To(BeEmpty())
-		})
-
-		It("removes the lastUpdate from the job after popping", func() {
 			folderID := model.FolderID(lib, path)
 			updateInfo := model.FolderUpdateInfo{
 				UpdatedAt: time.Now().Add(-30 * time.Minute),
@@ -69,8 +63,10 @@ var _ = Describe("folder_entry", func() {
 			}
 			job.lastUpdates[folderID] = updateInfo
 
-			newFolderEntry(job, path)
+			entry := job.createFolderEntry(path)
 
+			Expect(entry.updTime).To(Equal(updateInfo.UpdatedAt))
+			Expect(entry.prevHash).To(Equal(updateInfo.Hash))
 			Expect(job.lastUpdates).ToNot(HaveKey(folderID))
 		})
 	})
@@ -79,7 +75,8 @@ var _ = Describe("folder_entry", func() {
 		var entry *folderEntry
 
 		BeforeEach(func() {
-			entry = newFolderEntry(job, path)
+			folderID := model.FolderID(lib, path)
+			entry = newFolderEntry(job, folderID, path, time.Time{}, "")
 		})
 
 		Describe("hasNoFiles", func() {
@@ -458,7 +455,9 @@ var _ = Describe("folder_entry", func() {
 	Describe("integration scenarios", func() {
 		It("handles complete folder lifecycle", func() {
 			// Create new folder entry
-			entry := newFolderEntry(job, "music/rock/album")
+			folderPath := "music/rock/album"
+			folderID := model.FolderID(lib, folderPath)
+			entry := newFolderEntry(job, folderID, folderPath, time.Time{}, "")
 
 			// Initially new and has no files
 			Expect(entry.isNew()).To(BeTrue())

scanner/ignore_checker.go

@@ -0,0 +1,163 @@
+package scanner
+
+import (
+	"bufio"
+	"context"
+	"io/fs"
+	"path"
+	"strings"
+
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/log"
+	ignore "github.com/sabhiram/go-gitignore"
+)
+
+// IgnoreChecker manages .ndignore patterns using a stack-based approach.
+// Use Push() to add patterns when entering a folder, Pop() when leaving,
+// and ShouldIgnore() to check if a path should be ignored.
+type IgnoreChecker struct {
+	fsys            fs.FS
+	patternStack    [][]string        // Stack of patterns for each folder level
+	currentPatterns []string          // Flattened current patterns
+	matcher         *ignore.GitIgnore // Compiled matcher for current patterns
+}
+
+// newIgnoreChecker creates a new IgnoreChecker for the given filesystem.
+func newIgnoreChecker(fsys fs.FS) *IgnoreChecker {
+	return &IgnoreChecker{
+		fsys:         fsys,
+		patternStack: make([][]string, 0),
+	}
+}
+
+// Push loads .ndignore patterns from the specified folder and adds them to the pattern stack.
+// Use this when entering a folder during directory tree traversal.
+func (ic *IgnoreChecker) Push(ctx context.Context, folder string) error {
+	patterns := ic.loadPatternsFromFolder(ctx, folder)
+	ic.patternStack = append(ic.patternStack, patterns)
+	ic.rebuildCurrentPatterns()
+	return nil
+}
+
+// Pop removes the most recent patterns from the stack.
+// Use this when leaving a folder during directory tree traversal.
+func (ic *IgnoreChecker) Pop() {
+	if len(ic.patternStack) > 0 {
+		ic.patternStack = ic.patternStack[:len(ic.patternStack)-1]
+		ic.rebuildCurrentPatterns()
+	}
+}
+
+// PushAllParents pushes patterns from root down to the target path.
+// This is a convenience method for when you need to check a specific path
+// without recursively walking the tree. It handles the common pattern of
+// pushing all parent directories from root to the target.
+// This method is optimized to compile patterns only once at the end.
+func (ic *IgnoreChecker) PushAllParents(ctx context.Context, targetPath string) error {
+	if targetPath == "." || targetPath == "" {
+		// Simple case: just push root
+		return ic.Push(ctx, ".")
+	}
+
+	// Load patterns for root
+	patterns := ic.loadPatternsFromFolder(ctx, ".")
+	ic.patternStack = append(ic.patternStack, patterns)
+
+	// Load patterns for each parent directory
+	currentPath := "."
+	parts := strings.Split(path.Clean(targetPath), "/")
+	for _, part := range parts {
+		if part == "." || part == "" {
+			continue
+		}
+		currentPath = path.Join(currentPath, part)
+		patterns = ic.loadPatternsFromFolder(ctx, currentPath)
+		ic.patternStack = append(ic.patternStack, patterns)
+	}
+
+	// Rebuild and compile patterns only once at the end
+	ic.rebuildCurrentPatterns()
+	return nil
+}
+
+// ShouldIgnore checks if the given path should be ignored based on the current patterns.
+// Returns true if the path matches any ignore pattern, false otherwise.
+func (ic *IgnoreChecker) ShouldIgnore(ctx context.Context, relPath string) bool {
+	// Handle root/empty path - never ignore
+	if relPath == "" || relPath == "." {
+		return false
+	}
+
+	// If no patterns loaded, nothing to ignore
+	if ic.matcher == nil {
+		return false
+	}
+
+	matches := ic.matcher.MatchesPath(relPath)
+	if matches {
+		log.Trace(ctx, "Scanner: Ignoring entry matching .ndignore", "path", relPath)
+	}
+	return matches
+}
+
+// loadPatternsFromFolder reads the .ndignore file in the specified folder and returns the patterns.
+// If the file doesn't exist, returns an empty slice.
+// If the file exists but is empty, returns a pattern to ignore everything ("**/*").
+func (ic *IgnoreChecker) loadPatternsFromFolder(ctx context.Context, folder string) []string {
+	ignoreFilePath := path.Join(folder, consts.ScanIgnoreFile)
+	var patterns []string
+
+	// Check if .ndignore file exists
+	if _, err := fs.Stat(ic.fsys, ignoreFilePath); err != nil {
+		// No .ndignore file in this folder
+		return patterns
+	}
+
+	// Read and parse the .ndignore file
+	ignoreFile, err := ic.fsys.Open(ignoreFilePath)
+	if err != nil {
+		log.Warn(ctx, "Scanner: Error opening .ndignore file", "path", ignoreFilePath, err)
+		return patterns
+	}
+	defer ignoreFile.Close()
+
+	lineScanner := bufio.NewScanner(ignoreFile)
+	for lineScanner.Scan() {
+		line := strings.TrimSpace(lineScanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue // Skip empty lines, whitespace-only lines, and comments
+		}
+		patterns = append(patterns, line)
+	}
+
+	if err := lineScanner.Err(); err != nil {
+		log.Warn(ctx, "Scanner: Error reading .ndignore file", "path", ignoreFilePath, err)
+		return patterns
+	}
+
+	// If the .ndignore file is empty, ignore everything
+	if len(patterns) == 0 {
+		log.Trace(ctx, "Scanner: .ndignore file is empty, ignoring everything", "path", folder)
+		patterns = []string{"**/*"}
+	}
+
+	return patterns
+}
+
+// rebuildCurrentPatterns flattens the pattern stack into currentPatterns and recompiles the matcher.
+func (ic *IgnoreChecker) rebuildCurrentPatterns() {
+	ic.currentPatterns = make([]string, 0)
+	for _, patterns := range ic.patternStack {
+		ic.currentPatterns = append(ic.currentPatterns, patterns...)
+	}
+	ic.compilePatterns()
+}
+
+// compilePatterns compiles the current patterns into a GitIgnore matcher.
+func (ic *IgnoreChecker) compilePatterns() {
+	if len(ic.currentPatterns) == 0 {
+		ic.matcher = nil
+		return
+	}
+	ic.matcher = ignore.CompileIgnoreLines(ic.currentPatterns...)
+}

scanner/ignore_checker_test.go

@@ -0,0 +1,313 @@
+package scanner
+
+import (
+	"context"
+	"testing/fstest"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("IgnoreChecker", func() {
+	Describe("loadPatternsFromFolder", func() {
+		var ic *IgnoreChecker
+		var ctx context.Context
+
+		BeforeEach(func() {
+			ctx = context.Background()
+		})
+
+		Context("when .ndignore file does not exist", func() {
+			It("should return empty patterns", func() {
+				fsys := fstest.MapFS{}
+				ic = newIgnoreChecker(fsys)
+				patterns := ic.loadPatternsFromFolder(ctx, ".")
+				Expect(patterns).To(BeEmpty())
+			})
+		})
+
+		Context("when .ndignore file is empty", func() {
+			It("should return wildcard to ignore everything", func() {
+				fsys := fstest.MapFS{
+					".ndignore": &fstest.MapFile{Data: []byte("")},
+				}
+				ic = newIgnoreChecker(fsys)
+				patterns := ic.loadPatternsFromFolder(ctx, ".")
+				Expect(patterns).To(Equal([]string{"**/*"}))
+			})
+		})
+
+		DescribeTable("parsing .ndignore content",
+			func(content string, expectedPatterns []string) {
+				fsys := fstest.MapFS{
+					".ndignore": &fstest.MapFile{Data: []byte(content)},
+				}
+				ic = newIgnoreChecker(fsys)
+				patterns := ic.loadPatternsFromFolder(ctx, ".")
+				Expect(patterns).To(Equal(expectedPatterns))
+			},
+			Entry("single pattern", "*.txt", []string{"*.txt"}),
+			Entry("multiple patterns", "*.txt\n*.log", []string{"*.txt", "*.log"}),
+			Entry("with comments", "# comment\n*.txt\n# another\n*.log", []string{"*.txt", "*.log"}),
+			Entry("with empty lines", "*.txt\n\n*.log\n\n", []string{"*.txt", "*.log"}),
+			Entry("mixed content", "# header\n\n*.txt\n# middle\n*.log\n\n", []string{"*.txt", "*.log"}),
+			Entry("only comments and empty lines", "# comment\n\n# another\n", []string{"**/*"}),
+			Entry("trailing newline", "*.txt\n*.log\n", []string{"*.txt", "*.log"}),
+			Entry("directory pattern", "temp/", []string{"temp/"}),
+			Entry("wildcard pattern", "**/*.mp3", []string{"**/*.mp3"}),
+			Entry("multiple wildcards", "**/*.mp3\n**/*.flac\n*.log", []string{"**/*.mp3", "**/*.flac", "*.log"}),
+			Entry("negation pattern", "!important.txt", []string{"!important.txt"}),
+			Entry("comment with hash not at start is pattern", "not#comment", []string{"not#comment"}),
+			Entry("whitespace-only lines skipped", "*.txt\n   \n*.log\n\t\n", []string{"*.txt", "*.log"}),
+			Entry("patterns with whitespace trimmed", "  *.txt  \n\t*.log\t", []string{"*.txt", "*.log"}),
+		)
+	})
+
+	Describe("Push and Pop", func() {
+		var ic *IgnoreChecker
+		var fsys fstest.MapFS
+		var ctx context.Context
+
+		BeforeEach(func() {
+			ctx = context.Background()
+			fsys = fstest.MapFS{
+				".ndignore":         &fstest.MapFile{Data: []byte("*.txt")},
+				"folder1/.ndignore": &fstest.MapFile{Data: []byte("*.mp3")},
+				"folder2/.ndignore": &fstest.MapFile{Data: []byte("*.flac")},
+			}
+			ic = newIgnoreChecker(fsys)
+		})
+
+		Context("Push", func() {
+			It("should add patterns to stack", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(ic.patternStack)).To(Equal(1))
+				Expect(ic.currentPatterns).To(ContainElement("*.txt"))
+			})
+
+			It("should compile matcher after push", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.matcher).ToNot(BeNil())
+			})
+
+			It("should accumulate patterns from multiple levels", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				err = ic.Push(ctx, "folder1")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(ic.patternStack)).To(Equal(2))
+				Expect(ic.currentPatterns).To(ConsistOf("*.txt", "*.mp3"))
+			})
+
+			It("should handle push when no .ndignore exists", func() {
+				err := ic.Push(ctx, "nonexistent")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(ic.patternStack)).To(Equal(1))
+				Expect(ic.currentPatterns).To(BeEmpty())
+			})
+		})
+
+		Context("Pop", func() {
+			It("should remove most recent patterns", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				err = ic.Push(ctx, "folder1")
+				Expect(err).ToNot(HaveOccurred())
+				ic.Pop()
+				Expect(len(ic.patternStack)).To(Equal(1))
+				Expect(ic.currentPatterns).To(Equal([]string{"*.txt"}))
+			})
+
+			It("should handle Pop on empty stack gracefully", func() {
+				Expect(func() { ic.Pop() }).ToNot(Panic())
+				Expect(ic.patternStack).To(BeEmpty())
+			})
+
+			It("should set matcher to nil when all patterns popped", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.matcher).ToNot(BeNil())
+				ic.Pop()
+				Expect(ic.matcher).To(BeNil())
+			})
+
+			It("should update matcher after pop", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				err = ic.Push(ctx, "folder1")
+				Expect(err).ToNot(HaveOccurred())
+				matcher1 := ic.matcher
+				ic.Pop()
+				matcher2 := ic.matcher
+				Expect(matcher1).ToNot(Equal(matcher2))
+			})
+		})
+
+		Context("multiple Push/Pop cycles", func() {
+			It("should maintain correct state through cycles", func() {
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.currentPatterns).To(Equal([]string{"*.txt"}))
+
+				err = ic.Push(ctx, "folder1")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.currentPatterns).To(ConsistOf("*.txt", "*.mp3"))
+
+				ic.Pop()
+				Expect(ic.currentPatterns).To(Equal([]string{"*.txt"}))
+
+				err = ic.Push(ctx, "folder2")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.currentPatterns).To(ConsistOf("*.txt", "*.flac"))
+
+				ic.Pop()
+				Expect(ic.currentPatterns).To(Equal([]string{"*.txt"}))
+
+				ic.Pop()
+				Expect(ic.currentPatterns).To(BeEmpty())
+			})
+		})
+	})
+
+	Describe("PushAllParents", func() {
+		var ic *IgnoreChecker
+		var ctx context.Context
+
+		BeforeEach(func() {
+			ctx = context.Background()
+			fsys := fstest.MapFS{
+				".ndignore":                         &fstest.MapFile{Data: []byte("root.txt")},
+				"folder1/.ndignore":                 &fstest.MapFile{Data: []byte("level1.txt")},
+				"folder1/folder2/.ndignore":         &fstest.MapFile{Data: []byte("level2.txt")},
+				"folder1/folder2/folder3/.ndignore": &fstest.MapFile{Data: []byte("level3.txt")},
+			}
+			ic = newIgnoreChecker(fsys)
+		})
+
+		DescribeTable("loading parent patterns",
+			func(targetPath string, expectedStackDepth int, expectedPatterns []string) {
+				err := ic.PushAllParents(ctx, targetPath)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(ic.patternStack)).To(Equal(expectedStackDepth))
+				Expect(ic.currentPatterns).To(ConsistOf(expectedPatterns))
+			},
+			Entry("root path", ".", 1, []string{"root.txt"}),
+			Entry("empty path", "", 1, []string{"root.txt"}),
+			Entry("single level", "folder1", 2, []string{"root.txt", "level1.txt"}),
+			Entry("two levels", "folder1/folder2", 3, []string{"root.txt", "level1.txt", "level2.txt"}),
+			Entry("three levels", "folder1/folder2/folder3", 4, []string{"root.txt", "level1.txt", "level2.txt", "level3.txt"}),
+		)
+
+		It("should only compile patterns once at the end", func() {
+			// This is more of a behavioral test - we verify the matcher is not nil after PushAllParents
+			err := ic.PushAllParents(ctx, "folder1/folder2")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ic.matcher).ToNot(BeNil())
+		})
+
+		It("should handle paths with dot", func() {
+			err := ic.PushAllParents(ctx, "./folder1")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(ic.patternStack)).To(Equal(2))
+		})
+
+		Context("when some parent folders have no .ndignore", func() {
+			BeforeEach(func() {
+				fsys := fstest.MapFS{
+					".ndignore":                 &fstest.MapFile{Data: []byte("root.txt")},
+					"folder1/folder2/.ndignore": &fstest.MapFile{Data: []byte("level2.txt")},
+				}
+				ic = newIgnoreChecker(fsys)
+			})
+
+			It("should still push all parent levels", func() {
+				err := ic.PushAllParents(ctx, "folder1/folder2")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(ic.patternStack)).To(Equal(3)) // root, folder1 (empty), folder2
+				Expect(ic.currentPatterns).To(ConsistOf("root.txt", "level2.txt"))
+			})
+		})
+	})
+
+	Describe("ShouldIgnore", func() {
+		var ic *IgnoreChecker
+		var ctx context.Context
+
+		BeforeEach(func() {
+			ctx = context.Background()
+		})
+
+		Context("with no patterns loaded", func() {
+			It("should not ignore any path", func() {
+				fsys := fstest.MapFS{}
+				ic = newIgnoreChecker(fsys)
+				Expect(ic.ShouldIgnore(ctx, "anything.txt")).To(BeFalse())
+				Expect(ic.ShouldIgnore(ctx, "folder/file.mp3")).To(BeFalse())
+			})
+		})
+
+		Context("special paths", func() {
+			BeforeEach(func() {
+				fsys := fstest.MapFS{
+					".ndignore": &fstest.MapFile{Data: []byte("**/*")},
+				}
+				ic = newIgnoreChecker(fsys)
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("should never ignore root or empty paths", func() {
+				Expect(ic.ShouldIgnore(ctx, "")).To(BeFalse())
+				Expect(ic.ShouldIgnore(ctx, ".")).To(BeFalse())
+			})
+
+			It("should ignore all other paths with wildcard", func() {
+				Expect(ic.ShouldIgnore(ctx, "file.txt")).To(BeTrue())
+				Expect(ic.ShouldIgnore(ctx, "folder/file.mp3")).To(BeTrue())
+			})
+		})
+
+		DescribeTable("pattern matching",
+			func(pattern string, path string, shouldMatch bool) {
+				fsys := fstest.MapFS{
+					".ndignore": &fstest.MapFile{Data: []byte(pattern)},
+				}
+				ic = newIgnoreChecker(fsys)
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(ic.ShouldIgnore(ctx, path)).To(Equal(shouldMatch))
+			},
+			Entry("glob match", "*.txt", "file.txt", true),
+			Entry("glob no match", "*.txt", "file.mp3", false),
+			Entry("directory pattern match", "tmp/", "tmp/file.txt", true),
+			Entry("directory pattern no match", "tmp/", "temporary/file.txt", false),
+			Entry("nested glob match", "**/*.log", "deep/nested/file.log", true),
+			Entry("nested glob no match", "**/*.log", "deep/nested/file.txt", false),
+			Entry("specific file match", "ignore.me", "ignore.me", true),
+			Entry("specific file no match", "ignore.me", "keep.me", false),
+			Entry("wildcard all", "**/*", "any/path/file.txt", true),
+			Entry("nested specific match", "temp/*", "temp/cache.db", true),
+			Entry("nested specific no match", "temp/*", "temporary/cache.db", false),
+		)
+
+		Context("with multiple patterns", func() {
+			BeforeEach(func() {
+				fsys := fstest.MapFS{
+					".ndignore": &fstest.MapFile{Data: []byte("*.txt\n*.log\ntemp/")},
+				}
+				ic = newIgnoreChecker(fsys)
+				err := ic.Push(ctx, ".")
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("should match any of the patterns", func() {
+				Expect(ic.ShouldIgnore(ctx, "file.txt")).To(BeTrue())
+				Expect(ic.ShouldIgnore(ctx, "debug.log")).To(BeTrue())
+				Expect(ic.ShouldIgnore(ctx, "temp/cache")).To(BeTrue())
+				Expect(ic.ShouldIgnore(ctx, "music.mp3")).To(BeFalse())
+			})
+		})
+	})
+})

scanner/phase_1_folders.go

@@ -26,58 +26,46 @@ import (
 	"github.com/navidrome/navidrome/utils/slice"
 )
 
-func createPhaseFolders(ctx context.Context, state *scanState, ds model.DataStore, cw artwork.CacheWarmer, libs []model.Library) *phaseFolders {
+func createPhaseFolders(ctx context.Context, state *scanState, ds model.DataStore, cw artwork.CacheWarmer) *phaseFolders {
 	var jobs []*scanJob
-	var updatedLibs []model.Library
+
-	for _, lib := range libs {
+	// Create scan jobs for all libraries
-		if lib.LastScanStartedAt.IsZero() {
+	for _, lib := range state.libraries {
-			err := ds.Library(ctx).ScanBegin(lib.ID, state.fullScan)
+		// Get target folders for this library if selective scan
-			if err != nil {
+		var targetFolders []string
-				log.Error(ctx, "Scanner: Error updating last scan started at", "lib", lib.Name, err)
+		if state.isSelectiveScan() {
-				state.sendWarning(err.Error())
+			targetFolders = state.targets[lib.ID]
-				continue
-			}
-			// Reload library to get updated state
-			l, err := ds.Library(ctx).Get(lib.ID)
-			if err != nil {
-				log.Error(ctx, "Scanner: Error reloading library", "lib", lib.Name, err)
-				state.sendWarning(err.Error())
-				continue
-			}
-			lib = *l
-		} else {
-			log.Debug(ctx, "Scanner: Resuming previous scan", "lib", lib.Name, "lastScanStartedAt", lib.LastScanStartedAt, "fullScan", lib.FullScanInProgress)
 		}
-		job, err := newScanJob(ctx, ds, cw, lib, state.fullScan)
+
+		job, err := newScanJob(ctx, ds, cw, lib, state.fullScan, targetFolders)
 		if err != nil {
 			log.Error(ctx, "Scanner: Error creating scan context", "lib", lib.Name, err)
 			state.sendWarning(err.Error())
 			continue
 		}
 		jobs = append(jobs, job)
-		updatedLibs = append(updatedLibs, lib)
 	}
 
-	// Update the state with the libraries that have been processed and have their scan timestamps set
-	state.libraries = updatedLibs
-
 	return &phaseFolders{jobs: jobs, ctx: ctx, ds: ds, state: state}
 }
 
 type scanJob struct {
-	lib         model.Library
+	lib           model.Library
-	fs          storage.MusicFS
+	fs            storage.MusicFS
-	cw          artwork.CacheWarmer
+	cw            artwork.CacheWarmer
-	lastUpdates map[string]model.FolderUpdateInfo
+	lastUpdates   map[string]model.FolderUpdateInfo // Holds last update info for all (DB) folders in this library
-	lock        sync.Mutex
+	targetFolders []string                          // Specific folders to scan (including all descendants)
-	numFolders  atomic.Int64
+	lock          sync.Mutex
+	numFolders    atomic.Int64
 }
 
-func newScanJob(ctx context.Context, ds model.DataStore, cw artwork.CacheWarmer, lib model.Library, fullScan bool) (*scanJob, error) {
+func newScanJob(ctx context.Context, ds model.DataStore, cw artwork.CacheWarmer, lib model.Library, fullScan bool, targetFolders []string) (*scanJob, error) {
-	lastUpdates, err := ds.Folder(ctx).GetLastUpdates(lib)
+	// Get folder updates, optionally filtered to specific target folders
+	lastUpdates, err := ds.Folder(ctx).GetFolderUpdateInfo(lib, targetFolders...)
 	if err != nil {
 		return nil, fmt.Errorf("getting last updates: %w", err)
 	}
+
 	fileStore, err := storage.For(lib.Path)
 	if err != nil {
 		log.Error(ctx, "Error getting storage for library", "library", lib.Name, "path", lib.Path, err)
@@ -88,15 +76,17 @@ func newScanJob(ctx context.Context, ds model.DataStore, cw artwork.CacheWarmer,
 		log.Error(ctx, "Error getting fs for library", "library", lib.Name, "path", lib.Path, err)
 		return nil, fmt.Errorf("getting fs for library: %w", err)
 	}
-	lib.FullScanInProgress = lib.FullScanInProgress || fullScan
 	return &scanJob{
-		lib:         lib,
+		lib:           lib,
-		fs:          fsys,
+		fs:            fsys,
-		cw:          cw,
+		cw:            cw,
-		lastUpdates: lastUpdates,
+		lastUpdates:   lastUpdates,
+		targetFolders: targetFolders,
 	}, nil
 }
 
+// popLastUpdate retrieves and removes the last update info for the given folder ID
+// This is used to track which folders have been found during the walk_dir_tree
 func (j *scanJob) popLastUpdate(folderID string) model.FolderUpdateInfo {
 	j.lock.Lock()
 	defer j.lock.Unlock()
@@ -106,6 +96,15 @@ func (j *scanJob) popLastUpdate(folderID string) model.FolderUpdateInfo {
 	return lastUpdate
 }
 
+// createFolderEntry creates a new folderEntry for the given path, using the last update info from the job
+// to populate the previous update time and hash. It also removes the folder from the job's lastUpdates map.
+// This is used to track which folders have been found during the walk_dir_tree.
+func (j *scanJob) createFolderEntry(path string) *folderEntry {
+	id := model.FolderID(j.lib, path)
+	info := j.popLastUpdate(id)
+	return newFolderEntry(j, id, path, info.UpdatedAt, info.Hash)
+}
+
 // phaseFolders represents the first phase of the scanning process, which is responsible
 // for scanning all libraries and importing new or updated files. This phase involves
 // traversing the directory tree of each library, identifying new or modified media files,
@@ -144,7 +143,8 @@ func (p *phaseFolders) producer() ppl.Producer[*folderEntry] {
 			if utils.IsCtxDone(p.ctx) {
 				break
 			}
-			outputChan, err := walkDirTree(p.ctx, job)
+
+			outputChan, err := walkDirTree(p.ctx, job, job.targetFolders...)
 			if err != nil {
 				log.Warn(p.ctx, "Scanner: Error scanning library", "lib", job.lib.Name, err)
 			}

scanner/phase_2_missing_tracks.go

@@ -69,9 +69,6 @@ func (p *phaseMissingTracks) produce(put func(tracks *missingTracks)) error {
 		}
 	}
 	for _, lib := range p.state.libraries {
-		if lib.LastScanStartedAt.IsZero() {
-			continue
-		}
 		log.Debug(p.ctx, "Scanner: Checking missing tracks", "libraryId", lib.ID, "libraryName", lib.Name)
 		cursor, err := p.ds.MediaFile(p.ctx).GetMissingAndMatching(lib.ID)
 		if err != nil {

scanner/phase_3_refresh_albums.go

@@ -27,14 +27,13 @@ import (
 type phaseRefreshAlbums struct {
 	ds        model.DataStore
 	ctx       context.Context
-	libs      model.Libraries
 	refreshed atomic.Uint32
 	skipped   atomic.Uint32
 	state     *scanState
 }
 
-func createPhaseRefreshAlbums(ctx context.Context, state *scanState, ds model.DataStore, libs model.Libraries) *phaseRefreshAlbums {
+func createPhaseRefreshAlbums(ctx context.Context, state *scanState, ds model.DataStore) *phaseRefreshAlbums {
-	return &phaseRefreshAlbums{ctx: ctx, ds: ds, libs: libs, state: state}
+	return &phaseRefreshAlbums{ctx: ctx, ds: ds, state: state}
 }
 
 func (p *phaseRefreshAlbums) description() string {
@@ -47,7 +46,7 @@ func (p *phaseRefreshAlbums) producer() ppl.Producer[*model.Album] {
 
 func (p *phaseRefreshAlbums) produce(put func(album *model.Album)) error {
 	count := 0
-	for _, lib := range p.libs {
+	for _, lib := range p.state.libraries {
 		cursor, err := p.ds.Album(p.ctx).GetTouchedAlbums(lib.ID)
 		if err != nil {
 			return fmt.Errorf("loading touched albums: %w", err)

scanner/phase_3_refresh_albums_test.go

@@ -32,8 +32,8 @@ var _ = Describe("phaseRefreshAlbums", func() {
 			{ID: 1, Name: "Library 1"},
 			{ID: 2, Name: "Library 2"},
 		}
-		state = &scanState{}
+		state = &scanState{libraries: libs}
-		phase = createPhaseRefreshAlbums(ctx, state, ds, libs)
+		phase = createPhaseRefreshAlbums(ctx, state, ds)
 	})
 
 	Describe("description", func() {

scanner/scanner.go

@@ -3,6 +3,8 @@ package scanner
 import (
 	"context"
 	"fmt"
+	"maps"
+	"slices"
 	"sync/atomic"
 	"time"
 
@@ -15,6 +17,7 @@ import (
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils/run"
+	"github.com/navidrome/navidrome/utils/slice"
 )
 
 type scannerImpl struct {
@@ -28,7 +31,8 @@ type scanState struct {
 	progress        chan<- *ProgressInfo
 	fullScan        bool
 	changesDetected atomic.Bool
-	libraries       model.Libraries // Store libraries list for consistency across phases
+	libraries       model.Libraries  // Store libraries list for consistency across phases
+	targets         map[int][]string // Optional: map[libraryID][]folderPaths for selective scans
 }
 
 func (s *scanState) sendProgress(info *ProgressInfo) {
@@ -37,6 +41,10 @@ func (s *scanState) sendProgress(info *ProgressInfo) {
 	}
 }
 
+func (s *scanState) isSelectiveScan() bool {
+	return len(s.targets) > 0
+}
+
 func (s *scanState) sendWarning(msg string) {
 	s.sendProgress(&ProgressInfo{Warning: msg})
 }
@@ -45,7 +53,7 @@ func (s *scanState) sendError(err error) {
 	s.sendProgress(&ProgressInfo{Error: err.Error()})
 }
 
-func (s *scannerImpl) scanAll(ctx context.Context, fullScan bool, progress chan<- *ProgressInfo) {
+func (s *scannerImpl) scanFolders(ctx context.Context, fullScan bool, targets []model.ScanTarget, progress chan<- *ProgressInfo) {
 	startTime := time.Now()
 
 	state := scanState{
@@ -59,38 +67,75 @@ func (s *scannerImpl) scanAll(ctx context.Context, fullScan bool, progress chan<
 		state.changesDetected.Store(true)
 	}
 
-	libs, err := s.ds.Library(ctx).GetAll()
+	// Get libraries and optionally filter by targets
+	allLibs, err := s.ds.Library(ctx).GetAll()
 	if err != nil {
 		state.sendWarning(fmt.Sprintf("getting libraries: %s", err))
 		return
 	}
-	state.libraries = libs
 
-	log.Info(ctx, "Scanner: Starting scan", "fullScan", state.fullScan, "numLibraries", len(libs))
+	if len(targets) > 0 {
+		// Selective scan: filter libraries and build targets map
+		state.targets = make(map[int][]string)
+
+		for _, target := range targets {
+			folderPath := target.FolderPath
+			if folderPath == "" {
+				folderPath = "."
+			}
+			state.targets[target.LibraryID] = append(state.targets[target.LibraryID], folderPath)
+		}
+
+		// Filter libraries to only those in targets
+		state.libraries = slice.Filter(allLibs, func(lib model.Library) bool {
+			return len(state.targets[lib.ID]) > 0
+		})
+
+		log.Info(ctx, "Scanner: Starting selective scan", "fullScan", state.fullScan, "numLibraries", len(state.libraries), "numTargets", len(targets))
+	} else {
+		// Full library scan
+		state.libraries = allLibs
+		log.Info(ctx, "Scanner: Starting scan", "fullScan", state.fullScan, "numLibraries", len(state.libraries))
+	}
 
 	// Store scan type and start time
 	scanType := "quick"
 	if state.fullScan {
 		scanType = "full"
 	}
+	if state.isSelectiveScan() {
+		scanType += "-selective"
+	}
 	_ = s.ds.Property(ctx).Put(consts.LastScanTypeKey, scanType)
 	_ = s.ds.Property(ctx).Put(consts.LastScanStartTimeKey, startTime.Format(time.RFC3339))
 
 	// if there was a full scan in progress, force a full scan
 	if !state.fullScan {
-		for _, lib := range libs {
+		for _, lib := range state.libraries {
 			if lib.FullScanInProgress {
 				log.Info(ctx, "Scanner: Interrupted full scan detected", "lib", lib.Name)
 				state.fullScan = true
-				_ = s.ds.Property(ctx).Put(consts.LastScanTypeKey, "full")
+				if state.isSelectiveScan() {
+					_ = s.ds.Property(ctx).Put(consts.LastScanTypeKey, "full-selective")
+				} else {
+					_ = s.ds.Property(ctx).Put(consts.LastScanTypeKey, "full")
+				}
 				break
 			}
 		}
 	}
 
+	// Prepare libraries for scanning (initialize LastScanStartedAt if needed)
+	err = s.prepareLibrariesForScan(ctx, &state)
+	if err != nil {
+		log.Error(ctx, "Scanner: Error preparing libraries for scan", err)
+		state.sendError(err)
+		return
+	}
+
 	err = run.Sequentially(
 		// Phase 1: Scan all libraries and import new/updated files
-		runPhase[*folderEntry](ctx, 1, createPhaseFolders(ctx, &state, s.ds, s.cw, libs)),
+		runPhase[*folderEntry](ctx, 1, createPhaseFolders(ctx, &state, s.ds, s.cw)),
 
 		// Phase 2: Process missing files, checking for moves
 		runPhase[*missingTracks](ctx, 2, createPhaseMissingTracks(ctx, &state, s.ds)),
@@ -98,7 +143,7 @@ func (s *scannerImpl) scanAll(ctx context.Context, fullScan bool, progress chan<
 		// Phases 3 and 4 can be run in parallel
 		run.Parallel(
 			// Phase 3: Refresh all new/changed albums and update artists
-			runPhase[*model.Album](ctx, 3, createPhaseRefreshAlbums(ctx, &state, s.ds, libs)),
+			runPhase[*model.Album](ctx, 3, createPhaseRefreshAlbums(ctx, &state, s.ds)),
 
 			// Phase 4: Import/update playlists
 			runPhase[*model.Folder](ctx, 4, createPhasePlaylists(ctx, &state, s.ds, s.pls, s.cw)),
@@ -131,7 +176,53 @@ func (s *scannerImpl) scanAll(ctx context.Context, fullScan bool, progress chan<
 		state.sendProgress(&ProgressInfo{ChangesDetected: true})
 	}
 
-	log.Info(ctx, "Scanner: Finished scanning all libraries", "duration", time.Since(startTime))
+	if state.isSelectiveScan() {
+		log.Info(ctx, "Scanner: Finished scanning selected folders", "duration", time.Since(startTime), "numTargets", len(targets))
+	} else {
+		log.Info(ctx, "Scanner: Finished scanning all libraries", "duration", time.Since(startTime))
+	}
+}
+
+// prepareLibrariesForScan initializes the scan for all libraries in the state.
+// It calls ScanBegin for libraries that haven't started scanning yet (LastScanStartedAt is zero),
+// reloads them to get the updated state, and filters out any libraries that fail to initialize.
+func (s *scannerImpl) prepareLibrariesForScan(ctx context.Context, state *scanState) error {
+	var successfulLibs []model.Library
+
+	for _, lib := range state.libraries {
+		if lib.LastScanStartedAt.IsZero() {
+			// This is a new scan - mark it as started
+			err := s.ds.Library(ctx).ScanBegin(lib.ID, state.fullScan)
+			if err != nil {
+				log.Error(ctx, "Scanner: Error marking scan start", "lib", lib.Name, err)
+				state.sendWarning(err.Error())
+				continue
+			}
+
+			// Reload library to get updated state (timestamps, etc.)
+			reloadedLib, err := s.ds.Library(ctx).Get(lib.ID)
+			if err != nil {
+				log.Error(ctx, "Scanner: Error reloading library", "lib", lib.Name, err)
+				state.sendWarning(err.Error())
+				continue
+			}
+			lib = *reloadedLib
+		} else {
+			// This is a resumed scan
+			log.Debug(ctx, "Scanner: Resuming previous scan", "lib", lib.Name,
+				"lastScanStartedAt", lib.LastScanStartedAt, "fullScan", lib.FullScanInProgress)
+		}
+
+		successfulLibs = append(successfulLibs, lib)
+	}
+
+	if len(successfulLibs) == 0 {
+		return fmt.Errorf("no libraries available for scanning")
+	}
+
+	// Update state with only successfully initialized libraries
+	state.libraries = successfulLibs
+	return nil
 }
 
 func (s *scannerImpl) runGC(ctx context.Context, state *scanState) func() error {
@@ -140,7 +231,15 @@ func (s *scannerImpl) runGC(ctx context.Context, state *scanState) func() error
 		return s.ds.WithTx(func(tx model.DataStore) error {
 			if state.changesDetected.Load() {
 				start := time.Now()
-				err := tx.GC(ctx)
+
+				// For selective scans, extract library IDs to scope GC operations
+				var libraryIDs []int
+				if state.isSelectiveScan() {
+					libraryIDs = slices.Collect(maps.Keys(state.targets))
+					log.Debug(ctx, "Scanner: Running selective GC", "libraryIDs", libraryIDs)
+				}
+
+				err := tx.GC(ctx, libraryIDs...)
 				if err != nil {
 					log.Error(ctx, "Scanner: Error running GC", err)
 					return fmt.Errorf("running GC: %w", err)

scanner/scanner_multilibrary_test.go

@@ -32,7 +32,7 @@ var _ = Describe("Scanner - Multi-Library", Ordered, func() {
 	var ctx context.Context
 	var lib1, lib2 model.Library
 	var ds *tests.MockDataStore
-	var s scanner.Scanner
+	var s model.Scanner
 
 	createFS := func(path string, files fstest.MapFS) storagetest.FakeFS {
 		fs := storagetest.FakeFS{}

scanner/scanner_selective_test.go

@@ -0,0 +1,293 @@
+package scanner_test
+
+import (
+	"context"
+	"path/filepath"
+	"testing/fstest"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/core/artwork"
+	"github.com/navidrome/navidrome/core/metrics"
+	"github.com/navidrome/navidrome/core/storage/storagetest"
+	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/persistence"
+	"github.com/navidrome/navidrome/scanner"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/utils/slice"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("ScanFolders", Ordered, func() {
+	var ctx context.Context
+	var lib model.Library
+	var ds model.DataStore
+	var s model.Scanner
+	var fsys storagetest.FakeFS
+
+	BeforeAll(func() {
+		ctx = request.WithUser(GinkgoT().Context(), model.User{ID: "123", IsAdmin: true})
+		tmpDir := GinkgoT().TempDir()
+		conf.Server.DbPath = filepath.Join(tmpDir, "test-selective-scan.db?_journal_mode=WAL")
+		log.Warn("Using DB at " + conf.Server.DbPath)
+		db.Db().SetMaxOpenConns(1)
+	})
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.MusicFolder = "fake:///music"
+		conf.Server.DevExternalScanner = false
+
+		db.Init(ctx)
+		DeferCleanup(func() {
+			Expect(tests.ClearDB()).To(Succeed())
+		})
+
+		ds = persistence.New(db.Db())
+
+		// Create the admin user in the database to match the context
+		adminUser := model.User{
+			ID:          "123",
+			UserName:    "admin",
+			Name:        "Admin User",
+			IsAdmin:     true,
+			NewPassword: "password",
+		}
+		Expect(ds.User(ctx).Put(&adminUser)).To(Succeed())
+
+		s = scanner.New(ctx, ds, artwork.NoopCacheWarmer(), events.NoopBroker(),
+			core.NewPlaylists(ds), metrics.NewNoopInstance())
+
+		lib = model.Library{ID: 1, Name: "Fake Library", Path: "fake:///music"}
+		Expect(ds.Library(ctx).Put(&lib)).To(Succeed())
+
+		// Initialize fake filesystem
+		fsys = storagetest.FakeFS{}
+		storagetest.Register("fake", &fsys)
+	})
+
+	Describe("Adding tracks to the library", func() {
+		It("scans specified folders recursively including all subdirectories", func() {
+			rock := template(_t{"albumartist": "Rock Artist", "album": "Rock Album"})
+			jazz := template(_t{"albumartist": "Jazz Artist", "album": "Jazz Album"})
+			pop := template(_t{"albumartist": "Pop Artist", "album": "Pop Album"})
+			createFS(fstest.MapFS{
+				"rock/track1.mp3":        rock(track(1, "Rock Track 1")),
+				"rock/track2.mp3":        rock(track(2, "Rock Track 2")),
+				"rock/subdir/track3.mp3": rock(track(3, "Rock Track 3")),
+				"jazz/track4.mp3":        jazz(track(1, "Jazz Track 1")),
+				"jazz/subdir/track5.mp3": jazz(track(2, "Jazz Track 2")),
+				"pop/track6.mp3":         pop(track(1, "Pop Track 1")),
+			})
+
+			// Scan only the "rock" and "jazz" folders (including their subdirectories)
+			targets := []model.ScanTarget{
+				{LibraryID: lib.ID, FolderPath: "rock"},
+				{LibraryID: lib.ID, FolderPath: "jazz"},
+			}
+
+			warnings, err := s.ScanFolders(ctx, false, targets)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(warnings).To(BeEmpty())
+
+			// Verify all tracks in rock and jazz folders (including subdirectories) were imported
+			allFiles, err := ds.MediaFile(ctx).GetAll()
+			Expect(err).ToNot(HaveOccurred())
+
+			// Should have 5 tracks (all rock and jazz tracks including subdirectories)
+			Expect(allFiles).To(HaveLen(5))
+
+			// Get the file paths
+			paths := slice.Map(allFiles, func(mf model.MediaFile) string {
+				return filepath.ToSlash(mf.Path)
+			})
+
+			// Verify the correct files were scanned (including subdirectories)
+			Expect(paths).To(ContainElements(
+				"rock/track1.mp3",
+				"rock/track2.mp3",
+				"rock/subdir/track3.mp3",
+				"jazz/track4.mp3",
+				"jazz/subdir/track5.mp3",
+			))
+
+			// Verify files in the pop folder were NOT scanned
+			Expect(paths).ToNot(ContainElement("pop/track6.mp3"))
+		})
+	})
+
+	Describe("Deleting folders", func() {
+		Context("when a child folder is deleted", func() {
+			var (
+				revolver, help func(...map[string]any) *fstest.MapFile
+				artistFolderID string
+				album1FolderID string
+				album2FolderID string
+				album1TrackIDs []string
+				album2TrackIDs []string
+			)
+
+			BeforeEach(func() {
+				// Setup template functions for creating test files
+				revolver = storagetest.Template(_t{"albumartist": "The Beatles", "album": "Revolver", "year": 1966})
+				help = storagetest.Template(_t{"albumartist": "The Beatles", "album": "Help!", "year": 1965})
+
+				// Initial filesystem with nested folders
+				fsys.SetFiles(fstest.MapFS{
+					"The Beatles/Revolver/01 - Taxman.mp3":        revolver(storagetest.Track(1, "Taxman")),
+					"The Beatles/Revolver/02 - Eleanor Rigby.mp3": revolver(storagetest.Track(2, "Eleanor Rigby")),
+					"The Beatles/Help!/01 - Help!.mp3":            help(storagetest.Track(1, "Help!")),
+					"The Beatles/Help!/02 - The Night Before.mp3": help(storagetest.Track(2, "The Night Before")),
+				})
+
+				// First scan - import everything
+				_, err := s.ScanAll(ctx, true)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Verify initial state - all folders exist
+				folders, err := ds.Folder(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"library_id": lib.ID}})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(folders).To(HaveLen(4)) // root, Artist, Album1, Album2
+
+				// Store folder IDs for later verification
+				for _, f := range folders {
+					switch f.Name {
+					case "The Beatles":
+						artistFolderID = f.ID
+					case "Revolver":
+						album1FolderID = f.ID
+					case "Help!":
+						album2FolderID = f.ID
+					}
+				}
+
+				// Verify all tracks exist
+				allTracks, err := ds.MediaFile(ctx).GetAll()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(allTracks).To(HaveLen(4))
+
+				// Store track IDs for later verification
+				for _, t := range allTracks {
+					if t.Album == "Revolver" {
+						album1TrackIDs = append(album1TrackIDs, t.ID)
+					} else if t.Album == "Help!" {
+						album2TrackIDs = append(album2TrackIDs, t.ID)
+					}
+				}
+
+				// Verify no tracks are missing initially
+				for _, t := range allTracks {
+					Expect(t.Missing).To(BeFalse())
+				}
+			})
+
+			It("should mark child folder and its tracks as missing when parent is scanned", func() {
+				// Delete the child folder (Help!) from the filesystem
+				fsys.SetFiles(fstest.MapFS{
+					"The Beatles/Revolver/01 - Taxman.mp3":        revolver(storagetest.Track(1, "Taxman")),
+					"The Beatles/Revolver/02 - Eleanor Rigby.mp3": revolver(storagetest.Track(2, "Eleanor Rigby")),
+					// "The Beatles/Help!" folder and its contents are DELETED
+				})
+
+				// Run selective scan on the parent folder (Artist)
+				// This simulates what the watcher does when a child folder is deleted
+				_, err := s.ScanFolders(ctx, false, []model.ScanTarget{
+					{LibraryID: lib.ID, FolderPath: "The Beatles"},
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				// Verify the deleted child folder is now marked as missing
+				deletedFolder, err := ds.Folder(ctx).Get(album2FolderID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(deletedFolder.Missing).To(BeTrue(), "Deleted child folder should be marked as missing")
+
+				// Verify the deleted folder's tracks are marked as missing
+				for _, trackID := range album2TrackIDs {
+					track, err := ds.MediaFile(ctx).Get(trackID)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(track.Missing).To(BeTrue(), "Track in deleted folder should be marked as missing")
+				}
+
+				// Verify the parent folder is still present and not marked as missing
+				parentFolder, err := ds.Folder(ctx).Get(artistFolderID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(parentFolder.Missing).To(BeFalse(), "Parent folder should not be marked as missing")
+
+				// Verify the sibling folder and its tracks are still present and not missing
+				siblingFolder, err := ds.Folder(ctx).Get(album1FolderID)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(siblingFolder.Missing).To(BeFalse(), "Sibling folder should not be marked as missing")
+
+				for _, trackID := range album1TrackIDs {
+					track, err := ds.MediaFile(ctx).Get(trackID)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(track.Missing).To(BeFalse(), "Track in sibling folder should not be marked as missing")
+				}
+			})
+
+			It("should mark deeply nested child folders as missing", func() {
+				// Add a deeply nested folder structure
+				fsys.SetFiles(fstest.MapFS{
+					"The Beatles/Revolver/01 - Taxman.mp3":               revolver(storagetest.Track(1, "Taxman")),
+					"The Beatles/Revolver/02 - Eleanor Rigby.mp3":        revolver(storagetest.Track(2, "Eleanor Rigby")),
+					"The Beatles/Help!/01 - Help!.mp3":                   help(storagetest.Track(1, "Help!")),
+					"The Beatles/Help!/02 - The Night Before.mp3":        help(storagetest.Track(2, "The Night Before")),
+					"The Beatles/Help!/Bonus/01 - Bonus Track.mp3":       help(storagetest.Track(99, "Bonus Track")),
+					"The Beatles/Help!/Bonus/Nested/01 - Deep Track.mp3": help(storagetest.Track(100, "Deep Track")),
+				})
+
+				// Rescan to import the new nested structure
+				_, err := s.ScanAll(ctx, true)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Verify nested folders were created
+				allFolders, err := ds.Folder(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"library_id": lib.ID}})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(allFolders)).To(BeNumerically(">", 4), "Should have more folders with nested structure")
+
+				// Now delete the entire Help! folder including nested children
+				fsys.SetFiles(fstest.MapFS{
+					"The Beatles/Revolver/01 - Taxman.mp3":        revolver(storagetest.Track(1, "Taxman")),
+					"The Beatles/Revolver/02 - Eleanor Rigby.mp3": revolver(storagetest.Track(2, "Eleanor Rigby")),
+					// All Help! subfolders are deleted
+				})
+
+				// Run selective scan on parent
+				_, err = s.ScanFolders(ctx, false, []model.ScanTarget{
+					{LibraryID: lib.ID, FolderPath: "The Beatles"},
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				// Verify all Help! folders (including nested ones) are marked as missing
+				missingFolders, err := ds.Folder(ctx).GetAll(model.QueryOptions{
+					Filters: squirrel.And{
+						squirrel.Eq{"library_id": lib.ID},
+						squirrel.Eq{"missing": true},
+					},
+				})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(len(missingFolders)).To(BeNumerically(">", 0), "At least one folder should be marked as missing")
+
+				// Verify all tracks in deleted folders are marked as missing
+				allTracks, err := ds.MediaFile(ctx).GetAll()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(allTracks).To(HaveLen(6))
+
+				for _, track := range allTracks {
+					if track.Album == "Help!" {
+						Expect(track.Missing).To(BeTrue(), "All tracks in deleted Help! folder should be marked as missing")
+					} else if track.Album == "Revolver" {
+						Expect(track.Missing).To(BeFalse(), "Tracks in Revolver folder should not be marked as missing")
+					}
+				}
+			})
+		})
+	})
+})

scanner/scanner_test.go

@@ -34,19 +34,19 @@ type _t = map[string]any
 var template = storagetest.Template
 var track = storagetest.Track
 
+func createFS(files fstest.MapFS) storagetest.FakeFS {
+	fs := storagetest.FakeFS{}
+	fs.SetFiles(files)
+	storagetest.Register("fake", &fs)
+	return fs
+}
+
 var _ = Describe("Scanner", Ordered, func() {
 	var ctx context.Context
 	var lib model.Library
 	var ds *tests.MockDataStore
 	var mfRepo *mockMediaFileRepo
-	var s scanner.Scanner
+	var s model.Scanner
-
-	createFS := func(files fstest.MapFS) storagetest.FakeFS {
-		fs := storagetest.FakeFS{}
-		fs.SetFiles(files)
-		storagetest.Register("fake", &fs)
-		return fs
-	}
 
 	BeforeAll(func() {
 		ctx = request.WithUser(GinkgoT().Context(), model.User{ID: "123", IsAdmin: true})
@@ -478,6 +478,56 @@ var _ = Describe("Scanner", Ordered, func() {
 			Expect(mf.Missing).To(BeFalse())
 		})
 
+		It("marks tracks as missing when scanning a deleted folder with ScanFolders", func() {
+			By("Adding a third track to Revolver to have more test data")
+			fsys.Add("The Beatles/Revolver/03 - I'm Only Sleeping.mp3", revolver(track(3, "I'm Only Sleeping")))
+			Expect(runScanner(ctx, false)).To(Succeed())
+
+			By("Verifying initial state has 5 tracks")
+			Expect(ds.MediaFile(ctx).CountAll(model.QueryOptions{
+				Filters: squirrel.Eq{"missing": false},
+			})).To(Equal(int64(5)))
+
+			By("Removing the entire Revolver folder from filesystem")
+			fsys.Remove("The Beatles/Revolver/01 - Taxman.mp3")
+			fsys.Remove("The Beatles/Revolver/02 - Eleanor Rigby.mp3")
+			fsys.Remove("The Beatles/Revolver/03 - I'm Only Sleeping.mp3")
+
+			By("Scanning the parent folder (simulating watcher behavior)")
+			targets := []model.ScanTarget{
+				{LibraryID: lib.ID, FolderPath: "The Beatles"},
+			}
+			_, err := s.ScanFolders(ctx, false, targets)
+			Expect(err).To(Succeed())
+
+			By("Checking all Revolver tracks are marked as missing")
+			mf, err := findByPath("The Beatles/Revolver/01 - Taxman.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mf.Missing).To(BeTrue())
+
+			mf, err = findByPath("The Beatles/Revolver/02 - Eleanor Rigby.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mf.Missing).To(BeTrue())
+
+			mf, err = findByPath("The Beatles/Revolver/03 - I'm Only Sleeping.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mf.Missing).To(BeTrue())
+
+			By("Checking the Help! tracks are not affected")
+			mf, err = findByPath("The Beatles/Help!/01 - Help!.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mf.Missing).To(BeFalse())
+
+			mf, err = findByPath("The Beatles/Help!/02 - The Night Before.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mf.Missing).To(BeFalse())
+
+			By("Verifying only 2 non-missing tracks remain (Help! tracks)")
+			Expect(ds.MediaFile(ctx).CountAll(model.QueryOptions{
+				Filters: squirrel.Eq{"missing": false},
+			})).To(Equal(int64(2)))
+		})
+
 		It("does not override artist fields when importing an undertagged file", func() {
 			By("Making sure artist in the DB contains MBID and sort name")
 			aa, err := ds.Artist(ctx).GetAll(model.QueryOptions{

scanner/walk_dir_tree.go

@@ -1,7 +1,6 @@
 package scanner
 
 import (
-	"bufio"
 	"context"
 	"io/fs"
 	"maps"
@@ -11,37 +10,69 @@ import (
 	"strings"
 
 	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils"
-	ignore "github.com/sabhiram/go-gitignore"
 )
 
-func walkDirTree(ctx context.Context, job *scanJob) (<-chan *folderEntry, error) {
+// walkDirTree recursively walks the directory tree starting from the given targetFolders.
+// If no targetFolders are provided, it starts from the root folder (".").
+// It returns a channel of folderEntry pointers representing each folder found.
+func walkDirTree(ctx context.Context, job *scanJob, targetFolders ...string) (<-chan *folderEntry, error) {
 	results := make(chan *folderEntry)
+	folders := targetFolders
+	if len(targetFolders) == 0 {
+		// No specific folders provided, scan the root folder
+		folders = []string{"."}
+	}
 	go func() {
 		defer close(results)
-		err := walkFolder(ctx, job, ".", nil, results)
+		for _, folderPath := range folders {
-		if err != nil {
+			if utils.IsCtxDone(ctx) {
-			log.Error(ctx, "Scanner: There were errors reading directories from filesystem", "path", job.lib.Path, err)
+				return
-			return
+			}
+
+			// Check if target folder exists before walking it
+			// If it doesn't exist (e.g., deleted between watcher detection and scan execution),
+			// skip it so it remains in job.lastUpdates and gets handled in following steps
+			_, err := fs.Stat(job.fs, folderPath)
+			if err != nil {
+				log.Warn(ctx, "Scanner: Target folder does not exist.", "path", folderPath, err)
+				continue
+			}
+
+			// Create checker and push patterns from root to this folder
+			checker := newIgnoreChecker(job.fs)
+			err = checker.PushAllParents(ctx, folderPath)
+			if err != nil {
+				log.Error(ctx, "Scanner: Error pushing ignore patterns for target folder", "path", folderPath, err)
+				continue
+			}
+
+			// Recursively walk this folder and all its children
+			err = walkFolder(ctx, job, folderPath, checker, results)
+			if err != nil {
+				log.Error(ctx, "Scanner: Error walking target folder", "path", folderPath, err)
+				continue
+			}
 		}
-		log.Debug(ctx, "Scanner: Finished reading folders", "lib", job.lib.Name, "path", job.lib.Path, "numFolders", job.numFolders.Load())
+		log.Debug(ctx, "Scanner: Finished reading target folders", "lib", job.lib.Name, "path", job.lib.Path, "numFolders", job.numFolders.Load())
 	}()
 	return results, nil
 }
 
-func walkFolder(ctx context.Context, job *scanJob, currentFolder string, ignorePatterns []string, results chan<- *folderEntry) error {
+func walkFolder(ctx context.Context, job *scanJob, currentFolder string, checker *IgnoreChecker, results chan<- *folderEntry) error {
-	ignorePatterns = loadIgnoredPatterns(ctx, job.fs, currentFolder, ignorePatterns)
+	// Push patterns for this folder onto the stack
+	_ = checker.Push(ctx, currentFolder)
+	defer checker.Pop() // Pop patterns when leaving this folder
 
-	folder, children, err := loadDir(ctx, job, currentFolder, ignorePatterns)
+	folder, children, err := loadDir(ctx, job, currentFolder, checker)
 	if err != nil {
 		log.Warn(ctx, "Scanner: Error loading dir. Skipping", "path", currentFolder, err)
 		return nil
 	}
 	for _, c := range children {
-		err := walkFolder(ctx, job, c, ignorePatterns, results)
+		err := walkFolder(ctx, job, c, checker, results)
 		if err != nil {
 			return err
 		}
@@ -59,50 +90,17 @@ func walkFolder(ctx context.Context, job *scanJob, currentFolder string, ignoreP
 	return nil
 }
 
-func loadIgnoredPatterns(ctx context.Context, fsys fs.FS, currentFolder string, currentPatterns []string) []string {
+func loadDir(ctx context.Context, job *scanJob, dirPath string, checker *IgnoreChecker) (folder *folderEntry, children []string, err error) {
-	ignoreFilePath := path.Join(currentFolder, consts.ScanIgnoreFile)
+	// Check if directory exists before creating the folder entry
-	var newPatterns []string
+	// This is important to avoid removing the folder from lastUpdates if it doesn't exist
-	if _, err := fs.Stat(fsys, ignoreFilePath); err == nil {
-		// Read and parse the .ndignore file
-		ignoreFile, err := fsys.Open(ignoreFilePath)
-		if err != nil {
-			log.Warn(ctx, "Scanner: Error opening .ndignore file", "path", ignoreFilePath, err)
-			// Continue with previous patterns
-		} else {
-			defer ignoreFile.Close()
-			scanner := bufio.NewScanner(ignoreFile)
-			for scanner.Scan() {
-				line := scanner.Text()
-				if line == "" || strings.HasPrefix(line, "#") {
-					continue // Skip empty lines and comments
-				}
-				newPatterns = append(newPatterns, line)
-			}
-			if err := scanner.Err(); err != nil {
-				log.Warn(ctx, "Scanner: Error reading .ignore file", "path", ignoreFilePath, err)
-			}
-		}
-		// If the .ndignore file is empty, mimic the current behavior and ignore everything
-		if len(newPatterns) == 0 {
-			log.Trace(ctx, "Scanner: .ndignore file is empty, ignoring everything", "path", currentFolder)
-			newPatterns = []string{"**/*"}
-		} else {
-			log.Trace(ctx, "Scanner: .ndignore file found ", "path", ignoreFilePath, "patterns", newPatterns)
-		}
-	}
-	// Combine the patterns from the .ndignore file with the ones passed as argument
-	combinedPatterns := append([]string{}, currentPatterns...)
-	return append(combinedPatterns, newPatterns...)
-}
-
-func loadDir(ctx context.Context, job *scanJob, dirPath string, ignorePatterns []string) (folder *folderEntry, children []string, err error) {
-	folder = newFolderEntry(job, dirPath)
-
 	dirInfo, err := fs.Stat(job.fs, dirPath)
 	if err != nil {
 		log.Warn(ctx, "Scanner: Error stating dir", "path", dirPath, err)
 		return nil, nil, err
 	}
+
+	// Now that we know the folder exists, create the entry (which removes it from lastUpdates)
+	folder = job.createFolderEntry(dirPath)
 	folder.modTime = dirInfo.ModTime()
 
 	dir, err := job.fs.Open(dirPath)
@@ -117,12 +115,11 @@ func loadDir(ctx context.Context, job *scanJob, dirPath string, ignorePatterns [
 		return folder, children, err
 	}
 
-	ignoreMatcher := ignore.CompileIgnoreLines(ignorePatterns...)
 	entries := fullReadDir(ctx, dirFile)
 	children = make([]string, 0, len(entries))
 	for _, entry := range entries {
 		entryPath := path.Join(dirPath, entry.Name())
-		if len(ignorePatterns) > 0 && isScanIgnored(ctx, ignoreMatcher, entryPath) {
+		if checker.ShouldIgnore(ctx, entryPath) {
 			log.Trace(ctx, "Scanner: Ignoring entry", "path", entryPath)
 			continue
 		}
@@ -234,6 +231,7 @@ func isDirReadable(ctx context.Context, fsys fs.FS, dirPath string) bool {
 var ignoredDirs = []string{
 	"$RECYCLE.BIN",
 	"#snapshot",
+	"@Recycle",
 	"@Recently-Snapshot",
 	".streams",
 	"lost+found",
@@ -254,11 +252,3 @@ func isDirIgnored(name string) bool {
 func isEntryIgnored(name string) bool {
 	return strings.HasPrefix(name, ".") && !strings.HasPrefix(name, "..")
 }
-
-func isScanIgnored(ctx context.Context, matcher *ignore.GitIgnore, entryPath string) bool {
-	matches := matcher.MatchesPath(entryPath)
-	if matches {
-		log.Trace(ctx, "Scanner: Ignoring entry matching .ndignore: ", "path", entryPath)
-	}
-	return matches
-}

scanner/walk_dir_tree_test.go

@@ -25,82 +25,196 @@ var _ = Describe("walk_dir_tree", func() {
 			ctx  context.Context
 		)
 
-		BeforeEach(func() {
+		Context("full library", func() {
-			DeferCleanup(configtest.SetupConfig())
+			BeforeEach(func() {
-			ctx = GinkgoT().Context()
+				DeferCleanup(configtest.SetupConfig())
-			fsys = &mockMusicFS{
+				ctx = GinkgoT().Context()
-				FS: fstest.MapFS{
+				fsys = &mockMusicFS{
-					"root/a/.ndignore":       {Data: []byte("ignored/*")},
+					FS: fstest.MapFS{
-					"root/a/f1.mp3":          {},
+						"root/a/.ndignore":       {Data: []byte("ignored/*")},
-					"root/a/f2.mp3":          {},
+						"root/a/f1.mp3":          {},
-					"root/a/ignored/bad.mp3": {},
+						"root/a/f2.mp3":          {},
-					"root/b/cover.jpg":       {},
+						"root/a/ignored/bad.mp3": {},
-					"root/c/f3":              {},
+						"root/b/cover.jpg":       {},
-					"root/d":                 {},
+						"root/c/f3":              {},
-					"root/d/.ndignore":       {},
+						"root/d":                 {},
-					"root/d/f1.mp3":          {},
+						"root/d/.ndignore":       {},
-					"root/d/f2.mp3":          {},
+						"root/d/f1.mp3":          {},
-					"root/d/f3.mp3":          {},
+						"root/d/f2.mp3":          {},
-					"root/e/original/f1.mp3": {},
+						"root/d/f3.mp3":          {},
-					"root/e/symlink":         {Mode: fs.ModeSymlink, Data: []byte("original")},
+						"root/e/original/f1.mp3": {},
+						"root/e/symlink":         {Mode: fs.ModeSymlink, Data: []byte("original")},
+					},
+				}
+				job = &scanJob{
+					fs:  fsys,
+					lib: model.Library{Path: "/music"},
+				}
+			})
+
+			// Helper function to call walkDirTree and collect folders from the results channel
+			getFolders := func() map[string]*folderEntry {
+				results, err := walkDirTree(ctx, job)
+				Expect(err).ToNot(HaveOccurred())
+
+				folders := map[string]*folderEntry{}
+				g := errgroup.Group{}
+				g.Go(func() error {
+					for folder := range results {
+						folders[folder.path] = folder
+					}
+					return nil
+				})
+				_ = g.Wait()
+				return folders
+			}
+
+			DescribeTable("symlink handling",
+				func(followSymlinks bool, expectedFolderCount int) {
+					conf.Server.Scanner.FollowSymlinks = followSymlinks
+					folders := getFolders()
+
+					Expect(folders).To(HaveLen(expectedFolderCount + 2)) // +2 for `.` and `root`
+
+					// Basic folder structure checks
+					Expect(folders["root/a"].audioFiles).To(SatisfyAll(
+						HaveLen(2),
+						HaveKey("f1.mp3"),
+						HaveKey("f2.mp3"),
+					))
+					Expect(folders["root/a"].imageFiles).To(BeEmpty())
+					Expect(folders["root/b"].audioFiles).To(BeEmpty())
+					Expect(folders["root/b"].imageFiles).To(SatisfyAll(
+						HaveLen(1),
+						HaveKey("cover.jpg"),
+					))
+					Expect(folders["root/c"].audioFiles).To(BeEmpty())
+					Expect(folders["root/c"].imageFiles).To(BeEmpty())
+					Expect(folders).ToNot(HaveKey("root/d"))
+
+					// Symlink specific checks
+					if followSymlinks {
+						Expect(folders["root/e/symlink"].audioFiles).To(HaveLen(1))
+					} else {
+						Expect(folders).ToNot(HaveKey("root/e/symlink"))
+					}
 				},
-			}
+				Entry("with symlinks enabled", true, 7),
-			job = &scanJob{
+				Entry("with symlinks disabled", false, 6),
-				fs:  fsys,
+			)
-				lib: model.Library{Path: "/music"},
-			}
 		})
 
-		// Helper function to call walkDirTree and collect folders from the results channel
+		Context("with target folders", func() {
-		getFolders := func() map[string]*folderEntry {
+			BeforeEach(func() {
-			results, err := walkDirTree(ctx, job)
+				DeferCleanup(configtest.SetupConfig())
-			Expect(err).ToNot(HaveOccurred())
+				ctx = GinkgoT().Context()
-
+				fsys = &mockMusicFS{
-			folders := map[string]*folderEntry{}
+					FS: fstest.MapFS{
-			g := errgroup.Group{}
+						"Artist/Album1/track1.mp3":      {},
-			g.Go(func() error {
+						"Artist/Album1/track2.mp3":      {},
-				for folder := range results {
+						"Artist/Album2/track1.mp3":      {},
-					folders[folder.path] = folder
+						"Artist/Album2/track2.mp3":      {},
+						"Artist/Album2/Sub/track3.mp3":  {},
+						"OtherArtist/Album3/track1.mp3": {},
+					},
+				}
+				job = &scanJob{
+					fs:  fsys,
+					lib: model.Library{Path: "/music"},
 				}
-				return nil
 			})
-			_ = g.Wait()
-			return folders
-		}
 
-		DescribeTable("symlink handling",
+			It("should recursively walk all subdirectories of target folders", func() {
-			func(followSymlinks bool, expectedFolderCount int) {
+				results, err := walkDirTree(ctx, job, "Artist")
-				conf.Server.Scanner.FollowSymlinks = followSymlinks
+				Expect(err).ToNot(HaveOccurred())
-				folders := getFolders()
 
-				Expect(folders).To(HaveLen(expectedFolderCount + 2)) // +2 for `.` and `root`
+				folders := map[string]*folderEntry{}
+				g := errgroup.Group{}
+				g.Go(func() error {
+					for folder := range results {
+						folders[folder.path] = folder
+					}
+					return nil
+				})
+				_ = g.Wait()
 
-				// Basic folder structure checks
+				// Should include the target folder and all its descendants
-				Expect(folders["root/a"].audioFiles).To(SatisfyAll(
+				Expect(folders).To(SatisfyAll(
-					HaveLen(2),
+					HaveKey("Artist"),
-					HaveKey("f1.mp3"),
+					HaveKey("Artist/Album1"),
-					HaveKey("f2.mp3"),
+					HaveKey("Artist/Album2"),
+					HaveKey("Artist/Album2/Sub"),
 				))
-				Expect(folders["root/a"].imageFiles).To(BeEmpty())
-				Expect(folders["root/b"].audioFiles).To(BeEmpty())
-				Expect(folders["root/b"].imageFiles).To(SatisfyAll(
-					HaveLen(1),
-					HaveKey("cover.jpg"),
-				))
-				Expect(folders["root/c"].audioFiles).To(BeEmpty())
-				Expect(folders["root/c"].imageFiles).To(BeEmpty())
-				Expect(folders).ToNot(HaveKey("root/d"))
 
-				// Symlink specific checks
+				// Should not include folders outside the target
-				if followSymlinks {
+				Expect(folders).ToNot(HaveKey("OtherArtist"))
-					Expect(folders["root/e/symlink"].audioFiles).To(HaveLen(1))
+				Expect(folders).ToNot(HaveKey("OtherArtist/Album3"))
-				} else {
+
-					Expect(folders).ToNot(HaveKey("root/e/symlink"))
+				// Verify audio files are present
+				Expect(folders["Artist/Album1"].audioFiles).To(HaveLen(2))
+				Expect(folders["Artist/Album2"].audioFiles).To(HaveLen(2))
+				Expect(folders["Artist/Album2/Sub"].audioFiles).To(HaveLen(1))
+			})
+
+			It("should handle multiple target folders", func() {
+				results, err := walkDirTree(ctx, job, "Artist/Album1", "OtherArtist")
+				Expect(err).ToNot(HaveOccurred())
+
+				folders := map[string]*folderEntry{}
+				g := errgroup.Group{}
+				g.Go(func() error {
+					for folder := range results {
+						folders[folder.path] = folder
+					}
+					return nil
+				})
+				_ = g.Wait()
+
+				// Should include both target folders and their descendants
+				Expect(folders).To(SatisfyAll(
+					HaveKey("Artist/Album1"),
+					HaveKey("OtherArtist"),
+					HaveKey("OtherArtist/Album3"),
+				))
+
+				// Should not include other folders
+				Expect(folders).ToNot(HaveKey("Artist"))
+				Expect(folders).ToNot(HaveKey("Artist/Album2"))
+				Expect(folders).ToNot(HaveKey("Artist/Album2/Sub"))
+			})
+
+			It("should skip non-existent target folders and preserve them in lastUpdates", func() {
+				// Setup job with lastUpdates for both existing and non-existing folders
+				job.lastUpdates = map[string]model.FolderUpdateInfo{
+					model.FolderID(job.lib, "Artist/Album1"):             {},
+					model.FolderID(job.lib, "NonExistent/DeletedFolder"): {},
+					model.FolderID(job.lib, "OtherArtist/Album3"):        {},
 				}
-			},
+
-			Entry("with symlinks enabled", true, 7),
+				// Try to scan existing folder and non-existing folder
-			Entry("with symlinks disabled", false, 6),
+				results, err := walkDirTree(ctx, job, "Artist/Album1", "NonExistent/DeletedFolder")
-		)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Collect results
+				folders := map[string]struct{}{}
+				for folder := range results {
+					folders[folder.path] = struct{}{}
+				}
+
+				// Should only include the existing folder
+				Expect(folders).To(HaveKey("Artist/Album1"))
+				Expect(folders).ToNot(HaveKey("NonExistent/DeletedFolder"))
+
+				// The non-existent folder should still be in lastUpdates (not removed by popLastUpdate)
+				Expect(job.lastUpdates).To(HaveKey(model.FolderID(job.lib, "NonExistent/DeletedFolder")))
+
+				// The existing folder should have been removed from lastUpdates
+				Expect(job.lastUpdates).ToNot(HaveKey(model.FolderID(job.lib, "Artist/Album1")))
+
+				// Folders not in targets should remain in lastUpdates
+				Expect(job.lastUpdates).To(HaveKey(model.FolderID(job.lib, "OtherArtist/Album3")))
+			})
+		})
 	})
 
 	Describe("helper functions", func() {

scanner/watcher.go

@@ -24,9 +24,9 @@ type Watcher interface {
 type watcher struct {
 	mainCtx         context.Context
 	ds              model.DataStore
-	scanner         Scanner
+	scanner         model.Scanner
 	triggerWait     time.Duration
-	watcherNotify   chan model.Library
+	watcherNotify   chan scanNotification
 	libraryWatchers map[int]*libraryWatcherInstance
 	mu              sync.RWMutex
 }
@@ -36,14 +36,19 @@ type libraryWatcherInstance struct {
 	cancel  context.CancelFunc
 }
 
+type scanNotification struct {
+	Library    *model.Library
+	FolderPath string
+}
+
 // GetWatcher returns the watcher singleton
-func GetWatcher(ds model.DataStore, s Scanner) Watcher {
+func GetWatcher(ds model.DataStore, s model.Scanner) Watcher {
 	return singleton.GetInstance(func() *watcher {
 		return &watcher{
 			ds:              ds,
 			scanner:         s,
 			triggerWait:     conf.Server.Scanner.WatcherWait,
-			watcherNotify:   make(chan model.Library, 1),
+			watcherNotify:   make(chan scanNotification, 1),
 			libraryWatchers: make(map[int]*libraryWatcherInstance),
 		}
 	})
@@ -68,11 +73,11 @@ func (w *watcher) Run(ctx context.Context) error {
 	// Main scan triggering loop
 	trigger := time.NewTimer(w.triggerWait)
 	trigger.Stop()
-	waiting := false
+	targets := make(map[model.ScanTarget]struct{})
 	for {
 		select {
 		case <-trigger.C:
-			log.Info("Watcher: Triggering scan")
+			log.Info("Watcher: Triggering scan for changed folders", "numTargets", len(targets))
 			status, err := w.scanner.Status(ctx)
 			if err != nil {
 				log.Error(ctx, "Watcher: Error retrieving Scanner status", err)
@@ -83,9 +88,23 @@ func (w *watcher) Run(ctx context.Context) error {
 				trigger.Reset(w.triggerWait * 3)
 				continue
 			}
-			waiting = false
+
+			// Convert targets map to slice
+			targetSlice := make([]model.ScanTarget, 0, len(targets))
+			for target := range targets {
+				targetSlice = append(targetSlice, target)
+			}
+
+			// Clear targets for next batch
+			targets = make(map[model.ScanTarget]struct{})
+
 			go func() {
-				_, err := w.scanner.ScanAll(ctx, false)
+				var err error
+				if conf.Server.DevSelectiveWatcher {
+					_, err = w.scanner.ScanFolders(ctx, false, targetSlice)
+				} else {
+					_, err = w.scanner.ScanAll(ctx, false)
+				}
 				if err != nil {
 					log.Error(ctx, "Watcher: Error scanning", err)
 				} else {
@@ -102,13 +121,20 @@ func (w *watcher) Run(ctx context.Context) error {
 			w.libraryWatchers = make(map[int]*libraryWatcherInstance)
 			w.mu.Unlock()
 			return nil
-		case lib := <-w.watcherNotify:
+		case notification := <-w.watcherNotify:
-			if !waiting {
+			lib := notification.Library
-				log.Debug(ctx, "Watcher: Detected changes. Waiting for more changes before triggering scan",
+			folderPath := notification.FolderPath
-					"libraryID", lib.ID, "name", lib.Name, "path", lib.Path)
+
-				waiting = true
+			// If already scheduled for scan, skip
+			target := model.ScanTarget{LibraryID: lib.ID, FolderPath: folderPath}
+			if _, exists := targets[target]; exists {
+				continue
 			}
+			targets[target] = struct{}{}
 			trigger.Reset(w.triggerWait)
+
+			log.Debug(ctx, "Watcher: Detected changes. Waiting for more changes before triggering scan",
+				"libraryID", lib.ID, "name", lib.Name, "path", lib.Path, "folderPath", folderPath)
 		}
 	}
 }
@@ -199,13 +225,18 @@ func (w *watcher) watchLibrary(ctx context.Context, lib *model.Library) error {
 
 	log.Info(ctx, "Watcher started for library", "libraryID", lib.ID, "name", lib.Name, "path", lib.Path, "absoluteLibPath", absLibPath)
 
+	return w.processLibraryEvents(ctx, lib, fsys, c, absLibPath)
+}
+
+// processLibraryEvents processes filesystem events for a library.
+func (w *watcher) processLibraryEvents(ctx context.Context, lib *model.Library, fsys storage.MusicFS, events <-chan string, absLibPath string) error {
 	for {
 		select {
 		case <-ctx.Done():
 			log.Debug(ctx, "Watcher stopped due to context cancellation", "libraryID", lib.ID, "name", lib.Name)
 			return nil
-		case path := <-c:
+		case path := <-events:
-			path, err = filepath.Rel(absLibPath, path)
+			path, err := filepath.Rel(absLibPath, path)
 			if err != nil {
 				log.Error(ctx, "Error getting relative path", "libraryID", lib.ID, "absolutePath", absLibPath, "path", path, err)
 				continue
@@ -215,12 +246,27 @@ func (w *watcher) watchLibrary(ctx context.Context, lib *model.Library) error {
 				log.Trace(ctx, "Ignoring change", "libraryID", lib.ID, "path", path)
 				continue
 			}
-
 			log.Trace(ctx, "Detected change", "libraryID", lib.ID, "path", path, "absoluteLibPath", absLibPath)
 
+			// Check if the original path (before resolution) matches .ndignore patterns
+			// This is crucial for deleted folders - if a deleted folder matches .ndignore,
+			// we should ignore it BEFORE resolveFolderPath walks up to the parent
+			if w.shouldIgnoreFolderPath(ctx, fsys, path) {
+				log.Debug(ctx, "Ignoring change matching .ndignore pattern", "libraryID", lib.ID, "path", path)
+				continue
+			}
+
+			// Find the folder to scan - validate path exists as directory, walk up if needed
+			folderPath := resolveFolderPath(fsys, path)
+			// Double-check after resolution in case the resolved path is different and also matches patterns
+			if folderPath != path && w.shouldIgnoreFolderPath(ctx, fsys, folderPath) {
+				log.Trace(ctx, "Ignoring change in folder matching .ndignore pattern", "libraryID", lib.ID, "folderPath", folderPath)
+				continue
+			}
+
 			// Notify the main watcher of changes
 			select {
-			case w.watcherNotify <- *lib:
+			case w.watcherNotify <- scanNotification{Library: lib, FolderPath: folderPath}:
 			default:
 				// Channel is full, notification already pending
 			}
@@ -228,6 +274,47 @@ func (w *watcher) watchLibrary(ctx context.Context, lib *model.Library) error {
 	}
 }
 
+// resolveFolderPath takes a path (which may be a file or directory) and returns
+// the folder path to scan. If the path is a file, it walks up to find the parent
+// directory. Returns empty string if the path should scan the library root.
+func resolveFolderPath(fsys fs.FS, path string) string {
+	// Handle root paths immediately
+	if path == "." || path == "" {
+		return ""
+	}
+
+	folderPath := path
+	for {
+		info, err := fs.Stat(fsys, folderPath)
+		if err == nil && info.IsDir() {
+			// Found a valid directory
+			return folderPath
+		}
+		if folderPath == "." || folderPath == "" {
+			// Reached root, scan entire library
+			return ""
+		}
+		// Walk up the tree
+		dir, _ := filepath.Split(folderPath)
+		if dir == "" || dir == "." {
+			return ""
+		}
+		// Remove trailing slash
+		folderPath = filepath.Clean(dir)
+	}
+}
+
+// shouldIgnoreFolderPath checks if the given folderPath should be ignored based on .ndignore patterns
+// in the library. It pushes all parent folders onto the IgnoreChecker stack before checking.
+func (w *watcher) shouldIgnoreFolderPath(ctx context.Context, fsys storage.MusicFS, folderPath string) bool {
+	checker := newIgnoreChecker(fsys)
+	err := checker.PushAllParents(ctx, folderPath)
+	if err != nil {
+		log.Warn(ctx, "Watcher: Error pushing ignore patterns for folder", "path", folderPath, err)
+	}
+	return checker.ShouldIgnore(ctx, folderPath)
+}
+
 func isIgnoredPath(_ context.Context, _ fs.FS, path string) bool {
 	baseDir, name := filepath.Split(path)
 	switch {

scanner/watcher_test.go

@@ -0,0 +1,491 @@
+package scanner
+
+import (
+	"context"
+	"io/fs"
+	"path/filepath"
+	"testing/fstest"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Watcher", func() {
+	var ctx context.Context
+	var cancel context.CancelFunc
+	var mockScanner *tests.MockScanner
+	var mockDS *tests.MockDataStore
+	var w *watcher
+	var lib *model.Library
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.Scanner.WatcherWait = 50 * time.Millisecond // Short wait for tests
+
+		ctx, cancel = context.WithCancel(context.Background())
+		DeferCleanup(cancel)
+
+		lib = &model.Library{
+			ID:   1,
+			Name: "Test Library",
+			Path: "/test/library",
+		}
+
+		// Set up mocks
+		mockScanner = tests.NewMockScanner()
+		mockDS = &tests.MockDataStore{}
+		mockLibRepo := &tests.MockLibraryRepo{}
+		mockLibRepo.SetData(model.Libraries{*lib})
+		mockDS.MockedLibrary = mockLibRepo
+
+		// Create a new watcher instance (not singleton) for testing
+		w = &watcher{
+			ds:              mockDS,
+			scanner:         mockScanner,
+			triggerWait:     conf.Server.Scanner.WatcherWait,
+			watcherNotify:   make(chan scanNotification, 10),
+			libraryWatchers: make(map[int]*libraryWatcherInstance),
+			mainCtx:         ctx,
+		}
+	})
+
+	Describe("Target Collection and Deduplication", func() {
+		BeforeEach(func() {
+			// Start watcher in background
+			go func() {
+				_ = w.Run(ctx)
+			}()
+
+			// Give watcher time to initialize
+			time.Sleep(10 * time.Millisecond)
+		})
+
+		It("creates separate targets for different folders", func() {
+			// Send notifications for different folders
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1"}
+			time.Sleep(10 * time.Millisecond)
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist2"}
+
+			// Wait for watcher to process and trigger scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Verify two targets
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(2))
+
+			// Extract folder paths
+			folderPaths := make(map[string]bool)
+			for _, target := range calls[0].Targets {
+				Expect(target.LibraryID).To(Equal(1))
+				folderPaths[target.FolderPath] = true
+			}
+			Expect(folderPaths).To(HaveKey("artist1"))
+			Expect(folderPaths).To(HaveKey("artist2"))
+		})
+
+		It("handles different folder paths correctly", func() {
+			// Send notification for nested folder
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1/album1"}
+
+			// Wait for watcher to process and trigger scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Verify the target
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(1))
+			Expect(calls[0].Targets[0].FolderPath).To(Equal("artist1/album1"))
+		})
+
+		It("deduplicates folder and file within same folder", func() {
+			// Send notification for a folder
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1/album1"}
+			time.Sleep(10 * time.Millisecond)
+			// Send notification for same folder (as if file change was detected there)
+			// In practice, watchLibrary() would walk up from file path to folder
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1/album1"}
+			time.Sleep(10 * time.Millisecond)
+			// Send another for same folder
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1/album1"}
+
+			// Wait for watcher to process and trigger scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Verify only one target despite multiple file/folder changes
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(1))
+			Expect(calls[0].Targets[0].FolderPath).To(Equal("artist1/album1"))
+		})
+	})
+
+	Describe("Timer Behavior", func() {
+		BeforeEach(func() {
+			// Start watcher in background
+			go func() {
+				_ = w.Run(ctx)
+			}()
+
+			// Give watcher time to initialize
+			time.Sleep(10 * time.Millisecond)
+		})
+
+		It("resets timer on each change (debouncing)", func() {
+			// Send first notification
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1"}
+
+			// Wait a bit less than half the watcher wait time to ensure timer doesn't fire
+			time.Sleep(20 * time.Millisecond)
+
+			// No scan should have been triggered yet
+			Expect(mockScanner.GetScanFoldersCallCount()).To(Equal(0))
+
+			// Send another notification (resets timer)
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1"}
+
+			// Wait a bit less than half the watcher wait time again
+			time.Sleep(20 * time.Millisecond)
+
+			// Still no scan
+			Expect(mockScanner.GetScanFoldersCallCount()).To(Equal(0))
+
+			// Wait for full timer to expire after last notification (plus margin)
+			time.Sleep(60 * time.Millisecond)
+
+			// Now scan should have been triggered
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 100*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+		})
+
+		It("triggers scan after quiet period", func() {
+			// Send notification
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1"}
+
+			// No scan immediately
+			Expect(mockScanner.GetScanFoldersCallCount()).To(Equal(0))
+
+			// Wait for quiet period
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+		})
+	})
+
+	Describe("Empty and Root Paths", func() {
+		BeforeEach(func() {
+			// Start watcher in background
+			go func() {
+				_ = w.Run(ctx)
+			}()
+
+			// Give watcher time to initialize
+			time.Sleep(10 * time.Millisecond)
+		})
+
+		It("handles empty folder path (library root)", func() {
+			// Send notification with empty folder path
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: ""}
+
+			// Wait for scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Should scan the library root
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(1))
+			Expect(calls[0].Targets[0].FolderPath).To(Equal(""))
+		})
+
+		It("deduplicates empty and dot paths", func() {
+			// Send notifications with empty and dot paths
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: ""}
+			time.Sleep(10 * time.Millisecond)
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: ""}
+
+			// Wait for scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Should have only one target
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(1))
+		})
+	})
+
+	Describe("Multiple Libraries", func() {
+		var lib2 *model.Library
+
+		BeforeEach(func() {
+			// Create second library
+			lib2 = &model.Library{
+				ID:   2,
+				Name: "Test Library 2",
+				Path: "/test/library2",
+			}
+
+			mockLibRepo := mockDS.MockedLibrary.(*tests.MockLibraryRepo)
+			mockLibRepo.SetData(model.Libraries{*lib, *lib2})
+
+			// Start watcher in background
+			go func() {
+				_ = w.Run(ctx)
+			}()
+
+			// Give watcher time to initialize
+			time.Sleep(10 * time.Millisecond)
+		})
+
+		It("creates separate targets for different libraries", func() {
+			// Send notifications for both libraries
+			w.watcherNotify <- scanNotification{Library: lib, FolderPath: "artist1"}
+			time.Sleep(10 * time.Millisecond)
+			w.watcherNotify <- scanNotification{Library: lib2, FolderPath: "artist2"}
+
+			// Wait for scan
+			Eventually(func() int {
+				return mockScanner.GetScanFoldersCallCount()
+			}, 200*time.Millisecond, 10*time.Millisecond).Should(Equal(1))
+
+			// Verify two targets for different libraries
+			calls := mockScanner.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].Targets).To(HaveLen(2))
+
+			// Verify library IDs are different
+			libraryIDs := make(map[int]bool)
+			for _, target := range calls[0].Targets {
+				libraryIDs[target.LibraryID] = true
+			}
+			Expect(libraryIDs).To(HaveKey(1))
+			Expect(libraryIDs).To(HaveKey(2))
+		})
+	})
+
+	Describe(".ndignore handling", func() {
+		var ctx context.Context
+		var cancel context.CancelFunc
+		var w *watcher
+		var mockFS *mockMusicFS
+		var lib *model.Library
+		var eventChan chan string
+		var absLibPath string
+
+		BeforeEach(func() {
+			ctx, cancel = context.WithCancel(GinkgoT().Context())
+			DeferCleanup(cancel)
+
+			// Set up library
+			var err error
+			absLibPath, err = filepath.Abs(".")
+			Expect(err).NotTo(HaveOccurred())
+
+			lib = &model.Library{
+				ID:   1,
+				Name: "Test Library",
+				Path: absLibPath,
+			}
+
+			// Create watcher with notification channel
+			w = &watcher{
+				watcherNotify: make(chan scanNotification, 10),
+			}
+
+			eventChan = make(chan string, 10)
+		})
+
+		// Helper to send an event - converts relative path to absolute
+		sendEvent := func(relativePath string) {
+			path := filepath.Join(absLibPath, relativePath)
+			eventChan <- path
+		}
+
+		// Helper to start the real event processing loop
+		startEventProcessing := func() {
+			go func() {
+				defer GinkgoRecover()
+				// Call the actual processLibraryEvents method - testing the real implementation!
+				_ = w.processLibraryEvents(ctx, lib, mockFS, eventChan, absLibPath)
+			}()
+		}
+
+		Context("when a folder matching .ndignore is deleted", func() {
+			BeforeEach(func() {
+				// Create filesystem with .ndignore containing _TEMP pattern
+				// The deleted folder (_TEMP) will NOT exist in the filesystem
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"rock":                       &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/.ndignore":             &fstest.MapFile{Data: []byte("_TEMP\n")},
+						"rock/valid_album":           &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/valid_album/track.mp3": &fstest.MapFile{Data: []byte("audio")},
+					},
+				}
+			})
+
+			It("should NOT send scan notification when deleted folder matches .ndignore", func() {
+				startEventProcessing()
+
+				// Simulate deletion event for rock/_TEMP
+				sendEvent("rock/_TEMP")
+
+				// Wait a bit to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should have been sent
+				Consistently(eventChan, 100*time.Millisecond).Should(BeEmpty())
+			})
+
+			It("should send scan notification for valid folder deletion", func() {
+				startEventProcessing()
+
+				// Simulate deletion event for rock/other_folder (not in .ndignore and doesn't exist)
+				// Since it doesn't exist in mockFS, resolveFolderPath will walk up to "rock"
+				sendEvent("rock/other_folder")
+
+				// Should receive notification for parent folder
+				Eventually(w.watcherNotify, 200*time.Millisecond).Should(Receive(Equal(scanNotification{
+					Library:    lib,
+					FolderPath: "rock",
+				})))
+			})
+		})
+
+		Context("with nested folder patterns", func() {
+			BeforeEach(func() {
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"music":             &fstest.MapFile{Mode: fs.ModeDir},
+						"music/.ndignore":   &fstest.MapFile{Data: []byte("**/temp\n**/cache\n")},
+						"music/rock":        &fstest.MapFile{Mode: fs.ModeDir},
+						"music/rock/artist": &fstest.MapFile{Mode: fs.ModeDir},
+					},
+				}
+			})
+
+			It("should NOT send notification when nested ignored folder is deleted", func() {
+				startEventProcessing()
+
+				// Simulate deletion of music/rock/artist/temp (matches **/temp)
+				sendEvent("music/rock/artist/temp")
+
+				// Wait to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should be sent
+				Expect(w.watcherNotify).To(BeEmpty(), "Expected no scan notification for nested ignored folder")
+			})
+
+			It("should send notification for non-ignored nested folder", func() {
+				startEventProcessing()
+
+				// Simulate change in music/rock/artist (doesn't match any pattern)
+				sendEvent("music/rock/artist")
+
+				// Should receive notification
+				Eventually(w.watcherNotify, 200*time.Millisecond).Should(Receive(Equal(scanNotification{
+					Library:    lib,
+					FolderPath: "music/rock/artist",
+				})))
+			})
+		})
+
+		Context("with file events in ignored folders", func() {
+			BeforeEach(func() {
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"rock":           &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/.ndignore": &fstest.MapFile{Data: []byte("_TEMP\n")},
+					},
+				}
+			})
+
+			It("should NOT send notification for file changes in ignored folders", func() {
+				startEventProcessing()
+
+				// Simulate file change in rock/_TEMP/file.mp3
+				sendEvent("rock/_TEMP/file.mp3")
+
+				// Wait to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should be sent
+				Expect(w.watcherNotify).To(BeEmpty(), "Expected no scan notification for file in ignored folder")
+			})
+		})
+	})
+})
+
+var _ = Describe("resolveFolderPath", func() {
+	var mockFS fs.FS
+
+	BeforeEach(func() {
+		// Create a mock filesystem with some directories and files
+		mockFS = fstest.MapFS{
+			"artist1":                   &fstest.MapFile{Mode: fs.ModeDir},
+			"artist1/album1":            &fstest.MapFile{Mode: fs.ModeDir},
+			"artist1/album1/track1.mp3": &fstest.MapFile{Data: []byte("audio")},
+			"artist1/album1/track2.mp3": &fstest.MapFile{Data: []byte("audio")},
+			"artist1/album2":            &fstest.MapFile{Mode: fs.ModeDir},
+			"artist1/album2/song.flac":  &fstest.MapFile{Data: []byte("audio")},
+			"artist2":                   &fstest.MapFile{Mode: fs.ModeDir},
+			"artist2/cover.jpg":         &fstest.MapFile{Data: []byte("image")},
+		}
+	})
+
+	It("returns directory path when given a directory", func() {
+		result := resolveFolderPath(mockFS, "artist1/album1")
+		Expect(result).To(Equal("artist1/album1"))
+	})
+
+	It("walks up to parent directory when given a file path", func() {
+		result := resolveFolderPath(mockFS, "artist1/album1/track1.mp3")
+		Expect(result).To(Equal("artist1/album1"))
+	})
+
+	It("walks up multiple levels if needed", func() {
+		result := resolveFolderPath(mockFS, "artist1/album1/nonexistent/file.mp3")
+		Expect(result).To(Equal("artist1/album1"))
+	})
+
+	It("returns empty string for non-existent paths at root", func() {
+		result := resolveFolderPath(mockFS, "nonexistent/path/file.mp3")
+		Expect(result).To(Equal(""))
+	})
+
+	It("returns empty string for dot path", func() {
+		result := resolveFolderPath(mockFS, ".")
+		Expect(result).To(Equal(""))
+	})
+
+	It("returns empty string for empty path", func() {
+		result := resolveFolderPath(mockFS, "")
+		Expect(result).To(Equal(""))
+	})
+
+	It("handles nested file paths correctly", func() {
+		result := resolveFolderPath(mockFS, "artist1/album2/song.flac")
+		Expect(result).To(Equal("artist1/album2"))
+	})
+
+	It("resolves to top-level directory", func() {
+		result := resolveFolderPath(mockFS, "artist2/cover.jpg")
+		Expect(result).To(Equal("artist2"))
+	})
+})

server/subsonic/api.go

@@ -18,7 +18,6 @@ import (
 	"github.com/navidrome/navidrome/core/scrobbler"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/server"
 	"github.com/navidrome/navidrome/server/events"
 	"github.com/navidrome/navidrome/server/subsonic/responses"
@@ -39,7 +38,7 @@ type Router struct {
 	players   core.Players
 	provider  external.Provider
 	playlists core.Playlists
-	scanner   scanner.Scanner
+	scanner   model.Scanner
 	broker    events.Broker
 	scrobbler scrobbler.PlayTracker
 	share     core.Share
@@ -48,7 +47,7 @@ type Router struct {
 }
 
 func New(ds model.DataStore, artwork artwork.Artwork, streamer core.MediaStreamer, archiver core.Archiver,
-	players core.Players, provider external.Provider, scanner scanner.Scanner, broker events.Broker,
+	players core.Players, provider external.Provider, scanner model.Scanner, broker events.Broker,
 	playlists core.Playlists, scrobbler scrobbler.PlayTracker, share core.Share, playback playback.PlaybackServer,
 	metrics metrics.Metrics,
 ) *Router {

server/subsonic/library_scanning.go

@@ -1,10 +1,13 @@
 package subsonic
 
 import (
+	"fmt"
 	"net/http"
+	"slices"
 	"time"
 
 	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/request"
 	"github.com/navidrome/navidrome/server/subsonic/responses"
 	"github.com/navidrome/navidrome/utils/req"
@@ -44,15 +47,56 @@ func (api *Router) StartScan(r *http.Request) (*responses.Subsonic, error) {
 	p := req.Params(r)
 	fullScan := p.BoolOr("fullScan", false)
 
+	// Parse optional target parameters for selective scanning
+	var targets []model.ScanTarget
+	if targetParams, err := p.Strings("target"); err == nil && len(targetParams) > 0 {
+		targets, err = model.ParseTargets(targetParams)
+		if err != nil {
+			return nil, newError(responses.ErrorGeneric, fmt.Sprintf("Invalid target parameter: %v", err))
+		}
+
+		// Validate all libraries in targets exist and user has access to them
+		userLibraries, err := api.ds.User(ctx).GetUserLibraries(loggedUser.ID)
+		if err != nil {
+			return nil, newError(responses.ErrorGeneric, "Internal error")
+		}
+
+		// Check each target library
+		for _, target := range targets {
+			if !slices.ContainsFunc(userLibraries, func(lib model.Library) bool { return lib.ID == target.LibraryID }) {
+				return nil, newError(responses.ErrorDataNotFound, fmt.Sprintf("Library with ID %d not found", target.LibraryID))
+			}
+		}
+
+		// Special case: if single library with empty path and it's the only library in DB, call ScanAll
+		if len(targets) == 1 && targets[0].FolderPath == "" {
+			allLibs, err := api.ds.Library(ctx).GetAll()
+			if err != nil {
+				return nil, newError(responses.ErrorGeneric, "Internal error")
+			}
+			if len(allLibs) == 1 {
+				targets = nil // This will trigger ScanAll below
+			}
+		}
+	}
+
 	go func() {
 		start := time.Now()
-		log.Info(ctx, "Triggering manual scan", "fullScan", fullScan, "user", loggedUser.UserName)
+		var err error
-		_, err := api.scanner.ScanAll(ctx, fullScan)
+
+		if len(targets) > 0 {
+			log.Info(ctx, "Triggering on-demand scan", "fullScan", fullScan, "targets", len(targets), "user", loggedUser.UserName)
+			_, err = api.scanner.ScanFolders(ctx, fullScan, targets)
+		} else {
+			log.Info(ctx, "Triggering on-demand scan", "fullScan", fullScan, "user", loggedUser.UserName)
+			_, err = api.scanner.ScanAll(ctx, fullScan)
+		}
+
 		if err != nil {
 			log.Error(ctx, "Error scanning", err)
 			return
 		}
-		log.Info(ctx, "Manual scan complete", "user", loggedUser.UserName, "elapsed", time.Since(start))
+		log.Info(ctx, "On-demand scan complete", "user", loggedUser.UserName, "elapsed", time.Since(start))
 	}()
 
 	return api.GetScanStatus(r)

server/subsonic/library_scanning_test.go

@@ -0,0 +1,396 @@
+package subsonic
+
+import (
+	"context"
+	"errors"
+	"net/http/httptest"
+
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/server/subsonic/responses"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("LibraryScanning", func() {
+	var api *Router
+	var ms *tests.MockScanner
+
+	BeforeEach(func() {
+		ms = tests.NewMockScanner()
+		api = &Router{scanner: ms}
+	})
+
+	Describe("StartScan", func() {
+		It("requires admin authentication", func() {
+			// Create non-admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "user-id",
+				IsAdmin: false,
+			})
+
+			// Create request
+			r := httptest.NewRequest("GET", "/rest/startScan", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should return authorization error
+			Expect(err).To(HaveOccurred())
+			Expect(response).To(BeNil())
+			var subErr subError
+			ok := errors.As(err, &subErr)
+			Expect(ok).To(BeTrue())
+			Expect(subErr.code).To(Equal(responses.ErrorAuthorizationFail))
+		})
+
+		It("triggers a full scan with no parameters", func() {
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with no parameters
+			r := httptest.NewRequest("GET", "/rest/startScan", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanAll was called (eventually, since it's in a goroutine)
+			Eventually(func() int {
+				return ms.GetScanAllCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanAllCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].FullScan).To(BeFalse())
+		})
+
+		It("triggers a full scan with fullScan=true", func() {
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with fullScan parameter
+			r := httptest.NewRequest("GET", "/rest/startScan?fullScan=true", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanAll was called with fullScan=true
+			Eventually(func() int {
+				return ms.GetScanAllCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanAllCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].FullScan).To(BeTrue())
+		})
+
+		It("triggers a selective scan with single target parameter", func() {
+			// Setup mocks
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1, 2})
+			mockDS := &tests.MockDataStore{MockedUser: mockUserRepo}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with single target parameter
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1:Music/Rock", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanFolders was called with correct targets
+			Eventually(func() int {
+				return ms.GetScanFoldersCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			targets := calls[0].Targets
+			Expect(targets).To(HaveLen(1))
+			Expect(targets[0].LibraryID).To(Equal(1))
+			Expect(targets[0].FolderPath).To(Equal("Music/Rock"))
+		})
+
+		It("triggers a selective scan with multiple target parameters", func() {
+			// Setup mocks
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1, 2})
+			mockDS := &tests.MockDataStore{MockedUser: mockUserRepo}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with multiple target parameters
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1:Music/Reggae&target=2:Classical/Bach", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanFolders was called with correct targets
+			Eventually(func() int {
+				return ms.GetScanFoldersCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			targets := calls[0].Targets
+			Expect(targets).To(HaveLen(2))
+			Expect(targets[0].LibraryID).To(Equal(1))
+			Expect(targets[0].FolderPath).To(Equal("Music/Reggae"))
+			Expect(targets[1].LibraryID).To(Equal(2))
+			Expect(targets[1].FolderPath).To(Equal("Classical/Bach"))
+		})
+
+		It("triggers a selective full scan with target and fullScan parameters", func() {
+			// Setup mocks
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1})
+			mockDS := &tests.MockDataStore{MockedUser: mockUserRepo}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with target and fullScan parameters
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1:Music/Jazz&fullScan=true", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanFolders was called with fullScan=true
+			Eventually(func() int {
+				return ms.GetScanFoldersCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			Expect(calls[0].FullScan).To(BeTrue())
+			targets := calls[0].Targets
+			Expect(targets).To(HaveLen(1))
+		})
+
+		It("returns error for invalid target format", func() {
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with invalid target format (missing colon)
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1MusicRock", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should return error
+			Expect(err).To(HaveOccurred())
+			Expect(response).To(BeNil())
+			var subErr subError
+			ok := errors.As(err, &subErr)
+			Expect(ok).To(BeTrue())
+			Expect(subErr.code).To(Equal(responses.ErrorGeneric))
+		})
+
+		It("returns error for invalid library ID in target", func() {
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with invalid library ID
+			r := httptest.NewRequest("GET", "/rest/startScan?target=0:Music/Rock", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should return error
+			Expect(err).To(HaveOccurred())
+			Expect(response).To(BeNil())
+			var subErr subError
+			ok := errors.As(err, &subErr)
+			Expect(ok).To(BeTrue())
+			Expect(subErr.code).To(Equal(responses.ErrorGeneric))
+		})
+
+		It("returns error when library does not exist", func() {
+			// Setup mocks - user has access to library 1 and 2 only
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1, 2})
+			mockDS := &tests.MockDataStore{MockedUser: mockUserRepo}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with library ID that doesn't exist
+			r := httptest.NewRequest("GET", "/rest/startScan?target=999:Music/Rock", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should return ErrorDataNotFound
+			Expect(err).To(HaveOccurred())
+			Expect(response).To(BeNil())
+			var subErr subError
+			ok := errors.As(err, &subErr)
+			Expect(ok).To(BeTrue())
+			Expect(subErr.code).To(Equal(responses.ErrorDataNotFound))
+		})
+
+		It("calls ScanAll when single library with empty path and only one library exists", func() {
+			// Setup mocks - single library in DB
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1})
+			mockLibraryRepo := &tests.MockLibraryRepo{}
+			mockLibraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Music Library", Path: "/music"},
+			})
+			mockDS := &tests.MockDataStore{
+				MockedUser:    mockUserRepo,
+				MockedLibrary: mockLibraryRepo,
+			}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with single library and empty path
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1:", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanAll was called instead of ScanFolders
+			Eventually(func() int {
+				return ms.GetScanAllCallCount()
+			}).Should(BeNumerically(">", 0))
+			Expect(ms.GetScanFoldersCallCount()).To(Equal(0))
+		})
+
+		It("calls ScanFolders when single library with empty path but multiple libraries exist", func() {
+			// Setup mocks - multiple libraries in DB
+			mockUserRepo := tests.CreateMockUserRepo()
+			_ = mockUserRepo.SetUserLibraries("admin-id", []int{1, 2})
+			mockLibraryRepo := &tests.MockLibraryRepo{}
+			mockLibraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Music Library", Path: "/music"},
+				{ID: 2, Name: "Audiobooks", Path: "/audiobooks"},
+			})
+			mockDS := &tests.MockDataStore{
+				MockedUser:    mockUserRepo,
+				MockedLibrary: mockLibraryRepo,
+			}
+			api.ds = mockDS
+
+			// Create admin user
+			ctx := request.WithUser(context.Background(), model.User{
+				ID:      "admin-id",
+				IsAdmin: true,
+			})
+
+			// Create request with single library and empty path
+			r := httptest.NewRequest("GET", "/rest/startScan?target=1:", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.StartScan(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+
+			// Verify ScanFolders was called (not ScanAll)
+			Eventually(func() int {
+				return ms.GetScanFoldersCallCount()
+			}).Should(BeNumerically(">", 0))
+			calls := ms.GetScanFoldersCalls()
+			Expect(calls).To(HaveLen(1))
+			targets := calls[0].Targets
+			Expect(targets).To(HaveLen(1))
+			Expect(targets[0].LibraryID).To(Equal(1))
+			Expect(targets[0].FolderPath).To(Equal(""))
+		})
+	})
+
+	Describe("GetScanStatus", func() {
+		It("returns scan status", func() {
+			// Setup mock scanner status
+			ms.SetStatusResponse(&model.ScannerStatus{
+				Scanning:    false,
+				Count:       100,
+				FolderCount: 10,
+			})
+
+			// Create request
+			ctx := context.Background()
+			r := httptest.NewRequest("GET", "/rest/getScanStatus", nil)
+			r = r.WithContext(ctx)
+
+			// Call endpoint
+			response, err := api.GetScanStatus(r)
+
+			// Should succeed
+			Expect(err).ToNot(HaveOccurred())
+			Expect(response).ToNot(BeNil())
+			Expect(response.ScanStatus).ToNot(BeNil())
+			Expect(response.ScanStatus.Scanning).To(BeFalse())
+			Expect(response.ScanStatus.Count).To(Equal(int64(100)))
+			Expect(response.ScanStatus.FolderCount).To(Equal(int64(10)))
+		})
+	})
+})

tests/mock_data_store.go

@@ -28,6 +28,10 @@ type MockDataStore struct {
 	MockedRadio          model.RadioRepository
 	scrobbleBufferMu     sync.Mutex
 	repoMu               sync.Mutex
+
+	// GC tracking
+	GCCalled bool
+	GCError  error
 }
 
 func (db *MockDataStore) Library(ctx context.Context) model.LibraryRepository {
@@ -258,6 +262,10 @@ func (db *MockDataStore) Resource(ctx context.Context, m any) model.ResourceRepo
 	}
 }
 
-func (db *MockDataStore) GC(context.Context) error {
+func (db *MockDataStore) GC(context.Context, ...int) error {
+	db.GCCalled = true
+	if db.GCError != nil {
+		return db.GCError
+	}
 	return nil
 }

tests/mock_scanner.go

@@ -0,0 +1,120 @@
+package tests
+
+import (
+	"context"
+	"sync"
+
+	"github.com/navidrome/navidrome/model"
+)
+
+// MockScanner implements scanner.Scanner for testing with proper synchronization
+type MockScanner struct {
+	mu               sync.Mutex
+	scanAllCalls     []ScanAllCall
+	scanFoldersCalls []ScanFoldersCall
+	scanningStatus   bool
+	statusResponse   *model.ScannerStatus
+}
+
+type ScanAllCall struct {
+	FullScan bool
+}
+
+type ScanFoldersCall struct {
+	FullScan bool
+	Targets  []model.ScanTarget
+}
+
+func NewMockScanner() *MockScanner {
+	return &MockScanner{
+		scanAllCalls:     make([]ScanAllCall, 0),
+		scanFoldersCalls: make([]ScanFoldersCall, 0),
+	}
+}
+
+func (m *MockScanner) ScanAll(_ context.Context, fullScan bool) ([]string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	m.scanAllCalls = append(m.scanAllCalls, ScanAllCall{FullScan: fullScan})
+
+	return nil, nil
+}
+
+func (m *MockScanner) ScanFolders(_ context.Context, fullScan bool, targets []model.ScanTarget) ([]string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	// Make a copy of targets to avoid race conditions
+	targetsCopy := make([]model.ScanTarget, len(targets))
+	copy(targetsCopy, targets)
+
+	m.scanFoldersCalls = append(m.scanFoldersCalls, ScanFoldersCall{
+		FullScan: fullScan,
+		Targets:  targetsCopy,
+	})
+
+	return nil, nil
+}
+
+func (m *MockScanner) Status(_ context.Context) (*model.ScannerStatus, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.statusResponse != nil {
+		return m.statusResponse, nil
+	}
+
+	return &model.ScannerStatus{
+		Scanning: m.scanningStatus,
+	}, nil
+}
+
+func (m *MockScanner) GetScanAllCallCount() int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return len(m.scanAllCalls)
+}
+
+func (m *MockScanner) GetScanAllCalls() []ScanAllCall {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	// Return a copy to avoid race conditions
+	calls := make([]ScanAllCall, len(m.scanAllCalls))
+	copy(calls, m.scanAllCalls)
+	return calls
+}
+
+func (m *MockScanner) GetScanFoldersCallCount() int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return len(m.scanFoldersCalls)
+}
+
+func (m *MockScanner) GetScanFoldersCalls() []ScanFoldersCall {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	// Return a copy to avoid race conditions
+	calls := make([]ScanFoldersCall, len(m.scanFoldersCalls))
+	copy(calls, m.scanFoldersCalls)
+	return calls
+}
+
+func (m *MockScanner) Reset() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.scanAllCalls = make([]ScanAllCall, 0)
+	m.scanFoldersCalls = make([]ScanFoldersCall, 0)
+}
+
+func (m *MockScanner) SetScanning(scanning bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.scanningStatus = scanning
+}
+
+func (m *MockScanner) SetStatusResponse(status *model.ScannerStatus) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.statusResponse = status
+}

ui/src/i18n/en.json

@@ -302,6 +302,8 @@
       },
       "actions": {
         "scan": "Scan Library",
+        "quickScan": "Quick Scan",
+        "fullScan": "Full Scan",
         "manageUsers": "Manage User Access",
         "viewDetails": "View Details"
       },
@@ -310,6 +312,9 @@
         "updated": "Library updated successfully",
         "deleted": "Library deleted successfully",
         "scanStarted": "Library scan started",
+        "quickScanStarted": "Quick scan started",
+        "fullScanStarted": "Full scan started",
+        "scanError": "Error starting scan. Check logs",
         "scanCompleted": "Library scan completed"
       },
       "validation": {
@@ -600,11 +605,12 @@
   "activity": {
     "title": "Activity",
     "totalScanned": "Total Folders Scanned",
-    "quickScan": "Quick Scan",
+    "quickScan": "Quick",
-    "fullScan": "Full Scan",
+    "fullScan": "Full",
+    "selectiveScan": "Selective",
     "serverUptime": "Server Uptime",
     "serverDown": "OFFLINE",
-    "scanType": "Type",
+    "scanType": "Last Scan",
     "status": "Scan Error",
     "elapsedTime": "Elapsed Time"
   },

ui/src/layout/ActivityPanel.jsx

@@ -113,6 +113,9 @@ const ActivityPanel = () => {
         return translate('activity.fullScan')
       case 'quick':
         return translate('activity.quickScan')
+      case 'full-selective':
+      case 'quick-selective':
+        return translate('activity.selectiveScan')
       default:
         return ''
     }

ui/src/library/LibraryList.jsx

@@ -10,6 +10,8 @@ import {
 } from 'react-admin'
 import { useMediaQuery } from '@material-ui/core'
 import { List, DateField, useResourceRefresh, SizeField } from '../common'
+import LibraryListBulkActions from './LibraryListBulkActions'
+import LibraryListActions from './LibraryListActions'
 
 const LibraryFilter = (props) => (
   <Filter {...props} variant={'outlined'}>
@@ -26,8 +28,9 @@ const LibraryList = (props) => {
       {...props}
       sort={{ field: 'name', order: 'ASC' }}
       exporter={false}
-      bulkActionButtons={false}
+      bulkActionButtons={!isXsmall && <LibraryListBulkActions />}
       filters={<LibraryFilter />}
+      actions={<LibraryListActions />}
     >
       {isXsmall ? (
         <SimpleList

ui/src/library/LibraryListActions.jsx

@@ -0,0 +1,30 @@
+import React, { cloneElement } from 'react'
+import { sanitizeListRestProps, TopToolbar } from 'react-admin'
+import LibraryScanButton from './LibraryScanButton'
+
+const LibraryListActions = ({
+  className,
+  filters,
+  resource,
+  showFilter,
+  displayedFilters,
+  filterValues,
+  ...rest
+}) => {
+  return (
+    <TopToolbar className={className} {...sanitizeListRestProps(rest)}>
+      {filters &&
+        cloneElement(filters, {
+          resource,
+          showFilter,
+          displayedFilters,
+          filterValues,
+          context: 'button',
+        })}
+      <LibraryScanButton fullScan={false} />
+      <LibraryScanButton fullScan={true} />
+    </TopToolbar>
+  )
+}
+
+export default LibraryListActions

ui/src/library/LibraryListBulkActions.jsx

@@ -0,0 +1,11 @@
+import React from 'react'
+import LibraryScanButton from './LibraryScanButton'
+
+const LibraryListBulkActions = (props) => (
+  <>
+    <LibraryScanButton fullScan={false} {...props} />
+    <LibraryScanButton fullScan={true} {...props} />
+  </>
+)
+
+export default LibraryListBulkActions

ui/src/library/LibraryScanButton.jsx

@@ -0,0 +1,77 @@
+import React, { useState } from 'react'
+import PropTypes from 'prop-types'
+import {
+  Button,
+  useNotify,
+  useRefresh,
+  useTranslate,
+  useUnselectAll,
+} from 'react-admin'
+import { useSelector } from 'react-redux'
+import SyncIcon from '@material-ui/icons/Sync'
+import CachedIcon from '@material-ui/icons/Cached'
+import subsonic from '../subsonic'
+
+const LibraryScanButton = ({ fullScan, selectedIds, className }) => {
+  const [loading, setLoading] = useState(false)
+  const notify = useNotify()
+  const refresh = useRefresh()
+  const translate = useTranslate()
+  const unselectAll = useUnselectAll()
+  const scanStatus = useSelector((state) => state.activity.scanStatus)
+
+  const handleClick = async () => {
+    setLoading(true)
+    try {
+      // Build scan options
+      const options = { fullScan }
+
+      // If specific libraries are selected, scan only those
+      // Format: "libraryID:" to scan entire library (no folder path specified)
+      if (selectedIds && selectedIds.length > 0) {
+        options.target = selectedIds.map((id) => `${id}:`)
+      }
+
+      await subsonic.startScan(options)
+      const notificationKey = fullScan
+        ? 'resources.library.notifications.fullScanStarted'
+        : 'resources.library.notifications.quickScanStarted'
+      notify(notificationKey, 'info')
+      refresh()
+
+      // Unselect all items after successful scan
+      unselectAll('library')
+    } catch (error) {
+      notify('resources.library.notifications.scanError', 'warning')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  const isDisabled = loading || scanStatus.scanning
+
+  const label = fullScan
+    ? translate('resources.library.actions.fullScan')
+    : translate('resources.library.actions.quickScan')
+
+  const icon = fullScan ? <CachedIcon /> : <SyncIcon />
+
+  return (
+    <Button
+      onClick={handleClick}
+      disabled={isDisabled}
+      label={label}
+      className={className}
+    >
+      {icon}
+    </Button>
+  )
+}
+
+LibraryScanButton.propTypes = {
+  fullScan: PropTypes.bool.isRequired,
+  selectedIds: PropTypes.array,
+  className: PropTypes.string,
+}
+
+export default LibraryScanButton

ui/src/subsonic/index.js

@@ -23,7 +23,13 @@ const url = (command, id, options) => {
       delete options.ts
     }
     Object.keys(options).forEach((k) => {
-      params.append(k, options[k])
+      const value = options[k]
+      // Handle array parameters by appending each value separately
+      if (Array.isArray(value)) {
+        value.forEach((v) => params.append(k, v))
+      } else {
+        params.append(k, value)
+      }
     })
   }
   return `/rest/${command}?${params.toString()}`

utils/slice/slice.go

@@ -171,3 +171,14 @@ func SeqFunc[I, O any](s []I, f func(I) O) iter.Seq[O] {
 		}
 	}
 }
+
+// Filter returns a new slice containing only the elements of s for which filterFunc returns true
+func Filter[T any](s []T, filterFunc func(T) bool) []T {
+	var result []T
+	for _, item := range s {
+		if filterFunc(item) {
+			result = append(result, item)
+		}
+	}
+	return result
+}

utils/slice/slice_test.go

@@ -172,4 +172,42 @@ var _ = Describe("Slice Utils", func() {
 			Expect(result).To(ConsistOf("2", "4", "6", "8"))
 		})
 	})
+
+	Describe("Filter", func() {
+		It("returns empty slice for an empty input", func() {
+			filterFunc := func(v int) bool { return v > 0 }
+			result := slice.Filter([]int{}, filterFunc)
+			Expect(result).To(BeEmpty())
+		})
+
+		It("returns all elements when filter matches all", func() {
+			filterFunc := func(v int) bool { return v > 0 }
+			result := slice.Filter([]int{1, 2, 3, 4}, filterFunc)
+			Expect(result).To(HaveExactElements(1, 2, 3, 4))
+		})
+
+		It("returns empty slice when filter matches none", func() {
+			filterFunc := func(v int) bool { return v > 10 }
+			result := slice.Filter([]int{1, 2, 3, 4}, filterFunc)
+			Expect(result).To(BeEmpty())
+		})
+
+		It("returns only matching elements", func() {
+			filterFunc := func(v int) bool { return v%2 == 0 }
+			result := slice.Filter([]int{1, 2, 3, 4, 5, 6}, filterFunc)
+			Expect(result).To(HaveExactElements(2, 4, 6))
+		})
+
+		It("works with string slices", func() {
+			filterFunc := func(s string) bool { return len(s) > 3 }
+			result := slice.Filter([]string{"a", "abc", "abcd", "ab", "abcde"}, filterFunc)
+			Expect(result).To(HaveExactElements("abcd", "abcde"))
+		})
+
+		It("preserves order of elements", func() {
+			filterFunc := func(v int) bool { return v%2 == 1 }
+			result := slice.Filter([]int{9, 8, 7, 6, 5, 4, 3, 2, 1}, filterFunc)
+			Expect(result).To(HaveExactElements(9, 7, 5, 3, 1))
+		})
+	})
 })