perf(json): finish source-generated hot-path serialization

allstarr.Tests/JellyfinSearchResponseSerializationTests.cs

@@ -1,5 +1,6 @@
 using System.Reflection;
 using allstarr.Controllers;
+using allstarr.Models.Jellyfin;
 
 namespace allstarr.Tests;
 
@@ -8,16 +9,16 @@ public class JellyfinSearchResponseSerializationTests
     [Fact]
     public void SerializeSearchResponseJson_PreservesPascalCaseShape()
     {
-        var payload = new
+        var payload = new JellyfinItemsResponse
         {
-            Items = new[]
-            {
+            Items =
+            [
                 new Dictionary<string, object?>
                 {
                     ["Name"] = "BTS",
                     ["Type"] = "MusicAlbum"
                 }
-            },
+            ],
             TotalRecordCount = 1,
             StartIndex = 0
         };
@@ -28,8 +29,7 @@ public class JellyfinSearchResponseSerializationTests
 
         Assert.NotNull(method);
 
-        var closedMethod = method!.MakeGenericMethod(payload.GetType());
-        var json = (string)closedMethod.Invoke(null, new object?[] { payload })!;
+        var json = (string)method!.Invoke(null, new object?[] { payload })!;
 
         Assert.Equal(
             "{\"Items\":[{\"Name\":\"BTS\",\"Type\":\"MusicAlbum\"}],\"TotalRecordCount\":1,\"StartIndex\":0}",

allstarr.Tests/JellyfinSessionManagerTests.cs

@@ -52,9 +52,17 @@ public class JellyfinSessionManagerTests
     public async Task RemoveSessionAsync_ReportsPlaybackStopButDoesNotLogoutUserSession()
     {
         var requestedPaths = new ConcurrentBag<string>();
+        var requestBodies = new ConcurrentDictionary<string, string>();
         var handler = new DelegateHttpMessageHandler((request, _) =>
         {
-            requestedPaths.Add(request.RequestUri?.AbsolutePath ?? string.Empty);
+            var path = request.RequestUri?.AbsolutePath ?? string.Empty;
+            requestedPaths.Add(path);
+
+            if (request.Content != null)
+            {
+                requestBodies[path] = request.Content.ReadAsStringAsync().GetAwaiter().GetResult();
+            }
+
             return Task.FromResult(new HttpResponseMessage(HttpStatusCode.NoContent));
         });
 
@@ -89,6 +97,12 @@ public class JellyfinSessionManagerTests
         Assert.Contains("/Sessions/Capabilities/Full", requestedPaths);
         Assert.Contains("/Sessions/Playing/Stopped", requestedPaths);
         Assert.DoesNotContain("/Sessions/Logout", requestedPaths);
+        Assert.Equal(
+            "{\"PlayableMediaTypes\":[\"Audio\"],\"SupportedCommands\":[\"Play\",\"Playstate\",\"PlayNext\"],\"SupportsMediaControl\":true,\"SupportsPersistentIdentifier\":true,\"SupportsSync\":false}",
+            requestBodies["/Sessions/Capabilities/Full"]);
+        Assert.Equal(
+            "{\"ItemId\":\"item-123\",\"PositionTicks\":42}",
+            requestBodies["/Sessions/Playing/Stopped"]);
     }
 
     [Fact]

allstarr/Controllers/JellyfinController.PlaybackSessions.cs

@@ -1,7 +1,9 @@
 using System.Collections.Concurrent;
 using System.Text.Json;
 using System.Globalization;
+using allstarr.Models.Jellyfin;
 using allstarr.Models.Scrobbling;
+using allstarr.Serialization;
 using Microsoft.AspNetCore.Mvc;
 
 namespace allstarr.Controllers;
@@ -226,7 +228,7 @@ public partial class JellyfinController
 
                     // Build minimal playback start with just the ghost UUID
                     // Don't include the Item object - Jellyfin will just track the session without item details
-                    var playbackStart = new
+                    var playbackStart = new JellyfinPlaybackStatePayload
                     {
                         ItemId = ghostUuid,
                         PositionTicks = positionTicks ?? 0,
@@ -236,7 +238,7 @@ public partial class JellyfinController
                         PlayMethod = "DirectPlay"
                     };
 
-                    var playbackJson = JsonSerializer.Serialize(playbackStart);
+                    var playbackJson = AllstarrJsonSerializer.Serialize(playbackStart);
                     _logger.LogDebug("📤 Sending ghost playback start for external track: {Json}", playbackJson);
 
                     // Forward to Jellyfin with ghost UUID
@@ -357,14 +359,13 @@ public partial class JellyfinController
                         trackName ?? "Unknown", itemId);
 
                     // Build playback start info - Jellyfin will fetch item details itself
-                    var playbackStart = new
+                    var playbackStart = new JellyfinPlaybackStatePayload
                     {
-                        ItemId = itemId,
-                        PositionTicks = positionTicks ?? 0,
-                        // Let Jellyfin fetch the item details - don't include NowPlayingItem
+                        ItemId = itemId ?? string.Empty,
+                        PositionTicks = positionTicks ?? 0
                     };
 
-                    var playbackJson = JsonSerializer.Serialize(playbackStart);
+                    var playbackJson = AllstarrJsonSerializer.Serialize(playbackStart);
                     _logger.LogDebug("📤 Sending playback start: {Json}", playbackJson);
 
                     var (result, statusCode) =
@@ -624,7 +625,7 @@ public partial class JellyfinController
                                 externalId);
 
                             var inferredStartGhostUuid = GenerateUuidFromString(itemId);
-                            var inferredExternalStartPayload = JsonSerializer.Serialize(new
+                            var inferredExternalStartPayload = AllstarrJsonSerializer.Serialize(new JellyfinPlaybackStatePayload
                             {
                                 ItemId = inferredStartGhostUuid,
                                 PositionTicks = positionTicks ?? 0,
@@ -692,7 +693,7 @@ public partial class JellyfinController
                     var ghostUuid = GenerateUuidFromString(itemId);
 
                     // Build progress report with ghost UUID
-                    var progressReport = new
+                    var progressReport = new JellyfinPlaybackStatePayload
                     {
                         ItemId = ghostUuid,
                         PositionTicks = positionTicks ?? 0,
@@ -702,7 +703,7 @@ public partial class JellyfinController
                         PlayMethod = "DirectPlay"
                     };
 
-                    var progressJson = JsonSerializer.Serialize(progressReport);
+                    var progressJson = AllstarrJsonSerializer.Serialize(progressReport);
 
                     // Forward to Jellyfin with ghost UUID
                     var (progressResult, progressStatusCode) =
@@ -773,7 +774,7 @@ public partial class JellyfinController
                         _logger.LogInformation("🎵 Local track playback started (inferred from progress): {Name} (ID: {ItemId})",
                             trackName ?? "Unknown", itemId);
 
-                        var inferredStartPayload = JsonSerializer.Serialize(new
+                        var inferredStartPayload = AllstarrJsonSerializer.Serialize(new JellyfinPlaybackStatePayload
                         {
                             ItemId = itemId,
                             PositionTicks = positionTicks ?? 0
@@ -948,7 +949,7 @@ public partial class JellyfinController
             }
 
             var ghostUuid = GenerateUuidFromString(previousItemId);
-            var inferredExternalStopPayload = JsonSerializer.Serialize(new
+            var inferredExternalStopPayload = AllstarrJsonSerializer.Serialize(new JellyfinPlaybackStatePayload
             {
                 ItemId = ghostUuid,
                 PositionTicks = previousPositionTicks ?? 0,
@@ -997,7 +998,7 @@ public partial class JellyfinController
             });
         }
 
-        var inferredStopPayload = JsonSerializer.Serialize(new
+        var inferredStopPayload = AllstarrJsonSerializer.Serialize(new JellyfinPlaybackStatePayload
         {
             ItemId = previousItemId,
             PositionTicks = previousPositionTicks ?? 0,
@@ -1294,13 +1295,13 @@ public partial class JellyfinController
                     // Report stop to Jellyfin with ghost UUID
                     var ghostUuid = GenerateUuidFromString(itemId);
 
-                    var externalStopInfo = new
+                    var externalStopInfo = new JellyfinPlaybackStatePayload
                     {
                         ItemId = ghostUuid,
                         PositionTicks = positionTicks ?? 0
                     };
 
-                    var stopJson = JsonSerializer.Serialize(externalStopInfo);
+                    var stopJson = AllstarrJsonSerializer.Serialize(externalStopInfo);
                     _logger.LogDebug("📤 Sending ghost playback stop for external track: {Json}", stopJson);
 
                     var (stopResult, stopStatusCode) =
@@ -1469,7 +1470,7 @@ public partial class JellyfinController
                 stopInfo["PositionTicks"] = positionTicks.Value;
             }
 
-            body = JsonSerializer.Serialize(stopInfo);
+            body = AllstarrJsonSerializer.Serialize(stopInfo);
             _logger.LogDebug("📤 Sending playback stop body (IsPaused=false, {BodyLength} bytes)", body.Length);
 
             var (result, statusCode) =

allstarr/Controllers/JellyfinController.Search.cs

@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Text;
+using allstarr.Models.Jellyfin;
 using allstarr.Models.Search;
 using allstarr.Models.Subsonic;
 using allstarr.Serialization;
@@ -127,18 +128,12 @@ public partial class JellyfinController
                 var album = await _metadataService.GetAlbumAsync(provider!, externalId!, HttpContext.RequestAborted);
                 if (album == null)
                 {
-                    return new JsonResult(new
-                        { Items = Array.Empty<object>(), TotalRecordCount = 0, StartIndex = startIndex });
+                    return CreateItemsResponse([], 0, startIndex);
                 }
 
                 var albumItems = album.Songs.Select(song => _responseBuilder.ConvertSongToJellyfinItem(song)).ToList();
 
-                return new JsonResult(new
-                {
-                    Items = albumItems,
-                    TotalRecordCount = albumItems.Count,
-                    StartIndex = startIndex
-                });
+                return CreateItemsResponse(albumItems, albumItems.Count, startIndex);
             }
             // If library album, fall through to handle with ParentId or proxy
         }
@@ -559,7 +554,7 @@ public partial class JellyfinController
         try
         {
             // Return with PascalCase - use ContentResult to bypass JSON serialization issues
-            var response = new
+            var response = new JellyfinItemsResponse
             {
                 Items = pagedItems,
                 TotalRecordCount = items.Count,
@@ -604,27 +599,9 @@ public partial class JellyfinController
         }
     }
 
-    private static string SerializeSearchResponseJson<T>(T response) where T : class
+    private static string SerializeSearchResponseJson(JellyfinItemsResponse response)
     {
-        // Use source-gen context for registered types (no reflection, 3-8x faster)
-        try
-        {
-            var typeInfo = AllstarrJsonContext.Shared.GetTypeInfo(typeof(T));
-            if (typeInfo != null)
-            {
-                return JsonSerializer.Serialize(response, typeInfo);
-            }
-        }
-        catch
-        {
-            // Type not in source-gen context — fall through to reflection
-        }
-
-        return JsonSerializer.Serialize(response, new JsonSerializerOptions
-        {
-            PropertyNamingPolicy = null,
-            DictionaryKeyPolicy = null
-        });
+        return AllstarrJsonSerializer.Serialize(response);
     }
 
     /// <summary>
@@ -789,12 +766,26 @@ public partial class JellyfinController
 
     private static IActionResult CreateEmptyItemsResponse(int startIndex)
     {
-        return new JsonResult(new
+        return CreateItemsResponse([], 0, startIndex);
+    }
+
+    private static ContentResult CreateItemsResponse(
+        List<Dictionary<string, object?>> items,
+        int totalRecordCount,
+        int startIndex)
+    {
+        var response = new JellyfinItemsResponse
         {
-            Items = Array.Empty<object>(),
-            TotalRecordCount = 0,
+            Items = items,
+            TotalRecordCount = totalRecordCount,
             StartIndex = startIndex
-        });
+        };
+
+        return new ContentResult
+        {
+            Content = SerializeSearchResponseJson(response),
+            ContentType = "application/json"
+        };
     }
 
     /// <summary>

allstarr/Models/Jellyfin/JellyfinHotPathPayloads.cs

@@ -0,0 +1,37 @@
+namespace allstarr.Models.Jellyfin;
+
+/// <summary>
+/// Canonical Jellyfin Items response wrapper used by search-related hot paths.
+/// </summary>
+public class JellyfinItemsResponse
+{
+    public List<Dictionary<string, object?>> Items { get; set; } = [];
+    public int TotalRecordCount { get; set; }
+    public int StartIndex { get; set; }
+}
+
+/// <summary>
+/// Playback payload forwarded to Jellyfin for start/progress/stop events.
+/// Nullable members are omitted to preserve the lean request shapes clients expect.
+/// </summary>
+public class JellyfinPlaybackStatePayload
+{
+    public string ItemId { get; set; } = string.Empty;
+    public long PositionTicks { get; set; }
+    public bool? CanSeek { get; set; }
+    public bool? IsPaused { get; set; }
+    public bool? IsMuted { get; set; }
+    public string? PlayMethod { get; set; }
+}
+
+/// <summary>
+/// Synthetic capabilities payload used when allstarr needs to establish a Jellyfin session.
+/// </summary>
+public class JellyfinSessionCapabilitiesPayload
+{
+    public string[] PlayableMediaTypes { get; set; } = [];
+    public string[] SupportedCommands { get; set; } = [];
+    public bool SupportsMediaControl { get; set; }
+    public bool SupportsPersistentIdentifier { get; set; }
+    public bool SupportsSync { get; set; }
+}

allstarr/Serialization/AllstarrJsonContext.cs

@@ -1,6 +1,7 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 using allstarr.Models.Domain;
+using allstarr.Models.Jellyfin;
 using allstarr.Models.Lyrics;
 using allstarr.Models.Search;
 using allstarr.Models.Spotify;
@@ -25,6 +26,9 @@ namespace allstarr.Serialization;
 [JsonSerializable(typeof(Album))]
 [JsonSerializable(typeof(Artist))]
 [JsonSerializable(typeof(SearchResult))]
+[JsonSerializable(typeof(JellyfinItemsResponse))]
+[JsonSerializable(typeof(JellyfinPlaybackStatePayload))]
+[JsonSerializable(typeof(JellyfinSessionCapabilitiesPayload))]
 [JsonSerializable(typeof(List<Song>))]
 [JsonSerializable(typeof(List<Album>))]
 [JsonSerializable(typeof(List<Artist>))]
@@ -43,6 +47,7 @@ namespace allstarr.Serialization;
 // Collection types used in cache and playlist items
 [JsonSerializable(typeof(List<Dictionary<string, object?>>))]
 [JsonSerializable(typeof(Dictionary<string, object?>))]
+[JsonSerializable(typeof(string[]))]
 [JsonSerializable(typeof(List<string>))]
 [JsonSerializable(typeof(string))]
 [JsonSerializable(typeof(byte[]))]

allstarr/Serialization/AllstarrJsonSerializer.cs

@@ -0,0 +1,27 @@
+using System.Text.Json;
+using System.Text.Json.Serialization.Metadata;
+
+namespace allstarr.Serialization;
+
+internal static class AllstarrJsonSerializer
+{
+    public static string Serialize<T>(T value)
+    {
+        var typeInfo = GetTypeInfo<T>();
+        return typeInfo != null
+            ? JsonSerializer.Serialize(value, typeInfo)
+            : JsonSerializer.Serialize(value);
+    }
+
+    private static JsonTypeInfo<T>? GetTypeInfo<T>()
+    {
+        try
+        {
+            return (JsonTypeInfo<T>?)AllstarrJsonContext.Shared.GetTypeInfo(typeof(T));
+        }
+        catch
+        {
+            return null;
+        }
+    }
+}

allstarr/Services/Jellyfin/JellyfinSessionManager.cs

@@ -1,10 +1,11 @@
 using System.Collections.Concurrent;
 using System.Net.WebSockets;
 using System.Text;
-using System.Text.Json;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Options;
+using allstarr.Models.Jellyfin;
 using allstarr.Models.Settings;
+using allstarr.Serialization;
 
 namespace allstarr.Services.Jellyfin;
 
@@ -185,21 +186,21 @@ public class JellyfinSessionManager : IDisposable
     /// </summary>
     private async Task<bool> PostCapabilitiesAsync(IHeaderDictionary headers)
     {
-        var capabilities = new
+        var capabilities = new JellyfinSessionCapabilitiesPayload
         {
-            PlayableMediaTypes = new[] { "Audio" },
-            SupportedCommands = new[]
-            {
+            PlayableMediaTypes = ["Audio"],
+            SupportedCommands =
+            [
                 "Play",
                 "Playstate",
                 "PlayNext"
-            },
+            ],
             SupportsMediaControl = true,
             SupportsPersistentIdentifier = true,
             SupportsSync = false
         };
 
-        var json = JsonSerializer.Serialize(capabilities);
+        var json = AllstarrJsonSerializer.Serialize(capabilities);
         var (result, statusCode) = await _proxyService.PostJsonAsync("Sessions/Capabilities/Full", json, headers);
 
         if (statusCode == 204 || statusCode == 200)
@@ -455,12 +456,12 @@ public class JellyfinSessionManager : IDisposable
                 // Report playback stopped to Jellyfin if we have a playing item (for scrobbling)
                 if (!string.IsNullOrEmpty(session.LastPlayingItemId))
                 {
-                    var stopPayload = new
+                    var stopPayload = new JellyfinPlaybackStatePayload
                     {
                         ItemId = session.LastPlayingItemId,
                         PositionTicks = session.LastPlayingPositionTicks ?? 0
                     };
-                    var stopJson = JsonSerializer.Serialize(stopPayload);
+                    var stopJson = AllstarrJsonSerializer.Serialize(stopPayload);
                     await _proxyService.PostJsonAsync("Sessions/Playing/Stopped", stopJson, session.Headers);
                     _logger.LogInformation("🛑 SESSION: Reported playback stopped for {DeviceId} (ItemId: {ItemId}, Position: {Position})",
                         deviceId, session.LastPlayingItemId, session.LastPlayingPositionTicks);