feat(plugins): add PlaybackReport to scrobbler capability (#5452)

* feat(plugins): add PlaybackReport to Scrobbler interface and all implementations

* feat(plugins): add PlaybackReport worker and dispatch in PlayTracker

* feat(plugins): add PlaybackReportRequest to plugin scrobbler capability

* chore(plugins): regenerate PDK files with PlaybackReport

* feat(plugins): add PlaybackReport to test scrobbler plugin

* feat(plugins): add PlaybackReport to plugin scrobbler adapter

* refactor(plugins): fix double DB fetch in StateStopped and batch getActiveScrobblers

- Hoist mf from scrobble branch so PlaybackReport reuses it instead of
  fetching again from DB
- Call getActiveScrobblers once per drain batch instead of per-entry

* chore(plugins): include generated scrobbler schema with PlaybackReport

* fix(plugins): skip PlaybackReport for plugins that don't export it

Plugins detected as scrobblers only need to export one scrobbler
function. Older plugins that don't export nd_scrobbler_playback_report
would cause noisy error logs on every reportPlayback call. Now
errFunctionNotFound and errNotImplemented are treated as no-ops.

* refactor: rename NowPlayingInfo to PlaybackReport

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

* refactor: rename stopNowPlayingWorker to stopBackgroundWorkers

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

* refactor: move NowPlaying and PlaybackReport logic to separate worker files

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

* refactor(scrobbler): rename NowPlayingInfo to PlaybackSession and add expired state

Rename NowPlayingInfo struct to PlaybackSession to better reflect its role
as a complete playback session representation. Add UserId field to make
sessions self-contained, removing redundant userId parameters from
PlaybackReport interface method and internal dispatch functions. Introduce
StateExpired internal state that fires when a session cache entry expires
without an explicit stop, ensuring plugins always receive a terminal event
regardless of client behavior.

* fix(scrobbler): update playback state description to include 'expired'

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

* fix(scrobbler): resolve data race in OnExpiration callback

Capture conf.Server.EnableNowPlaying at construction time instead of
reading it from the background ttlcache eviction goroutine. The previous
code raced with test config cleanup that writes to the same field
concurrently.

* fix(scrobbler): return error when media file lookup fails in StateStopped

Simplify the MediaFile population logic in the stopped case to return an
error if the track cannot be found. A stop report with an empty MediaFile
is useless to plugins, and returning the error allows clients to retry
or alert the user when auto-scrobble is enabled.

* refactor(scrobbler): use session data directly in PlaybackReport adapter

Use info.Username from PlaybackSession instead of extracting it from
context in the plugin adapter, since the session is now self-contained.
Add debug/trace logging for session expiration and enqueue the expired
report with a user-enriched context so downstream handlers can identify
the user.

---------

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

adapters/lastfm/agent.go

@@ -416,6 +416,10 @@ func (l *lastfmAgent) IsAuthorized(ctx context.Context, userId string) bool {
 	return err == nil && sk != ""
 }
 
+func (l *lastfmAgent) PlaybackReport(context.Context, scrobbler.PlaybackSession) error {
+	return nil
+}
+
 func init() {
 	conf.AddHook(func() {
 		agents.Register(lastFMAgentName, func(ds model.DataStore) agents.Interface {

adapters/listenbrainz/agent.go

@@ -212,6 +212,10 @@ func (l *listenBrainzAgent) GetSimilarSongsByTrack(ctx context.Context, id strin
 	return songs, nil
 }
 
+func (l *listenBrainzAgent) PlaybackReport(context.Context, scrobbler.PlaybackSession) error {
+	return nil
+}
+
 func init() {
 	conf.AddHook(func() {
 		if conf.Server.ListenBrainz.Enabled {

core/scrobbler/buffered_scrobbler.go

@@ -80,6 +80,14 @@ func (b *bufferedScrobbler) Scrobble(ctx context.Context, userId string, s Scrob
 	return nil
 }
 
+func (b *bufferedScrobbler) PlaybackReport(ctx context.Context, info PlaybackSession) error {
+	s, ok := b.loader()
+	if !ok {
+		return errors.New("scrobbler not available")
+	}
+	return s.PlaybackReport(ctx, info)
+}
+
 func (b *bufferedScrobbler) sendWakeSignal() {
 	// Don't block if the previous signal was not read yet
 	select {

core/scrobbler/interfaces.go

@@ -23,6 +23,7 @@ type Scrobbler interface {
 	IsAuthorized(ctx context.Context, userId string) bool
 	NowPlaying(ctx context.Context, userId string, track *model.MediaFile, position int) error
 	Scrobble(ctx context.Context, userId string, s Scrobble) error
+	PlaybackReport(ctx context.Context, info PlaybackSession) error
 }
 
 type Constructor func(ds model.DataStore) Scrobbler

core/scrobbler/nowplaying_worker.go

@@ -0,0 +1,78 @@
+package scrobbler
+
+import (
+	"context"
+	"time"
+
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+)
+
+func (p *playTracker) enqueueNowPlaying(ctx context.Context, playerId string, userId string, track *model.MediaFile, position int) {
+	p.npMu.Lock()
+	defer p.npMu.Unlock()
+	ctx = context.WithoutCancel(ctx) // Prevent cancellation from affecting background processing
+	p.npQueue[playerId] = nowPlayingEntry{
+		ctx:      ctx,
+		userId:   userId,
+		track:    track,
+		position: position,
+	}
+	p.sendNowPlayingSignal()
+}
+
+func (p *playTracker) sendNowPlayingSignal() {
+	// Don't block if the previous signal was not read yet
+	select {
+	case p.npSignal <- struct{}{}:
+	default:
+	}
+}
+
+func (p *playTracker) nowPlayingWorker() {
+	defer close(p.workerDone)
+	for {
+		select {
+		case <-p.shutdown:
+			return
+		case <-time.After(time.Second):
+		case <-p.npSignal:
+		}
+
+		p.npMu.Lock()
+		if len(p.npQueue) == 0 {
+			p.npMu.Unlock()
+			continue
+		}
+
+		// Keep a copy of the entries to process and clear the queue
+		entries := p.npQueue
+		p.npQueue = make(map[string]nowPlayingEntry)
+		p.npMu.Unlock()
+
+		// Process entries without holding lock
+		for _, entry := range entries {
+			p.dispatchNowPlaying(entry.ctx, entry.userId, entry.track, entry.position)
+		}
+	}
+}
+
+func (p *playTracker) dispatchNowPlaying(ctx context.Context, userId string, t *model.MediaFile, position int) {
+	if t.Artist == consts.UnknownArtist {
+		log.Debug(ctx, "Ignoring external NowPlaying update for track with unknown artist", "track", t.Title, "artist", t.Artist)
+		return
+	}
+	allScrobblers := p.getActiveScrobblers()
+	for name, s := range allScrobblers {
+		if !s.IsAuthorized(ctx, userId) {
+			continue
+		}
+		log.Debug(ctx, "Sending NowPlaying update", "scrobbler", name, "track", t.Title, "artist", t.Artist, "position", position)
+		err := s.NowPlaying(ctx, userId, t, position)
+		if err != nil {
+			log.Error(ctx, "Error sending PlaybackSession", "scrobbler", name, "track", t.Title, "artist", t.Artist, err)
+			continue
+		}
+	}
+}

core/scrobbler/play_tracker.go

@@ -22,6 +22,7 @@ const (
 	StatePlaying  = "playing"
 	StatePaused   = "paused"
 	StateStopped  = "stopped"
+	StateExpired  = "expired"
 )
 
 var ValidStates = map[string]bool{
@@ -31,9 +32,10 @@ var ValidStates = map[string]bool{
 	StateStopped:  true,
 }
 
-type NowPlayingInfo struct {
+type PlaybackSession struct {
 	MediaFile    model.MediaFile
 	Start        time.Time
+	UserId       string
 	Username     string
 	PlayerId     string
 	PlayerName   string
@@ -65,8 +67,13 @@ type nowPlayingEntry struct {
 	position int
 }
 
+type playbackReportEntry struct {
+	ctx  context.Context
+	info PlaybackSession
+}
+
 type PlayTracker interface {
-	GetNowPlaying(ctx context.Context) ([]NowPlayingInfo, error)
+	GetNowPlaying(ctx context.Context) ([]PlaybackSession, error)
 	Submit(ctx context.Context, submissions []Submission) error
 	ReportPlayback(ctx context.Context, params ReportPlaybackParams) error
 }
@@ -81,7 +88,7 @@ type PluginLoader interface {
 type playTracker struct {
 	ds                model.DataStore
 	broker            events.Broker
-	playMap           cache.SimpleCache[string, NowPlayingInfo]
+	playMap           cache.SimpleCache[string, PlaybackSession]
 	builtinScrobblers map[string]Scrobbler
 	pluginScrobblers  map[string]Scrobbler
 	pluginLoader      PluginLoader
@@ -91,6 +98,10 @@ type playTracker struct {
 	npSignal          chan struct{}
 	shutdown          chan struct{}
 	workerDone        chan struct{}
+	prQueue           []playbackReportEntry
+	prMu              sync.Mutex
+	prSignal          chan struct{}
+	prWorkerDone      chan struct{}
 }
 
 func GetPlayTracker(ds model.DataStore, broker events.Broker, pluginManager PluginLoader) PlayTracker {
@@ -106,7 +117,7 @@ func NewPlayTracker(ds model.DataStore, broker events.Broker, pluginManager Plug
 }
 
 func newPlayTracker(ds model.DataStore, broker events.Broker, pluginManager PluginLoader) *playTracker {
-	m := cache.NewSimpleCache[string, NowPlayingInfo]()
+	m := cache.NewSimpleCache[string, PlaybackSession]()
 	p := &playTracker{
 		ds:                ds,
 		playMap:           m,
@@ -118,12 +129,24 @@ func newPlayTracker(ds model.DataStore, broker events.Broker, pluginManager Plug
 		npSignal:          make(chan struct{}, 1),
 		shutdown:          make(chan struct{}),
 		workerDone:        make(chan struct{}),
+		prSignal:          make(chan struct{}, 1),
+		prWorkerDone:      make(chan struct{}),
 	}
-	if conf.Server.EnableNowPlaying {
+	enableNowPlaying := conf.Server.EnableNowPlaying
-		m.OnExpiration(func(_ string, _ NowPlayingInfo) {
+	m.OnExpiration(func(_ string, info PlaybackSession) {
+		log.Debug("PlaybackSession expired", "clientId", info.PlayerId, "mediaId", info.MediaFile.ID, "state",
+			info.State, "username", info.Username, "userId", info.UserId)
+		if enableNowPlaying {
 			broker.SendBroadcastMessage(context.Background(), &events.NowPlayingCount{Count: m.Len()})
-		})
 		}
+		ctx := request.WithUser(context.Background(), model.User{ID: info.UserId, UserName: info.Username})
+		if info.State != StateStopped {
+			log.Trace("Enqueueing PlaybackReport for expired session", "session", info)
+			info.State = StateExpired
+			info.LastReport = time.Now()
+			p.enqueuePlaybackReport(ctx, info)
+		}
+	})
 
 	var enabled []string
 	for name, constructor := range constructors {
@@ -138,13 +161,15 @@ func newPlayTracker(ds model.DataStore, broker events.Broker, pluginManager Plug
 	}
 	log.Debug("List of builtin scrobblers enabled", "names", enabled)
 	go p.nowPlayingWorker()
+	go p.playbackReportWorker()
 	return p
 }
 
-// stopNowPlayingWorker stops the background worker. This is primarily for testing.
+// stopBackgroundWorkers stops the background workers. This is primarily for testing.
-func (p *playTracker) stopNowPlayingWorker() {
+func (p *playTracker) stopBackgroundWorkers() {
 	close(p.shutdown)
-	<-p.workerDone // Wait for worker to finish
+	<-p.workerDone   // Wait for nowPlaying worker to finish
+	<-p.prWorkerDone // Wait for playbackReport worker to finish
 }
 
 // pluginNamesMatchScrobblers returns true if the set of pluginNames matches the keys in pluginScrobblers.
@@ -247,9 +272,10 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 		if err != nil {
 			return err
 		}
-		info := NowPlayingInfo{
+		info := PlaybackSession{
 			MediaFile:    *mf,
 			Start:        now,
+			UserId:       user.ID,
 			Username:     user.UserName,
 			PlayerId:     clientId,
 			PlayerName:   client,
@@ -260,8 +286,9 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 		}
 		err = p.playMap.AddWithTTL(clientId, info, remainingTTL(mf.Duration, params.PositionMs, params.PlaybackRate))
 		if err != nil {
-			log.Warn(ctx, "Error adding NowPlayingInfo to cache", "clientId", clientId, "mediaId", params.MediaId, "state", params.State, err)
+			log.Warn(ctx, "Error adding PlaybackSession to cache", "clientId", clientId, "mediaId", params.MediaId, "state", params.State, err)
 		}
+		p.enqueuePlaybackReport(ctx, info)
 
 	case StatePlaying, StatePaused:
 		info, getErr := p.playMap.Get(clientId)
@@ -270,9 +297,10 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 			if err != nil {
 				return err
 			}
-			info = NowPlayingInfo{
+			info = PlaybackSession{
 				MediaFile:  *mf,
 				Start:      now.Add(-time.Duration(params.PositionMs) * time.Millisecond),
+				UserId:     user.ID,
 				Username:   user.UserName,
 				PlayerId:   clientId,
 				PlayerName: client,
@@ -286,17 +314,21 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 		if params.State == StatePlaying {
 			ttl = remainingTTL(info.MediaFile.Duration, params.PositionMs, params.PlaybackRate)
 		}
+		log.Trace(ctx, "Updating PlaybackSession in cache", "clientId", clientId, "mediaId", params.MediaId, "state", params.State, "positionMs", params.PositionMs, "playbackRate", params.PlaybackRate, "ttl", ttl)
 		err := p.playMap.AddWithTTL(clientId, info, ttl)
 		if err != nil {
-			log.Warn(ctx, "Error updating NowPlayingInfo in cache", "clientId", clientId, "mediaId", params.MediaId, "state", params.State, err)
+			log.Warn(ctx, "Error updating PlaybackSession in cache", "clientId", clientId, "mediaId", params.MediaId, "state", params.State, err)
 		}
+		p.enqueuePlaybackReport(ctx, info)
 
 	case StateStopped:
+		var loadedMF *model.MediaFile
 		if !params.IgnoreScrobble && player.ScrobbleEnabled {
 			mf, err := p.ds.MediaFile(ctx).GetWithParticipants(params.MediaId)
 			if err != nil {
 				return err
 			}
+			loadedMF = mf
 			trackDurationMs := int64(mf.Duration * 1000)
 			threshold := min(trackDurationMs*50/100, 240_000)
 			if params.PositionMs >= threshold {
@@ -307,6 +339,31 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 				p.dispatchScrobble(ctx, mf, now)
 			}
 		}
+		stoppedInfo := PlaybackSession{
+			UserId:       user.ID,
+			Username:     user.UserName,
+			PlayerId:     clientId,
+			PlayerName:   client,
+			State:        params.State,
+			PositionMs:   params.PositionMs,
+			PlaybackRate: params.PlaybackRate,
+			LastReport:   now,
+		}
+		if info, getErr := p.playMap.Get(clientId); getErr == nil {
+			stoppedInfo.MediaFile = info.MediaFile
+			stoppedInfo.Start = info.Start
+		} else {
+			mf := loadedMF
+			if mf == nil {
+				var mfErr error
+				mf, mfErr = p.ds.MediaFile(ctx).GetWithParticipants(params.MediaId)
+				if mfErr != nil {
+					return mfErr
+				}
+			}
+			stoppedInfo.MediaFile = *mf
+		}
+		p.enqueuePlaybackReport(ctx, stoppedInfo)
 		p.playMap.Remove(clientId)
 	}
 
@@ -324,77 +381,9 @@ func (p *playTracker) ReportPlayback(ctx context.Context, params ReportPlaybackP
 	return nil
 }
 
-func (p *playTracker) enqueueNowPlaying(ctx context.Context, playerId string, userId string, track *model.MediaFile, position int) {
+func (p *playTracker) GetNowPlaying(_ context.Context) ([]PlaybackSession, error) {
-	p.npMu.Lock()
-	defer p.npMu.Unlock()
-	ctx = context.WithoutCancel(ctx) // Prevent cancellation from affecting background processing
-	p.npQueue[playerId] = nowPlayingEntry{
-		ctx:      ctx,
-		userId:   userId,
-		track:    track,
-		position: position,
-	}
-	p.sendNowPlayingSignal()
-}
-
-func (p *playTracker) sendNowPlayingSignal() {
-	// Don't block if the previous signal was not read yet
-	select {
-	case p.npSignal <- struct{}{}:
-	default:
-	}
-}
-
-func (p *playTracker) nowPlayingWorker() {
-	defer close(p.workerDone)
-	for {
-		select {
-		case <-p.shutdown:
-			return
-		case <-time.After(time.Second):
-		case <-p.npSignal:
-		}
-
-		p.npMu.Lock()
-		if len(p.npQueue) == 0 {
-			p.npMu.Unlock()
-			continue
-		}
-
-		// Keep a copy of the entries to process and clear the queue
-		entries := p.npQueue
-		p.npQueue = make(map[string]nowPlayingEntry)
-		p.npMu.Unlock()
-
-		// Process entries without holding lock
-		for _, entry := range entries {
-			p.dispatchNowPlaying(entry.ctx, entry.userId, entry.track, entry.position)
-		}
-	}
-}
-
-func (p *playTracker) dispatchNowPlaying(ctx context.Context, userId string, t *model.MediaFile, position int) {
-	if t.Artist == consts.UnknownArtist {
-		log.Debug(ctx, "Ignoring external NowPlaying update for track with unknown artist", "track", t.Title, "artist", t.Artist)
-		return
-	}
-	allScrobblers := p.getActiveScrobblers()
-	for name, s := range allScrobblers {
-		if !s.IsAuthorized(ctx, userId) {
-			continue
-		}
-		log.Debug(ctx, "Sending NowPlaying update", "scrobbler", name, "track", t.Title, "artist", t.Artist, "position", position)
-		err := s.NowPlaying(ctx, userId, t, position)
-		if err != nil {
-			log.Error(ctx, "Error sending NowPlayingInfo", "scrobbler", name, "track", t.Title, "artist", t.Artist, err)
-			continue
-		}
-	}
-}
-
-func (p *playTracker) GetNowPlaying(_ context.Context) ([]NowPlayingInfo, error) {
 	res := p.playMap.Values()
-	slices.SortFunc(res, func(a, b NowPlayingInfo) int {
+	slices.SortFunc(res, func(a, b PlaybackSession) int {
 		return b.Start.Compare(a.Start)
 	})
 	for i := range res {

core/scrobbler/play_tracker_test.go

@@ -48,7 +48,7 @@ func (m *mockPluginLoader) LoadScrobbler(name string) (Scrobbler, bool) {
 var _ = Describe("PlayTracker", func() {
 	var ctx context.Context
 	var ds model.DataStore
-	var tracker PlayTracker
+	var tracker *playTracker
 	var eventBroker *fakeEventBroker
 	var track model.MediaFile
 	var album model.Album
@@ -71,7 +71,7 @@ var _ = Describe("PlayTracker", func() {
 		})
 		eventBroker = &fakeEventBroker{}
 		tracker = newPlayTracker(ds, eventBroker, nil)
-		tracker.(*playTracker).builtinScrobblers["fake"] = fake // Bypass buffering for tests
+		tracker.builtinScrobblers["fake"] = fake // Bypass buffering for tests
 
 		track = model.MediaFile{
 			ID:             "123",
@@ -96,12 +96,12 @@ var _ = Describe("PlayTracker", func() {
 
 	AfterEach(func() {
 		// Stop the worker goroutine to prevent data races between tests
-		tracker.(*playTracker).stopNowPlayingWorker()
+		tracker.stopBackgroundWorkers()
 	})
 
 	It("does not register disabled scrobblers", func() {
-		Expect(tracker.(*playTracker).builtinScrobblers).To(HaveKey("fake"))
+		Expect(tracker.builtinScrobblers).To(HaveKey("fake"))
-		Expect(tracker.(*playTracker).builtinScrobblers).ToNot(HaveKey("disabled"))
+		Expect(tracker.builtinScrobblers).ToNot(HaveKey("disabled"))
 	})
 
 	Describe("GetNowPlaying", func() {
@@ -138,8 +138,8 @@ var _ = Describe("PlayTracker", func() {
 
 	Describe("Expiration events", func() {
 		It("sends event when entry expires", func() {
-			info := NowPlayingInfo{MediaFile: track, Start: time.Now(), Username: "user"}
+			info := PlaybackSession{MediaFile: track, Start: time.Now(), Username: "user"}
-			_ = tracker.(*playTracker).playMap.AddWithTTL("player-1", info, 10*time.Millisecond)
+			_ = tracker.playMap.AddWithTTL("player-1", info, 10*time.Millisecond)
 			Eventually(func() int { return len(eventBroker.getEvents()) }).Should(BeNumerically(">", 0))
 			eventList := eventBroker.getEvents()
 			evt, ok := eventList[len(eventList)-1].(*events.NowPlayingCount)
@@ -150,10 +150,48 @@ var _ = Describe("PlayTracker", func() {
 		It("does not send event when disabled", func() {
 			conf.Server.EnableNowPlaying = false
 			tracker = newPlayTracker(ds, eventBroker, nil)
-			info := NowPlayingInfo{MediaFile: track, Start: time.Now(), Username: "user"}
+			info := PlaybackSession{MediaFile: track, Start: time.Now(), Username: "user"}
-			_ = tracker.(*playTracker).playMap.AddWithTTL("player-2", info, 10*time.Millisecond)
+			_ = tracker.playMap.AddWithTTL("player-2", info, 10*time.Millisecond)
 			Consistently(func() int { return len(eventBroker.getEvents()) }).Should(Equal(0))
 		})
+
+		It("sends expired playback report when session expires", func() {
+			info := PlaybackSession{
+				MediaFile:  track,
+				Start:      time.Now(),
+				UserId:     "u-1",
+				Username:   "user",
+				PlayerId:   "player-3",
+				PlayerName: "test-player",
+				State:      StatePlaying,
+				PositionMs: 5000,
+			}
+			_ = tracker.playMap.AddWithTTL("player-3", info, 10*time.Millisecond)
+			Eventually(func() *PlaybackSession {
+				return fake.LastPlaybackReport.Load()
+			}).ShouldNot(BeNil())
+			report := fake.LastPlaybackReport.Load()
+			Expect(report.State).To(Equal(StateExpired))
+			Expect(report.MediaFile.ID).To(Equal("123"))
+			Expect(report.PlayerId).To(Equal("player-3"))
+		})
+
+		It("does not send expired report when session was already stopped", func() {
+			info := PlaybackSession{
+				MediaFile:  track,
+				Start:      time.Now(),
+				UserId:     "u-1",
+				Username:   "user",
+				PlayerId:   "player-4",
+				PlayerName: "test-player",
+				State:      StateStopped,
+				PositionMs: 180000,
+			}
+			_ = tracker.playMap.AddWithTTL("player-4", info, 10*time.Millisecond)
+			Consistently(func() *PlaybackSession {
+				return fake.LastPlaybackReport.Load()
+			}).Should(BeNil())
+		})
 	})
 
 	Describe("Submit", func() {
@@ -375,7 +413,7 @@ var _ = Describe("PlayTracker", func() {
 			BeforeEach(func() {
 				eventBroker = &fakeEventBroker{}
 				tracker = newPlayTracker(ds, eventBroker, nil)
-				tracker.(*playTracker).builtinScrobblers["fake"] = fake
+				tracker.builtinScrobblers["fake"] = fake
 			})
 
 			It("broadcasts NowPlayingCount on every state change", func() {
@@ -420,7 +458,7 @@ var _ = Describe("PlayTracker", func() {
 			It("does NOT broadcast when EnableNowPlaying is false", func() {
 				conf.Server.EnableNowPlaying = false
 				tracker = newPlayTracker(ds, eventBroker, nil)
-				tracker.(*playTracker).builtinScrobblers["fake"] = fake
+				tracker.builtinScrobblers["fake"] = fake
 
 				err := tracker.ReportPlayback(ctx, ReportPlaybackParams{
 					MediaId: "123", PositionMs: 0, State: "starting", PlaybackRate: 1.0, ClientId: defaultClientId,
@@ -697,6 +735,96 @@ var _ = Describe("PlayTracker", func() {
 				Consistently(func() bool { return fake.GetNowPlayingCalled() }).Should(BeFalse())
 			})
 		})
+
+		Describe("PlaybackReport dispatch", func() {
+			It("dispatches PlaybackReport for starting state", func() {
+				err := tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 0, State: StateStarting, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				Eventually(func() bool {
+					return fake.PlaybackReportCalled.Load()
+				}).Should(BeTrue())
+
+				info := fake.LastPlaybackReport.Load()
+				Expect(info).ToNot(BeNil())
+				Expect(info.MediaFile.ID).To(Equal("123"))
+				Expect(info.State).To(Equal(StateStarting))
+				Expect(info.PositionMs).To(Equal(int64(0)))
+				Expect(info.PlaybackRate).To(Equal(1.0))
+				Expect(info.PlayerId).To(Equal("client-1"))
+				Expect(info.PlayerName).To(Equal("Test Player"))
+			})
+
+			It("dispatches PlaybackReport for playing state", func() {
+				err := tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 0, State: StateStarting, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				fake.PlaybackReportCalled.Store(false)
+				fake.LastPlaybackReport.Store(nil)
+
+				err = tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 30000, State: StatePlaying, PlaybackRate: 1.5,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				info := fake.LastPlaybackReport.Load()
+				Expect(info.State).To(Equal(StatePlaying))
+				Expect(info.PositionMs).To(Equal(int64(30000)))
+				Expect(info.PlaybackRate).To(Equal(1.5))
+			})
+
+			It("dispatches PlaybackReport for paused state", func() {
+				err := tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 0, State: StateStarting, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				fake.PlaybackReportCalled.Store(false)
+				fake.LastPlaybackReport.Store(nil)
+
+				err = tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 45000, State: StatePaused, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				info := fake.LastPlaybackReport.Load()
+				Expect(info.State).To(Equal(StatePaused))
+				Expect(info.PositionMs).To(Equal(int64(45000)))
+			})
+
+			It("dispatches PlaybackReport for stopped state", func() {
+				err := tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 0, State: StateStarting, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				fake.PlaybackReportCalled.Store(false)
+				fake.LastPlaybackReport.Store(nil)
+
+				err = tracker.ReportPlayback(ctx, ReportPlaybackParams{
+					MediaId: "123", PositionMs: 100000, State: StateStopped, PlaybackRate: 1.0,
+					ClientId: "client-1", ClientName: "Test Player",
+				})
+				Expect(err).ToNot(HaveOccurred())
+
+				Eventually(func() bool { return fake.PlaybackReportCalled.Load() }).Should(BeTrue())
+				info := fake.LastPlaybackReport.Load()
+				Expect(info.State).To(Equal(StateStopped))
+				Expect(info.PositionMs).To(Equal(int64(100000)))
+			})
+		})
 	})
 
 	Describe("Plugin scrobbler logic", func() {
@@ -712,8 +840,8 @@ var _ = Describe("PlayTracker", func() {
 			tracker = newPlayTracker(ds, events.GetBroker(), pluginLoader)
 
 			// Bypass buffering for both built-in and plugin scrobblers
-			tracker.(*playTracker).builtinScrobblers["fake"] = fake
+			tracker.builtinScrobblers["fake"] = fake
-			tracker.(*playTracker).pluginScrobblers["plugin1"] = pluginFake
+			tracker.pluginScrobblers["plugin1"] = pluginFake
 		})
 
 		It("registers and uses plugin scrobbler for NowPlaying", func() {
@@ -830,7 +958,7 @@ var _ = Describe("PlayTracker", func() {
 		})
 
 		AfterEach(func() {
-			pTracker.stopNowPlayingWorker()
+			pTracker.stopBackgroundWorkers()
 		})
 
 		It("uses the new plugin instance after reload (simulating config update)", func() {
@@ -940,11 +1068,13 @@ type fakeScrobbler struct {
 	Authorized           bool
 	nowPlayingCalled     atomic.Bool
 	ScrobbleCalled       atomic.Bool
+	PlaybackReportCalled atomic.Bool
 	userID               atomic.Pointer[string]
 	username             atomic.Pointer[string]
 	track                atomic.Pointer[model.MediaFile]
 	position             atomic.Int32
 	LastScrobble         atomic.Pointer[Scrobble]
+	LastPlaybackReport   atomic.Pointer[PlaybackSession]
 	Error                error
 }
 
@@ -998,6 +1128,17 @@ func (f *fakeScrobbler) Scrobble(ctx context.Context, userId string, s Scrobble)
 	return nil
 }
 
+func (f *fakeScrobbler) PlaybackReport(ctx context.Context, info PlaybackSession) error {
+	f.PlaybackReportCalled.Store(true)
+	if f.Error != nil {
+		return f.Error
+	}
+	uid := info.UserId
+	f.userID.Store(&uid)
+	f.LastPlaybackReport.Store(&info)
+	return nil
+}
+
 func _p(id, name string, sortName ...string) model.Participant {
 	p := model.Participant{Artist: model.Artist{ID: id, Name: name}}
 	if len(sortName) > 0 {
@@ -1053,3 +1194,7 @@ func (m *mockBufferedScrobbler) NowPlaying(ctx context.Context, userId string, t
 func (m *mockBufferedScrobbler) Scrobble(ctx context.Context, userId string, s Scrobble) error {
 	return m.wrapped.Scrobble(ctx, userId, s)
 }
+
+func (m *mockBufferedScrobbler) PlaybackReport(ctx context.Context, info PlaybackSession) error {
+	return m.wrapped.PlaybackReport(ctx, info)
+}

core/scrobbler/playbackreport_worker.go

@@ -0,0 +1,64 @@
+package scrobbler
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/log"
+)
+
+func (p *playTracker) enqueuePlaybackReport(ctx context.Context, info PlaybackSession) {
+	p.prMu.Lock()
+	defer p.prMu.Unlock()
+	ctx = context.WithoutCancel(ctx)
+	p.prQueue = append(p.prQueue, playbackReportEntry{
+		ctx:  ctx,
+		info: info,
+	})
+	p.sendPlaybackReportSignal()
+}
+
+func (p *playTracker) sendPlaybackReportSignal() {
+	select {
+	case p.prSignal <- struct{}{}:
+	default:
+	}
+}
+
+func (p *playTracker) playbackReportWorker() {
+	defer close(p.prWorkerDone)
+	for {
+		select {
+		case <-p.shutdown:
+			return
+		case <-p.prSignal:
+		}
+
+		p.prMu.Lock()
+		if len(p.prQueue) == 0 {
+			p.prMu.Unlock()
+			continue
+		}
+		entries := p.prQueue
+		p.prQueue = nil
+		p.prMu.Unlock()
+
+		allScrobblers := p.getActiveScrobblers()
+		for _, entry := range entries {
+			p.dispatchPlaybackReport(entry.ctx, entry.info, allScrobblers)
+		}
+	}
+}
+
+func (p *playTracker) dispatchPlaybackReport(ctx context.Context, info PlaybackSession, allScrobblers map[string]Scrobbler) {
+	for name, s := range allScrobblers {
+		if !s.IsAuthorized(ctx, info.UserId) {
+			continue
+		}
+		log.Debug(ctx, "Sending PlaybackReport", "scrobbler", name, "track", info.MediaFile.Title, "state", info.State, "positionMs", info.PositionMs)
+		err := s.PlaybackReport(ctx, info)
+		if err != nil {
+			log.Error(ctx, "Error sending PlaybackReport", "scrobbler", name, "track", info.MediaFile.Title, "state", info.State, err)
+			continue
+		}
+	}
+}

plugins/capabilities/scrobbler.go

@@ -5,7 +5,7 @@ package capabilities
 // ListenBrainz, or custom scrobbling backends.
 //
 // All methods are required - plugins implementing this capability must provide
-// all three functions: IsAuthorized, NowPlaying, and Scrobble.
+// all four functions: IsAuthorized, NowPlaying, Scrobble, and PlaybackReport.
 //
 //nd:capability name=scrobbler required=true
 type Scrobbler interface {
@@ -20,6 +20,10 @@ type Scrobbler interface {
 	// Scrobble submits a completed scrobble to the scrobbling service.
 	//nd:export name=nd_scrobbler_scrobble
 	Scrobble(ScrobbleRequest) error
+
+	// PlaybackReport sends a playback state report to the scrobbling service.
+	//nd:export name=nd_scrobbler_playback_report
+	PlaybackReport(PlaybackReportRequest) error
 }
 
 // IsAuthorizedRequest is the request for authorization check.
@@ -96,6 +100,26 @@ type ScrobbleRequest struct {
 	Timestamp int64 `json:"timestamp"`
 }
 
+// PlaybackReportRequest is the request for playback report notifications.
+type PlaybackReportRequest struct {
+	// Username is the username of the user.
+	Username string `json:"username"`
+	// Track is the track being played.
+	Track TrackInfo `json:"track"`
+	// State is the current playback state (starting/playing/paused/stopped/expired).
+	State string `json:"state"`
+	// PositionMs is the current playback position in milliseconds.
+	PositionMs int64 `json:"positionMs"`
+	// PlaybackRate is the playback speed (1.0 = normal).
+	PlaybackRate float64 `json:"playbackRate"`
+	// PlayerId is the unique client identifier.
+	PlayerId string `json:"playerId"`
+	// PlayerName is the human-readable player name.
+	PlayerName string `json:"playerName"`
+	// Timestamp is the Unix timestamp when this report was generated.
+	Timestamp int64 `json:"timestamp"`
+}
+
 // ScrobblerError represents an error type for scrobbling operations.
 type ScrobblerError string
 

plugins/capabilities/scrobbler.yaml

@@ -18,6 +18,11 @@ exports:
         input:
             $ref: '#/components/schemas/ScrobbleRequest'
             contentType: application/json
+    nd_scrobbler_playback_report:
+        description: PlaybackReport sends a playback state report to the scrobbling service.
+        input:
+            $ref: '#/components/schemas/PlaybackReportRequest'
+            contentType: application/json
 components:
     schemas:
         ArtistRef:
@@ -59,6 +64,45 @@ components:
                 - username
                 - track
                 - position
+        PlaybackReportRequest:
+            description: PlaybackReportRequest is the request for playback report notifications.
+            properties:
+                username:
+                    type: string
+                    description: Username is the username of the user.
+                track:
+                    $ref: '#/components/schemas/TrackInfo'
+                    description: Track is the track being played.
+                state:
+                    type: string
+                    description: State is the current playback state (starting/playing/paused/stopped/expired).
+                positionMs:
+                    type: integer
+                    format: int64
+                    description: PositionMs is the current playback position in milliseconds.
+                playbackRate:
+                    type: number
+                    format: float
+                    description: PlaybackRate is the playback speed (1.0 = normal).
+                playerId:
+                    type: string
+                    description: PlayerId is the unique client identifier.
+                playerName:
+                    type: string
+                    description: PlayerName is the human-readable player name.
+                timestamp:
+                    type: integer
+                    format: int64
+                    description: Timestamp is the Unix timestamp when this report was generated.
+            required:
+                - username
+                - track
+                - state
+                - positionMs
+                - playbackRate
+                - playerId
+                - playerName
+                - timestamp
         ScrobbleRequest:
             description: ScrobbleRequest is the request for submitting a scrobble.
             properties:

plugins/pdk/go/scrobbler/scrobbler.go

@@ -52,6 +52,26 @@ type NowPlayingRequest struct {
 	Position int32 `json:"position"`
 }
 
+// PlaybackReportRequest is the request for playback report notifications.
+type PlaybackReportRequest struct {
+	// Username is the username of the user.
+	Username string `json:"username"`
+	// Track is the track being played.
+	Track TrackInfo `json:"track"`
+	// State is the current playback state (starting/playing/paused/stopped/expired).
+	State string `json:"state"`
+	// PositionMs is the current playback position in milliseconds.
+	PositionMs int64 `json:"positionMs"`
+	// PlaybackRate is the playback speed (1.0 = normal).
+	PlaybackRate float64 `json:"playbackRate"`
+	// PlayerId is the unique client identifier.
+	PlayerId string `json:"playerId"`
+	// PlayerName is the human-readable player name.
+	PlayerName string `json:"playerName"`
+	// Timestamp is the Unix timestamp when this report was generated.
+	Timestamp int64 `json:"timestamp"`
+}
+
 // ScrobbleRequest is the request for submitting a scrobble.
 type ScrobbleRequest struct {
 	// Username is the username of the user.
@@ -106,7 +126,7 @@ type TrackInfo struct {
 // ListenBrainz, or custom scrobbling backends.
 //
 // All methods are required - plugins implementing this capability must provide
-// all three functions: IsAuthorized, NowPlaying, and Scrobble.
+// all four functions: IsAuthorized, NowPlaying, Scrobble, and PlaybackReport.
 type Scrobbler interface {
 	// IsAuthorized - IsAuthorized checks if a user is authorized to scrobble to this service.
 	IsAuthorized(IsAuthorizedRequest) (bool, error)
@@ -114,11 +134,14 @@ type Scrobbler interface {
 	NowPlaying(NowPlayingRequest) error
 	// Scrobble - Scrobble submits a completed scrobble to the scrobbling service.
 	Scrobble(ScrobbleRequest) error
+	// PlaybackReport - PlaybackReport sends a playback state report to the scrobbling service.
+	PlaybackReport(PlaybackReportRequest) error
 } // Internal implementation holders
 var (
 	isAuthorizedImpl   func(IsAuthorizedRequest) (bool, error)
 	nowPlayingImpl     func(NowPlayingRequest) error
 	scrobbleImpl       func(ScrobbleRequest) error
+	playbackReportImpl func(PlaybackReportRequest) error
 )
 
 // Register registers a scrobbler implementation.
@@ -127,6 +150,7 @@ func Register(impl Scrobbler) {
 	isAuthorizedImpl = impl.IsAuthorized
 	nowPlayingImpl = impl.NowPlaying
 	scrobbleImpl = impl.Scrobble
+	playbackReportImpl = impl.PlaybackReport
 }
 
 // NotImplementedCode is the standard return code for unimplemented functions.
@@ -201,3 +225,24 @@ func _NdScrobblerScrobble() int32 {
 
 	return 0
 }
+
+//go:wasmexport nd_scrobbler_playback_report
+func _NdScrobblerPlaybackReport() int32 {
+	if playbackReportImpl == nil {
+		// Return standard code - host will skip this plugin gracefully
+		return NotImplementedCode
+	}
+
+	var input PlaybackReportRequest
+	if err := pdk.InputJSON(&input); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+
+	if err := playbackReportImpl(input); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+
+	return 0
+}

plugins/pdk/go/scrobbler/scrobbler_stub.go

@@ -49,6 +49,26 @@ type NowPlayingRequest struct {
 	Position int32 `json:"position"`
 }
 
+// PlaybackReportRequest is the request for playback report notifications.
+type PlaybackReportRequest struct {
+	// Username is the username of the user.
+	Username string `json:"username"`
+	// Track is the track being played.
+	Track TrackInfo `json:"track"`
+	// State is the current playback state (starting/playing/paused/stopped/expired).
+	State string `json:"state"`
+	// PositionMs is the current playback position in milliseconds.
+	PositionMs int64 `json:"positionMs"`
+	// PlaybackRate is the playback speed (1.0 = normal).
+	PlaybackRate float64 `json:"playbackRate"`
+	// PlayerId is the unique client identifier.
+	PlayerId string `json:"playerId"`
+	// PlayerName is the human-readable player name.
+	PlayerName string `json:"playerName"`
+	// Timestamp is the Unix timestamp when this report was generated.
+	Timestamp int64 `json:"timestamp"`
+}
+
 // ScrobbleRequest is the request for submitting a scrobble.
 type ScrobbleRequest struct {
 	// Username is the username of the user.
@@ -103,7 +123,7 @@ type TrackInfo struct {
 // ListenBrainz, or custom scrobbling backends.
 //
 // All methods are required - plugins implementing this capability must provide
-// all three functions: IsAuthorized, NowPlaying, and Scrobble.
+// all four functions: IsAuthorized, NowPlaying, Scrobble, and PlaybackReport.
 type Scrobbler interface {
 	// IsAuthorized - IsAuthorized checks if a user is authorized to scrobble to this service.
 	IsAuthorized(IsAuthorizedRequest) (bool, error)
@@ -111,6 +131,8 @@ type Scrobbler interface {
 	NowPlaying(NowPlayingRequest) error
 	// Scrobble - Scrobble submits a completed scrobble to the scrobbling service.
 	Scrobble(ScrobbleRequest) error
+	// PlaybackReport - PlaybackReport sends a playback state report to the scrobbling service.
+	PlaybackReport(PlaybackReportRequest) error
 }
 
 // NotImplementedCode is the standard return code for unimplemented functions.

plugins/pdk/rust/nd-pdk-capabilities/src/scrobbler.rs

@@ -62,6 +62,35 @@ pub struct NowPlayingRequest {
     #[serde(default)]
     pub position: i32,
 }
+/// PlaybackReportRequest is the request for playback report notifications.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PlaybackReportRequest {
+    /// Username is the username of the user.
+    #[serde(default)]
+    pub username: String,
+    /// Track is the track being played.
+    #[serde(default)]
+    pub track: TrackInfo,
+    /// State is the current playback state (starting/playing/paused/stopped/expired).
+    #[serde(default)]
+    pub state: String,
+    /// PositionMs is the current playback position in milliseconds.
+    #[serde(default)]
+    pub position_ms: i64,
+    /// PlaybackRate is the playback speed (1.0 = normal).
+    #[serde(default)]
+    pub playback_rate: f64,
+    /// PlayerId is the unique client identifier.
+    #[serde(default)]
+    pub player_id: String,
+    /// PlayerName is the human-readable player name.
+    #[serde(default)]
+    pub player_name: String,
+    /// Timestamp is the Unix timestamp when this report was generated.
+    #[serde(default)]
+    pub timestamp: i64,
+}
 /// ScrobbleRequest is the request for submitting a scrobble.
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
@@ -158,7 +187,7 @@ impl Error {
 /// ListenBrainz, or custom scrobbling backends.
 /// 
 /// All methods are required - plugins implementing this capability must provide
-/// all three functions: IsAuthorized, NowPlaying, and Scrobble.
+/// all four functions: IsAuthorized, NowPlaying, Scrobble, and PlaybackReport.
 pub trait Scrobbler {
     /// IsAuthorized - IsAuthorized checks if a user is authorized to scrobble to this service.
     fn is_authorized(&self, req: IsAuthorizedRequest) -> Result<bool, Error>;
@@ -166,6 +195,8 @@ pub trait Scrobbler {
     fn now_playing(&self, req: NowPlayingRequest) -> Result<(), Error>;
     /// Scrobble - Scrobble submits a completed scrobble to the scrobbling service.
     fn scrobble(&self, req: ScrobbleRequest) -> Result<(), Error>;
+    /// PlaybackReport - PlaybackReport sends a playback state report to the scrobbling service.
+    fn playback_report(&self, req: PlaybackReportRequest) -> Result<(), Error>;
 }
 
 /// Register all exports for the Scrobbler capability.
@@ -197,5 +228,13 @@ macro_rules! register_scrobbler {
             $crate::scrobbler::Scrobbler::scrobble(&plugin, req.into_inner())?;
             Ok(())
         }
+        #[extism_pdk::plugin_fn]
+        pub fn nd_scrobbler_playback_report(
+            req: extism_pdk::Json<$crate::scrobbler::PlaybackReportRequest>
+        ) -> extism_pdk::FnResult<()> {
+            let plugin = <$plugin_type>::default();
+            $crate::scrobbler::Scrobbler::playback_report(&plugin, req.into_inner())?;
+            Ok(())
+        }
     };
 }

plugins/scrobbler_adapter.go

@@ -2,6 +2,7 @@ package plugins
 
 import (
 	"context"
+	"errors"
 	"strings"
 
 	"github.com/navidrome/navidrome/core/scrobbler"
@@ -19,6 +20,7 @@ const (
 	FuncScrobblerIsAuthorized   = "nd_scrobbler_is_authorized"
 	FuncScrobblerNowPlaying     = "nd_scrobbler_now_playing"
 	FuncScrobblerScrobble       = "nd_scrobbler_scrobble"
+	FuncScrobblerPlaybackReport = "nd_scrobbler_playback_report"
 )
 
 func init() {
@@ -27,6 +29,7 @@ func init() {
 		FuncScrobblerIsAuthorized,
 		FuncScrobblerNowPlaying,
 		FuncScrobblerScrobble,
+		FuncScrobblerPlaybackReport,
 	)
 }
 
@@ -182,5 +185,25 @@ func mapScrobblerError(err error) error {
 	}
 }
 
+// PlaybackReport sends a playback state report to the scrobbler
+func (s *ScrobblerPlugin) PlaybackReport(ctx context.Context, info scrobbler.PlaybackSession) error {
+	input := capabilities.PlaybackReportRequest{
+		Username:     info.Username,
+		Track:        mediaFileToTrackInfo(s.plugin, &info.MediaFile),
+		State:        info.State,
+		PositionMs:   info.PositionMs,
+		PlaybackRate: info.PlaybackRate,
+		PlayerId:     info.PlayerId,
+		PlayerName:   info.PlayerName,
+		Timestamp:    info.LastReport.Unix(),
+	}
+
+	err := callPluginFunctionNoOutput(ctx, s.plugin, FuncScrobblerPlaybackReport, input)
+	if errors.Is(err, errFunctionNotFound) || errors.Is(err, errNotImplemented) {
+		return nil
+	}
+	return mapScrobblerError(err)
+}
+
 // Verify interface implementation at compile time
 var _ scrobbler.Scrobbler = (*ScrobblerPlugin)(nil)

plugins/scrobbler_adapter_test.go

@@ -229,6 +229,62 @@ var _ = Describe("ScrobblerPlugin", Ordered, func() {
 		})
 	})
 
+	Describe("PlaybackReport", func() {
+		It("successfully calls the plugin", func() {
+			info := scrobbler.PlaybackSession{
+				MediaFile: model.MediaFile{
+					ID:          "track-1",
+					Title:       "Test Song",
+					Album:       "Test Album",
+					Artist:      "Test Artist",
+					AlbumArtist: "Test Album Artist",
+					Duration:    180,
+					TrackNumber: 1,
+					DiscNumber:  1,
+					Participants: model.Participants{
+						model.RoleArtist:      {{Artist: model.Artist{ID: "artist-1", Name: "Test Artist"}}},
+						model.RoleAlbumArtist: {{Artist: model.Artist{ID: "album-artist-1", Name: "Test Album Artist"}}},
+					},
+				},
+				Username:     "testuser",
+				PlayerId:     "player-1",
+				PlayerName:   "Test Player",
+				State:        "playing",
+				PositionMs:   30000,
+				PlaybackRate: 1.0,
+				LastReport:   time.Now(),
+			}
+
+			err := s.PlaybackReport(ctxWithUser(), info)
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		Context("when plugin returns error", Ordered, func() {
+			var retryScrobbler scrobbler.Scrobbler
+
+			BeforeAll(func() {
+				mgr, _ := createTestManagerWithPlugins(map[string]map[string]string{
+					"test-scrobbler": {"error": "service unavailable", "error_type": "scrobbler(retry_later)"},
+				}, "test-scrobbler"+PackageExtension)
+
+				var ok bool
+				retryScrobbler, ok = mgr.LoadScrobbler("test-scrobbler")
+				Expect(ok).To(BeTrue())
+			})
+
+			It("returns ErrRetryLater", func() {
+				info := scrobbler.PlaybackSession{
+					MediaFile:  model.MediaFile{ID: "track-1", Title: "Test Song"},
+					State:      "playing",
+					LastReport: time.Now(),
+				}
+				err := retryScrobbler.PlaybackReport(ctxWithUser(), info)
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(scrobbler.ErrRetryLater))
+			})
+		})
+	})
+
 	Describe("PluginNames", func() {
 		It("returns plugin names with Scrobbler capability", func() {
 			names := scrobblerManager.PluginNames("Scrobbler")

plugins/testdata/test-scrobbler/main.go

@@ -53,6 +53,20 @@ func (t *testScrobbler) Scrobble(input scrobbler.ScrobbleRequest) error {
 	return nil
 }
 
+// PlaybackReport receives a playback state report.
+func (t *testScrobbler) PlaybackReport(input scrobbler.PlaybackReportRequest) error {
+	if err := checkConfigError(); err != nil {
+		return err
+	}
+
+	artistName := ""
+	if len(input.Track.Artists) > 0 {
+		artistName = input.Track.Artists[0].Name
+	}
+	pdk.Log(pdk.LogInfo, "PlaybackReport: "+input.Track.Title+" by "+artistName+" state="+input.State)
+	return nil
+}
+
 // checkConfigError checks if the plugin is configured to return an error.
 // If "error" config is set, it returns the appropriate ScrobblerError.
 // Error types: "not_authorized", "retry_later", "unrecoverable"

server/subsonic/album_lists.go

@@ -212,7 +212,7 @@ func (api *Router) GetNowPlaying(r *http.Request) (*responses.Subsonic, error) {
 	response := newResponse()
 	response.NowPlaying = &responses.NowPlaying{}
 	var i int32
-	response.NowPlaying.Entry = slice.Map(npInfo, func(np scrobbler.NowPlayingInfo) responses.NowPlayingEntry {
+	response.NowPlaying.Entry = slice.Map(npInfo, func(np scrobbler.PlaybackSession) responses.NowPlayingEntry {
 		i++
 		return responses.NowPlayingEntry{
 			Child:        childFromMediaFile(ctx, np.MediaFile),

server/subsonic/media_annotation_test.go

@@ -193,7 +193,7 @@ type fakePlayTracker struct {
 	Error            error
 }
 
-func (f *fakePlayTracker) GetNowPlaying(_ context.Context) ([]scrobbler.NowPlayingInfo, error) {
+func (f *fakePlayTracker) GetNowPlaying(_ context.Context) ([]scrobbler.PlaybackSession, error) {
 	return nil, f.Error
 }