refactor(plugins): simplify goroutine management in task queue service

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

conf/configuration.go

@@ -155,6 +155,7 @@ type scannerOptions struct {
 
 type subsonicOptions struct {
 	AppendSubtitle        bool
+	AppendAlbumVersion    bool
 	ArtistParticipations  bool
 	DefaultReportRealPath bool
 	EnableAverageRating   bool
@@ -689,6 +690,7 @@ func setViperDefaults() {
 	viper.SetDefault("scanner.followsymlinks", true)
 	viper.SetDefault("scanner.purgemissing", consts.PurgeMissingNever)
 	viper.SetDefault("subsonic.appendsubtitle", true)
+	viper.SetDefault("subsonic.appendalbumversion", true)
 	viper.SetDefault("subsonic.artistparticipations", false)
 	viper.SetDefault("subsonic.defaultreportrealpath", false)
 	viper.SetDefault("subsonic.enableaveragerating", true)

model/album.go

@@ -1,11 +1,14 @@
 package model
 
 import (
+	"fmt"
 	"iter"
 	"math"
 	"sync"
 	"time"
 
+	"github.com/navidrome/navidrome/conf"
+
 	"github.com/gohugoio/hashstructure"
 )
 
@@ -70,6 +73,13 @@ func (a Album) CoverArtID() ArtworkID {
 	return artworkIDFromAlbum(a)
 }
 
+func (a Album) FullName() string {
+	if conf.Server.Subsonic.AppendAlbumVersion && len(a.Tags[TagAlbumVersion]) > 0 {
+		return fmt.Sprintf("%s (%s)", a.Name, a.Tags[TagAlbumVersion][0])
+	}
+	return a.Name
+}
+
 // Equals compares two Album structs, ignoring calculated fields
 func (a Album) Equals(other Album) bool {
 	// Normalize float32 values to avoid false negatives

model/album_test.go

@@ -3,11 +3,30 @@ package model_test
 import (
 	"encoding/json"
 
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
 	. "github.com/navidrome/navidrome/model"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
+var _ = Describe("Album", func() {
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+	})
+	DescribeTable("FullName",
+		func(enabled bool, tags Tags, expected string) {
+			conf.Server.Subsonic.AppendAlbumVersion = enabled
+			a := Album{Name: "Album", Tags: tags}
+			Expect(a.FullName()).To(Equal(expected))
+		},
+		Entry("appends version when enabled and tag is present", true, Tags{TagAlbumVersion: []string{"Remastered"}}, "Album (Remastered)"),
+		Entry("returns just name when disabled", false, Tags{TagAlbumVersion: []string{"Remastered"}}, "Album"),
+		Entry("returns just name when tag is absent", true, Tags{}, "Album"),
+		Entry("returns just name when tag is an empty slice", true, Tags{TagAlbumVersion: []string{}}, "Album"),
+	)
+})
+
 var _ = Describe("Albums", func() {
 	var albums Albums
 

model/mediafile.go

@@ -95,12 +95,19 @@ type MediaFile struct {
 }
 
 func (mf MediaFile) FullTitle() string {
-	if conf.Server.Subsonic.AppendSubtitle && mf.Tags[TagSubtitle] != nil {
+	if conf.Server.Subsonic.AppendSubtitle && len(mf.Tags[TagSubtitle]) > 0 {
 		return fmt.Sprintf("%s (%s)", mf.Title, mf.Tags[TagSubtitle][0])
 	}
 	return mf.Title
 }
 
+func (mf MediaFile) FullAlbumName() string {
+	if conf.Server.Subsonic.AppendAlbumVersion && len(mf.Tags[TagAlbumVersion]) > 0 {
+		return fmt.Sprintf("%s (%s)", mf.Album, mf.Tags[TagAlbumVersion][0])
+	}
+	return mf.Album
+}
+
 func (mf MediaFile) ContentType() string {
 	return mime.TypeByExtension("." + mf.Suffix)
 }

model/mediafile_test.go

@@ -475,7 +475,29 @@ var _ = Describe("MediaFile", func() {
 		DeferCleanup(configtest.SetupConfig())
 		conf.Server.EnableMediaFileCoverArt = true
 	})
-	Describe(".CoverArtId()", func() {
+	DescribeTable("FullTitle",
+		func(enabled bool, tags Tags, expected string) {
+			conf.Server.Subsonic.AppendSubtitle = enabled
+			mf := MediaFile{Title: "Song", Tags: tags}
+			Expect(mf.FullTitle()).To(Equal(expected))
+		},
+		Entry("appends subtitle when enabled and tag is present", true, Tags{TagSubtitle: []string{"Live"}}, "Song (Live)"),
+		Entry("returns just title when disabled", false, Tags{TagSubtitle: []string{"Live"}}, "Song"),
+		Entry("returns just title when tag is absent", true, Tags{}, "Song"),
+		Entry("returns just title when tag is an empty slice", true, Tags{TagSubtitle: []string{}}, "Song"),
+	)
+	DescribeTable("FullAlbumName",
+		func(enabled bool, tags Tags, expected string) {
+			conf.Server.Subsonic.AppendAlbumVersion = enabled
+			mf := MediaFile{Album: "Album", Tags: tags}
+			Expect(mf.FullAlbumName()).To(Equal(expected))
+		},
+		Entry("appends version when enabled and tag is present", true, Tags{TagAlbumVersion: []string{"Deluxe Edition"}}, "Album (Deluxe Edition)"),
+		Entry("returns just album name when disabled", false, Tags{TagAlbumVersion: []string{"Deluxe Edition"}}, "Album"),
+		Entry("returns just album name when tag is absent", true, Tags{}, "Album"),
+		Entry("returns just album name when tag is an empty slice", true, Tags{TagAlbumVersion: []string{}}, "Album"),
+	)
+	Describe("CoverArtId()", func() {
 		It("returns its own id if it HasCoverArt", func() {
 			mf := MediaFile{ID: "111", AlbumID: "1", HasCoverArt: true}
 			id := mf.CoverArtID()

plugins/capabilities/taskworker.go

@@ -0,0 +1,33 @@
+package capabilities
+
+// TaskWorker provides task execution handling.
+// This capability allows plugins to receive callbacks when their queued tasks
+// are ready to execute. Plugins that use the taskqueue host service must
+// implement this capability.
+//
+//nd:capability name=taskworker
+type TaskWorker interface {
+	// OnTaskExecute is called when a queued task is ready to run.
+	// Return an error to trigger retry (if retries are configured).
+	//nd:export name=nd_task_execute
+	OnTaskExecute(TaskExecuteRequest) (TaskExecuteResponse, error)
+}
+
+// TaskExecuteRequest is the request provided when a task is ready to execute.
+type TaskExecuteRequest struct {
+	// QueueName is the name of the queue this task belongs to.
+	QueueName string `json:"queueName"`
+	// TaskID is the unique identifier for this task.
+	TaskID string `json:"taskId"`
+	// Payload is the opaque data provided when the task was enqueued.
+	Payload []byte `json:"payload"`
+	// Attempt is the current attempt number (1-based: first attempt = 1).
+	Attempt int32 `json:"attempt"`
+}
+
+// TaskExecuteResponse is the response from task execution.
+type TaskExecuteResponse struct {
+	// Error, if non-empty, indicates the task failed. The task will be retried
+	// if retries are configured and attempts remain.
+	Error string `json:"error,omitempty"`
+}

plugins/capabilities/taskworker.yaml

@@ -0,0 +1,45 @@
+version: v1-draft
+exports:
+    nd_task_execute:
+        description: |-
+            OnTaskExecute is called when a queued task is ready to run.
+            Return an error to trigger retry (if retries are configured).
+        input:
+            $ref: '#/components/schemas/TaskExecuteRequest'
+            contentType: application/json
+        output:
+            $ref: '#/components/schemas/TaskExecuteResponse'
+            contentType: application/json
+components:
+    schemas:
+        TaskExecuteRequest:
+            description: TaskExecuteRequest is the request provided when a task is ready to execute.
+            properties:
+                queueName:
+                    type: string
+                    description: QueueName is the name of the queue this task belongs to.
+                taskId:
+                    type: string
+                    description: TaskID is the unique identifier for this task.
+                payload:
+                    type: array
+                    description: Payload is the opaque data provided when the task was enqueued.
+                    items:
+                        type: object
+                attempt:
+                    type: integer
+                    format: int32
+                    description: 'Attempt is the current attempt number (1-based: first attempt = 1).'
+            required:
+                - queueName
+                - taskId
+                - payload
+                - attempt
+        TaskExecuteResponse:
+            description: TaskExecuteResponse is the response from task execution.
+            properties:
+                error:
+                    type: string
+                    description: |-
+                        Error, if non-empty, indicates the task failed. The task will be retried
+                        if retries are configured and attempts remain.

plugins/host/taskqueue.go

@@ -0,0 +1,57 @@
+package host
+
+import "context"
+
+// QueueConfig holds configuration for a task queue.
+type QueueConfig struct {
+	// Concurrency is the max number of parallel workers. Default: 1.
+	// Capped by the plugin's manifest maxConcurrency.
+	Concurrency int32 `json:"concurrency"`
+
+	// MaxRetries is the number of times to retry a failed task. Default: 0.
+	MaxRetries int32 `json:"maxRetries"`
+
+	// BackoffMs is the initial backoff between retries in milliseconds.
+	// Doubles each retry (exponential: backoffMs * 2^(attempt-1)). Default: 1000.
+	BackoffMs int64 `json:"backoffMs"`
+
+	// DelayMs is the minimum delay between starting consecutive tasks
+	// in milliseconds. Useful for rate limiting. Default: 0.
+	DelayMs int64 `json:"delayMs"`
+
+	// RetentionMs is how long completed/failed/cancelled tasks are kept
+	// in milliseconds. Default: 3600000 (1h). Min: 60000 (1m). Max: 604800000 (1w).
+	RetentionMs int64 `json:"retentionMs"`
+}
+
+// TaskQueueService provides persistent task queues for plugins.
+//
+// This service allows plugins to create named queues with configurable concurrency,
+// retry policies, and rate limiting. Tasks are persisted to SQLite and survive
+// server restarts. When a task is ready to execute, the host calls the plugin's
+// nd_task_execute callback function.
+//
+//nd:hostservice name=TaskQueue permission=taskqueue
+type TaskQueueService interface {
+	// CreateQueue creates a named task queue with the given configuration.
+	// Zero-value fields in config use sensible defaults.
+	// If a queue with the same name already exists, returns an error.
+	// On startup, this also recovers any stale "running" tasks from a previous crash.
+	//nd:hostfunc
+	CreateQueue(ctx context.Context, name string, config QueueConfig) error
+
+	// Enqueue adds a task to the named queue. Returns the task ID.
+	// payload is opaque bytes passed back to the plugin on execution.
+	//nd:hostfunc
+	Enqueue(ctx context.Context, queueName string, payload []byte) (string, error)
+
+	// GetTaskStatus returns the status of a task: "pending", "running",
+	// "completed", "failed", or "cancelled".
+	//nd:hostfunc
+	GetTaskStatus(ctx context.Context, taskID string) (string, error)
+
+	// CancelTask cancels a pending task. Returns error if already
+	// running, completed, or failed.
+	//nd:hostfunc
+	CancelTask(ctx context.Context, taskID string) error
+}

plugins/host/taskqueue_gen.go

@@ -0,0 +1,220 @@
+// Code generated by ndpgen. DO NOT EDIT.
+
+package host
+
+import (
+	"context"
+	"encoding/json"
+
+	extism "github.com/extism/go-sdk"
+)
+
+// TaskQueueCreateQueueRequest is the request type for TaskQueue.CreateQueue.
+type TaskQueueCreateQueueRequest struct {
+	Name   string      `json:"name"`
+	Config QueueConfig `json:"config"`
+}
+
+// TaskQueueCreateQueueResponse is the response type for TaskQueue.CreateQueue.
+type TaskQueueCreateQueueResponse struct {
+	Error string `json:"error,omitempty"`
+}
+
+// TaskQueueEnqueueRequest is the request type for TaskQueue.Enqueue.
+type TaskQueueEnqueueRequest struct {
+	QueueName string `json:"queueName"`
+	Payload   []byte `json:"payload"`
+}
+
+// TaskQueueEnqueueResponse is the response type for TaskQueue.Enqueue.
+type TaskQueueEnqueueResponse struct {
+	Result string `json:"result,omitempty"`
+	Error  string `json:"error,omitempty"`
+}
+
+// TaskQueueGetTaskStatusRequest is the request type for TaskQueue.GetTaskStatus.
+type TaskQueueGetTaskStatusRequest struct {
+	TaskID string `json:"taskId"`
+}
+
+// TaskQueueGetTaskStatusResponse is the response type for TaskQueue.GetTaskStatus.
+type TaskQueueGetTaskStatusResponse struct {
+	Result string `json:"result,omitempty"`
+	Error  string `json:"error,omitempty"`
+}
+
+// TaskQueueCancelTaskRequest is the request type for TaskQueue.CancelTask.
+type TaskQueueCancelTaskRequest struct {
+	TaskID string `json:"taskId"`
+}
+
+// TaskQueueCancelTaskResponse is the response type for TaskQueue.CancelTask.
+type TaskQueueCancelTaskResponse struct {
+	Error string `json:"error,omitempty"`
+}
+
+// RegisterTaskQueueHostFunctions registers TaskQueue service host functions.
+// The returned host functions should be added to the plugin's configuration.
+func RegisterTaskQueueHostFunctions(service TaskQueueService) []extism.HostFunction {
+	return []extism.HostFunction{
+		newTaskQueueCreateQueueHostFunction(service),
+		newTaskQueueEnqueueHostFunction(service),
+		newTaskQueueGetTaskStatusHostFunction(service),
+		newTaskQueueCancelTaskHostFunction(service),
+	}
+}
+
+func newTaskQueueCreateQueueHostFunction(service TaskQueueService) extism.HostFunction {
+	return extism.NewHostFunctionWithStack(
+		"taskqueue_createqueue",
+		func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
+			// Read JSON request from plugin memory
+			reqBytes, err := p.ReadBytes(stack[0])
+			if err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+			var req TaskQueueCreateQueueRequest
+			if err := json.Unmarshal(reqBytes, &req); err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+
+			// Call the service method
+			if svcErr := service.CreateQueue(ctx, req.Name, req.Config); svcErr != nil {
+				taskqueueWriteError(p, stack, svcErr)
+				return
+			}
+
+			// Write JSON response to plugin memory
+			resp := TaskQueueCreateQueueResponse{}
+			taskqueueWriteResponse(p, stack, resp)
+		},
+		[]extism.ValueType{extism.ValueTypePTR},
+		[]extism.ValueType{extism.ValueTypePTR},
+	)
+}
+
+func newTaskQueueEnqueueHostFunction(service TaskQueueService) extism.HostFunction {
+	return extism.NewHostFunctionWithStack(
+		"taskqueue_enqueue",
+		func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
+			// Read JSON request from plugin memory
+			reqBytes, err := p.ReadBytes(stack[0])
+			if err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+			var req TaskQueueEnqueueRequest
+			if err := json.Unmarshal(reqBytes, &req); err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+
+			// Call the service method
+			result, svcErr := service.Enqueue(ctx, req.QueueName, req.Payload)
+			if svcErr != nil {
+				taskqueueWriteError(p, stack, svcErr)
+				return
+			}
+
+			// Write JSON response to plugin memory
+			resp := TaskQueueEnqueueResponse{
+				Result: result,
+			}
+			taskqueueWriteResponse(p, stack, resp)
+		},
+		[]extism.ValueType{extism.ValueTypePTR},
+		[]extism.ValueType{extism.ValueTypePTR},
+	)
+}
+
+func newTaskQueueGetTaskStatusHostFunction(service TaskQueueService) extism.HostFunction {
+	return extism.NewHostFunctionWithStack(
+		"taskqueue_gettaskstatus",
+		func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
+			// Read JSON request from plugin memory
+			reqBytes, err := p.ReadBytes(stack[0])
+			if err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+			var req TaskQueueGetTaskStatusRequest
+			if err := json.Unmarshal(reqBytes, &req); err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+
+			// Call the service method
+			result, svcErr := service.GetTaskStatus(ctx, req.TaskID)
+			if svcErr != nil {
+				taskqueueWriteError(p, stack, svcErr)
+				return
+			}
+
+			// Write JSON response to plugin memory
+			resp := TaskQueueGetTaskStatusResponse{
+				Result: result,
+			}
+			taskqueueWriteResponse(p, stack, resp)
+		},
+		[]extism.ValueType{extism.ValueTypePTR},
+		[]extism.ValueType{extism.ValueTypePTR},
+	)
+}
+
+func newTaskQueueCancelTaskHostFunction(service TaskQueueService) extism.HostFunction {
+	return extism.NewHostFunctionWithStack(
+		"taskqueue_canceltask",
+		func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
+			// Read JSON request from plugin memory
+			reqBytes, err := p.ReadBytes(stack[0])
+			if err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+			var req TaskQueueCancelTaskRequest
+			if err := json.Unmarshal(reqBytes, &req); err != nil {
+				taskqueueWriteError(p, stack, err)
+				return
+			}
+
+			// Call the service method
+			if svcErr := service.CancelTask(ctx, req.TaskID); svcErr != nil {
+				taskqueueWriteError(p, stack, svcErr)
+				return
+			}
+
+			// Write JSON response to plugin memory
+			resp := TaskQueueCancelTaskResponse{}
+			taskqueueWriteResponse(p, stack, resp)
+		},
+		[]extism.ValueType{extism.ValueTypePTR},
+		[]extism.ValueType{extism.ValueTypePTR},
+	)
+}
+
+// taskqueueWriteResponse writes a JSON response to plugin memory.
+func taskqueueWriteResponse(p *extism.CurrentPlugin, stack []uint64, resp any) {
+	respBytes, err := json.Marshal(resp)
+	if err != nil {
+		taskqueueWriteError(p, stack, err)
+		return
+	}
+	respPtr, err := p.WriteBytes(respBytes)
+	if err != nil {
+		stack[0] = 0
+		return
+	}
+	stack[0] = respPtr
+}
+
+// taskqueueWriteError writes an error response to plugin memory.
+func taskqueueWriteError(p *extism.CurrentPlugin, stack []uint64, err error) {
+	errResp := struct {
+		Error string `json:"error"`
+	}{Error: err.Error()}
+	respBytes, _ := json.Marshal(errResp)
+	respPtr, _ := p.WriteBytes(respBytes)
+	stack[0] = respPtr
+}

plugins/host_scheduler.go

@@ -188,12 +188,6 @@ func (s *schedulerServiceImpl) invokeCallback(ctx context.Context, scheduleID st
 		return
 	}
 
-	// Check if plugin has the scheduler capability
-	if !hasCapability(instance.capabilities, CapabilityScheduler) {
-		log.Warn(ctx, "Plugin does not have scheduler capability", "plugin", s.pluginName, "scheduleID", scheduleID)
-		return
-	}
-
 	// Prepare callback input
 	input := capabilities.SchedulerCallbackRequest{
 		ScheduleID:  scheduleID,

plugins/host_taskqueue.go

@@ -0,0 +1,562 @@
+package plugins
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model/id"
+	"github.com/navidrome/navidrome/plugins/capabilities"
+	"github.com/navidrome/navidrome/plugins/host"
+	"golang.org/x/time/rate"
+)
+
+const (
+	defaultConcurrency int32 = 1
+	defaultBackoffMs   int64 = 1000
+	defaultRetentionMs int64 = 3_600_000   // 1 hour
+	minRetentionMs     int64 = 60_000      // 1 minute
+	maxRetentionMs     int64 = 604_800_000 // 1 week
+	maxQueueNameLength       = 128
+	maxPayloadSize           = 1 * 1024 * 1024 // 1MB
+	maxBackoffMs       int64 = 3_600_000       // 1 hour
+	cleanupInterval          = 5 * time.Minute
+	pollInterval             = 5 * time.Second
+	shutdownTimeout          = 10 * time.Second
+
+	taskStatusPending   = "pending"
+	taskStatusRunning   = "running"
+	taskStatusCompleted = "completed"
+	taskStatusFailed    = "failed"
+	taskStatusCancelled = "cancelled"
+)
+
+// CapabilityTaskWorker indicates the plugin can receive task execution callbacks.
+const CapabilityTaskWorker Capability = "TaskWorker"
+
+const FuncTaskWorkerCallback = "nd_task_execute"
+
+func init() {
+	registerCapability(CapabilityTaskWorker, FuncTaskWorkerCallback)
+}
+
+type queueState struct {
+	config  host.QueueConfig
+	signal  chan struct{}
+	limiter *rate.Limiter
+}
+
+// notifyWorkers sends a non-blocking signal to wake up queue workers.
+func (qs *queueState) notifyWorkers() {
+	select {
+	case qs.signal <- struct{}{}:
+	default:
+	}
+}
+
+// taskQueueServiceImpl implements host.TaskQueueService with SQLite persistence
+// and background worker goroutines for task execution.
+type taskQueueServiceImpl struct {
+	pluginName     string
+	manager        *Manager
+	maxConcurrency int32
+	db             *sql.DB
+	ctx            context.Context
+	cancel         context.CancelFunc
+	wg             sync.WaitGroup
+	mu             sync.Mutex
+	queues         map[string]*queueState
+
+	// For testing: override how callbacks are invoked
+	invokeCallbackFn func(ctx context.Context, queueName, taskID string, payload []byte, attempt int32) error
+}
+
+// newTaskQueueService creates a new taskQueueServiceImpl with its own SQLite database.
+func newTaskQueueService(pluginName string, manager *Manager, maxConcurrency int32) (*taskQueueServiceImpl, error) {
+	dataDir := filepath.Join(conf.Server.DataFolder, "plugins", pluginName)
+	if err := os.MkdirAll(dataDir, 0700); err != nil {
+		return nil, fmt.Errorf("creating plugin data directory: %w", err)
+	}
+
+	dbPath := filepath.Join(dataDir, "taskqueue.db")
+	db, err := sql.Open("sqlite3", dbPath+"?_busy_timeout=5000&_journal_mode=WAL&_foreign_keys=off")
+	if err != nil {
+		return nil, fmt.Errorf("opening taskqueue database: %w", err)
+	}
+
+	db.SetMaxOpenConns(3)
+	db.SetMaxIdleConns(1)
+
+	if err := createTaskQueueSchema(db); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("creating taskqueue schema: %w", err)
+	}
+
+	ctx, cancel := context.WithCancel(manager.ctx)
+
+	s := &taskQueueServiceImpl{
+		pluginName:     pluginName,
+		manager:        manager,
+		maxConcurrency: maxConcurrency,
+		db:             db,
+		ctx:            ctx,
+		cancel:         cancel,
+		queues:         make(map[string]*queueState),
+	}
+	s.invokeCallbackFn = s.defaultInvokeCallback
+
+	s.wg.Go(s.cleanupLoop)
+
+	log.Debug("Initialized plugin taskqueue", "plugin", pluginName, "path", dbPath, "maxConcurrency", maxConcurrency)
+	return s, nil
+}
+
+func createTaskQueueSchema(db *sql.DB) error {
+	_, err := db.Exec(`
+		CREATE TABLE IF NOT EXISTS queues (
+			name TEXT PRIMARY KEY,
+			concurrency INTEGER NOT NULL DEFAULT 1,
+			max_retries INTEGER NOT NULL DEFAULT 0,
+			backoff_ms INTEGER NOT NULL DEFAULT 1000,
+			delay_ms INTEGER NOT NULL DEFAULT 0,
+			retention_ms INTEGER NOT NULL DEFAULT 3600000
+		);
+
+		CREATE TABLE IF NOT EXISTS tasks (
+			id TEXT PRIMARY KEY,
+			queue_name TEXT NOT NULL REFERENCES queues(name),
+			payload BLOB NOT NULL,
+			status TEXT NOT NULL DEFAULT 'pending',
+			attempt INTEGER NOT NULL DEFAULT 0,
+			max_retries INTEGER NOT NULL,
+			next_run_at INTEGER NOT NULL,
+			created_at INTEGER NOT NULL,
+			updated_at INTEGER NOT NULL
+		);
+
+		CREATE INDEX IF NOT EXISTS idx_tasks_dequeue ON tasks(queue_name, status, next_run_at);
+	`)
+	return err
+}
+
+// applyConfigDefaults fills zero-value config fields with sensible defaults
+// and clamps values to valid ranges, logging warnings for clamped values.
+func (s *taskQueueServiceImpl) applyConfigDefaults(ctx context.Context, name string, config *host.QueueConfig) {
+	if config.Concurrency <= 0 {
+		config.Concurrency = defaultConcurrency
+	}
+	if config.BackoffMs <= 0 {
+		config.BackoffMs = defaultBackoffMs
+	}
+	if config.RetentionMs <= 0 {
+		config.RetentionMs = defaultRetentionMs
+	}
+
+	if config.RetentionMs < minRetentionMs {
+		log.Warn(ctx, "TaskQueue retention clamped to minimum", "plugin", s.pluginName, "queue", name,
+			"requested", config.RetentionMs, "min", minRetentionMs)
+		config.RetentionMs = minRetentionMs
+	}
+	if config.RetentionMs > maxRetentionMs {
+		log.Warn(ctx, "TaskQueue retention clamped to maximum", "plugin", s.pluginName, "queue", name,
+			"requested", config.RetentionMs, "max", maxRetentionMs)
+		config.RetentionMs = maxRetentionMs
+	}
+}
+
+// clampConcurrency reduces config.Concurrency if it exceeds the remaining budget.
+// Returns an error when the concurrency budget is fully exhausted.
+// Must be called with s.mu held.
+func (s *taskQueueServiceImpl) clampConcurrency(ctx context.Context, name string, config *host.QueueConfig) error {
+	var allocated int32
+	for _, qs := range s.queues {
+		allocated += qs.config.Concurrency
+	}
+	available := s.maxConcurrency - allocated
+	if available <= 0 {
+		log.Warn(ctx, "TaskQueue concurrency budget exhausted", "plugin", s.pluginName, "queue", name,
+			"allocated", allocated, "maxConcurrency", s.maxConcurrency)
+		return fmt.Errorf("concurrency budget exhausted (%d/%d allocated)", allocated, s.maxConcurrency)
+	}
+	if config.Concurrency > available {
+		log.Warn(ctx, "TaskQueue concurrency clamped", "plugin", s.pluginName, "queue", name,
+			"requested", config.Concurrency, "available", available, "maxConcurrency", s.maxConcurrency)
+		config.Concurrency = available
+	}
+	return nil
+}
+
+func (s *taskQueueServiceImpl) CreateQueue(ctx context.Context, name string, config host.QueueConfig) error {
+	if len(name) == 0 {
+		return fmt.Errorf("queue name cannot be empty")
+	}
+	if len(name) > maxQueueNameLength {
+		return fmt.Errorf("queue name exceeds maximum length of %d bytes", maxQueueNameLength)
+	}
+
+	s.applyConfigDefaults(ctx, name, &config)
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if err := s.clampConcurrency(ctx, name, &config); err != nil {
+		return err
+	}
+
+	if _, exists := s.queues[name]; exists {
+		return fmt.Errorf("queue %q already exists", name)
+	}
+
+	// Upsert into queues table (idempotent across restarts)
+	_, err := s.db.ExecContext(ctx, `
+		INSERT INTO queues (name, concurrency, max_retries, backoff_ms, delay_ms, retention_ms)
+		VALUES (?, ?, ?, ?, ?, ?)
+		ON CONFLICT(name) DO UPDATE SET
+			concurrency = excluded.concurrency,
+			max_retries = excluded.max_retries,
+			backoff_ms = excluded.backoff_ms,
+			delay_ms = excluded.delay_ms,
+			retention_ms = excluded.retention_ms
+	`, name, config.Concurrency, config.MaxRetries, config.BackoffMs, config.DelayMs, config.RetentionMs)
+	if err != nil {
+		return fmt.Errorf("creating queue: %w", err)
+	}
+
+	// Reset stale running tasks from previous crash
+	now := time.Now().UnixMilli()
+	_, err = s.db.ExecContext(ctx, `
+		UPDATE tasks SET status = ?, updated_at = ? WHERE queue_name = ? AND status = ?
+	`, taskStatusPending, now, name, taskStatusRunning)
+	if err != nil {
+		return fmt.Errorf("resetting stale tasks: %w", err)
+	}
+
+	qs := &queueState{
+		config: config,
+		signal: make(chan struct{}, 1),
+	}
+	if config.DelayMs > 0 {
+		// Rate limit dispatches to enforce delay between tasks.
+		// Burst of 1 allows one immediate dispatch, then enforces the delay interval.
+		qs.limiter = rate.NewLimiter(rate.Every(time.Duration(config.DelayMs)*time.Millisecond), 1)
+	}
+	s.queues[name] = qs
+
+	for i := int32(0); i < config.Concurrency; i++ {
+		s.wg.Go(func() { s.worker(name, qs) })
+	}
+
+	log.Debug(ctx, "Created task queue", "plugin", s.pluginName, "queue", name,
+		"concurrency", config.Concurrency, "maxRetries", config.MaxRetries,
+		"backoffMs", config.BackoffMs, "delayMs", config.DelayMs, "retentionMs", config.RetentionMs)
+	return nil
+}
+
+func (s *taskQueueServiceImpl) Enqueue(ctx context.Context, queueName string, payload []byte) (string, error) {
+	s.mu.Lock()
+	qs, exists := s.queues[queueName]
+	s.mu.Unlock()
+
+	if !exists {
+		return "", fmt.Errorf("queue %q does not exist", queueName)
+	}
+	if len(payload) > maxPayloadSize {
+		return "", fmt.Errorf("payload size %d exceeds maximum of %d bytes", len(payload), maxPayloadSize)
+	}
+
+	taskID := id.NewRandom()
+	now := time.Now().UnixMilli()
+
+	_, err := s.db.ExecContext(ctx, `
+		INSERT INTO tasks (id, queue_name, payload, status, attempt, max_retries, next_run_at, created_at, updated_at)
+		VALUES (?, ?, ?, ?, 0, ?, ?, ?, ?)
+	`, taskID, queueName, payload, taskStatusPending, qs.config.MaxRetries, now, now, now)
+	if err != nil {
+		return "", fmt.Errorf("enqueuing task: %w", err)
+	}
+
+	qs.notifyWorkers()
+	log.Trace(ctx, "Enqueued task", "plugin", s.pluginName, "queue", queueName, "taskID", taskID)
+	return taskID, nil
+}
+
+// GetTaskStatus returns the status of a task.
+func (s *taskQueueServiceImpl) GetTaskStatus(ctx context.Context, taskID string) (string, error) {
+	var status string
+	err := s.db.QueryRowContext(ctx, `SELECT status FROM tasks WHERE id = ?`, taskID).Scan(&status)
+	if errors.Is(err, sql.ErrNoRows) {
+		return "", fmt.Errorf("task %q not found", taskID)
+	}
+	if err != nil {
+		return "", fmt.Errorf("getting task status: %w", err)
+	}
+	return status, nil
+}
+
+// CancelTask cancels a pending task.
+func (s *taskQueueServiceImpl) CancelTask(ctx context.Context, taskID string) error {
+	now := time.Now().UnixMilli()
+	result, err := s.db.ExecContext(ctx, `
+		UPDATE tasks SET status = ?, updated_at = ? WHERE id = ? AND status = ?
+	`, taskStatusCancelled, now, taskID, taskStatusPending)
+	if err != nil {
+		return fmt.Errorf("cancelling task: %w", err)
+	}
+
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("checking cancel result: %w", err)
+	}
+
+	if rowsAffected == 0 {
+		// Check if task exists at all
+		var status string
+		err := s.db.QueryRowContext(ctx, `SELECT status FROM tasks WHERE id = ?`, taskID).Scan(&status)
+		if errors.Is(err, sql.ErrNoRows) {
+			return fmt.Errorf("task %q not found", taskID)
+		}
+		if err != nil {
+			return fmt.Errorf("checking task existence: %w", err)
+		}
+		return fmt.Errorf("task %q cannot be cancelled (status: %s)", taskID, status)
+	}
+
+	log.Trace(ctx, "Cancelled task", "plugin", s.pluginName, "taskID", taskID)
+	return nil
+}
+
+// worker is the main loop for a single worker goroutine.
+func (s *taskQueueServiceImpl) worker(queueName string, qs *queueState) {
+	// Process any existing pending tasks immediately on startup
+	s.drainQueue(queueName, qs)
+
+	ticker := time.NewTicker(pollInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			return
+		case <-qs.signal:
+			s.drainQueue(queueName, qs)
+		case <-ticker.C:
+			s.drainQueue(queueName, qs)
+		}
+	}
+}
+
+func (s *taskQueueServiceImpl) drainQueue(queueName string, qs *queueState) {
+	for s.ctx.Err() == nil && s.processTask(queueName, qs) {
+	}
+}
+
+// processTask dequeues and processes a single task. Returns true if a task was processed.
+func (s *taskQueueServiceImpl) processTask(queueName string, qs *queueState) bool {
+	now := time.Now().UnixMilli()
+
+	// Atomically dequeue a task
+	var taskID string
+	var payload []byte
+	var attempt, maxRetries int32
+	err := s.db.QueryRowContext(s.ctx, `
+		UPDATE tasks SET status = ?, attempt = attempt + 1, updated_at = ?
+		WHERE id = (
+			SELECT id FROM tasks
+			WHERE queue_name = ? AND status = ? AND next_run_at <= ?
+			ORDER BY next_run_at, created_at LIMIT 1
+		)
+		RETURNING id, payload, attempt, max_retries
+	`, taskStatusRunning, now, queueName, taskStatusPending, now).Scan(&taskID, &payload, &attempt, &maxRetries)
+	if errors.Is(err, sql.ErrNoRows) {
+		return false
+	}
+	if err != nil {
+		log.Error(s.ctx, "Failed to dequeue task", "plugin", s.pluginName, "queue", queueName, err)
+		return false
+	}
+
+	// Enforce delay between task dispatches using a rate limiter.
+	// This is done after dequeue so that empty polls don't consume rate tokens.
+	if qs.limiter != nil {
+		if err := qs.limiter.Wait(s.ctx); err != nil {
+			// Context cancelled during wait — revert task to pending for recovery
+			s.revertTaskToPending(taskID)
+			return false
+		}
+	}
+
+	// Invoke callback
+	log.Debug(s.ctx, "Executing task", "plugin", s.pluginName, "queue", queueName, "taskID", taskID, "attempt", attempt)
+	callbackErr := s.invokeCallbackFn(s.ctx, queueName, taskID, payload, attempt)
+
+	// If context was cancelled (shutdown), revert task to pending for recovery
+	if s.ctx.Err() != nil {
+		s.revertTaskToPending(taskID)
+		return false
+	}
+
+	if callbackErr == nil {
+		s.completeTask(queueName, taskID)
+	} else {
+		s.handleTaskFailure(queueName, taskID, attempt, maxRetries, qs, callbackErr)
+	}
+	return true
+}
+
+func (s *taskQueueServiceImpl) completeTask(queueName, taskID string) {
+	now := time.Now().UnixMilli()
+	if _, err := s.db.ExecContext(s.ctx, `UPDATE tasks SET status = ?, updated_at = ? WHERE id = ?`, taskStatusCompleted, now, taskID); err != nil {
+		log.Error(s.ctx, "Failed to mark task as completed", "plugin", s.pluginName, "taskID", taskID, err)
+	}
+	log.Debug(s.ctx, "Task completed", "plugin", s.pluginName, "queue", queueName, "taskID", taskID)
+}
+
+func (s *taskQueueServiceImpl) handleTaskFailure(queueName, taskID string, attempt, maxRetries int32, qs *queueState, callbackErr error) {
+	log.Warn(s.ctx, "Task execution failed", "plugin", s.pluginName, "queue", queueName,
+		"taskID", taskID, "attempt", attempt, "maxRetries", maxRetries, "err", callbackErr)
+
+	now := time.Now().UnixMilli()
+	if attempt > maxRetries {
+		if _, err := s.db.ExecContext(s.ctx, `UPDATE tasks SET status = ?, updated_at = ? WHERE id = ?`, taskStatusFailed, now, taskID); err != nil {
+			log.Error(s.ctx, "Failed to mark task as failed", "plugin", s.pluginName, "taskID", taskID, err)
+		}
+		log.Warn(s.ctx, "Task failed after all retries", "plugin", s.pluginName, "queue", queueName, "taskID", taskID)
+		return
+	}
+
+	// Exponential backoff: backoffMs * 2^(attempt-1)
+	backoff := qs.config.BackoffMs << (attempt - 1)
+	if backoff <= 0 || backoff > maxBackoffMs {
+		backoff = maxBackoffMs
+	}
+	nextRunAt := now + backoff
+	if _, err := s.db.ExecContext(s.ctx, `
+		UPDATE tasks SET status = ?, next_run_at = ?, updated_at = ? WHERE id = ?
+	`, taskStatusPending, nextRunAt, now, taskID); err != nil {
+		log.Error(s.ctx, "Failed to reschedule task for retry", "plugin", s.pluginName, "taskID", taskID, err)
+	}
+
+	// Wake worker after backoff expires
+	time.AfterFunc(time.Duration(backoff)*time.Millisecond, func() {
+		qs.notifyWorkers()
+	})
+}
+
+// revertTaskToPending puts a running task back to pending status and decrements the attempt
+// counter (used during shutdown to ensure the interrupted attempt doesn't count).
+func (s *taskQueueServiceImpl) revertTaskToPending(taskID string) {
+	now := time.Now().UnixMilli()
+	_, err := s.db.Exec(`UPDATE tasks SET status = ?, attempt = MAX(attempt - 1, 0), updated_at = ? WHERE id = ? AND status = ?`, taskStatusPending, now, taskID, taskStatusRunning)
+	if err != nil {
+		log.Error("Failed to revert task to pending", "plugin", s.pluginName, "taskID", taskID, err)
+	}
+}
+
+// defaultInvokeCallback calls the plugin's nd_task_execute function.
+func (s *taskQueueServiceImpl) defaultInvokeCallback(ctx context.Context, queueName, taskID string, payload []byte, attempt int32) error {
+	s.manager.mu.RLock()
+	p, ok := s.manager.plugins[s.pluginName]
+	s.manager.mu.RUnlock()
+
+	if !ok {
+		return fmt.Errorf("plugin %s not loaded", s.pluginName)
+	}
+
+	input := capabilities.TaskExecuteRequest{
+		QueueName: queueName,
+		TaskID:    taskID,
+		Payload:   payload,
+		Attempt:   attempt,
+	}
+
+	result, err := callPluginFunction[capabilities.TaskExecuteRequest, capabilities.TaskExecuteResponse](ctx, p, FuncTaskWorkerCallback, input)
+	if err != nil {
+		return err
+	}
+	if result.Error != "" {
+		return fmt.Errorf("%s", result.Error)
+	}
+	return nil
+}
+
+// cleanupLoop periodically removes terminal tasks past their retention period.
+func (s *taskQueueServiceImpl) cleanupLoop() {
+	ticker := time.NewTicker(cleanupInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			return
+		case <-ticker.C:
+			s.runCleanup()
+		}
+	}
+}
+
+// runCleanup deletes terminal tasks past their retention period.
+func (s *taskQueueServiceImpl) runCleanup() {
+	s.mu.Lock()
+	queues := make(map[string]*queueState, len(s.queues))
+	for k, v := range s.queues {
+		queues[k] = v
+	}
+	s.mu.Unlock()
+
+	now := time.Now().UnixMilli()
+	for name, qs := range queues {
+		result, err := s.db.ExecContext(s.ctx, `
+			DELETE FROM tasks WHERE queue_name = ? AND status IN (?, ?, ?) AND updated_at + ? < ?
+		`, name, taskStatusCompleted, taskStatusFailed, taskStatusCancelled, qs.config.RetentionMs, now)
+		if err != nil {
+			log.Error(s.ctx, "Failed to cleanup tasks", "plugin", s.pluginName, "queue", name, err)
+			continue
+		}
+		if deleted, _ := result.RowsAffected(); deleted > 0 {
+			log.Debug(s.ctx, "Cleaned up terminal tasks", "plugin", s.pluginName, "queue", name, "deleted", deleted)
+		}
+	}
+}
+
+// Close shuts down the task queue service, stopping all workers and closing the database.
+func (s *taskQueueServiceImpl) Close() error {
+	// Cancel context to signal all goroutines
+	s.cancel()
+
+	// Wait for goroutines with timeout
+	done := make(chan struct{})
+	go func() {
+		s.wg.Wait()
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(shutdownTimeout):
+		log.Warn("TaskQueue shutdown timed out", "plugin", s.pluginName)
+	}
+
+	// Mark running tasks as pending for recovery on next startup
+	if s.db != nil {
+		now := time.Now().UnixMilli()
+		if _, err := s.db.Exec(`UPDATE tasks SET status = ?, updated_at = ? WHERE status = ?`, taskStatusPending, now, taskStatusRunning); err != nil {
+			log.Error("Failed to reset running tasks on shutdown", "plugin", s.pluginName, err)
+		}
+		log.Debug("Closing plugin taskqueue", "plugin", s.pluginName)
+		return s.db.Close()
+	}
+	return nil
+}
+
+// Compile-time verification
+var _ host.TaskQueueService = (*taskQueueServiceImpl)(nil)
+var _ io.Closer = (*taskQueueServiceImpl)(nil)

plugins/host_taskqueue_test.go

@@ -0,0 +1,968 @@
+//go:build !windows
+
+package plugins
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/plugins/host"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("TaskQueueService", func() {
+	var tmpDir string
+	var service *taskQueueServiceImpl
+	var ctx context.Context
+	var manager *Manager
+
+	BeforeEach(func() {
+		ctx = GinkgoT().Context()
+		var err error
+		tmpDir, err = os.MkdirTemp("", "taskqueue-test-*")
+		Expect(err).ToNot(HaveOccurred())
+
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.DataFolder = tmpDir
+
+		// Create a mock manager with context
+		managerCtx, cancel := context.WithCancel(ctx)
+		manager = &Manager{
+			plugins: make(map[string]*plugin),
+			ctx:     managerCtx,
+		}
+		DeferCleanup(cancel)
+
+		service, err = newTaskQueueService("test_plugin", manager, 5)
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	AfterEach(func() {
+		if service != nil {
+			service.Close()
+		}
+		os.RemoveAll(tmpDir)
+	})
+
+	Describe("CreateQueue", func() {
+		It("creates a queue successfully", func() {
+			err := service.CreateQueue(ctx, "my-queue", host.QueueConfig{
+				Concurrency: 2,
+				MaxRetries:  3,
+				BackoffMs:   2000,
+				RetentionMs: 7200000,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs, exists := service.queues["my-queue"]
+			service.mu.Unlock()
+			Expect(exists).To(BeTrue())
+			Expect(qs.config.Concurrency).To(Equal(int32(2)))
+			Expect(qs.config.MaxRetries).To(Equal(int32(3)))
+			Expect(qs.config.BackoffMs).To(Equal(int64(2000)))
+			Expect(qs.config.RetentionMs).To(Equal(int64(7200000)))
+		})
+
+		It("returns error for duplicate queue name", func() {
+			err := service.CreateQueue(ctx, "dup-queue", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			err = service.CreateQueue(ctx, "dup-queue", host.QueueConfig{})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("already exists"))
+		})
+	})
+
+	Describe("CreateQueue name validation", func() {
+		It("rejects empty queue name", func() {
+			err := service.CreateQueue(ctx, "", host.QueueConfig{})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("queue name cannot be empty"))
+		})
+
+		It("rejects over-length queue name", func() {
+			longName := strings.Repeat("a", maxQueueNameLength+1)
+			err := service.CreateQueue(ctx, longName, host.QueueConfig{})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("exceeds maximum length"))
+		})
+
+		It("accepts queue name at maximum length", func() {
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				return nil
+			}
+			exactName := strings.Repeat("a", maxQueueNameLength)
+			err := service.CreateQueue(ctx, exactName, host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+		})
+	})
+
+	Describe("CreateQueue defaults", func() {
+		It("applies defaults for zero-value config", func() {
+			err := service.CreateQueue(ctx, "defaults-queue", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs := service.queues["defaults-queue"]
+			service.mu.Unlock()
+			Expect(qs.config.Concurrency).To(Equal(defaultConcurrency))
+			Expect(qs.config.BackoffMs).To(Equal(defaultBackoffMs))
+			Expect(qs.config.RetentionMs).To(Equal(defaultRetentionMs))
+		})
+	})
+
+	Describe("CreateQueue defaults with negative values", func() {
+		It("applies default RetentionMs for negative value", func() {
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				return nil
+			}
+			err := service.CreateQueue(ctx, "neg-retention", host.QueueConfig{
+				RetentionMs: -500,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs := service.queues["neg-retention"]
+			service.mu.Unlock()
+			Expect(qs.config.RetentionMs).To(Equal(defaultRetentionMs))
+		})
+	})
+
+	Describe("CreateQueue clamping", func() {
+		It("clamps concurrency exceeding maxConcurrency", func() {
+			// maxConcurrency is 5; request 10
+			err := service.CreateQueue(ctx, "clamped-queue", host.QueueConfig{
+				Concurrency: 10,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs := service.queues["clamped-queue"]
+			service.mu.Unlock()
+			Expect(qs.config.Concurrency).To(Equal(int32(5)))
+		})
+
+		It("returns error when concurrency budget is exhausted", func() {
+			// maxConcurrency is 5; create a queue that uses all 5
+			err := service.CreateQueue(ctx, "full-budget", host.QueueConfig{
+				Concurrency: 5,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Next queue should fail — no budget remaining
+			err = service.CreateQueue(ctx, "over-budget", host.QueueConfig{
+				Concurrency: 1,
+			})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("concurrency budget exhausted"))
+		})
+
+		It("clamps retention below minimum", func() {
+			err := service.CreateQueue(ctx, "low-retention", host.QueueConfig{
+				RetentionMs: 100, // below minRetentionMs
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs := service.queues["low-retention"]
+			service.mu.Unlock()
+			Expect(qs.config.RetentionMs).To(Equal(minRetentionMs))
+		})
+
+		It("clamps retention above maximum", func() {
+			err := service.CreateQueue(ctx, "high-retention", host.QueueConfig{
+				RetentionMs: 999_999_999_999, // above maxRetentionMs
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.mu.Lock()
+			qs := service.queues["high-retention"]
+			service.mu.Unlock()
+			Expect(qs.config.RetentionMs).To(Equal(maxRetentionMs))
+		})
+	})
+
+	Describe("Enqueue", func() {
+		BeforeEach(func() {
+			// Use a no-op callback to prevent actual execution attempts
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				return nil
+			}
+			err := service.CreateQueue(ctx, "enqueue-test", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("enqueues a task and returns task ID", func() {
+			taskID, err := service.Enqueue(ctx, "enqueue-test", []byte("payload"))
+			Expect(err).ToNot(HaveOccurred())
+			Expect(taskID).ToNot(BeEmpty())
+		})
+
+		It("returns error for non-existent queue", func() {
+			_, err := service.Enqueue(ctx, "no-such-queue", []byte("payload"))
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("does not exist"))
+		})
+
+		It("rejects payload exceeding maximum size", func() {
+			bigPayload := make([]byte, maxPayloadSize+1)
+			_, err := service.Enqueue(ctx, "enqueue-test", bigPayload)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("exceeds maximum"))
+		})
+
+		It("accepts payload at maximum size", func() {
+			exactPayload := make([]byte, maxPayloadSize)
+			taskID, err := service.Enqueue(ctx, "enqueue-test", exactPayload)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(taskID).ToNot(BeEmpty())
+		})
+	})
+
+	Describe("GetTaskStatus", func() {
+		BeforeEach(func() {
+			// Use a callback that blocks until context is cancelled so tasks stay pending
+			service.invokeCallbackFn = func(ctx context.Context, _, _ string, _ []byte, _ int32) error {
+				<-ctx.Done()
+				return ctx.Err()
+			}
+		})
+
+		It("returns pending for a new task", func() {
+			err := service.CreateQueue(ctx, "status-test", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "status-test", []byte("data"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// The task may get picked up quickly; check initial status
+			// Since the callback blocks, it should be either pending or running
+			status, err := service.GetTaskStatus(ctx, taskID)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(status).To(BeElementOf("pending", "running"))
+		})
+
+		It("returns error for unknown task ID", func() {
+			_, err := service.GetTaskStatus(ctx, "nonexistent-id")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("not found"))
+		})
+	})
+
+	Describe("CancelTask", func() {
+		BeforeEach(func() {
+			// Block callback so tasks stay in pending/running
+			service.invokeCallbackFn = func(ctx context.Context, _, _ string, _ []byte, _ int32) error {
+				<-ctx.Done()
+				return ctx.Err()
+			}
+		})
+
+		It("cancels a pending task", func() {
+			// Block the callback so the first task occupies the worker
+			started := make(chan struct{})
+			service.invokeCallbackFn = func(ctx context.Context, _, _ string, _ []byte, _ int32) error {
+				close(started)
+				<-ctx.Done()
+				return ctx.Err()
+			}
+
+			err := service.CreateQueue(ctx, "cancel-test", host.QueueConfig{
+				Concurrency: 1,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue a blocker task to occupy the single worker
+			_, err = service.Enqueue(ctx, "cancel-test", []byte("blocker"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Wait for the blocker task to start running
+			Eventually(started).WithTimeout(5 * time.Second).Should(BeClosed())
+
+			// Enqueue a second task — it stays pending since the worker is busy
+			taskID, err := service.Enqueue(ctx, "cancel-test", []byte("cancel-me"))
+			Expect(err).ToNot(HaveOccurred())
+
+			err = service.CancelTask(ctx, taskID)
+			Expect(err).ToNot(HaveOccurred())
+
+			status, err := service.GetTaskStatus(ctx, taskID)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(status).To(Equal("cancelled"))
+		})
+
+		It("returns error for unknown task ID", func() {
+			err := service.CancelTask(ctx, "nonexistent-id")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("not found"))
+		})
+
+		It("returns error for non-pending task", func() {
+			// Create a queue where tasks complete immediately
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				return nil
+			}
+			err := service.CreateQueue(ctx, "completed-test", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "completed-test", []byte("data"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Wait for task to complete
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+
+			// Try to cancel completed task
+			err = service.CancelTask(ctx, taskID)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("cannot be cancelled"))
+		})
+	})
+
+	Describe("Worker execution", func() {
+		It("invokes callback and completes task", func() {
+			var callCount atomic.Int32
+			var receivedQueueName, receivedTaskID string
+			var receivedPayload []byte
+			var receivedAttempt int32
+
+			service.invokeCallbackFn = func(_ context.Context, queueName, taskID string, payload []byte, attempt int32) error {
+				callCount.Add(1)
+				receivedQueueName = queueName
+				receivedTaskID = taskID
+				receivedPayload = payload
+				receivedAttempt = attempt
+				return nil
+			}
+
+			err := service.CreateQueue(ctx, "worker-test", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "worker-test", []byte("test-payload"))
+			Expect(err).ToNot(HaveOccurred())
+
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+
+			Expect(callCount.Load()).To(Equal(int32(1)))
+			Expect(receivedQueueName).To(Equal("worker-test"))
+			Expect(receivedTaskID).To(Equal(taskID))
+			Expect(receivedPayload).To(Equal([]byte("test-payload")))
+			Expect(receivedAttempt).To(Equal(int32(1)))
+		})
+	})
+
+	Describe("Retry on failure", func() {
+		It("retries and eventually fails after exhausting retries", func() {
+			var callCount atomic.Int32
+
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				callCount.Add(1)
+				return fmt.Errorf("task failed")
+			}
+
+			err := service.CreateQueue(ctx, "retry-test", host.QueueConfig{
+				MaxRetries: 2,
+				BackoffMs:  10, // Very short for testing
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "retry-test", []byte("retry-payload"))
+			Expect(err).ToNot(HaveOccurred())
+
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(10 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("failed"))
+
+			// 1 initial attempt + 2 retries = 3 total calls
+			Expect(callCount.Load()).To(Equal(int32(3)))
+		})
+	})
+
+	Describe("Retry then succeed", func() {
+		It("retries and succeeds on second attempt", func() {
+			var callCount atomic.Int32
+
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, attempt int32) error {
+				callCount.Add(1)
+				if attempt == 1 {
+					return fmt.Errorf("temporary error")
+				}
+				return nil
+			}
+
+			err := service.CreateQueue(ctx, "retry-succeed", host.QueueConfig{
+				MaxRetries: 1,
+				BackoffMs:  10, // Very short for testing
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "retry-succeed", []byte("data"))
+			Expect(err).ToNot(HaveOccurred())
+
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(10 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+
+			Expect(callCount.Load()).To(Equal(int32(2)))
+		})
+	})
+
+	Describe("Backoff overflow cap", func() {
+		It("caps backoff at maxRetentionMs to prevent overflow", func() {
+			var callCount atomic.Int32
+
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				callCount.Add(1)
+				return fmt.Errorf("always fail")
+			}
+
+			err := service.CreateQueue(ctx, "backoff-overflow", host.QueueConfig{
+				MaxRetries: 3,
+				BackoffMs:  1_000_000_000, // Very large backoff to trigger overflow on exponentiation
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "backoff-overflow", []byte("overflow-test"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Wait for first attempt to fail
+			Eventually(func() int32 {
+				return callCount.Load()
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(BeNumerically(">=", int32(1)))
+
+			// Check next_run_at is positive and reasonable (capped at maxRetentionMs from now)
+			var nextRunAt int64
+			err = service.db.QueryRow(`SELECT next_run_at FROM tasks WHERE id = ?`, taskID).Scan(&nextRunAt)
+			Expect(err).ToNot(HaveOccurred())
+
+			now := time.Now().UnixMilli()
+			Expect(nextRunAt).To(BeNumerically(">", int64(0)), "next_run_at should be positive")
+			Expect(nextRunAt).To(BeNumerically("<=", now+maxBackoffMs+1000), "next_run_at should be at most maxBackoffMs from now")
+		})
+	})
+
+	Describe("Delay enforcement with concurrent workers", func() {
+		It("enforces delay between dispatches even with multiple workers", func() {
+			var mu sync.Mutex
+			var dispatchTimes []time.Time
+
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				mu.Lock()
+				dispatchTimes = append(dispatchTimes, time.Now())
+				mu.Unlock()
+				return nil
+			}
+
+			err := service.CreateQueue(ctx, "delay-concurrent", host.QueueConfig{
+				Concurrency: 3,
+				DelayMs:     200,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue 5 tasks
+			for i := 0; i < 5; i++ {
+				_, err := service.Enqueue(ctx, "delay-concurrent", []byte(fmt.Sprintf("task-%d", i)))
+				Expect(err).ToNot(HaveOccurred())
+			}
+
+			// Wait for all tasks to complete
+			Eventually(func() int {
+				mu.Lock()
+				defer mu.Unlock()
+				return len(dispatchTimes)
+			}).WithTimeout(10 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal(5))
+
+			// Sort dispatch times and verify gaps
+			mu.Lock()
+			sort.Slice(dispatchTimes, func(i, j int) bool {
+				return dispatchTimes[i].Before(dispatchTimes[j])
+			})
+			times := make([]time.Time, len(dispatchTimes))
+			copy(times, dispatchTimes)
+			mu.Unlock()
+
+			// Consecutive dispatches should have at least ~160ms gap (80% of 200ms)
+			for i := 1; i < len(times); i++ {
+				gap := times[i].Sub(times[i-1])
+				Expect(gap).To(BeNumerically(">=", 160*time.Millisecond),
+					fmt.Sprintf("gap between dispatch %d and %d was %v, expected >= 160ms", i-1, i, gap))
+			}
+		})
+	})
+
+	Describe("Shutdown recovery", func() {
+		It("resets stale running tasks on CreateQueue", func() {
+			// Create a first service and queue, enqueue a task
+			service.invokeCallbackFn = func(ctx context.Context, _, _ string, _ []byte, _ int32) error {
+				<-ctx.Done()
+				return ctx.Err()
+			}
+			err := service.CreateQueue(ctx, "recovery-queue", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID, err := service.Enqueue(ctx, "recovery-queue", []byte("stale-task"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Wait for the task to start running
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("running"))
+
+			// Close the service (simulates crash - tasks left in running state)
+			service.Close()
+
+			// Create a new service pointing to the same DB
+			managerCtx2, cancel2 := context.WithCancel(ctx)
+			DeferCleanup(cancel2)
+			manager2 := &Manager{
+				plugins: make(map[string]*plugin),
+				ctx:     managerCtx2,
+			}
+
+			service, err = newTaskQueueService("test_plugin", manager2, 5)
+			Expect(err).ToNot(HaveOccurred())
+
+			// Override callback to succeed
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error {
+				return nil
+			}
+
+			// Re-create the queue - the upsert handles the existing row from the old service
+			err = service.CreateQueue(ctx, "recovery-queue", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			// The stale running task should now be reset to pending and eventually completed
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID)
+				return status
+			}).WithTimeout(10 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+		})
+	})
+
+	Describe("Close", func() {
+		It("prevents subsequent operations after close", func() {
+			err := service.CreateQueue(ctx, "close-test", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			service.Close()
+
+			// After close, operations should fail
+			_, err = service.Enqueue(ctx, "close-test", []byte("data"))
+			Expect(err).To(HaveOccurred())
+		})
+	})
+
+	Describe("Plugin isolation", func() {
+		It("uses separate databases for different plugins", func() {
+			managerCtx2, cancel2 := context.WithCancel(ctx)
+			DeferCleanup(cancel2)
+			manager2 := &Manager{
+				plugins: make(map[string]*plugin),
+				ctx:     managerCtx2,
+			}
+
+			service2, err := newTaskQueueService("other_plugin", manager2, 5)
+			Expect(err).ToNot(HaveOccurred())
+			defer service2.Close()
+
+			// Check that separate database files exist
+			_, err = os.Stat(filepath.Join(tmpDir, "plugins", "test_plugin", "taskqueue.db"))
+			Expect(err).ToNot(HaveOccurred())
+			_, err = os.Stat(filepath.Join(tmpDir, "plugins", "other_plugin", "taskqueue.db"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Both services should be able to create queues with the same name independently
+			service.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error { return nil }
+			service2.invokeCallbackFn = func(_ context.Context, _, _ string, _ []byte, _ int32) error { return nil }
+
+			err = service.CreateQueue(ctx, "shared-name", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+			err = service2.CreateQueue(ctx, "shared-name", host.QueueConfig{})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue to each and verify they work independently
+			taskID1, err := service.Enqueue(ctx, "shared-name", []byte("plugin1"))
+			Expect(err).ToNot(HaveOccurred())
+			taskID2, err := service2.Enqueue(ctx, "shared-name", []byte("plugin2"))
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(taskID1).ToNot(Equal(taskID2))
+
+			// Both should complete
+			Eventually(func() string {
+				status, _ := service.GetTaskStatus(ctx, taskID1)
+				return status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+
+			Eventually(func() string {
+				status, _ := service2.GetTaskStatus(ctx, taskID2)
+				return status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+		})
+	})
+})
+
+var _ = Describe("TaskQueueService Integration", Ordered, func() {
+	var manager *Manager
+	var tmpDir string
+
+	BeforeAll(func() {
+		var err error
+		tmpDir, err = os.MkdirTemp("", "taskqueue-integration-test-*")
+		Expect(err).ToNot(HaveOccurred())
+
+		// Copy the test-taskqueue plugin
+		srcPath := filepath.Join(testdataDir, "test-taskqueue"+PackageExtension)
+		destPath := filepath.Join(tmpDir, "test-taskqueue"+PackageExtension)
+		data, err := os.ReadFile(srcPath)
+		Expect(err).ToNot(HaveOccurred())
+		err = os.WriteFile(destPath, data, 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		// Compute SHA256 for the plugin
+		hash := sha256.Sum256(data)
+		hashHex := hex.EncodeToString(hash[:])
+
+		// Setup config
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.Plugins.Enabled = true
+		conf.Server.Plugins.Folder = tmpDir
+		conf.Server.Plugins.AutoReload = false
+		conf.Server.CacheFolder = filepath.Join(tmpDir, "cache")
+		conf.Server.DataFolder = tmpDir
+
+		// Setup mock DataStore with pre-enabled plugin
+		mockPluginRepo := tests.CreateMockPluginRepo()
+		mockPluginRepo.Permitted = true
+		mockPluginRepo.SetData(model.Plugins{{
+			ID:      "test-taskqueue",
+			Path:    destPath,
+			SHA256:  hashHex,
+			Enabled: true,
+		}})
+		dataStore := &tests.MockDataStore{MockedPlugin: mockPluginRepo}
+
+		// Create and start manager
+		manager = &Manager{
+			plugins:        make(map[string]*plugin),
+			ds:             dataStore,
+			metrics:        noopMetricsRecorder{},
+			subsonicRouter: http.NotFoundHandler(),
+		}
+		err = manager.Start(GinkgoT().Context())
+		Expect(err).ToNot(HaveOccurred())
+
+		DeferCleanup(func() {
+			_ = manager.Stop()
+			_ = os.RemoveAll(tmpDir)
+		})
+	})
+
+	// Helper types for calling the test plugin
+	type testQueueConfig struct {
+		Concurrency int32 `json:"concurrency,omitempty"`
+		MaxRetries  int32 `json:"maxRetries,omitempty"`
+		BackoffMs   int64 `json:"backoffMs,omitempty"`
+		DelayMs     int64 `json:"delayMs,omitempty"`
+		RetentionMs int64 `json:"retentionMs,omitempty"`
+	}
+
+	type testTaskQueueInput struct {
+		Operation string           `json:"operation"`
+		QueueName string           `json:"queueName,omitempty"`
+		Config    *testQueueConfig `json:"config,omitempty"`
+		Payload   []byte           `json:"payload,omitempty"`
+		TaskID    string           `json:"taskId,omitempty"`
+	}
+
+	type testTaskQueueOutput struct {
+		TaskID string  `json:"taskId,omitempty"`
+		Status string  `json:"status,omitempty"`
+		Error  *string `json:"error,omitempty"`
+	}
+
+	callTestTaskQueue := func(ctx context.Context, input testTaskQueueInput) (*testTaskQueueOutput, error) {
+		manager.mu.RLock()
+		p := manager.plugins["test-taskqueue"]
+		manager.mu.RUnlock()
+
+		instance, err := p.instance(ctx)
+		if err != nil {
+			return nil, err
+		}
+		defer instance.Close(ctx)
+
+		inputBytes, _ := json.Marshal(input)
+		_, outputBytes, err := instance.Call("nd_test_taskqueue", inputBytes)
+		if err != nil {
+			return nil, err
+		}
+
+		var output testTaskQueueOutput
+		if err := json.Unmarshal(outputBytes, &output); err != nil {
+			return nil, err
+		}
+		if output.Error != nil {
+			return nil, errors.New(*output.Error)
+		}
+		return &output, nil
+	}
+
+	Describe("Plugin Loading", func() {
+		It("should load plugin with taskqueue permission and TaskWorker capability", func() {
+			manager.mu.RLock()
+			p, ok := manager.plugins["test-taskqueue"]
+			manager.mu.RUnlock()
+			Expect(ok).To(BeTrue())
+			Expect(p.manifest.Permissions).ToNot(BeNil())
+			Expect(p.manifest.Permissions.Taskqueue).ToNot(BeNil())
+			Expect(p.manifest.Permissions.Taskqueue.MaxConcurrency).To(Equal(10))
+			Expect(p.capabilities).To(ContainElement(CapabilityTaskWorker))
+		})
+	})
+
+	Describe("Create Queue", func() {
+		It("should create a queue without error", func() {
+			ctx := GinkgoT().Context()
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-create",
+			})
+			Expect(err).ToNot(HaveOccurred())
+		})
+
+		It("should return error for duplicate queue name", func() {
+			ctx := GinkgoT().Context()
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-dup",
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			_, err = callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-dup",
+			})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("already exists"))
+		})
+	})
+
+	Describe("Enqueue and Task Completion", func() {
+		It("should enqueue a task and complete successfully", func() {
+			ctx := GinkgoT().Context()
+
+			// Create queue
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-complete",
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue task with payload "hello"
+			output, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "enqueue",
+				QueueName: "test-complete",
+				Payload:   []byte("hello"),
+			})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(output.TaskID).ToNot(BeEmpty())
+
+			taskID := output.TaskID
+
+			// Poll until completed
+			Eventually(func() string {
+				out, err := callTestTaskQueue(ctx, testTaskQueueInput{
+					Operation: "get_task_status",
+					TaskID:    taskID,
+				})
+				if err != nil {
+					return "error"
+				}
+				return out.Status
+			}).WithTimeout(5 * time.Second).WithPolling(100 * time.Millisecond).Should(Equal("completed"))
+		})
+	})
+
+	Describe("Enqueue with Failure, No Retries", func() {
+		It("should fail when payload is 'fail' and maxRetries is 0", func() {
+			ctx := GinkgoT().Context()
+
+			// Create queue with no retries
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-fail-no-retry",
+				Config: &testQueueConfig{
+					MaxRetries: 0,
+				},
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue task that will fail
+			output, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "enqueue",
+				QueueName: "test-fail-no-retry",
+				Payload:   []byte("fail"),
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID := output.TaskID
+
+			// Poll until failed
+			Eventually(func() string {
+				out, err := callTestTaskQueue(ctx, testTaskQueueInput{
+					Operation: "get_task_status",
+					TaskID:    taskID,
+				})
+				if err != nil {
+					return "error"
+				}
+				return out.Status
+			}).WithTimeout(5 * time.Second).WithPolling(100 * time.Millisecond).Should(Equal("failed"))
+		})
+	})
+
+	Describe("Enqueue with Retry Then Success", func() {
+		It("should retry and eventually succeed with 'fail-then-succeed' payload", func() {
+			ctx := GinkgoT().Context()
+
+			// Create queue with retries and short backoff
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-retry-succeed",
+				Config: &testQueueConfig{
+					MaxRetries: 2,
+					BackoffMs:  100,
+				},
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue task that fails on attempt < 2, then succeeds
+			output, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "enqueue",
+				QueueName: "test-retry-succeed",
+				Payload:   []byte("fail-then-succeed"),
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			taskID := output.TaskID
+
+			// Poll until completed
+			Eventually(func() string {
+				out, err := callTestTaskQueue(ctx, testTaskQueueInput{
+					Operation: "get_task_status",
+					TaskID:    taskID,
+				})
+				if err != nil {
+					return "error"
+				}
+				return out.Status
+			}).WithTimeout(5 * time.Second).WithPolling(100 * time.Millisecond).Should(Equal("completed"))
+		})
+	})
+
+	Describe("Cancel Pending Task", func() {
+		It("should cancel a pending task", func() {
+			ctx := GinkgoT().Context()
+
+			// Create queue with concurrency=1 and a large delay between dispatches.
+			// The first task completes immediately (burst token), the second is dequeued
+			// but blocks on the rate limiter. Tasks 3+ remain in 'pending' and can be cancelled.
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "create_queue",
+				QueueName: "test-cancel",
+				Config: &testQueueConfig{
+					Concurrency: 1,
+					DelayMs:     60000,
+				},
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Enqueue several tasks - the first will complete immediately,
+			// the second will be dequeued but block on the rate limiter (status=running),
+			// the rest will stay pending.
+			var taskIDs []string
+			for i := 0; i < 5; i++ {
+				output, err := callTestTaskQueue(ctx, testTaskQueueInput{
+					Operation: "enqueue",
+					QueueName: "test-cancel",
+					Payload:   []byte("hello"),
+				})
+				Expect(err).ToNot(HaveOccurred())
+				taskIDs = append(taskIDs, output.TaskID)
+			}
+
+			// Wait for the first task to complete (it has no delay)
+			Eventually(func() string {
+				out, err := callTestTaskQueue(ctx, testTaskQueueInput{
+					Operation: "get_task_status",
+					TaskID:    taskIDs[0],
+				})
+				if err != nil {
+					return "error"
+				}
+				return out.Status
+			}).WithTimeout(5 * time.Second).WithPolling(50 * time.Millisecond).Should(Equal("completed"))
+
+			// Give the worker a moment to dequeue the second task (which will
+			// block on the delay) so tasks 3+ stay in 'pending'
+			time.Sleep(100 * time.Millisecond)
+
+			// Cancel the last task - it should still be pending
+			lastTaskID := taskIDs[len(taskIDs)-1]
+			_, err = callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "cancel_task",
+				TaskID:    lastTaskID,
+			})
+			Expect(err).ToNot(HaveOccurred())
+
+			// Verify status is cancelled
+			statusOut, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "get_task_status",
+				TaskID:    lastTaskID,
+			})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(statusOut.Status).To(Equal("cancelled"))
+		})
+	})
+
+	Describe("Enqueue to Non-Existent Queue", func() {
+		It("should return error when enqueueing to a queue that does not exist", func() {
+			ctx := GinkgoT().Context()
+
+			_, err := callTestTaskQueue(ctx, testTaskQueueInput{
+				Operation: "enqueue",
+				QueueName: "nonexistent-queue",
+				Payload:   []byte("payload"),
+			})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("does not exist"))
+		})
+	})
+})

plugins/manager_loader.go

@@ -128,6 +128,23 @@ var hostServices = []hostServiceEntry{
 			return host.RegisterHTTPHostFunctions(service), nil
 		},
 	},
+	{
+		name:          "TaskQueue",
+		hasPermission: func(p *Permissions) bool { return p != nil && p.Taskqueue != nil },
+		create: func(ctx *serviceContext) ([]extism.HostFunction, io.Closer) {
+			perm := ctx.permissions.Taskqueue
+			maxConcurrency := int32(1)
+			if perm.MaxConcurrency > 0 {
+				maxConcurrency = int32(perm.MaxConcurrency)
+			}
+			service, err := newTaskQueueService(ctx.pluginName, ctx.manager, maxConcurrency)
+			if err != nil {
+				log.Error("Failed to create TaskQueue service", "plugin", ctx.pluginName, err)
+				return nil, nil
+			}
+			return host.RegisterTaskQueueHostFunctions(service), service
+		},
+	},
 }
 
 // extractManifest reads manifest from an .ndp package and computes its SHA-256 hash.

plugins/manifest-schema.json

@@ -110,6 +110,9 @@
         },
         "users": {
           "$ref": "#/$defs/UsersPermission"
+        },
+        "taskqueue": {
+          "$ref": "#/$defs/TaskQueuePermission"
         }
       }
     },
@@ -224,6 +227,23 @@
         }
       }
     },
+    "TaskQueuePermission": {
+      "type": "object",
+      "description": "Task queue permissions for background task processing",
+      "additionalProperties": false,
+      "properties": {
+        "reason": {
+          "type": "string",
+          "description": "Explanation for why task queue access is needed"
+        },
+        "maxConcurrency": {
+          "type": "integer",
+          "description": "Maximum total concurrent workers across all queues. Default: 1",
+          "minimum": 1,
+          "default": 1
+        }
+      }
+    },
     "UsersPermission": {
       "type": "object",
       "description": "Users service permissions for accessing user information",

plugins/manifest.go

@@ -64,6 +64,21 @@ func ValidateWithCapabilities(m *Manifest, capabilities []Capability) error {
 			return fmt.Errorf("scrobbler capability requires 'users' permission to be declared in manifest")
 		}
 	}
+
+	// Scheduler permission requires SchedulerCallback capability
+	if m.Permissions != nil && m.Permissions.Scheduler != nil {
+		if !hasCapability(capabilities, CapabilityScheduler) {
+			return fmt.Errorf("'scheduler' permission requires plugin to export '%s' function", FuncSchedulerCallback)
+		}
+	}
+
+	// TaskQueue permission requires TaskWorker capability
+	if m.Permissions != nil && m.Permissions.Taskqueue != nil {
+		if !hasCapability(capabilities, CapabilityTaskWorker) {
+			return fmt.Errorf("'taskqueue' permission requires plugin to export '%s' function", FuncTaskWorkerCallback)
+		}
+	}
+
 	return nil
 }
 

plugins/manifest_gen.go

@@ -181,6 +181,9 @@ type Permissions struct {
 	// Subsonicapi corresponds to the JSON schema field "subsonicapi".
 	Subsonicapi *SubsonicAPIPermission `json:"subsonicapi,omitempty" yaml:"subsonicapi,omitempty" mapstructure:"subsonicapi,omitempty"`
 
+	// Taskqueue corresponds to the JSON schema field "taskqueue".
+	Taskqueue *TaskQueuePermission `json:"taskqueue,omitempty" yaml:"taskqueue,omitempty" mapstructure:"taskqueue,omitempty"`
+
 	// Users corresponds to the JSON schema field "users".
 	Users *UsersPermission `json:"users,omitempty" yaml:"users,omitempty" mapstructure:"users,omitempty"`
 
@@ -200,6 +203,36 @@ type SubsonicAPIPermission struct {
 	Reason *string `json:"reason,omitempty" yaml:"reason,omitempty" mapstructure:"reason,omitempty"`
 }
 
+// Task queue permissions for background task processing
+type TaskQueuePermission struct {
+	// Maximum total concurrent workers across all queues. Default: 1
+	MaxConcurrency int `json:"maxConcurrency,omitempty" yaml:"maxConcurrency,omitempty" mapstructure:"maxConcurrency,omitempty"`
+
+	// Explanation for why task queue access is needed
+	Reason *string `json:"reason,omitempty" yaml:"reason,omitempty" mapstructure:"reason,omitempty"`
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *TaskQueuePermission) UnmarshalJSON(value []byte) error {
+	var raw map[string]interface{}
+	if err := json.Unmarshal(value, &raw); err != nil {
+		return err
+	}
+	type Plain TaskQueuePermission
+	var plain Plain
+	if err := json.Unmarshal(value, &plain); err != nil {
+		return err
+	}
+	if v, ok := raw["maxConcurrency"]; !ok || v == nil {
+		plain.MaxConcurrency = 1.0
+	}
+	if 1 > plain.MaxConcurrency {
+		return fmt.Errorf("field %s: must be >= %v", "maxConcurrency", 1)
+	}
+	*j = TaskQueuePermission(plain)
+	return nil
+}
+
 // Enable experimental WebAssembly threads support
 type ThreadsFeature struct {
 	// Explanation for why threads support is needed

plugins/pdk/go/go.mod

@@ -6,3 +6,10 @@ require (
 	github.com/extism/go-pdk v1.1.3
 	github.com/stretchr/testify v1.11.1
 )
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

plugins/pdk/go/host/doc.go

@@ -43,6 +43,7 @@ The following host services are available:
   - Library: provides access to music library metadata for plugins.
   - Scheduler: provides task scheduling capabilities for plugins.
   - SubsonicAPI: provides access to Navidrome's Subsonic API from plugins.
+  - TaskQueue: provides persistent task queues for plugins.
   - Users: provides access to user information for plugins.
   - WebSocket: provides WebSocket communication capabilities for plugins.
 

plugins/pdk/go/host/nd_host_http.go

@@ -14,6 +14,7 @@ import (
 	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
 )
 
+// HTTPRequest represents the HTTPRequest data structure.
 // HTTPRequest represents an outbound HTTP request from a plugin.
 type HTTPRequest struct {
 	Method    string            `json:"method"`
@@ -23,6 +24,7 @@ type HTTPRequest struct {
 	TimeoutMs int32             `json:"timeoutMs"`
 }
 
+// HTTPResponse represents the HTTPResponse data structure.
 // HTTPResponse represents the response from an outbound HTTP request.
 type HTTPResponse struct {
 	StatusCode int32             `json:"statusCode"`
@@ -35,11 +37,11 @@ type HTTPResponse struct {
 //go:wasmimport extism:host/user http_send
 func http_send(uint64) uint64
 
-type httpSendRequest struct {
+type hTTPSendRequest struct {
 	Request HTTPRequest `json:"request"`
 }
 
-type httpSendResponse struct {
+type hTTPSendResponse struct {
 	Result *HTTPResponse `json:"result,omitempty"`
 	Error  string        `json:"error,omitempty"`
 }
@@ -55,7 +57,7 @@ type httpSendResponse struct {
 // Successful HTTP calls (including 4xx/5xx status codes) return a non-nil response with nil error.
 func HTTPSend(request HTTPRequest) (*HTTPResponse, error) {
 	// Marshal request to JSON
-	req := httpSendRequest{
+	req := hTTPSendRequest{
 		Request: request,
 	}
 	reqBytes, err := json.Marshal(req)
@@ -73,7 +75,7 @@ func HTTPSend(request HTTPRequest) (*HTTPResponse, error) {
 	responseBytes := responseMem.ReadBytes()
 
 	// Parse the response
-	var response httpSendResponse
+	var response hTTPSendResponse
 	if err := json.Unmarshal(responseBytes, &response); err != nil {
 		return nil, err
 	}

plugins/pdk/go/host/nd_host_http_stub.go

@@ -10,6 +10,7 @@ package host
 
 import "github.com/stretchr/testify/mock"
 
+// HTTPRequest represents the HTTPRequest data structure.
 // HTTPRequest represents an outbound HTTP request from a plugin.
 type HTTPRequest struct {
 	Method    string            `json:"method"`
@@ -19,6 +20,7 @@ type HTTPRequest struct {
 	TimeoutMs int32             `json:"timeoutMs"`
 }
 
+// HTTPResponse represents the HTTPResponse data structure.
 // HTTPResponse represents the response from an outbound HTTP request.
 type HTTPResponse struct {
 	StatusCode int32             `json:"statusCode"`

plugins/pdk/go/host/nd_host_taskqueue.go

@@ -0,0 +1,219 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains client wrappers for the TaskQueue host service.
+// It is intended for use in Navidrome plugins built with TinyGo.
+//
+//go:build wasip1
+
+package host
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+)
+
+// QueueConfig represents the QueueConfig data structure.
+// QueueConfig holds configuration for a task queue.
+type QueueConfig struct {
+	Concurrency int32 `json:"concurrency"`
+	MaxRetries  int32 `json:"maxRetries"`
+	BackoffMs   int64 `json:"backoffMs"`
+	DelayMs     int64 `json:"delayMs"`
+	RetentionMs int64 `json:"retentionMs"`
+}
+
+// taskqueue_createqueue is the host function provided by Navidrome.
+//
+//go:wasmimport extism:host/user taskqueue_createqueue
+func taskqueue_createqueue(uint64) uint64
+
+// taskqueue_enqueue is the host function provided by Navidrome.
+//
+//go:wasmimport extism:host/user taskqueue_enqueue
+func taskqueue_enqueue(uint64) uint64
+
+// taskqueue_gettaskstatus is the host function provided by Navidrome.
+//
+//go:wasmimport extism:host/user taskqueue_gettaskstatus
+func taskqueue_gettaskstatus(uint64) uint64
+
+// taskqueue_canceltask is the host function provided by Navidrome.
+//
+//go:wasmimport extism:host/user taskqueue_canceltask
+func taskqueue_canceltask(uint64) uint64
+
+type taskQueueCreateQueueRequest struct {
+	Name   string      `json:"name"`
+	Config QueueConfig `json:"config"`
+}
+
+type taskQueueEnqueueRequest struct {
+	QueueName string `json:"queueName"`
+	Payload   []byte `json:"payload"`
+}
+
+type taskQueueEnqueueResponse struct {
+	Result string `json:"result,omitempty"`
+	Error  string `json:"error,omitempty"`
+}
+
+type taskQueueGetTaskStatusRequest struct {
+	TaskID string `json:"taskId"`
+}
+
+type taskQueueGetTaskStatusResponse struct {
+	Result string `json:"result,omitempty"`
+	Error  string `json:"error,omitempty"`
+}
+
+type taskQueueCancelTaskRequest struct {
+	TaskID string `json:"taskId"`
+}
+
+// TaskQueueCreateQueue calls the taskqueue_createqueue host function.
+// CreateQueue creates a named task queue with the given configuration.
+// Zero-value fields in config use sensible defaults.
+// If a queue with the same name already exists, returns an error.
+// On startup, this also recovers any stale "running" tasks from a previous crash.
+func TaskQueueCreateQueue(name string, config QueueConfig) error {
+	// Marshal request to JSON
+	req := taskQueueCreateQueueRequest{
+		Name:   name,
+		Config: config,
+	}
+	reqBytes, err := json.Marshal(req)
+	if err != nil {
+		return err
+	}
+	reqMem := pdk.AllocateBytes(reqBytes)
+	defer reqMem.Free()
+
+	// Call the host function
+	responsePtr := taskqueue_createqueue(reqMem.Offset())
+
+	// Read the response from memory
+	responseMem := pdk.FindMemory(responsePtr)
+	responseBytes := responseMem.ReadBytes()
+
+	// Parse error-only response
+	var response struct {
+		Error string `json:"error,omitempty"`
+	}
+	if err := json.Unmarshal(responseBytes, &response); err != nil {
+		return err
+	}
+	if response.Error != "" {
+		return errors.New(response.Error)
+	}
+	return nil
+}
+
+// TaskQueueEnqueue calls the taskqueue_enqueue host function.
+// Enqueue adds a task to the named queue. Returns the task ID.
+// payload is opaque bytes passed back to the plugin on execution.
+func TaskQueueEnqueue(queueName string, payload []byte) (string, error) {
+	// Marshal request to JSON
+	req := taskQueueEnqueueRequest{
+		QueueName: queueName,
+		Payload:   payload,
+	}
+	reqBytes, err := json.Marshal(req)
+	if err != nil {
+		return "", err
+	}
+	reqMem := pdk.AllocateBytes(reqBytes)
+	defer reqMem.Free()
+
+	// Call the host function
+	responsePtr := taskqueue_enqueue(reqMem.Offset())
+
+	// Read the response from memory
+	responseMem := pdk.FindMemory(responsePtr)
+	responseBytes := responseMem.ReadBytes()
+
+	// Parse the response
+	var response taskQueueEnqueueResponse
+	if err := json.Unmarshal(responseBytes, &response); err != nil {
+		return "", err
+	}
+
+	// Convert Error field to Go error
+	if response.Error != "" {
+		return "", errors.New(response.Error)
+	}
+
+	return response.Result, nil
+}
+
+// TaskQueueGetTaskStatus calls the taskqueue_gettaskstatus host function.
+// GetTaskStatus returns the status of a task: "pending", "running",
+// "completed", "failed", or "cancelled".
+func TaskQueueGetTaskStatus(taskID string) (string, error) {
+	// Marshal request to JSON
+	req := taskQueueGetTaskStatusRequest{
+		TaskID: taskID,
+	}
+	reqBytes, err := json.Marshal(req)
+	if err != nil {
+		return "", err
+	}
+	reqMem := pdk.AllocateBytes(reqBytes)
+	defer reqMem.Free()
+
+	// Call the host function
+	responsePtr := taskqueue_gettaskstatus(reqMem.Offset())
+
+	// Read the response from memory
+	responseMem := pdk.FindMemory(responsePtr)
+	responseBytes := responseMem.ReadBytes()
+
+	// Parse the response
+	var response taskQueueGetTaskStatusResponse
+	if err := json.Unmarshal(responseBytes, &response); err != nil {
+		return "", err
+	}
+
+	// Convert Error field to Go error
+	if response.Error != "" {
+		return "", errors.New(response.Error)
+	}
+
+	return response.Result, nil
+}
+
+// TaskQueueCancelTask calls the taskqueue_canceltask host function.
+// CancelTask cancels a pending task. Returns error if already
+// running, completed, or failed.
+func TaskQueueCancelTask(taskID string) error {
+	// Marshal request to JSON
+	req := taskQueueCancelTaskRequest{
+		TaskID: taskID,
+	}
+	reqBytes, err := json.Marshal(req)
+	if err != nil {
+		return err
+	}
+	reqMem := pdk.AllocateBytes(reqBytes)
+	defer reqMem.Free()
+
+	// Call the host function
+	responsePtr := taskqueue_canceltask(reqMem.Offset())
+
+	// Read the response from memory
+	responseMem := pdk.FindMemory(responsePtr)
+	responseBytes := responseMem.ReadBytes()
+
+	// Parse error-only response
+	var response struct {
+		Error string `json:"error,omitempty"`
+	}
+	if err := json.Unmarshal(responseBytes, &response); err != nil {
+		return err
+	}
+	if response.Error != "" {
+		return errors.New(response.Error)
+	}
+	return nil
+}

plugins/pdk/go/host/nd_host_taskqueue_stub.go

@@ -0,0 +1,84 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains mock implementations for non-WASM builds.
+// These mocks allow IDE support, compilation, and unit testing on non-WASM platforms.
+// Plugin authors can use the exported mock instances to set expectations in tests.
+//
+//go:build !wasip1
+
+package host
+
+import "github.com/stretchr/testify/mock"
+
+// QueueConfig represents the QueueConfig data structure.
+// QueueConfig holds configuration for a task queue.
+type QueueConfig struct {
+	Concurrency int32 `json:"concurrency"`
+	MaxRetries  int32 `json:"maxRetries"`
+	BackoffMs   int64 `json:"backoffMs"`
+	DelayMs     int64 `json:"delayMs"`
+	RetentionMs int64 `json:"retentionMs"`
+}
+
+// mockTaskQueueService is the mock implementation for testing.
+type mockTaskQueueService struct {
+	mock.Mock
+}
+
+// TaskQueueMock is the auto-instantiated mock instance for testing.
+// Use this to set expectations: host.TaskQueueMock.On("MethodName", args...).Return(values...)
+var TaskQueueMock = &mockTaskQueueService{}
+
+// CreateQueue is the mock method for TaskQueueCreateQueue.
+func (m *mockTaskQueueService) CreateQueue(name string, config QueueConfig) error {
+	args := m.Called(name, config)
+	return args.Error(0)
+}
+
+// TaskQueueCreateQueue delegates to the mock instance.
+// CreateQueue creates a named task queue with the given configuration.
+// Zero-value fields in config use sensible defaults.
+// If a queue with the same name already exists, returns an error.
+// On startup, this also recovers any stale "running" tasks from a previous crash.
+func TaskQueueCreateQueue(name string, config QueueConfig) error {
+	return TaskQueueMock.CreateQueue(name, config)
+}
+
+// Enqueue is the mock method for TaskQueueEnqueue.
+func (m *mockTaskQueueService) Enqueue(queueName string, payload []byte) (string, error) {
+	args := m.Called(queueName, payload)
+	return args.String(0), args.Error(1)
+}
+
+// TaskQueueEnqueue delegates to the mock instance.
+// Enqueue adds a task to the named queue. Returns the task ID.
+// payload is opaque bytes passed back to the plugin on execution.
+func TaskQueueEnqueue(queueName string, payload []byte) (string, error) {
+	return TaskQueueMock.Enqueue(queueName, payload)
+}
+
+// GetTaskStatus is the mock method for TaskQueueGetTaskStatus.
+func (m *mockTaskQueueService) GetTaskStatus(taskID string) (string, error) {
+	args := m.Called(taskID)
+	return args.String(0), args.Error(1)
+}
+
+// TaskQueueGetTaskStatus delegates to the mock instance.
+// GetTaskStatus returns the status of a task: "pending", "running",
+// "completed", "failed", or "cancelled".
+func TaskQueueGetTaskStatus(taskID string) (string, error) {
+	return TaskQueueMock.GetTaskStatus(taskID)
+}
+
+// CancelTask is the mock method for TaskQueueCancelTask.
+func (m *mockTaskQueueService) CancelTask(taskID string) error {
+	args := m.Called(taskID)
+	return args.Error(0)
+}
+
+// TaskQueueCancelTask delegates to the mock instance.
+// CancelTask cancels a pending task. Returns error if already
+// running, completed, or failed.
+func TaskQueueCancelTask(taskID string) error {
+	return TaskQueueMock.CancelTask(taskID)
+}

plugins/pdk/go/taskworker/taskworker.go

@@ -0,0 +1,86 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains export wrappers for the TaskWorker capability.
+// It is intended for use in Navidrome plugins built with TinyGo.
+//
+//go:build wasip1
+
+package taskworker
+
+import (
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+)
+
+// TaskExecuteRequest is the request provided when a task is ready to execute.
+type TaskExecuteRequest struct {
+	// QueueName is the name of the queue this task belongs to.
+	QueueName string `json:"queueName"`
+	// TaskID is the unique identifier for this task.
+	TaskID string `json:"taskId"`
+	// Payload is the opaque data provided when the task was enqueued.
+	Payload []byte `json:"payload"`
+	// Attempt is the current attempt number (1-based: first attempt = 1).
+	Attempt int32 `json:"attempt"`
+}
+
+// TaskExecuteResponse is the response from task execution.
+type TaskExecuteResponse struct {
+	// Error, if non-empty, indicates the task failed. The task will be retried
+	// if retries are configured and attempts remain.
+	Error string `json:"error,omitempty"`
+}
+
+// TaskWorker is the marker interface for taskworker plugins.
+// Implement one or more of the provider interfaces below.
+// TaskWorker provides task execution handling.
+// This capability allows plugins to receive callbacks when their queued tasks
+// are ready to execute. Plugins that use the taskqueue host service must
+// implement this capability.
+type TaskWorker interface{}
+
+// TaskExecuteProvider provides the OnTaskExecute function.
+type TaskExecuteProvider interface {
+	OnTaskExecute(TaskExecuteRequest) (TaskExecuteResponse, error)
+} // Internal implementation holders
+var (
+	taskExecuteImpl func(TaskExecuteRequest) (TaskExecuteResponse, error)
+)
+
+// Register registers a taskworker implementation.
+// The implementation is checked for optional provider interfaces.
+func Register(impl TaskWorker) {
+	if p, ok := impl.(TaskExecuteProvider); ok {
+		taskExecuteImpl = p.OnTaskExecute
+	}
+}
+
+// NotImplementedCode is the standard return code for unimplemented functions.
+// The host recognizes this and skips the plugin gracefully.
+const NotImplementedCode int32 = -2
+
+//go:wasmexport nd_task_execute
+func _NdTaskExecute() int32 {
+	if taskExecuteImpl == nil {
+		// Return standard code - host will skip this plugin gracefully
+		return NotImplementedCode
+	}
+
+	var input TaskExecuteRequest
+	if err := pdk.InputJSON(&input); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+
+	output, err := taskExecuteImpl(input)
+	if err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+
+	if err := pdk.OutputJSON(output); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+
+	return 0
+}

plugins/pdk/go/taskworker/taskworker_stub.go

@@ -0,0 +1,48 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file provides stub implementations for non-WASM platforms.
+// It allows Go plugins to compile and run tests outside of WASM,
+// but the actual functionality is only available in WASM builds.
+//
+//go:build !wasip1
+
+package taskworker
+
+// TaskExecuteRequest is the request provided when a task is ready to execute.
+type TaskExecuteRequest struct {
+	// QueueName is the name of the queue this task belongs to.
+	QueueName string `json:"queueName"`
+	// TaskID is the unique identifier for this task.
+	TaskID string `json:"taskId"`
+	// Payload is the opaque data provided when the task was enqueued.
+	Payload []byte `json:"payload"`
+	// Attempt is the current attempt number (1-based: first attempt = 1).
+	Attempt int32 `json:"attempt"`
+}
+
+// TaskExecuteResponse is the response from task execution.
+type TaskExecuteResponse struct {
+	// Error, if non-empty, indicates the task failed. The task will be retried
+	// if retries are configured and attempts remain.
+	Error string `json:"error,omitempty"`
+}
+
+// TaskWorker is the marker interface for taskworker plugins.
+// Implement one or more of the provider interfaces below.
+// TaskWorker provides task execution handling.
+// This capability allows plugins to receive callbacks when their queued tasks
+// are ready to execute. Plugins that use the taskqueue host service must
+// implement this capability.
+type TaskWorker interface{}
+
+// TaskExecuteProvider provides the OnTaskExecute function.
+type TaskExecuteProvider interface {
+	OnTaskExecute(TaskExecuteRequest) (TaskExecuteResponse, error)
+}
+
+// NotImplementedCode is the standard return code for unimplemented functions.
+const NotImplementedCode int32 = -2
+
+// Register is a no-op on non-WASM platforms.
+// This stub allows code to compile outside of WASM.
+func Register(_ TaskWorker) {}

plugins/pdk/python/host/nd_host_http.py

@@ -0,0 +1,59 @@
+# Code generated by ndpgen. DO NOT EDIT.
+#
+# This file contains client wrappers for the HTTP host service.
+# It is intended for use in Navidrome plugins built with extism-py.
+#
+# IMPORTANT: Due to a limitation in extism-py, you cannot import this file directly.
+# The @extism.import_fn decorators are only detected when defined in the plugin's
+# main __init__.py file. Copy the needed functions from this file into your plugin.
+
+from dataclasses import dataclass
+from typing import Any
+
+import extism
+import json
+
+
+class HostFunctionError(Exception):
+    """Raised when a host function returns an error."""
+    pass
+
+
+@extism.import_fn("extism:host/user", "http_send")
+def _http_send(offset: int) -> int:
+    """Raw host function - do not call directly."""
+    ...
+
+
+def http_send(request: Any) -> Any:
+    """Send executes an HTTP request and returns the response.
+
+Parameters:
+  - request: The HTTP request to execute, including method, URL, headers, body, and timeout
+
+Returns the HTTP response with status code, headers, and body.
+Network errors, timeouts, and permission failures are returned as Go errors.
+Successful HTTP calls (including 4xx/5xx status codes) return a non-nil response with nil error.
+
+    Args:
+        request: Any parameter.
+
+    Returns:
+        Any: The result value.
+
+    Raises:
+        HostFunctionError: If the host function returns an error.
+    """
+    request = {
+        "request": request,
+    }
+    request_bytes = json.dumps(request).encode("utf-8")
+    request_mem = extism.memory.alloc(request_bytes)
+    response_offset = _http_send(request_mem.offset)
+    response_mem = extism.memory.find(response_offset)
+    response = json.loads(extism.memory.string(response_mem))
+
+    if response.get("error"):
+        raise HostFunctionError(response["error"])
+
+    return response.get("result", None)

plugins/pdk/python/host/nd_host_taskqueue.py

@@ -0,0 +1,153 @@
+# Code generated by ndpgen. DO NOT EDIT.
+#
+# This file contains client wrappers for the TaskQueue host service.
+# It is intended for use in Navidrome plugins built with extism-py.
+#
+# IMPORTANT: Due to a limitation in extism-py, you cannot import this file directly.
+# The @extism.import_fn decorators are only detected when defined in the plugin's
+# main __init__.py file. Copy the needed functions from this file into your plugin.
+
+from dataclasses import dataclass
+from typing import Any
+
+import extism
+import json
+
+
+class HostFunctionError(Exception):
+    """Raised when a host function returns an error."""
+    pass
+
+
+@extism.import_fn("extism:host/user", "taskqueue_createqueue")
+def _taskqueue_createqueue(offset: int) -> int:
+    """Raw host function - do not call directly."""
+    ...
+
+
+@extism.import_fn("extism:host/user", "taskqueue_enqueue")
+def _taskqueue_enqueue(offset: int) -> int:
+    """Raw host function - do not call directly."""
+    ...
+
+
+@extism.import_fn("extism:host/user", "taskqueue_gettaskstatus")
+def _taskqueue_gettaskstatus(offset: int) -> int:
+    """Raw host function - do not call directly."""
+    ...
+
+
+@extism.import_fn("extism:host/user", "taskqueue_canceltask")
+def _taskqueue_canceltask(offset: int) -> int:
+    """Raw host function - do not call directly."""
+    ...
+
+
+def taskqueue_create_queue(name: str, config: Any) -> None:
+    """CreateQueue creates a named task queue with the given configuration.
+Zero-value fields in config use sensible defaults.
+If a queue with the same name already exists, returns an error.
+On startup, this also recovers any stale "running" tasks from a previous crash.
+
+    Args:
+        name: str parameter.
+        config: Any parameter.
+
+    Raises:
+        HostFunctionError: If the host function returns an error.
+    """
+    request = {
+        "name": name,
+        "config": config,
+    }
+    request_bytes = json.dumps(request).encode("utf-8")
+    request_mem = extism.memory.alloc(request_bytes)
+    response_offset = _taskqueue_createqueue(request_mem.offset)
+    response_mem = extism.memory.find(response_offset)
+    response = json.loads(extism.memory.string(response_mem))
+
+    if response.get("error"):
+        raise HostFunctionError(response["error"])
+
+
+
+def taskqueue_enqueue(queue_name: str, payload: bytes) -> str:
+    """Enqueue adds a task to the named queue. Returns the task ID.
+payload is opaque bytes passed back to the plugin on execution.
+
+    Args:
+        queue_name: str parameter.
+        payload: bytes parameter.
+
+    Returns:
+        str: The result value.
+
+    Raises:
+        HostFunctionError: If the host function returns an error.
+    """
+    request = {
+        "queueName": queue_name,
+        "payload": payload,
+    }
+    request_bytes = json.dumps(request).encode("utf-8")
+    request_mem = extism.memory.alloc(request_bytes)
+    response_offset = _taskqueue_enqueue(request_mem.offset)
+    response_mem = extism.memory.find(response_offset)
+    response = json.loads(extism.memory.string(response_mem))
+
+    if response.get("error"):
+        raise HostFunctionError(response["error"])
+
+    return response.get("result", "")
+
+
+def taskqueue_get_task_status(task_id: str) -> str:
+    """GetTaskStatus returns the status of a task: "pending", "running",
+"completed", "failed", or "cancelled".
+
+    Args:
+        task_id: str parameter.
+
+    Returns:
+        str: The result value.
+
+    Raises:
+        HostFunctionError: If the host function returns an error.
+    """
+    request = {
+        "taskId": task_id,
+    }
+    request_bytes = json.dumps(request).encode("utf-8")
+    request_mem = extism.memory.alloc(request_bytes)
+    response_offset = _taskqueue_gettaskstatus(request_mem.offset)
+    response_mem = extism.memory.find(response_offset)
+    response = json.loads(extism.memory.string(response_mem))
+
+    if response.get("error"):
+        raise HostFunctionError(response["error"])
+
+    return response.get("result", "")
+
+
+def taskqueue_cancel_task(task_id: str) -> None:
+    """CancelTask cancels a pending task. Returns error if already
+running, completed, or failed.
+
+    Args:
+        task_id: str parameter.
+
+    Raises:
+        HostFunctionError: If the host function returns an error.
+    """
+    request = {
+        "taskId": task_id,
+    }
+    request_bytes = json.dumps(request).encode("utf-8")
+    request_mem = extism.memory.alloc(request_bytes)
+    response_offset = _taskqueue_canceltask(request_mem.offset)
+    response_mem = extism.memory.find(response_offset)
+    response = json.loads(extism.memory.string(response_mem))
+
+    if response.get("error"):
+        raise HostFunctionError(response["error"])
+

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

@@ -9,4 +9,5 @@ pub mod lifecycle;
 pub mod metadata;
 pub mod scheduler;
 pub mod scrobbler;
+pub mod taskworker;
 pub mod websocket;

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

@@ -0,0 +1,87 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains export wrappers for the TaskWorker capability.
+// It is intended for use in Navidrome plugins built with extism-pdk.
+
+use serde::{Deserialize, Serialize};
+
+// Helper functions for skip_serializing_if with numeric types
+#[allow(dead_code)]
+fn is_zero_i32(value: &i32) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_u32(value: &u32) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_i64(value: &i64) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_u64(value: &u64) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_f32(value: &f32) -> bool { *value == 0.0 }
+#[allow(dead_code)]
+fn is_zero_f64(value: &f64) -> bool { *value == 0.0 }
+/// TaskExecuteRequest is the request provided when a task is ready to execute.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TaskExecuteRequest {
+    /// QueueName is the name of the queue this task belongs to.
+    #[serde(default)]
+    pub queue_name: String,
+    /// TaskID is the unique identifier for this task.
+    #[serde(default)]
+    pub task_id: String,
+    /// Payload is the opaque data provided when the task was enqueued.
+    #[serde(default)]
+    pub payload: Vec<u8>,
+    /// Attempt is the current attempt number (1-based: first attempt = 1).
+    #[serde(default)]
+    pub attempt: i32,
+}
+/// TaskExecuteResponse is the response from task execution.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TaskExecuteResponse {
+    /// Error, if non-empty, indicates the task failed. The task will be retried
+    /// if retries are configured and attempts remain.
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub error: String,
+}
+
+/// Error represents an error from a capability method.
+#[derive(Debug)]
+pub struct Error {
+    pub message: String,
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl Error {
+    pub fn new(message: impl Into<String>) -> Self {
+        Self { message: message.into() }
+    }
+}
+
+/// TaskExecuteProvider provides the OnTaskExecute function.
+pub trait TaskExecuteProvider {
+    fn on_task_execute(&self, req: TaskExecuteRequest) -> Result<TaskExecuteResponse, Error>;
+}
+
+/// Register the on_task_execute export.
+/// This macro generates the WASM export function for this method.
+#[macro_export]
+macro_rules! register_taskworker_task_execute {
+    ($plugin_type:ty) => {
+        #[extism_pdk::plugin_fn]
+        pub fn nd_task_execute(
+            req: extism_pdk::Json<$crate::taskworker::TaskExecuteRequest>
+        ) -> extism_pdk::FnResult<extism_pdk::Json<$crate::taskworker::TaskExecuteResponse>> {
+            let plugin = <$plugin_type>::default();
+            let result = $crate::taskworker::TaskExecuteProvider::on_task_execute(&plugin, req.into_inner())?;
+            Ok(extism_pdk::Json(result))
+        }
+    };
+}

plugins/pdk/rust/nd-pdk-host/src/lib.rs

@@ -40,6 +40,7 @@
 //! - [`library`] - provides access to music library metadata for plugins.
 //! - [`scheduler`] - provides task scheduling capabilities for plugins.
 //! - [`subsonicapi`] - provides access to Navidrome's Subsonic API from plugins.
+//! - [`taskqueue`] - provides persistent task queues for plugins.
 //! - [`users`] - provides access to user information for plugins.
 //! - [`websocket`] - provides WebSocket communication capabilities for plugins.
 
@@ -99,6 +100,13 @@ pub mod subsonicapi {
     pub use super::nd_host_subsonicapi::*;
 }
 
+#[doc(hidden)]
+mod nd_host_taskqueue;
+/// provides persistent task queues for plugins.
+pub mod taskqueue {
+    pub use super::nd_host_taskqueue::*;
+}
+
 #[doc(hidden)]
 mod nd_host_users;
 /// provides access to user information for plugins.

plugins/pdk/rust/nd-pdk-host/src/nd_host_http.rs

@@ -9,7 +9,7 @@ use serde::{Deserialize, Serialize};
 /// HTTPRequest represents an outbound HTTP request from a plugin.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct HttpRequest {
+pub struct HTTPRequest {
     pub method: String,
     pub url: String,
     #[serde(default)]
@@ -23,7 +23,7 @@ pub struct HttpRequest {
 /// HTTPResponse represents the response from an outbound HTTP request.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct HttpResponse {
+pub struct HTTPResponse {
     pub status_code: i32,
     #[serde(default)]
     pub headers: std::collections::HashMap<String, String>,
@@ -34,14 +34,14 @@ pub struct HttpResponse {
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
 struct HTTPSendRequest {
-    request: HttpRequest,
+    request: HTTPRequest,
 }
 
 #[derive(Debug, Clone, Deserialize)]
 #[serde(rename_all = "camelCase")]
 struct HTTPSendResponse {
     #[serde(default)]
-    result: Option<HttpResponse>,
+    result: Option<HTTPResponse>,
     #[serde(default)]
     error: Option<String>,
 }
@@ -52,23 +52,23 @@ extern "ExtismHost" {
 }
 
 /// Send executes an HTTP request and returns the response.
-///
+/// 
 /// Parameters:
 ///   - request: The HTTP request to execute, including method, URL, headers, body, and timeout
-///
+/// 
 /// Returns the HTTP response with status code, headers, and body.
-/// Network errors, timeouts, and permission failures are returned as errors.
+/// Network errors, timeouts, and permission failures are returned as Go errors.
 /// Successful HTTP calls (including 4xx/5xx status codes) return a non-nil response with nil error.
 ///
 /// # Arguments
-/// * `request` - HttpRequest parameter.
+/// * `request` - HTTPRequest parameter.
 ///
 /// # Returns
 /// The result value.
 ///
 /// # Errors
 /// Returns an error if the host function call fails.
-pub fn send(request: HttpRequest) -> Result<Option<HttpResponse>, Error> {
+pub fn send(request: HTTPRequest) -> Result<Option<HTTPResponse>, Error> {
     let response = unsafe {
         http_send(Json(HTTPSendRequest {
             request: request,

plugins/pdk/rust/nd-pdk-host/src/nd_host_taskqueue.rs

@@ -0,0 +1,184 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains client wrappers for the TaskQueue host service.
+// It is intended for use in Navidrome plugins built with extism-pdk.
+
+use extism_pdk::*;
+use serde::{Deserialize, Serialize};
+
+/// QueueConfig holds configuration for a task queue.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct QueueConfig {
+    pub concurrency: i32,
+    pub max_retries: i32,
+    pub backoff_ms: i64,
+    pub delay_ms: i64,
+    pub retention_ms: i64,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueCreateQueueRequest {
+    name: String,
+    config: QueueConfig,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueCreateQueueResponse {
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueEnqueueRequest {
+    queue_name: String,
+    payload: Vec<u8>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueEnqueueResponse {
+    #[serde(default)]
+    result: String,
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueGetTaskStatusRequest {
+    task_id: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueGetTaskStatusResponse {
+    #[serde(default)]
+    result: String,
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueCancelTaskRequest {
+    task_id: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskQueueCancelTaskResponse {
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[host_fn]
+extern "ExtismHost" {
+    fn taskqueue_createqueue(input: Json<TaskQueueCreateQueueRequest>) -> Json<TaskQueueCreateQueueResponse>;
+    fn taskqueue_enqueue(input: Json<TaskQueueEnqueueRequest>) -> Json<TaskQueueEnqueueResponse>;
+    fn taskqueue_gettaskstatus(input: Json<TaskQueueGetTaskStatusRequest>) -> Json<TaskQueueGetTaskStatusResponse>;
+    fn taskqueue_canceltask(input: Json<TaskQueueCancelTaskRequest>) -> Json<TaskQueueCancelTaskResponse>;
+}
+
+/// CreateQueue creates a named task queue with the given configuration.
+/// Zero-value fields in config use sensible defaults.
+/// If a queue with the same name already exists, returns an error.
+/// On startup, this also recovers any stale "running" tasks from a previous crash.
+///
+/// # Arguments
+/// * `name` - String parameter.
+/// * `config` - QueueConfig parameter.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn create_queue(name: &str, config: QueueConfig) -> Result<(), Error> {
+    let response = unsafe {
+        taskqueue_createqueue(Json(TaskQueueCreateQueueRequest {
+            name: name.to_owned(),
+            config: config,
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(())
+}
+
+/// Enqueue adds a task to the named queue. Returns the task ID.
+/// payload is opaque bytes passed back to the plugin on execution.
+///
+/// # Arguments
+/// * `queue_name` - String parameter.
+/// * `payload` - Vec<u8> parameter.
+///
+/// # Returns
+/// The result value.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn enqueue(queue_name: &str, payload: Vec<u8>) -> Result<String, Error> {
+    let response = unsafe {
+        taskqueue_enqueue(Json(TaskQueueEnqueueRequest {
+            queue_name: queue_name.to_owned(),
+            payload: payload,
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(response.0.result)
+}
+
+/// GetTaskStatus returns the status of a task: "pending", "running",
+/// "completed", "failed", or "cancelled".
+///
+/// # Arguments
+/// * `task_id` - String parameter.
+///
+/// # Returns
+/// The result value.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn get_task_status(task_id: &str) -> Result<String, Error> {
+    let response = unsafe {
+        taskqueue_gettaskstatus(Json(TaskQueueGetTaskStatusRequest {
+            task_id: task_id.to_owned(),
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(response.0.result)
+}
+
+/// CancelTask cancels a pending task. Returns error if already
+/// running, completed, or failed.
+///
+/// # Arguments
+/// * `task_id` - String parameter.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn cancel_task(task_id: &str) -> Result<(), Error> {
+    let response = unsafe {
+        taskqueue_canceltask(Json(TaskQueueCancelTaskRequest {
+            task_id: task_id.to_owned(),
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(())
+}

plugins/testdata/test-taskqueue/go.mod

@@ -0,0 +1,16 @@
+module test-taskqueue
+
+go 1.25
+
+require github.com/navidrome/navidrome/plugins/pdk/go v0.0.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/extism/go-pdk v1.1.3 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/navidrome/navidrome/plugins/pdk/go => ../../pdk/go

plugins/testdata/test-taskqueue/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/extism/go-pdk v1.1.3 h1:hfViMPWrqjN6u67cIYRALZTZLk/enSPpNKa+rZ9X2SQ=
+github.com/extism/go-pdk v1.1.3/go.mod h1:Gz+LIU/YCKnKXhgge8yo5Yu1F/lbv7KtKFkiCSzW/P4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

plugins/testdata/test-taskqueue/main.go

@@ -0,0 +1,100 @@
+// Test TaskQueue plugin for Navidrome plugin system integration tests.
+// Build with: tinygo build -o ../test-taskqueue.wasm -target wasip1 -buildmode=c-shared .
+package main
+
+import (
+	"github.com/navidrome/navidrome/plugins/pdk/go/host"
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+	"github.com/navidrome/navidrome/plugins/pdk/go/taskworker"
+)
+
+func init() {
+	taskworker.Register(&handler{})
+}
+
+type handler struct{}
+
+func (h *handler) OnTaskExecute(req taskworker.TaskExecuteRequest) (taskworker.TaskExecuteResponse, error) {
+	payload := string(req.Payload)
+	if payload == "fail" {
+		return taskworker.TaskExecuteResponse{Error: "task failed as instructed"}, nil
+	}
+	if payload == "fail-then-succeed" && req.Attempt < 2 {
+		return taskworker.TaskExecuteResponse{Error: "transient failure"}, nil
+	}
+	return taskworker.TaskExecuteResponse{}, nil
+}
+
+// Test helper types
+type TestInput struct {
+	Operation string            `json:"operation"`
+	QueueName string            `json:"queueName,omitempty"`
+	Config    *host.QueueConfig `json:"config,omitempty"`
+	Payload   []byte            `json:"payload,omitempty"`
+	TaskID    string            `json:"taskId,omitempty"`
+}
+
+type TestOutput struct {
+	TaskID string  `json:"taskId,omitempty"`
+	Status string  `json:"status,omitempty"`
+	Error  *string `json:"error,omitempty"`
+}
+
+//go:wasmexport nd_test_taskqueue
+func ndTestTaskQueue() int32 {
+	var input TestInput
+	if err := pdk.InputJSON(&input); err != nil {
+		errStr := err.Error()
+		pdk.OutputJSON(TestOutput{Error: &errStr})
+		return 0
+	}
+
+	switch input.Operation {
+	case "create_queue":
+		config := host.QueueConfig{}
+		if input.Config != nil {
+			config = *input.Config
+		}
+		err := host.TaskQueueCreateQueue(input.QueueName, config)
+		if err != nil {
+			errStr := err.Error()
+			pdk.OutputJSON(TestOutput{Error: &errStr})
+			return 0
+		}
+		pdk.OutputJSON(TestOutput{})
+
+	case "enqueue":
+		taskID, err := host.TaskQueueEnqueue(input.QueueName, input.Payload)
+		if err != nil {
+			errStr := err.Error()
+			pdk.OutputJSON(TestOutput{Error: &errStr})
+			return 0
+		}
+		pdk.OutputJSON(TestOutput{TaskID: taskID})
+
+	case "get_task_status":
+		status, err := host.TaskQueueGetTaskStatus(input.TaskID)
+		if err != nil {
+			errStr := err.Error()
+			pdk.OutputJSON(TestOutput{Error: &errStr})
+			return 0
+		}
+		pdk.OutputJSON(TestOutput{Status: status})
+
+	case "cancel_task":
+		err := host.TaskQueueCancelTask(input.TaskID)
+		if err != nil {
+			errStr := err.Error()
+			pdk.OutputJSON(TestOutput{Error: &errStr})
+			return 0
+		}
+		pdk.OutputJSON(TestOutput{})
+
+	default:
+		errStr := "unknown operation: " + input.Operation
+		pdk.OutputJSON(TestOutput{Error: &errStr})
+	}
+	return 0
+}
+
+func main() {}

plugins/testdata/test-taskqueue/manifest.json

@@ -0,0 +1,12 @@
+{
+  "name": "Test TaskQueue Plugin",
+  "author": "Navidrome Test",
+  "version": "1.0.0",
+  "description": "A test plugin for TaskQueue integration testing",
+  "permissions": {
+    "taskqueue": {
+      "reason": "For testing task queue operations",
+      "maxConcurrency": 10
+    }
+  }
+}

server/subsonic/browsing.go

@@ -443,7 +443,7 @@ func (api *Router) buildArtist(r *http.Request, artist *model.Artist) (*response
 func (api *Router) buildAlbumDirectory(ctx context.Context, album *model.Album) (*responses.Directory, error) {
 	dir := &responses.Directory{}
 	dir.Id = album.ID
-	dir.Name = album.Name
+	dir.Name = album.FullName()
 	dir.Parent = album.AlbumArtistID
 	dir.PlayCount = album.PlayCount
 	if album.PlayCount > 0 {

server/subsonic/helpers.go

@@ -197,7 +197,7 @@ func childFromMediaFile(ctx context.Context, mf model.MediaFile) responses.Child
 	}
 
 	child.Parent = mf.AlbumID
-	child.Album = mf.Album
+	child.Album = mf.FullAlbumName()
 	child.Year = int32(mf.Year)
 	child.Artist = mf.Artist
 	child.Genre = mf.Genre
@@ -302,7 +302,7 @@ func artistRefs(participants model.ParticipantList) []responses.ArtistID3Ref {
 func fakePath(mf model.MediaFile) string {
 	builder := strings.Builder{}
 
-	builder.WriteString(fmt.Sprintf("%s/%s/", sanitizeSlashes(mf.AlbumArtist), sanitizeSlashes(mf.Album)))
+	builder.WriteString(fmt.Sprintf("%s/%s/", sanitizeSlashes(mf.AlbumArtist), sanitizeSlashes(mf.FullAlbumName())))
 	if mf.DiscNumber != 0 {
 		builder.WriteString(fmt.Sprintf("%02d-", mf.DiscNumber))
 	}
@@ -321,9 +321,10 @@ func childFromAlbum(ctx context.Context, al model.Album) responses.Child {
 	child := responses.Child{}
 	child.Id = al.ID
 	child.IsDir = true
-	child.Title = al.Name
-	child.Name = al.Name
-	child.Album = al.Name
+	fullName := al.FullName()
+	child.Title = fullName
+	child.Name = fullName
+	child.Album = fullName
 	child.Artist = al.AlbumArtist
 	child.Year = int32(cmp.Or(al.MaxOriginalYear, al.MaxYear))
 	child.Genre = al.Genre
@@ -405,7 +406,7 @@ func buildDiscSubtitles(a model.Album) []responses.DiscTitle {
 func buildAlbumID3(ctx context.Context, album model.Album) responses.AlbumID3 {
 	dir := responses.AlbumID3{}
 	dir.Id = album.ID
-	dir.Name = album.Name
+	dir.Name = album.FullName()
 	dir.Artist = album.AlbumArtist
 	dir.ArtistId = album.AlbumArtistID
 	dir.CoverArt = album.CoverArtID().String()