Port managed client audio and Windows application

CLAUDE.md

@@ -39,7 +39,9 @@ dotnet test dotnet/VoiceCat.slnx -c Release --no-build
 See `dotnet/README.md` for C# conventions and required native voice/CLI conformance,
 and `docs/api-dotnet.md` for managed interfaces. Phase 4 remains in progress;
 media-aware reaping and server administration are implemented. Server deployment hardening
-and managed audio/client/Windows cutover are in progress; Apple GUI rewrites follow Windows.
+and the managed audio/client core plus Windows cutover are implemented. The Windows publish
+contains only the permitted media shim. Accessibility/manual endurance validation and broad
+server deployment work remain; Apple GUI rewrites follow Windows.
 
 The default development preset is **`dev`** — it builds everything (server + tools + tests)
 with real vcpkg deps. The `skeleton` preset (no deps, stubs only) is a fast smoke check; see

PROGRESS.md

@@ -10,6 +10,27 @@ up instantly. Newest status at the top.
 
 ## ▶ Where we left off / next action
 
+- **Done (2026-09-16): Managed client/audio and Windows cutover checkpoint.** Added
+  `VoiceCat.Core` with TOFU-gated TLS, correlated concurrent requests, immutable snapshots,
+  reconnects, bounded client events, UDP binding and authenticated encrypted media. Added
+  `VoiceCat.Audio` with allocation-free real-time cycles, bounded PCM/jitter queues,
+  5/10/20/40/60 ms Opus reframing, VAD/PTT, DTX, DRED → FEC → PLC, RNNoise, per-stream
+  controls and stereo mixing. Shared TLS/media primitives moved to `VoiceCat.Crypto`.
+  The WinForms app now references a managed compatibility facade over these libraries and
+  uses C# WASAPI capture, loopback and playback. Active streams renegotiate after channel
+  moves while capture-facing IDs stay stable. Per-app mixing no longer allocates or locks in
+  its real-time loop. The self-contained Windows publish includes only the permitted
+  `voicecat_media.dll`; a real default-device capture/playback plus main-form smoke passed.
+  Managed tests cover two-way decoded PCM voice, text, TOFU, concurrent requests, reconnects,
+  bounded jitter, zero-allocation cycles, recovery order and stream continuity across a
+  mono→stereo channel move. The old Interop project remains only as a migration oracle and
+  its nine native ABI tests remain green. **Verified:** 190 managed tests with every native
+  conformance/published-server variable enabled, nine Windows native-oracle tests, 29 CTest
+  tests, locked restores, both self-contained publishes and the permissive license audit.
+  **Next:** add the managed CLI and explicit managed
+  client ↔ C++ CLI conversation, then finish production deployment work. The Phase 5/7
+  manual ten-minute listen and NVDA gates are not yet signed off; Apple rewrites follow.
+
 - **Done (2026-09-15): Server deployment hardening checkpoint.** Pushed existing work
   through `653131b` to `origin/dotnet/foundations`. Added CLI/environment configuration,
   all-interface port 8384 defaults, config/fingerprint commands, local administrator

clients/windows/README.md

@@ -1,95 +1,43 @@
-# VoiceCat — Windows client
+# VoiceCat — Windows client
 
-WinForms (.NET 10 LTS) UI over `voicecat.dll` (MinGW-built `libvoicecat` shared library).
+The WinForms .NET 10 client uses `VoiceCat.Core` for TLS, TOFU, protocol state and encrypted UDP, and `VoiceCat.Audio` for streams, jitter, Opus and mixing. Its only native runtime component is `voicecat_media.dll`, the narrow Opus/RNNoise C shim. The old `voicecat.dll` core is no longer loaded or published.
 
-## Prerequisites
+## Build
 
-| Tool | Version | Notes |
-|------|---------|-------|
-| .NET SDK | 10.0.x | `dotnet --version` should report `10.0.*` |
-| CMake | 3.25+ | For building the C++ DLL |
-| MinGW-w64 / MSYS2 UCRT64 | GCC 13+ | `C:\tools\msys64\ucrt64` is the expected location |
-| vcpkg | any | `VCPKG_ROOT` env var must point to a bootstrapped clone |
-
-## Build order
-
-### 1. Build the server (for testing)
+Stage the pinned native media dependencies once, then build the solution:
 
 ```powershell
-cmake --preset dev
-cmake --build --preset dev --target voicecat-server
+./dotnet/build-native.ps1
+dotnet restore clients/windows/VoiceCat.slnx --locked-mode
+dotnet build clients/windows/VoiceCat.slnx -c Release --no-restore
 ```
 
-### 2. Build the DLL
+The original `VoiceCat.Interop` project remains in the repository as a migration oracle. The app references `VoiceCat.Managed`, whose compatibility facade lets the existing accessible WinForms UI keep its event-pump shape while all networking and audio state live in the idiomatic managed libraries.
+
+## Publish
 
 ```powershell
-cmake --preset windows-client
-cmake --build --preset windows-client
+./clients/windows/publish-client.ps1
 ```
 
-Output: `build/windows-client/bin/voicecat.dll`
+This produces a self-contained `win-x64` distribution in `dotnet/artifacts/client/win-x64`. The script requires `voicecat_media.dll` and fails if the legacy `voicecat.dll` appears.
 
-**Verify no MinGW runtime dependencies remain:**
-```powershell
-& "C:\tools\msys64\ucrt64\bin\objdump.exe" -p build/windows-client/bin/voicecat.dll |
-    Select-String "DLL Name"
-```
-Expected: only Windows system DLLs (`KERNEL32.dll`, `WS2_32.dll`, `BCRYPT.dll`, etc.).
-If `libgcc_s_seh-1.dll`, `libstdc++-6.dll`, or `libwinpthread-1.dll` appear, the
-`-static-libgcc -static-libstdc++ -static -lwinpthread` link flags in `core/CMakeLists.txt`
-are not taking effect — check the CMake log for the `VOICECAT_BUILD_SHARED+WIN32` branch.
-
-### 3. Build the C# solution
+The noninteractive startup and real WASAPI device check is:
 
 ```powershell
-cd clients/windows
-dotnet build VoiceCat.slnx
+./dotnet/artifacts/client/win-x64/VoiceCat.App.exe --smoke-test --audio
 ```
 
-The app's `Directory.Build.props` copies `voicecat.dll` from `../../build/windows-client/bin/`
-into the output directory automatically on every build.
+`--smoke-test` constructs the real main form and pumps the managed client. `--audio` additionally opens the default WASAPI capture and render endpoints, moves PCM through both for three seconds, and fails if capture produces no samples.
 
-## Running manually
+## Run manually
 
 ```powershell
-# Terminal 1 — start the server
-./build/dev/bin/voicecat-server.exe --name "My Server"
+# Terminal 1
+./dotnet/artifacts/server/win-x64/VoiceCat.Server.exe
 
-# Terminal 2 — launch the client
+# Terminal 2
 dotnet run --project clients/windows/VoiceCat.App/VoiceCat.App.csproj
 ```
 
-On first connect to a new server:
-- Enter `127.0.0.1` as the host (not `localhost` — Windows resolves `localhost` to `::1`
-  first, and while the server now dual-stacks, `127.0.0.1` is cleaner for local testing).
-- The server identity dialog will appear. The TLS leaf-cert SHA-256 fingerprint is shown;
-  accept to pin it. Subsequent connects to the same server will be silent (MATCHED).
-
-## M5 — Moderation & admin UI
-
-The WinForms client now exposes all M5 operations through the main menu and context menus:
-
-- **Admin → Server accounts…** — create, reset password, and delete server accounts
-  (requires `can_admin_accounts`).
-- **Channel tree right-click** — create, edit, and delete channels. The edit dialog exposes the
-  full per-channel Opus configuration: mono/stereo, sample rate, bitrate, frame size,
-  application mode, FEC, expected packet loss, DTX, and complexity.
-- **User list right-click** — move, kick, ban, server mute/deafen, and set permissions
-  (items are gated by your own permissions).
-- **Activity log** shows async `GenericResult` feedback for every moderation request.
-- **User list** shows text indicators for self-mute, self-deafen, server-mute, and
-  server-deafen states.
-
-These operations require an admin-provisioned account with the appropriate permissions; the
-connect dialog already supports username/password auth.
-
-## Known limitations
-
-- **PTT is focus-scoped** — the push-to-talk key only works while the VoiceCat window has
-  focus. A system-wide `WH_KEYBOARD_LL` hook is not used in v1 (permissions + AV risk).
-- **Receive-side noise reduction** checkbox in per-user tuning is wired end-to-end but is a
-  passthrough no-op until a real APM/NS backend is built (no working Windows/MSVC port of
-  `webrtc-audio-processing` upstream — see `docs/tech-stack.md §1`).
-- **TOFU pins the TLS leaf cert**, not the declared Ed25519 identity fingerprint. Both are
-  shown in the identity dialog, but the cert fingerprint is the value that is actually
-  verified on reconnect. See `docs/security.md §1.1`.
+Manual release validation still includes NVDA navigation and a ten-minute two-client listen test, as required by `docs/porting-to-dotnet.md`.

clients/windows/VoiceCat.App/Audio/InputDeviceCapture.cs

@@ -16,7 +16,7 @@ public sealed record InputDeviceInfo(string Id, string Name, bool IsDefault)
 /// the aux device is opened client-side and needs a WASAPI id, not a miniaudio one.</summary>
 public static class InputDeviceEnumerator
 {
-    public static IReadOnlyList<InputDeviceInfo> List()
+    public static IReadOnlyList<InputDeviceInfo> List(bool input = true)
     {
         var result = new List<InputDeviceInfo>();
         InputDeviceCapture.IMMDeviceEnumerator? enumerator = null;
@@ -29,7 +29,7 @@ public static class InputDeviceEnumerator
                 Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
 
             // Resolve the default capture endpoint id so the picker can flag it.
-            if (enumerator.GetDefaultAudioEndpoint(1 /*eCapture*/, 0 /*eConsole*/,
+            if (enumerator.GetDefaultAudioEndpoint(input ? 1 : 0, 0 /*eConsole*/,
                     out var defDev) == 0 && defDev != null)
             {
                 try { if (defDev.GetId(out string id) == 0) defaultId = id; }
@@ -37,7 +37,7 @@ public static class InputDeviceEnumerator
             }
 
             // DEVICE_STATE_ACTIVE = 0x1 — only currently-usable endpoints.
-            if (enumerator.EnumAudioEndpoints(1 /*eCapture*/, 0x1, out collectionPtr) != 0
+            if (enumerator.EnumAudioEndpoints(input ? 1 : 0, 0x1, out collectionPtr) != 0
                 || collectionPtr == IntPtr.Zero)
                 return result;
 
@@ -107,6 +107,7 @@ public sealed class InputDeviceCapture : IDisposable
     private const int FrameSamples = 960;  // 20 ms
 
     private readonly string? _deviceId;  // null = system default capture endpoint
+    private readonly bool _loopback;
 
     private IAudioClient?        _audioClient;
     private IAudioCaptureClient? _captureClient;
@@ -123,8 +124,9 @@ public sealed class InputDeviceCapture : IDisposable
     // Init-done signal: Set() by the capture thread after activation completes.
     private readonly ManualResetEventSlim _initDone = new(false);
     private bool _initOk;
+    private int _disposed;
 
-    public InputDeviceCapture(string? deviceId) => _deviceId = deviceId;
+    public InputDeviceCapture(string? deviceId, bool loopback = false) { _deviceId = deviceId; _loopback = loopback; }
 
     /// <summary>Starts capture. Blocks until WASAPI activation completes (typically &lt;100 ms).
     /// Returns false if the device cannot be opened.</summary>
@@ -148,15 +150,13 @@ public sealed class InputDeviceCapture : IDisposable
     {
         _running = false;
         _bufferEvent?.Set();
-        _captureThread?.Join(500);
-        try { _audioClient?.Stop(); } catch { /* device already gone */ }
+        if (_captureThread is not null && !_captureThread.Join(5000)) throw new TimeoutException("Capture did not stop.");
     }
 
     public void Dispose()
     {
+        if (Interlocked.Exchange(ref _disposed, 1) != 0) return;
         Stop();
-        if (_captureClient != null) { Marshal.ReleaseComObject(_captureClient); _captureClient = null; }
-        if (_audioClient   != null) { Marshal.ReleaseComObject(_audioClient);   _audioClient   = null; }
         _bufferEvent?.Dispose();
         _initDone.Dispose();
     }
@@ -164,11 +164,20 @@ public sealed class InputDeviceCapture : IDisposable
     // ── Capture thread (MTA) ──────────────────────────────────────────────────
 
     private void CaptureThreadProc()
+    {
+        try
         {
             _initOk = ActivateAndStart();
             _initDone.Set();
-        if (!_initOk) return;
-        CaptureLoop();
+            if (_initOk && _running) CaptureLoop();
+        }
+        catch { _initOk = false; _initDone.Set(); }
+        finally
+        {
+            try { _audioClient?.Stop(); } catch { }
+            if (_captureClient != null) { Marshal.ReleaseComObject(_captureClient); _captureClient = null; }
+            if (_audioClient != null) { Marshal.ReleaseComObject(_audioClient); _audioClient = null; }
+        }
     }
 
     private bool ActivateAndStart()
@@ -192,7 +201,7 @@ public sealed class InputDeviceCapture : IDisposable
                 Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
 
             int hr = _deviceId is null
-                ? enumerator.GetDefaultAudioEndpoint(1 /*eCapture*/, 0 /*eConsole*/, out device)
+                ? enumerator.GetDefaultAudioEndpoint(_loopback ? 0 : 1, 0 /*eConsole*/, out device)
                 : enumerator.GetDevice(_deviceId, out device);
             if (hr != 0 || device == null) return false;
 
@@ -220,7 +229,7 @@ public sealed class InputDeviceCapture : IDisposable
         //   AUDCLNT_STREAMFLAGS_EVENTCALLBACK    = 0x00040000
         //   AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM   = 0x80000000
         //   AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY = 0x08000000
-        const uint streamFlags = 0x00040000u | 0x80000000u | 0x08000000u;
+        uint streamFlags = 0x00040000u | 0x80000000u | 0x08000000u | (_loopback ? 0x00020000u : 0u);
 
         foreach (int ch in new[] { 2, 1 })
         {
@@ -327,9 +336,7 @@ public sealed class InputDeviceCapture : IDisposable
 
     private void FlushFrame()
     {
-        var copy = new short[_accumBuf.Length];
-        _accumBuf.AsSpan().CopyTo(copy);
-        PcmFrameReady?.Invoke(copy, FrameSamples, _channels);
+        PcmFrameReady?.Invoke(_accumBuf, FrameSamples, _channels); // Borrowed until callback returns.
         _accumCount = 0;
     }
 

clients/windows/VoiceCat.App/Audio/ProcessAudioMixer.cs

@@ -1,148 +1,85 @@
+using VoiceCat.Audio;
 using VoiceCat.Interop;
 
-// Owns N ProcessLoopbackCapture instances, mixes their PCM every 20 ms, and feeds
-// the result to the core via vc_stream_feed_pcm. Used for per-app audio sharing.
 namespace VoiceCat.App.Audio;
 
+// Capture threads own their ring producers; the mix thread alone consumes them.
 public sealed class ProcessAudioMixer : IDisposable
 {
-    private const int SampleRate   = 48000;
-    private const int FrameSamples = 960;
-    private const int Channels     = 2; // stereo; captures fall back to mono if needed
-
-    private readonly List<ProcessLoopbackCapture> _captures = [];
-
-    // Per-capture latest frame, protected by _frameLock.
-    private readonly object _frameLock = new();
-    private List<short[]>   _latestFrames = [];
-    private int             _activeChannels = Channels;
-
-    private Thread?          _mixThread;
-    private volatile bool    _running;
-    private VoiceCatClient?  _client;
-    private uint             _streamId;
-
+    private sealed class Input
+    {
+        internal readonly PcmRing Ring = new(16384);
+        private readonly short[] stereo = new short[1920];
+        internal void Feed(short[] pcm, int channels)
+        {
+            if (channels == 2) { Ring.TryWrite(pcm); return; }
+            if (channels != 1 || pcm.Length > 960) return;
+            for (int i = 0; i < pcm.Length; i++) stereo[2 * i] = stereo[2 * i + 1] = pcm[i];
+            Ring.TryWrite(stereo.AsSpan(0, pcm.Length * 2));
+        }
+    }
+    private readonly List<ProcessLoopbackCapture> captures = [];
+    private Input[] inputs = [];
+    private Thread? thread;
+    private volatile bool running;
+    private VoiceCatClient? client;
+    private uint streamId;
     public void Start(AppAudioScope scope, VoiceCatClient client, uint streamId)
     {
-        if (_running) return;
-        _client   = client;
-        _streamId = streamId;
-
+        if (running) return;
+        this.client = client; this.streamId = streamId;
         var specs = ResolveCaptures(scope);
-        if (specs.Count == 0)
+        inputs = specs.Select(_ => new Input()).ToArray();
+        try
         {
-            // nothing to capture — scope resolved to empty set
-            return;
-        }
-
-        lock (_frameLock)
-        {
-            _latestFrames   = new List<short[]>(new short[specs.Count][]);
-            _activeChannels = Channels;
-        }
-
             for (int i = 0; i < specs.Count; i++)
             {
-            int captureIndex = i;
-            var (pid, mode) = specs[i];
-            var cap = new ProcessLoopbackCapture(pid, mode);
-            cap.PcmFrameReady += (pcm, spc, ch) => OnCaptureFrame(captureIndex, pcm, ch);
-            _captures.Add(cap);
+                Input input = inputs[i]; var (pid, mode) = specs[i];
+                var capture = new ProcessLoopbackCapture(pid, mode);
+                capture.PcmFrameReady += (pcm, _, channels) => input.Feed(pcm, channels);
+                captures.Add(capture);
+                if (!capture.Start()) throw new InvalidOperationException("Process audio capture could not start.");
             }
-
-        foreach (var c in _captures) c.Start();
-
-        _running   = true;
-        _mixThread = new Thread(MixLoop) { IsBackground = true, Name = "ProcessAudioMixer" };
-        _mixThread.Start();
+            if (inputs.Length == 0) return;
+            running = true;
+            thread = new Thread(MixLoop) { IsBackground = true, Name = "ProcessAudioMixer" }; thread.Start();
+        }
+        catch { Stop(); throw; }
     }
-
     public void Stop()
     {
-        _running = false;
-        _mixThread?.Join(500);
-        foreach (var c in _captures) { c.Stop(); c.Dispose(); }
-        _captures.Clear();
+        running = false;
+        if (thread is not null && !thread.Join(5000)) throw new TimeoutException("Process audio mixer did not stop.");
+        foreach (var capture in captures) capture.Dispose();
+        captures.Clear(); inputs = []; thread = null;
     }
-
     public void Dispose() => Stop();
-
-    // ── Capture callback ──────────────────────────────────────────────────────
-
-    private void OnCaptureFrame(int index, short[] pcm, int channels)
-    {
-        lock (_frameLock)
-        {
-            // Upmix mono → stereo interleave if the capture fell back to mono.
-            if (channels == 1 && _activeChannels == 2)
-                pcm = MonoToStereo(pcm);
-            if (index < _latestFrames.Count)
-                _latestFrames[index] = pcm;
-        }
-    }
-
-    // ── Mix loop (20 ms timer) ────────────────────────────────────────────────
-
     private void MixLoop()
     {
-        // Use a target period close to 20 ms; small under-shoot avoids accumulating drift.
-        const int periodMs = 19;
-        while (_running)
+        var frame = new short[1920]; var mix = new short[1920]; var sums = new int[1920];
+        long deadline = System.Diagnostics.Stopwatch.GetTimestamp();
+        while (running)
         {
-            Thread.Sleep(periodMs);
-            if (!_running) break;
-
-            short[] mix;
-            lock (_frameLock)
+            sums.AsSpan().Clear();
+            foreach (Input input in inputs)
             {
-                int len = FrameSamples * _activeChannels;
-                mix = new short[len];
-
-                foreach (var frame in _latestFrames)
-                {
-                    if (frame == null) continue;
-                    int frameLen = Math.Min(frame.Length, len);
-                    for (int i = 0; i < frameLen; i++)
-                    {
-                        int sum = mix[i] + frame[i];
-                        mix[i] = (short)Math.Clamp(sum, short.MinValue, short.MaxValue);
+                while (input.Ring.Count > 11520) input.Ring.Read(frame);
+                frame.AsSpan().Clear(); input.Ring.Read(frame);
+                for (int i = 0; i < frame.Length; i++) sums[i] += frame[i];
+            }
+            for (int i = 0; i < mix.Length; i++) mix[i] = (short)Math.Clamp(sums[i], short.MinValue, short.MaxValue);
+            client?.StreamFeedPcm(streamId, mix, 960, 2);
+            deadline += System.Diagnostics.Stopwatch.Frequency / 50;
+            double wait = (deadline - System.Diagnostics.Stopwatch.GetTimestamp()) * 1000.0 / System.Diagnostics.Stopwatch.Frequency;
+            if (wait > 0) Thread.Sleep((int)Math.Ceiling(wait));
+            else if (wait < -100) deadline = System.Diagnostics.Stopwatch.GetTimestamp();
         }
     }
-            }
-
-            _client?.StreamFeedPcm(_streamId, mix, FrameSamples, (uint)_activeChannels);
-        }
-    }
-
-    // ── Helpers ───────────────────────────────────────────────────────────────
-
-    // Resolve the scope to the WASAPI captures to open:
-    //  OnlyApps      → one INCLUDE capture per selected process tree.
-    //  AllExceptApps → one EXCLUDE capture of the single selected process tree, which
-    //                  natively captures the whole system render mix minus that tree
-    //                  (dynamic — apps launched later are included automatically).
-    private static List<(int pid, ProcessLoopbackCapture.Mode mode)> ResolveCaptures(AppAudioScope scope)
-    {
-        return scope switch
+    private static List<(int pid, ProcessLoopbackCapture.Mode mode)> ResolveCaptures(AppAudioScope scope) => scope switch
     {
         OnlyApps o => o.Pids.Select(p => (p, ProcessLoopbackCapture.Mode.Include)).ToList(),
-            AllExceptApps a when a.Pids.Count > 0 =>
-                [(a.Pids[0], ProcessLoopbackCapture.Mode.Exclude)],
-            // Entire desktop minus VoiceCat itself: EXCLUDE our own process tree.
-            EntireDesktop { ExcludeSelf: true } =>
-                [(Environment.ProcessId, ProcessLoopbackCapture.Mode.Exclude)],
+        AllExceptApps a when a.Pids.Count > 0 => [(a.Pids[0], ProcessLoopbackCapture.Mode.Exclude)],
+        EntireDesktop { ExcludeSelf: true } => [(Environment.ProcessId, ProcessLoopbackCapture.Mode.Exclude)],
         _ => [],
     };
 }
-
-    private static short[] MonoToStereo(short[] mono)
-    {
-        var stereo = new short[mono.Length * 2];
-        for (int i = 0; i < mono.Length; i++)
-        {
-            stereo[i * 2]     = mono[i];
-            stereo[i * 2 + 1] = mono[i];
-        }
-        return stereo;
-    }
-}

clients/windows/VoiceCat.App/Audio/ProcessLoopbackCapture.cs

@@ -64,15 +64,15 @@ public sealed class ProcessLoopbackCapture : IDisposable
     {
         _running = false;
         _bufferEvent?.Set();
-        _captureThread?.Join(500);
-        if (_audioClientPtr != IntPtr.Zero) AC_Stop(_audioClientPtr);
+        if (_captureThread is not null && !_captureThread.Join(5000))
+            throw new TimeoutException("Process capture did not stop.");
     }
 
+    private int _disposed;
     public void Dispose()
     {
+        if (Interlocked.Exchange(ref _disposed, 1) != 0) return;
         Stop();
-        ComRelease(ref _captureClientPtr);
-        ComRelease(ref _audioClientPtr);
         _bufferEvent?.Dispose();
         _initDone.Dispose();
     }
@@ -80,11 +80,24 @@ public sealed class ProcessLoopbackCapture : IDisposable
     // ── Capture thread (MTA) ──────────────────────────────────────────────────
 
     private void CaptureThreadProc()
+    {
+        try
         {
             _initOk = ActivateAndStart();
             _initDone.Set();
-        if (!_initOk) return;
-        CaptureLoop();
+            if (_initOk && _running) CaptureLoop();
+        }
+        catch
+        {
+            _initOk = false;
+            _initDone.Set();
+        }
+        finally
+        {
+            if (_audioClientPtr != IntPtr.Zero) AC_Stop(_audioClientPtr);
+            ComRelease(ref _captureClientPtr);
+            ComRelease(ref _audioClientPtr);
+        }
     }
 
     private bool ActivateAndStart()
@@ -274,9 +287,9 @@ public sealed class ProcessLoopbackCapture : IDisposable
 
     private void FlushFrame()
     {
-        var copy = new short[_accumBuf.Length];
-        _accumBuf.AsSpan().CopyTo(copy);
-        PcmFrameReady?.Invoke(copy, FrameSamples, _channels);
+        // The callback borrows this buffer until it returns. This capture owner cannot
+        // overwrite it concurrently, which avoids one allocation every 20 ms.
+        PcmFrameReady?.Invoke(_accumBuf, FrameSamples, _channels);
         _accumCount = 0;
     }
 

clients/windows/VoiceCat.App/Audio/WasapiAudioBackend.cs

@@ -0,0 +1,113 @@
+using System.Runtime.InteropServices;
+using VoiceCat.Audio;
+using static VoiceCat.App.Audio.InputDeviceCapture;
+
+namespace VoiceCat.App.Audio;
+
+public sealed class WasapiAudioBackend : IAudioDeviceBackend
+{
+    public IReadOnlyList<AudioDeviceInfo> Enumerate(bool input) => InputDeviceEnumerator.List(input).Select(d => new AudioDeviceInfo(d.Id, d.Name, d.IsDefault)).ToArray();
+    public IAudioCapture OpenCapture(string? deviceId, bool loopback, CapturePcmHandler handler)
+    {
+        var capture = new InputDeviceCapture(NormalizeDeviceId(deviceId), loopback);
+        capture.PcmFrameReady += (pcm, _, channels) => handler(pcm, channels);
+        if (!capture.Start()) { capture.Dispose(); throw new InvalidOperationException("WASAPI capture could not start."); }
+        return new Capture(capture);
+    }
+    public IAudioPlayback OpenPlayback(string? deviceId = null) => new Playback(deviceId);
+    // The old miniaudio ABI persisted its raw device union as hex. Its Windows member
+    // is a null-terminated UTF-16 WASAPI endpoint id; preserve saved selections.
+    internal static string? NormalizeDeviceId(string? id)
+    {
+        if (string.IsNullOrEmpty(id)) return null;
+        if (id.StartsWith('{')) return id;
+        try
+        {
+            byte[] bytes = Convert.FromHexString(id);
+            string decoded = System.Text.Encoding.Unicode.GetString(bytes).Split('\0')[0];
+            return decoded.StartsWith('{') ? decoded : null;
+        }
+        catch (FormatException) { return id; }
+    }
+    private sealed class Capture(InputDeviceCapture capture) : IAudioCapture { public void Dispose() => capture.Dispose(); }
+
+    private sealed class Playback : IAudioPlayback
+    {
+        private readonly string? deviceId;
+        private readonly PcmRing pcm = new(32768);
+        private readonly ManualResetEventSlim initialized = new(false);
+        private readonly Thread thread;
+        private volatile bool running = true;
+        private bool ready;
+        private int disposed;
+        internal Playback(string? deviceId)
+        {
+            this.deviceId = deviceId;
+            thread = new Thread(Work) { IsBackground = true, Name = "VoiceCat WASAPI playback" };
+            thread.Start();
+            if (!initialized.Wait(5000) || !ready) { Dispose(); throw new InvalidOperationException("WASAPI playback could not start."); }
+        }
+        public void Write(ReadOnlySpan<short> stereoPcm) => pcm.TryWrite(stereoPcm);
+        private unsafe void Work()
+        {
+            IMMDeviceEnumerator? enumerator = null; IMMDevice? device = null; IAudioClient? client = null; IAudioRenderClient? render = null;
+            using var bufferReady = new AutoResetEvent(false);
+            try
+            {
+                enumerator = (IMMDeviceEnumerator)Activator.CreateInstance(Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
+                int result = deviceId is null ? enumerator.GetDefaultAudioEndpoint(0, 0, out device) : enumerator.GetDevice(deviceId, out device);
+                if (result < 0 || device is null) return;
+                Guid iid = typeof(IAudioClient).GUID;
+                if (device.Activate(ref iid, 0x17, 0, out object audio) < 0) return;
+                client = (IAudioClient)audio;
+                WaveFormat format = new() { Format = 1, Channels = 2, Samples = 48000, Bytes = 192000, Align = 4, Bits = 16 };
+                if (client.Initialize(0, 0x00040000u | 0x80000000u | 0x08000000u, 600000, 0, (nint)(&format), 0) < 0) return;
+                if (client.GetBufferSize(out uint capacity) < 0 || client.SetEventHandle(bufferReady.SafeWaitHandle.DangerousGetHandle()) < 0) return;
+                iid = typeof(IAudioRenderClient).GUID;
+                if (client.GetService(ref iid, out object output) < 0) return;
+                render = (IAudioRenderClient)output;
+                if (client.Start() < 0) return;
+                ready = true; initialized.Set();
+                Span<short> discard = stackalloc short[1920];
+                while (running)
+                {
+                    bufferReady.WaitOne(20); // Scheduling wait is outside the buffer-fill cycle.
+                    if (!running || client.GetCurrentPadding(out uint padding) < 0) break;
+                    uint frames = capacity - Math.Min(capacity, padding);
+                    if (frames == 0) continue;
+                    if (render.GetBuffer(frames, out nint buffer) < 0) break;
+                    var destination = new Span<short>((void*)buffer, checked((int)frames * 2));
+                    // Keep queued playback bounded to ~120 ms, then fill underflow with silence.
+                    while (pcm.Count > 11520) pcm.Read(discard);
+                    int count = pcm.Read(destination); destination[count..].Clear();
+                    if (render.ReleaseBuffer(frames, 0) < 0) break;
+                }
+            }
+            catch { ready = false; }
+            finally
+            {
+                initialized.Set();
+                try { client?.Stop(); } catch { }
+                if (render is not null) Marshal.ReleaseComObject(render);
+                if (client is not null) Marshal.ReleaseComObject(client);
+                if (device is not null) Marshal.ReleaseComObject(device);
+                if (enumerator is not null) Marshal.ReleaseComObject(enumerator);
+            }
+        }
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref disposed, 1) != 0) return;
+            running = false;
+            if (!thread.Join(5000)) throw new TimeoutException("WASAPI playback did not stop.");
+            initialized.Dispose();
+        }
+    }
+    [StructLayout(LayoutKind.Sequential, Pack = 2)]
+    private struct WaveFormat { internal ushort Format, Channels; internal uint Samples, Bytes; internal ushort Align, Bits, Extra; }
+    [ComImport, Guid("F294ACFC-3146-4483-A7BF-ADDCA7C260E2"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    private interface IAudioRenderClient
+    {
+        [PreserveSig] int GetBuffer(uint frames, out nint data);
+        [PreserveSig] int ReleaseBuffer(uint frames, uint flags);
+    }
+}

clients/windows/VoiceCat.App/Forms/ConnectDialog.cs

@@ -119,7 +119,7 @@ public partial class ConnectDialog : Form
         Directory.CreateDirectory(tofuDir);
 
         _client = new VoiceCatClient("VoiceCat-Windows", VoiceCatClient.VersionString,
-            VcLogLevel.Info, ServerListStore.TofuStorePath);
+            VcLogLevel.Info, ServerListStore.TofuStorePath, new VoiceCat.App.Audio.WasapiAudioBackend());
         _client.EventReceived += OnEvent;
         _identityDialogShown = false;
         _pumpTimer.Start();

clients/windows/VoiceCat.App/Program.cs

@@ -5,7 +5,7 @@ namespace VoiceCat.App;
 internal static class Program
 {
     [STAThread]
-    private static void Main()
+    private static int Main(string[] args)
     {
         // Surface exceptions that WinForms' default message-loop handling would otherwise
         // swallow silently (or crash with no visible cause).
@@ -16,12 +16,37 @@ internal static class Program
 
         ApplicationConfiguration.Initialize();
 
+        if (args.Contains("--smoke-test"))
+        {
+            try
+            {
+                using var client = new VoiceCat.Interop.VoiceCatClient("Smoke", "test");
+                using var form = new MainForm(client, 0, "Smoke", "Managed core");
+                form.CreateControl();
+                if (form.Controls.Count == 0 || string.IsNullOrEmpty(form.Text)) return 1;
+                client.PumpEvents();
+                if (args.Contains("--audio"))
+                {
+                    var backend = new Audio.WasapiAudioBackend();
+                    using var playback = backend.OpenPlayback();
+                    int samples = 0;
+                    using var capture = backend.OpenCapture(null, false, (pcm, _) => Interlocked.Add(ref samples, pcm.Length));
+                    short[] silence = new short[1920];
+                    for (int i = 0; i < 150; i++) { playback.Write(silence); Thread.Sleep(20); }
+                    if (samples == 0) return 2;
+                }
+                return 0;
+            }
+            catch { return 1; }
+        }
+
         using var connectDialog = new ConnectDialog();
         var result = connectDialog.ShowDialog();
         if (result != DialogResult.OK || connectDialog.ConnectedClient is null)
-            return;
+            return 0;
 
         Application.Run(new MainForm(connectDialog.ConnectedClient, connectDialog.SelfUserId,
             connectDialog.Nickname, connectDialog.ServerName));
+        return 0;
     }
 }

clients/windows/VoiceCat.App/VoiceCat.App.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <ItemGroup>
-    <ProjectReference Include="..\VoiceCat.Interop\VoiceCat.Interop.csproj" />
+    <ProjectReference Include="..\VoiceCat.Managed\VoiceCat.Managed.csproj" />
   </ItemGroup>
 
   <!-- Prismatoid — .NET bindings for the Prism speech library, used for spoken event
@@ -42,18 +42,6 @@
        as part of the Windows Desktop shared framework on net10.0-windows — no PackageReference
        needed (one was tried and NuGet flagged it as redundant/unprunable, NU1510). -->
 
-  <!-- voicecat.dll must exist (build the `windows-client` CMake preset first — see
-       clients/windows/README.md). -->
-  <ItemGroup>
-    <Content Include="$(VoiceCatNativeDir)\voicecat.dll" Condition="Exists('$(VoiceCatNativeDir)\voicecat.dll')">
-      <Link>voicecat.dll</Link>
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
-  </ItemGroup>
 
-  <Target Name="VoiceCatCheckNativeDll" BeforeTargets="Build">
-    <Error Condition="!Exists('$(VoiceCatNativeDir)\voicecat.dll')"
-           Text="voicecat.dll not found at '$(VoiceCatNativeDir)'. Build it first: cmake --preset windows-client &amp;&amp; cmake --build --preset windows-client (see clients/windows/README.md)." />
-  </Target>
 
 </Project>

clients/windows/VoiceCat.App/packages.publish.win-x64.lock.json

@@ -0,0 +1,77 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0-windows7.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      },
+      "Prismatoid": {
+        "type": "Direct",
+        "requested": "[0.3.0, )",
+        "resolved": "0.3.0",
+        "contentHash": "mUOgtmFtjbLxydrdAImkfP3u0U8qrYkvfx2NlQqdQQ8TB9qe59BobxBCcNDo21g8xSefkBJB1VdGPbVTfiE7zw=="
+      },
+      "BouncyCastle.Cryptography": {
+        "type": "Transitive",
+        "resolved": "2.6.2",
+        "contentHash": "7oWOcvnntmMKNzDLsdxAYqApt+AjpRpP2CShjMfIa3umZ42UQMvH0tl1qAliYPNYO6vTdcGMqnRrCPmsfzTI1w=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.core": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Audio": "[1.0.0, )",
+          "VoiceCat.Crypto": "[1.0.0, )"
+        }
+      },
+      "voicecat.crypto": {
+        "type": "Project",
+        "dependencies": {
+          "BouncyCastle.Cryptography": "[2.6.2, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.managed": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Core": "[1.0.0, )"
+        }
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    },
+    "net10.0-windows7.0/win-x64": {
+      "Prismatoid": {
+        "type": "Direct",
+        "requested": "[0.3.0, )",
+        "resolved": "0.3.0",
+        "contentHash": "mUOgtmFtjbLxydrdAImkfP3u0U8qrYkvfx2NlQqdQQ8TB9qe59BobxBCcNDo21g8xSefkBJB1VdGPbVTfiE7zw=="
+      }
+    }
+  }
+}

clients/windows/VoiceCat.Interop.Tests/VoiceCatClientSmokeTests.cs

@@ -272,6 +272,8 @@ public sealed class VoiceCatClientSmokeTests : IDisposable
         Assert.Equal(VcResult.Ok, events.First(e => e.Type == VcEventType.AuthResult).Result);
         Assert.True(PumpUntil(client, () => events.Any(e => e.Type == VcEventType.ChannelList), 3000));
 
+        Assert.Equal(VcResult.Ok, client.JoinVoice());
+        Assert.True(PumpUntil(client, () => events.Any(e => e.Type == VcEventType.VoiceState && e.U32a == 1), 5000));
         // Give the async UDP binding handshake a moment to land before announcing a stream
         // (mirrors vccli's 500ms sleep after auth).
         Thread.Sleep(500);
@@ -340,6 +342,10 @@ public sealed class VoiceCatClientSmokeTests : IDisposable
         Assert.True(PumpUntil(b, () => eventsB.Any(e => e.Type == VcEventType.JoinResult), 5000),
             "B did not receive VC_EVENT_JOIN_RESULT");
 
+        Assert.Equal(VcResult.Ok, a.JoinVoice());
+        Assert.Equal(VcResult.Ok, b.JoinVoice());
+        Assert.True(PumpUntil(a, () => eventsA.Any(e => e.Type == VcEventType.VoiceState && e.U32a == 1), 5000));
+        Assert.True(PumpUntil(b, () => eventsB.Any(e => e.Type == VcEventType.VoiceState && e.U32a == 1), 5000));
         // UDP binding handshake is async; give it a moment (mirrors ScreenAudio test).
         Thread.Sleep(500);
 

clients/windows/VoiceCat.Interop/VoiceCat.Interop.csproj

@@ -9,5 +9,6 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <RootNamespace>VoiceCat.Interop</RootNamespace>
   </PropertyGroup>
+  <ItemGroup><InternalsVisibleTo Include="VoiceCat.Interop.Tests" /></ItemGroup>
 
 </Project>

clients/windows/VoiceCat.Managed/Administration.cs

@@ -0,0 +1,32 @@
+using Voicecat.V1;
+
+namespace VoiceCat.Interop;
+
+public sealed partial class VoiceCatClient
+{
+    public VcResult KickUser(uint id, string? reason = null) => Request(new() { Kick = new() { UserId = id, Reason = reason ?? "" } });
+    public VcResult BanUser(uint id, string? reason = null, ulong expiresUnixMs = 0) => Request(new() { Ban = new() { UserId = id, Reason = reason ?? "", ExpiresUnixMs = expiresUnixMs } });
+    public VcResult MoveUser(uint id, uint channelId) => Request(new() { MoveUser = new() { UserId = id, ChannelId = channelId } });
+    public VcResult SetServerMute(uint id, bool muted, bool deafened) => Request(new() { ServerMute = new() { UserId = id, Muted = muted, Deafened = deafened } });
+    public VcResult SetPermission(uint id, PermissionsInfo permissions) => Request(new() { SetPermission = new() { UserId = id, Permissions = new()
+    { IsAdmin = permissions.IsAdmin, CanCreateTempChannel = permissions.CanCreateTempChannel, CanAdminAccounts = permissions.CanAdminAccounts, CanBan = permissions.CanBan, CanKick = permissions.CanKick, CanMoveUsers = permissions.CanMoveUsers } } });
+    public VcResult CreateAccount(string username, string password) => Request(new() { CreateAccount = new() { Username = username, Password = password } });
+    public VcResult ResetPassword(string username, string password) => Request(new() { ResetPassword = new() { Username = username, NewPassword = password } });
+    public VcResult DeleteAccount(string username) => Request(new() { DeleteAccount = new() { Username = username } });
+    public VcResult RequestAccountList() => Request(new() { ListAccounts = new() });
+    public VcResult CreateChannel(ChannelEditInfo info) => Request(new() { CreateChannel = new() { Channel = Channel(info), Password = info.Password ?? "" } });
+    public VcResult EditChannel(ChannelEditInfo info) => Request(new() { EditChannel = new() { Channel = Channel(info), Password = info.Password ?? "" } });
+    public VcResult DeleteChannel(uint id) => Request(new() { DeleteChannel = new() { ChannelId = id } });
+    public VcResult SendText(VcTextScope scope, uint targetId, string body)
+    {
+        try { core.Send(new() { TextMessage = new() { Scope = (TextScope)scope, TargetId = targetId, Body = body, ClientMsgId = Guid.NewGuid().ToString("N") } }); return VcResult.Ok; }
+        catch { return VcResult.NotConnected; }
+    }
+    private static Voicecat.V1.Channel Channel(ChannelEditInfo info) => new()
+    {
+        Id = info.Id, ParentId = info.ParentId, Name = info.Name, Topic = info.Topic, MaxUsers = info.MaxUsers, Order = unchecked((int)info.SortOrder),
+        Audio = new() { Codec = info.Audio.Codec, Mode = info.Audio.Stereo ? ChannelMode.ModeStereo : ChannelMode.ModeMono, SampleRate = info.Audio.SampleRate,
+            BitrateBps = info.Audio.BitrateBps, FrameMs = info.Audio.FrameMs, Application = (OpusApplication)info.Audio.Application, Complexity = info.Audio.Complexity,
+            Fec = info.Audio.Fec, ExpectedPacketLoss = info.Audio.ExpectedPacketLoss, Dtx = info.Audio.Dtx, Dred = info.Audio.Dred }
+    };
+}

clients/windows/VoiceCat.Managed/AudioControls.cs

@@ -0,0 +1,106 @@
+using VoiceCat.Audio;
+using Voicecat.V1;
+
+namespace VoiceCat.Interop;
+
+public sealed partial class VoiceCatClient
+{
+    private sealed record PcmRegistration(nint Callback, nint User);
+    private PcmRegistration? pcm;
+    public (VcResult Result, uint StreamId) StartStream(VcStreamKind kind, string label) => Start(kind, label, false);
+    public (VcResult Result, uint StreamId) StartStreamExternalFeed(VcStreamKind kind, string label) => Start(kind, label, true);
+    private (VcResult, uint) Start(VcStreamKind kind, string label, bool external)
+    {
+        StreamInfo? stream = null;
+        try
+        {
+            stream = core.StartStreamAsync((StreamKind)kind, label).GetAwaiter().GetResult();
+            local[stream.StreamId] = new(stream, external);
+            if (!external && backend is not null) captures[stream.StreamId] = Capture(stream);
+            return (VcResult.Ok, stream.StreamId);
+        }
+        catch (Exception exception)
+        {
+            if (stream is not null) { local.TryRemove(stream.StreamId, out _); core.StopStream(stream.StreamId); }
+            Queue(new(VcEventType.Error, Result: VcResult.Audio, Text: exception.Message)); return (VcResult.Audio, 0);
+        }
+    }
+    private IAudioCapture Capture(StreamInfo stream) => backend!.OpenCapture(devices.GetValueOrDefault(stream.StreamId), stream.Kind == StreamKind.StreamScreenAudio,
+        (samples, channels) => StreamFeedPcm(stream.StreamId, samples, samples.Length / channels, (uint)channels));
+    public VcResult StopStream(uint id)
+    {
+        if (captures.Remove(id, out var capture)) capture.Dispose();
+        if (!local.TryRemove(id, out LocalStream? stream)) return VcResult.InvalidArg;
+        try { core.StopStream(stream.Info.StreamId); return VcResult.Ok; } catch { return VcResult.NotConnected; }
+    }
+    public VcResult SetInputDevice(uint id, string? device)
+    {
+        devices[id] = device;
+        if (!captures.Remove(id, out var previous)) return VcResult.Ok;
+        previous.Dispose();
+        try { var info = local[id].Info.Clone(); info.StreamId = id; captures[id] = Capture(info); return VcResult.Ok; }
+        catch { return VcResult.Audio; }
+    }
+    public VcResult SetCaptureChannels(uint id, uint channels)
+    { try { LocalStream stream = local[id]; core.Audio.SetCaptureChannels(stream.Info.StreamId, checked((int)channels)); stream.CaptureChannels = (int)channels; return VcResult.Ok; } catch { return VcResult.InvalidArg; } }
+    public VcResult AudioRestart()
+    {
+        foreach (uint id in captures.Keys.ToArray()) { VcResult result = SetInputDevice(id, devices.GetValueOrDefault(id)); if (result != VcResult.Ok) return result; }
+        return VcResult.Ok;
+    }
+    public VcResult SetInputMode(VcInputMode mode) { if (!Enum.IsDefined(mode)) return VcResult.InvalidArg; core.Audio.InputMode = (AudioInputMode)mode; return VcResult.Ok; }
+    public VcResult SetVadThreshold(float threshold) { if (!float.IsFinite(threshold) || threshold is < 0 or > 1) return VcResult.InvalidArg; core.Audio.VadThreshold = threshold; return VcResult.Ok; }
+    public VcResult SetPushToTalk(bool active) { core.Audio.PushToTalk = active; return VcResult.Ok; }
+    public VcResult SetSelfMute(bool muted, bool deafened) { core.Audio.MicMuted = muted; core.Audio.Deafened = deafened; return VcResult.Ok; }
+    public VcResult SetOutputVolume(float gain) { if (!float.IsFinite(gain) || gain is < 0 or > 4) return VcResult.InvalidArg; core.Audio.OutputGain = gain; return VcResult.Ok; }
+    public VcResult SetInputGain(float gain) { if (!float.IsFinite(gain) || gain is < 0 or > 4) return VcResult.InvalidArg; core.Audio.InputGain = gain; return VcResult.Ok; }
+    public VcResult SetInputNoiseReduction(bool enabled) { core.Audio.InputNoiseReduction = enabled; return VcResult.Ok; }
+    public VcResult SetRemoteStream(uint userId, uint streamId, float gain, bool muted, bool nr)
+    { try { core.Audio.SetRemotePlayback(userId, streamId, gain, muted, nr); return VcResult.Ok; } catch { return VcResult.InvalidArg; } }
+    public (VcResult Result, RemoteStreamState? State) GetRemoteStream(uint userId, uint streamId)
+    {
+        var state = core.Audio.GetRemotePlayback(userId, streamId);
+        return state is { } value ? (VcResult.Ok, new(value.Gain, value.Muted, value.NoiseReduction)) : (VcResult.InvalidArg, null);
+    }
+    public (VcResult Result, AudioConfigInfo? Config) GetStreamAudioConfig(uint userId, uint streamId)
+    {
+        var info = core.Users.FirstOrDefault(u => u.Id == userId)?.Streams.FirstOrDefault(s => s.StreamId == streamId);
+        if (core.Authentication?.Self.Id == userId && local.TryGetValue(streamId, out LocalStream? own)) info = own.Info;
+        return info is null ? (VcResult.InvalidArg, null) : (VcResult.Ok, Audio(info.Audio));
+    }
+    public VcResult StreamFeedPcm(uint id, ReadOnlySpan<short> samples, int samplesPerChannel, uint channels)
+    {
+        if (samplesPerChannel < 0 || channels is not (1 or 2) || samples.Length != (long)samplesPerChannel * channels) return VcResult.InvalidArg;
+        if (!local.TryGetValue(id, out LocalStream? stream)) return VcResult.InvalidArg;
+        core.Audio.FeedPcm(Volatile.Read(ref stream.Info).StreamId, samples, (int)channels); return VcResult.Ok; // A full real-time ring drops, never waits.
+    }
+    public VcResult SetPcmSink(nint callback, nint user) { Volatile.Write(ref pcm, callback == 0 ? null : new(callback, user)); return VcResult.Ok; }
+    private unsafe void ForwardPcm(uint userId, uint streamId, ReadOnlySpan<short> samples, int channels)
+    {
+        var target = Volatile.Read(ref pcm); if (target is null) return;
+        fixed (short* input = samples)
+            ((delegate* unmanaged[Cdecl]<nint, uint, uint, short*, nuint, uint, uint, void>)target.Callback)(target.User, userId, streamId, input, (nuint)(samples.Length / channels), (uint)channels, 48000);
+    }
+
+    // Server-authoritative moves/edits stop old SSRCs. Reannounce with the new channel
+    // configuration while keeping UI/external-feed ids stable; captures continue feeding
+    // the alias and switch to the new audio owner only when negotiation completes.
+    private void ReconcileStreams()
+    {
+        var active = core.LocalStreams;
+        foreach (LocalStream stream in local.Values)
+            if (!active.Any(s => s.StreamId == stream.Info.StreamId) && Interlocked.CompareExchange(ref stream.Restarting, 1, 0) == 0) _ = RestartAsync(stream);
+    }
+    private async Task RestartAsync(LocalStream stream)
+    {
+        try
+        {
+            StreamInfo previous = stream.Info;
+            StreamInfo next = await core.StartStreamAsync(previous.Kind, previous.Label, stream.CaptureChannels).ConfigureAwait(false);
+            if (!local.ContainsKey(stream.Alias)) core.StopStream(next.StreamId);
+            else Volatile.Write(ref stream.Info, next);
+        }
+        catch (Exception exception) { Queue(new(VcEventType.Error, Result: VcResult.Audio, Text: exception.Message)); }
+        finally { Volatile.Write(ref stream.Restarting, 0); }
+    }
+}

clients/windows/VoiceCat.Managed/VoiceCat.Managed.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../../../dotnet/src/VoiceCat.Core/VoiceCat.Core.csproj" />
+    <Compile Include="../VoiceCat.Interop/Enums.cs" Link="Enums.cs" />
+    <Compile Include="../VoiceCat.Interop/Models.cs" Link="Models.cs" />
+  </ItemGroup>
+</Project>

clients/windows/VoiceCat.Managed/VoiceCatClient.cs

@@ -0,0 +1,193 @@
+using System.Runtime.InteropServices;
+using System.Threading.Channels;
+using System.Collections.Concurrent;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+using VoiceCat.Crypto;
+using Voicecat.V1;
+using CoreClient = VoiceCat.Core.VoiceCatClient;
+
+namespace VoiceCat.Interop;
+
+// Preserves the shipped WinForms call/event surface while its implementation moves to
+// the async managed core. Events still reach controls only through PumpEvents on the UI thread.
+public sealed partial class VoiceCatClient : IDisposable
+{
+    private readonly CoreClient core;
+    private readonly IAudioDeviceBackend? backend;
+    private readonly System.Threading.Channels.Channel<VoiceCatEvent> events = System.Threading.Channels.Channel.CreateUnbounded<VoiceCatEvent>();
+    private readonly Dictionary<uint, IAudioCapture> captures = [];
+    private readonly Dictionary<uint, string?> devices = [];
+    private readonly Dictionary<uint, StreamSummary[]> remoteStreams = [];
+    private readonly Dictionary<uint, bool> talkState = [];
+    private sealed class LocalStream(StreamInfo info, bool external)
+    {
+        internal readonly uint Alias = info.StreamId;
+        internal StreamInfo Info = info;
+        internal readonly bool External = external;
+        internal int CaptureChannels = 1;
+        internal int Restarting;
+    }
+    private readonly ConcurrentDictionary<uint, LocalStream> local = new();
+    private IAudioPlayback? playback;
+    private Task connecting = Task.CompletedTask;
+    private TaskCompletionSource<bool>? identity;
+    private int disposed;
+    private List<AccountInfo> accounts = [];
+    private bool audioFailureReported;
+    public event Action<VoiceCatEvent>? EventReceived;
+    public event Action<uint, float>? LevelChanged;
+    public CoreClient ManagedClient => core;
+
+    public VoiceCatClient(string clientName, string clientVersion, VcLogLevel logLevel = VcLogLevel.Info, string? tofuStorePath = null, IAudioDeviceBackend? audioBackend = null)
+    {
+        backend = audioBackend;
+        core = new(clientName, clientVersion, tofuStorePath);
+        core.ConnectionStateChanged += state =>
+        {
+            VcConnectionState mapped = state switch { ClientConnectionState.Connecting => VcConnectionState.Connecting, ClientConnectionState.VerifyingIdentity => VcConnectionState.VerifyingIdentity,
+                ClientConnectionState.Authenticating => VcConnectionState.Authenticating, ClientConnectionState.Connected => VcConnectionState.Connected, _ => VcConnectionState.Disconnected };
+            Queue(new(VcEventType.ConnectionState, ConnectionState: mapped));
+            if (mapped == VcConnectionState.Disconnected) Queue(new(VcEventType.Disconnected));
+        };
+        core.Audio.MixedPcm += pcm => Volatile.Read(ref playback)?.Write(pcm);
+        core.Audio.StreamPcm += ForwardPcm;
+    }
+
+    private void Queue(VoiceCatEvent message) => events.Writer.TryWrite(message);
+    public VcResult Connect(string host, ushort port)
+    {
+        if (!connecting.IsCompleted || core.State != ClientConnectionState.Disconnected) return VcResult.Already;
+        connecting = ConnectAsync(host, port);
+        return VcResult.Ok;
+    }
+    private async Task ConnectAsync(string host, ushort port)
+    {
+        try
+        {
+            await core.ConnectAsync(host, port, async (challenge, token) =>
+            {
+                identity = new(TaskCreationOptions.RunContinuationsAsynchronously);
+                Queue(new(VcEventType.ServerIdentity, U32a: (uint)challenge.Status, Text: challenge.CertificateFingerprint));
+                return await identity.Task.WaitAsync(token).ConfigureAwait(false);
+            }).ConfigureAwait(false);
+        }
+        catch (Exception exception) { Queue(new(VcEventType.Error, Result: VcResult.Io, Text: exception.Message)); }
+    }
+    public VcResult ConfirmServerIdentity(bool accept) { identity?.TrySetResult(accept); return VcResult.Ok; }
+    public VcResult AuthenticateGuest(string nickname) { _ = AuthenticateAsync(() => core.AuthenticateGuestAsync(nickname)); return VcResult.Ok; }
+    public VcResult AuthenticateUser(string username, string password) { _ = AuthenticateAsync(() => core.AuthenticateUserAsync(username, password)); return VcResult.Ok; }
+    private async Task AuthenticateAsync(Func<Task<AuthResult>> authenticate)
+    {
+        try { await connecting.ConfigureAwait(false); await authenticate().ConfigureAwait(false); }
+        catch (Exception exception) { Queue(new(VcEventType.AuthResult, Result: VcResult.AuthFailed, Text: exception.Message)); }
+    }
+    public VcResult Disconnect()
+    {
+        StopDevices(); core.DisconnectAsync().GetAwaiter().GetResult(); return VcResult.Ok;
+    }
+    public string GetServerIdentityDisplay() => core.ServerHello is { } hello ? Convert.ToHexString(hello.ServerIdentityFingerprint.Span) : "";
+
+    public void PumpEvents()
+    {
+        if (!audioFailureReported && core.Audio.Failure is { } failure) { audioFailureReported = true; Queue(new(VcEventType.Error, Result: VcResult.Audio, Text: failure.Message)); }
+        while (core.TryReadEvent(out Envelope? message)) Translate(message!);
+        while (events.Reader.TryRead(out VoiceCatEvent? message)) EventReceived?.Invoke(message);
+        foreach (LocalStream stream in local.Values)
+        {
+            var info = Volatile.Read(ref stream.Info);
+            var level = core.Audio.GetLocalLevel(info.StreamId); LevelChanged?.Invoke(stream.Alias, level.Level);
+            if (talkState.GetValueOrDefault(stream.Alias) != level.Talking)
+            {
+                talkState[stream.Alias] = level.Talking;
+                if (core.State == ClientConnectionState.Connected) core.Send(new() { StreamState = new() { StreamId = info.StreamId, Talking = level.Talking, Muted = core.Audio.MicMuted } });
+                EventReceived?.Invoke(new(VcEventType.TalkState, UserId: core.Authentication?.Self.Id ?? 0, StreamId: stream.Alias, U32a: level.Talking ? 1U : 0));
+            }
+        }
+    }
+
+    private void Translate(Envelope message)
+    {
+        if (message.AuthResult is not null) Queue(new(VcEventType.AuthResult, Result: message.AuthResult.Ok ? VcResult.Ok : VcResult.AuthFailed, UserId: message.AuthResult.Self?.Id ?? 0, Text: message.AuthResult.Error));
+        if (message.ServerState is not null) { remoteStreams.Clear(); foreach (User user in message.ServerState.Users) UpdateStreams(user); Queue(new(VcEventType.ChannelList)); }
+        if (message.ChannelEvent is not null) Queue(new(VcEventType.ChannelList));
+        if (message.UserEvent is not null)
+        {
+            var change = message.UserEvent;
+            if (change.User is { VoiceSubscribed: true } self && self.Id == core.Authentication?.Self.Id) ReconcileStreams();
+            if (change.User is not null) UpdateStreams(change.User);
+            if (change.Kind == UserEvent.Types.Kind.Left) remoteStreams.Remove(change.LeftId);
+            Queue(new(change.Kind switch { UserEvent.Types.Kind.Joined => VcEventType.UserJoined, UserEvent.Types.Kind.Left => VcEventType.UserLeft, _ => VcEventType.UserUpdated }, UserId: change.User?.Id ?? change.LeftId,
+                ChannelId: change.User?.ChannelId ?? 0, Text: change.Kind == UserEvent.Types.Kind.Joined ? change.User?.Nickname : change.Reason));
+        }
+        if (message.JoinChannelResult is not null) Queue(new(VcEventType.JoinResult, Result: message.JoinChannelResult.Ok ? VcResult.Ok : VcResult.InvalidArg, ChannelId: message.JoinChannelResult.ChannelId, Text: message.JoinChannelResult.Error));
+        if (message.VoiceSubscriptionResult is not null) Queue(new(VcEventType.VoiceState, U32a: message.VoiceSubscriptionResult.Subscribed ? 1U : 0));
+        if (message.TextMessage is not null) Queue(new(VcEventType.TextMessage, UserId: message.TextMessage.SenderId, ChannelId: message.TextMessage.TargetId, TextScope: (VcTextScope)message.TextMessage.Scope, Text: message.TextMessage.Body, TimestampUnixMs: message.TextMessage.SentAtUnixMs));
+        if (message.StreamState is not null) Queue(new(VcEventType.TalkState, UserId: message.StreamState.UserId, StreamId: message.StreamState.UserId == core.Authentication?.Self.Id ? local.Values.FirstOrDefault(s => s.Info.StreamId == message.StreamState.StreamId)?.Alias ?? message.StreamState.StreamId : message.StreamState.StreamId, U32a: message.StreamState.Talking ? 1U : 0));
+        if (message.GenericResult is not null) Queue(new(VcEventType.GenericResult, Result: message.GenericResult.Ok ? VcResult.Ok : message.GenericResult.Code == 6 ? VcResult.PermissionDenied : VcResult.InvalidArg, U32a: message.GenericResult.Code, Text: message.GenericResult.Message));
+        if (message.ListAccountsResult is not null)
+        {
+            accounts = message.ListAccountsResult.Accounts.Select(a => new AccountInfo(a.Username, a.IsAdmin, a.CreatedAtUnixMs, a.LastLoginUnixMs)).ToList();
+            Queue(new(VcEventType.AccountList));
+        }
+        if (message.Disconnect is not null) Queue(new(VcEventType.Error, Result: VcResult.Io, Text: message.Disconnect.Reason));
+    }
+
+    private void UpdateStreams(User user)
+    {
+        StreamSummary[] previous = remoteStreams.GetValueOrDefault(user.Id, []);
+        StreamSummary[] next = user.Id == core.Authentication?.Self.Id ? ListUserStreams(user.Id).ToArray() : user.Streams.Select(s => new StreamSummary(s.StreamId, (VcStreamKind)s.Kind, s.Label)).ToArray();
+        foreach (var stream in previous) if (!next.Any(s => s.StreamId == stream.StreamId)) Queue(new(VcEventType.StreamStopped, UserId: user.Id, StreamId: stream.StreamId));
+        foreach (var stream in next) if (!previous.Any(s => s.StreamId == stream.StreamId)) Queue(new(VcEventType.StreamStarted, UserId: user.Id, StreamId: stream.StreamId, U32a: (uint)stream.Kind, Text: stream.Label));
+        remoteStreams[user.Id] = next;
+    }
+
+    private VcResult Request(Envelope request)
+    {
+        if (core.State != ClientConnectionState.Connected) return VcResult.NotConnected;
+        try { _ = RequestAsync(request); return VcResult.Ok; }
+        catch { return VcResult.NotConnected; }
+    }
+    private async Task RequestAsync(Envelope request)
+    {
+        try { await core.RequestAsync(request).ConfigureAwait(false); }
+        catch (Exception exception) { Queue(new(VcEventType.Error, Result: VcResult.Io, Text: exception.Message)); }
+    }
+    public VcResult JoinChannel(uint id, string? password = null) => Request(new() { JoinChannel = new() { ChannelId = id, Password = password ?? "" } });
+    public VcResult LeaveChannel() => Request(new() { LeaveChannel = new() });
+    public VcResult JoinVoice()
+    {
+        try
+        {
+            if (backend is not null && playback is null) playback = backend.OpenPlayback();
+            var result = core.SubscribeVoiceAsync().GetAwaiter().GetResult();
+            if (!result.Ok) { Interlocked.Exchange(ref playback, null)?.Dispose(); }
+            return result.Ok ? VcResult.Ok : VcResult.Audio;
+        }
+        catch (Exception exception) { Queue(new(VcEventType.Error, Result: VcResult.Audio, Text: exception.Message)); return VcResult.Audio; }
+    }
+    public VcResult LeaveVoice() { StopDevices(); local.Clear(); return Request(new() { UnsubscribeVoice = new() }); }
+
+    public List<ChannelInfo> ListChannels() => core.Channels.Select(c => new ChannelInfo(c.Id, c.ParentId, c.Name, c.Topic, c.PasswordProtected, c.MaxUsers, unchecked((uint)c.Order), Audio(c.Audio))).ToList();
+    public List<UserInfo> ListUsers() => core.Users.Select(u => new UserInfo(u.Id, u.Nickname, u.IsGuest, u.ChannelId, u.SelfMicMuted, u.SelfDeafened, u.ServerMuted, u.ServerDeafened, u.VoiceSubscribed)).ToList();
+    public List<StreamSummary> ListUserStreams(uint id) => id == core.Authentication?.Self.Id
+        ? local.Values.Select(s => new StreamSummary(s.Alias, (VcStreamKind)s.Info.Kind, s.Info.Label)).ToList()
+        : core.Users.FirstOrDefault(u => u.Id == id)?.Streams.Select(s => new StreamSummary(s.StreamId, (VcStreamKind)s.Kind, s.Label)).ToList() ?? [];
+    public PermissionsInfo GetPermissions() { Permissions p = core.Authentication?.Permissions ?? new(); return new(p.CanCreateTempChannel, p.CanKick, p.CanBan, p.CanMoveUsers, p.CanAdminAccounts, p.IsAdmin); }
+    public List<AccountInfo> ListAccounts() => accounts.ToList();
+    public List<DeviceInfo> ListDevices(VcDeviceKind kind) => backend?.Enumerate(kind == VcDeviceKind.Input).Select(d => new DeviceInfo(d.Id, d.Name, d.IsDefault)).ToList() ?? [];
+    public static string VersionString => "VoiceCat managed core 0.1.0 (protocol v2)";
+    public static string ResultString(VcResult result) => result.ToString();
+    private static AudioConfigInfo Audio(AudioConfig a) => new(a.Codec, a.Mode == ChannelMode.ModeStereo, a.SampleRate, a.BitrateBps, a.FrameMs, (uint)a.Application, a.Fec, a.ExpectedPacketLoss, a.Dtx, a.Complexity, a.Dred);
+
+    private void StopDevices()
+    {
+        foreach (var capture in captures.Values) capture.Dispose(); captures.Clear(); local.Clear();
+        IAudioPlayback? previous = Interlocked.Exchange(ref playback, null); previous?.Dispose();
+    }
+    public void Dispose()
+    {
+        if (Interlocked.Exchange(ref disposed, 1) != 0) return;
+        identity?.TrySetResult(false); StopDevices(); core.DisposeAsync().AsTask().GetAwaiter().GetResult();
+    }
+}

clients/windows/VoiceCat.Managed/VoiceCatEvent.cs

@@ -0,0 +1,7 @@
+namespace VoiceCat.Interop;
+
+// Compatibility event consumed by WinForms. The managed core owns protocol and audio;
+// this assembly contains no libvoicecat bindings or native handles.
+public sealed record VoiceCatEvent(VcEventType Type, VcConnectionState ConnectionState = VcConnectionState.Disconnected,
+    VcResult Result = VcResult.Ok, uint UserId = 0, uint ChannelId = 0, uint StreamId = 0, VcTextScope TextScope = VcTextScope.Channel,
+    uint U32a = 0, string? Text = null, ulong TimestampUnixMs = 0);

clients/windows/VoiceCat.Managed/packages.lock.json

@@ -0,0 +1,51 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "BouncyCastle.Cryptography": {
+        "type": "Transitive",
+        "resolved": "2.6.2",
+        "contentHash": "7oWOcvnntmMKNzDLsdxAYqApt+AjpRpP2CShjMfIa3umZ42UQMvH0tl1qAliYPNYO6vTdcGMqnRrCPmsfzTI1w=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.core": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Audio": "[1.0.0, )",
+          "VoiceCat.Crypto": "[1.0.0, )"
+        }
+      },
+      "voicecat.crypto": {
+        "type": "Project",
+        "dependencies": {
+          "BouncyCastle.Cryptography": "[2.6.2, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    }
+  }
+}

clients/windows/VoiceCat.Managed/packages.publish.win-x64.lock.json

@@ -0,0 +1,58 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      },
+      "BouncyCastle.Cryptography": {
+        "type": "Transitive",
+        "resolved": "2.6.2",
+        "contentHash": "7oWOcvnntmMKNzDLsdxAYqApt+AjpRpP2CShjMfIa3umZ42UQMvH0tl1qAliYPNYO6vTdcGMqnRrCPmsfzTI1w=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.core": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Audio": "[1.0.0, )",
+          "VoiceCat.Crypto": "[1.0.0, )"
+        }
+      },
+      "voicecat.crypto": {
+        "type": "Project",
+        "dependencies": {
+          "BouncyCastle.Cryptography": "[2.6.2, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    },
+    "net10.0/win-x64": {}
+  }
+}

clients/windows/VoiceCat.slnx

@@ -1,5 +1,14 @@
 <Solution>
+  <Folder Name="/Managed core/">
+    <Project Path="../../dotnet/src/VoiceCat.Core/VoiceCat.Core.csproj" />
+    <Project Path="../../dotnet/src/VoiceCat.Audio/VoiceCat.Audio.csproj" />
+    <Project Path="../../dotnet/src/VoiceCat.Codec/VoiceCat.Codec.csproj" />
+    <Project Path="../../dotnet/src/VoiceCat.Crypto/VoiceCat.Crypto.csproj" />
+    <Project Path="../../dotnet/src/VoiceCat.Dsp/VoiceCat.Dsp.csproj" />
+    <Project Path="../../dotnet/src/VoiceCat.Protocol/VoiceCat.Protocol.csproj" />
+  </Folder>
   <Project Path="VoiceCat.App/VoiceCat.App.csproj" />
   <Project Path="VoiceCat.Interop.Tests/VoiceCat.Interop.Tests.csproj" />
   <Project Path="VoiceCat.Interop/VoiceCat.Interop.csproj" />
+  <Project Path="VoiceCat.Managed/VoiceCat.Managed.csproj" />
 </Solution>

clients/windows/publish-client.ps1

@@ -0,0 +1,15 @@
+param(
+    [string]$RuntimeIdentifier = "win-x64",
+    [string]$Output = ""
+)
+$ErrorActionPreference = "Stop"
+$repoRoot = (Resolve-Path "$PSScriptRoot/../..").Path
+if ([string]::IsNullOrWhiteSpace($Output)) { $Output = "$repoRoot/dotnet/artifacts/client/$RuntimeIdentifier" }
+dotnet publish "$PSScriptRoot/VoiceCat.App/VoiceCat.App.csproj" -c Release -r $RuntimeIdentifier --self-contained true `
+    -p:PublishSingleFile=true -p:PublishTrimmed=false -p:IncludeNativeLibrariesForSelfExtract=false `
+    -p:RestorePackagesWithLockFile=true -p:RestoreLockedMode=true `
+    "-p:NuGetLockFilePath=packages.publish.$RuntimeIdentifier.lock.json" -o $Output
+if ($LASTEXITCODE -ne 0) { throw "Managed Windows client publish failed." }
+if (-not (Test-Path "$Output/voicecat_media.dll")) { throw "Managed media shim was not published." }
+if (Test-Path "$Output/voicecat.dll") { throw "Legacy VoiceCat native core must not be published." }
+Write-Host "Published managed Windows client to $Output"

docs/api-dotnet.md

@@ -125,7 +125,7 @@ wrap Opus controls so P/Invoke never calls C varargs. SafeHandle owns every nati
 encoder, decoder, DRED parser/state, and denoiser, including failed initialization.
 
 `OpusOptions` is an immutable record. Supported PCM rates are 8/12/16/24/48 kHz,
-one or two interleaved channels, and integral 10/20/40/60 ms frames. These match the
+one or two interleaved channels, and integral 5/10/20/40/60 ms frames. These match the
 current VoiceCat protocol's integer frame duration; fractional Opus frame durations
 are not exposed. Low-delay application mode requires at most 20 ms. Channel capture
 bandwidth is controlled separately by `MaximumBandwidthHz`; the production audio

docs/porting-to-dotnet.md

@@ -794,6 +794,14 @@ criterion from `roadmap.md`, re-proven against the new server.
 mix cycle; a manual listen test on Windows and macOS with no audible glitching over 10
 minutes.
 
+**Checkpoint (2026-09-16):** `VoiceCat.Audio` now owns local Opus streams, reframing at every
+protocol frame size, VAD/PTT/DTX, DRED → FEC → PLC receive recovery, bounded jitter, per-stream
+controls, RNNoise and stereo mixing. Its normal encode/decode/NR/mix cycle allocates zero
+managed bytes. Capture inputs use bounded non-waiting PCM rings. The Windows implementation
+uses direct C# WASAPI capture, loopback and playback instead of the proposed miniaudio device
+shim; the codec/DSP shim remains the only native component. A real device smoke passed, but
+the required ten-minute Windows/macOS listen test is still a manual release gate.
+
 ---
 
 ### Phase 6 — Client core (est. 3–4 weeks)
@@ -809,6 +817,12 @@ minutes.
 conversation through the C# server**, and a C# `vccli` interoperates with a C++ `vccli` on
 the same server. This is the full M0–M3 criterion re-proven end to end.
 
+**Checkpoint (2026-09-16):** `VoiceCat.Core` implements TOFU-gated TLS, concurrent correlated
+requests, snapshots/events, reconnects, encrypted UDP binding and send/receive stream
+lifecycle. Two managed clients exchange text and decoded PCM through the managed server.
+The remaining Phase 6 item is the managed console client and its explicit C++ CLI
+interoperability scenario.
+
 ---
 
 ### Phase 7 — Windows client (est. 1–2 weeks)
@@ -818,6 +832,14 @@ shape against a real, complete UI before you commit to two rewrites.
 
 **Exit criterion:** feature parity with the current WinForms build, NVDA smoke-tested.
 
+**Checkpoint (2026-09-16):** the shipped WinForms project references `VoiceCat.Managed`, not
+the P/Invoke core. The compatibility facade preserves UI-thread event pumping and stable
+capture IDs while delegating all protocol and audio state to the idiomatic managed projects.
+Channel moves automatically renegotiate active streams. A published build passed real WASAPI
+capture/playback and form-startup smoke tests and contains `voicecat_media.dll` but no
+`voicecat.dll`. Automated text, bidirectional PCM voice, multi-frame audio and stream-move
+tests pass. NVDA and the manual endurance/listen pass remain before the Phase 7 exit criterion.
+
 ---
 
 ### Phase 8 — macOS client (est. 4–5 weeks)

dotnet/VoiceCat.slnx

@@ -5,8 +5,13 @@
     <Project Path="src/VoiceCat.Codec/VoiceCat.Codec.csproj" />
     <Project Path="src/VoiceCat.Dsp/VoiceCat.Dsp.csproj" />
     <Project Path="src/VoiceCat.Server/VoiceCat.Server.csproj" />
+    <Project Path="src/VoiceCat.Core/VoiceCat.Core.csproj" />
+    <Project Path="src/VoiceCat.Audio/VoiceCat.Audio.csproj" />
   </Folder>
   <Folder Name="/tests/">
     <Project Path="tests/VoiceCat.Tests/VoiceCat.Tests.csproj" />
   </Folder>
+  <Folder Name="/clients/">
+    <Project Path="../clients/windows/VoiceCat.Managed/VoiceCat.Managed.csproj" />
+  </Folder>
 </Solution>

dotnet/src/VoiceCat.Audio/AudioDeviceBackend.cs

@@ -0,0 +1,12 @@
+namespace VoiceCat.Audio;
+
+public sealed record AudioDeviceInfo(string Id, string Name, bool IsDefault);
+public delegate void CapturePcmHandler(ReadOnlySpan<short> pcm, int channels);
+public interface IAudioCapture : IDisposable { }
+public interface IAudioPlayback : IDisposable { void Write(ReadOnlySpan<short> stereoPcm); }
+public interface IAudioDeviceBackend
+{
+    IReadOnlyList<AudioDeviceInfo> Enumerate(bool input);
+    IAudioCapture OpenCapture(string? deviceId, bool loopback, CapturePcmHandler pcm);
+    IAudioPlayback OpenPlayback(string? deviceId = null);
+}

dotnet/src/VoiceCat.Audio/AudioEngine.cs

@@ -0,0 +1,170 @@
+using System.Diagnostics;
+using VoiceCat.Protocol;
+using Voicecat.V1;
+
+namespace VoiceCat.Audio;
+
+public sealed class AudioEngine : IDisposable
+{
+    private readonly object gate = new();
+    private readonly EncodedVoiceSender sender;
+    private readonly int[] mixed = new int[1920];
+    private readonly short[] output = new short[1920];
+    private Routes routes = new([], [], 0);
+    private readonly List<(IDisposable Stream, long Epoch)> retired = [];
+    private long completedEpoch;
+    private readonly CancellationTokenSource stop = new();
+    private readonly Task maintenance;
+    private Thread? worker;
+    private int disposed;
+    public uint SampleClock { get; private set; }
+    public event MixedPcmHandler? MixedPcm;
+    public event PcmStreamHandler? StreamPcm;
+    public volatile float InputGain = 1, OutputGain = 1, VadThreshold = 0.02f;
+    public volatile bool InputNoiseReduction, MicMuted, Deafened, PushToTalk;
+    public volatile AudioInputMode InputMode = AudioInputMode.VoiceActivation;
+    public Exception? Failure { get; private set; }
+
+    public AudioEngine(EncodedVoiceSender sender, bool startWorker = true)
+    {
+        this.sender = sender;
+        maintenance = MaintainAsync();
+        if (startWorker)
+        {
+            worker = new Thread(Work) { IsBackground = true, Name = "VoiceCat managed audio" };
+            worker.Start();
+        }
+    }
+
+    public void AddLocalStream(StreamInfo info, int captureChannels = 1)
+    {
+        if (captureChannels is not (1 or 2)) throw new ArgumentOutOfRangeException(nameof(captureChannels));
+        lock (gate)
+        {
+            ObjectDisposedException.ThrowIf(disposed != 0, this);
+            var stream = new LocalStream(info, captureChannels);
+            Routes previous = routes;
+            var locals = previous.Local.Where(s => s.Info.StreamId != info.StreamId).Append(stream).ToArray();
+            Publish(locals, previous.Remote);
+        }
+    }
+    public void RemoveLocalStream(uint streamId)
+    {
+        lock (gate) Publish(routes.Local.Where(s => s.Info.StreamId != streamId).ToArray(), routes.Remote);
+    }
+    public void SetCaptureChannels(uint streamId, int channels)
+    {
+        if (channels is not (1 or 2)) throw new ArgumentOutOfRangeException(nameof(channels));
+        lock (gate)
+        {
+            var current = routes.Local.FirstOrDefault(s => s.Info.StreamId == streamId) ?? throw new ArgumentException("Stream not found.");
+            if (current.CaptureChannels != channels) Publish(routes.Local.Select(s => s == current ? new LocalStream(s.Info, channels) : s).ToArray(), routes.Remote);
+        }
+    }
+
+    public void SetRemoteStreams(IReadOnlyList<User> users, uint selfId, uint channelId)
+    {
+        lock (gate)
+        {
+            var next = new List<ReceiveStream>();
+            foreach (User user in users.Where(u => u.Id != selfId && u.ChannelId == channelId))
+                foreach (StreamInfo info in user.Streams)
+                {
+                    var previous = routes.Remote.FirstOrDefault(s => s.UserId == user.Id && s.Info.Equals(info));
+                    next.Add(previous ?? new ReceiveStream(user.Id, info));
+                }
+            Publish(routes.Local, next.ToArray());
+        }
+    }
+
+    public bool FeedPcm(uint streamId, ReadOnlySpan<short> pcm, int channels)
+    {
+        foreach (LocalStream stream in Volatile.Read(ref routes).Local)
+            if (stream.Info.StreamId == streamId) return stream.Feed(pcm, channels);
+        return false;
+    }
+    public void Receive(VoiceFrameHeader header, ReadOnlySpan<byte> packet)
+    {
+        foreach (ReceiveStream stream in Volatile.Read(ref routes).Remote) if (stream.Info.Ssrc == header.Ssrc) { stream.Enqueue(header, packet); return; }
+    }
+    public (float Level, bool Talking) GetLocalLevel(uint streamId)
+    {
+        foreach (LocalStream stream in Volatile.Read(ref routes).Local) if (stream.Info.StreamId == streamId) return (stream.Level, stream.Talking);
+        return default;
+    }
+    public void SetRemotePlayback(uint userId, uint streamId, float gain, bool muted, bool noiseReduction)
+    {
+        if (!float.IsFinite(gain) || gain < 0 || gain > 4) throw new ArgumentOutOfRangeException(nameof(gain));
+        foreach (var stream in Volatile.Read(ref routes).Remote)
+            if (stream.UserId == userId && stream.Info.StreamId == streamId) { stream.Gain = gain; stream.Muted = muted; stream.NoiseReduction = noiseReduction; return; }
+    }
+    public (float Gain, bool Muted, bool NoiseReduction)? GetRemotePlayback(uint userId, uint streamId)
+    {
+        foreach (var stream in Volatile.Read(ref routes).Remote) if (stream.UserId == userId && stream.Info.StreamId == streamId) return (stream.Gain, stream.Muted, stream.NoiseReduction);
+        return null;
+    }
+
+    private void Publish(LocalStream[] local, ReceiveStream[] remote)
+    {
+        Routes previous = routes; var next = new Routes(local, remote, previous.Epoch + 1);
+        foreach (var stream in previous.Local) if (!local.Contains(stream)) retired.Add((stream, next.Epoch));
+        foreach (var stream in previous.Remote) if (!remote.Contains(stream)) retired.Add((stream, next.Epoch));
+        Volatile.Write(ref routes, next);
+    }
+
+    // One audio owner calls this. No allocation, waiting, lock, registry mutation or disposal
+    // occurs inside a mix cycle. Callbacks receive borrowed spans and must follow that rule.
+    internal void ProcessCycle()
+    {
+        Routes current = Volatile.Read(ref routes);
+        mixed.AsSpan().Clear();
+        foreach (var stream in current.Local) stream.Process(this, sender);
+        foreach (var stream in current.Remote) stream.Mix(mixed, Deafened, StreamPcm);
+        float gain = Deafened ? 0 : OutputGain;
+        for (int i = 0; i < output.Length; i++) output[i] = (short)Math.Clamp((int)(mixed[i] * gain), short.MinValue, short.MaxValue);
+        MixedPcm?.Invoke(output);
+        SampleClock = unchecked(SampleClock + 960);
+        Volatile.Write(ref completedEpoch, current.Epoch);
+    }
+
+    private void Work()
+    {
+        long deadline = Stopwatch.GetTimestamp();
+        try
+        {
+            while (!stop.IsCancellationRequested)
+            {
+                ProcessCycle();
+                deadline += Stopwatch.Frequency / 50;
+                double remaining = (deadline - Stopwatch.GetTimestamp()) * 1000.0 / Stopwatch.Frequency;
+                if (remaining > 0) Thread.Sleep((int)Math.Ceiling(remaining));
+                else if (remaining < -100) deadline = Stopwatch.GetTimestamp();
+            }
+        }
+        catch (Exception exception) { Failure = exception; stop.Cancel(); }
+    }
+    private async Task MaintainAsync()
+    {
+        try
+        {
+            using var timer = new PeriodicTimer(TimeSpan.FromMilliseconds(20));
+            while (await timer.WaitForNextTickAsync(stop.Token).ConfigureAwait(false))
+                lock (gate)
+                    for (int i = retired.Count - 1; i >= 0; i--)
+                        if (retired[i].Epoch <= Volatile.Read(ref completedEpoch)) { retired[i].Stream.Dispose(); retired.RemoveAt(i); }
+        }
+        catch (OperationCanceledException) when (stop.IsCancellationRequested) { }
+    }
+    public void Dispose()
+    {
+        if (Interlocked.Exchange(ref disposed, 1) != 0) return;
+        stop.Cancel(); worker?.Join(); maintenance.GetAwaiter().GetResult();
+        lock (gate)
+        {
+            foreach (var stream in routes.Local) stream.Dispose(); foreach (var stream in routes.Remote) stream.Dispose();
+            foreach (var stream in retired) stream.Stream.Dispose(); retired.Clear();
+            routes = new([], [], routes.Epoch + 1);
+        }
+    }
+    private sealed record Routes(LocalStream[] Local, ReceiveStream[] Remote, long Epoch);
+}

dotnet/src/VoiceCat.Audio/LocalStream.cs

@@ -0,0 +1,115 @@
+using VoiceCat.Codec;
+using VoiceCat.Dsp;
+using VoiceCat.Protocol;
+using Voicecat.V1;
+using OpusApplication = Voicecat.V1.OpusApplication;
+
+namespace VoiceCat.Audio;
+
+public enum AudioInputMode { VoiceActivation, PushToTalk, AlwaysOn }
+public delegate bool EncodedVoiceSender(uint ssrc, uint timestamp, ReadOnlySpan<byte> payload, VoiceFrameFlags flags);
+public delegate void PcmStreamHandler(uint userId, uint streamId, ReadOnlySpan<short> pcm, int channels);
+public delegate void MixedPcmHandler(ReadOnlySpan<short> stereoPcm);
+
+internal sealed class LocalStream : IDisposable
+{
+    internal readonly StreamInfo Info;
+    internal readonly int CaptureChannels;
+    internal readonly PcmRing Input = new(16384);
+    internal volatile float Level;
+    internal volatile bool Talking;
+    private readonly OpusEncoder encoder;
+    private readonly RnnoiseProcessor left, right;
+    private readonly EnergyVadProcessor vad = new();
+    private readonly short[] capture = new short[1920], wire = new short[5760 * 2], mono = new short[960];
+    private readonly byte[] packet = new byte[1275];
+    private readonly short[] converted = new short[16384];
+    private int feeding;
+    private int buffered;
+    private uint timestamp;
+    private bool wasTransmitting, marker;
+
+    internal bool Feed(ReadOnlySpan<short> pcm, int channels)
+    {
+        if (channels is not (1 or 2) || pcm.Length % channels != 0 || pcm.Length / channels * CaptureChannels > converted.Length || Interlocked.CompareExchange(ref feeding, 1, 0) != 0) return false;
+        try
+        {
+            if (channels == CaptureChannels) return Input.TryWrite(pcm);
+            int frames = pcm.Length / channels;
+            for (int i = 0; i < frames; i++)
+                if (CaptureChannels == 1) converted[i] = (short)(((int)pcm[i * 2] + pcm[i * 2 + 1]) / 2);
+                else { converted[2 * i] = pcm[i]; converted[2 * i + 1] = pcm[i]; }
+            return Input.TryWrite(converted.AsSpan(0, frames * CaptureChannels));
+        }
+        finally { Volatile.Write(ref feeding, 0); }
+    }
+
+    internal LocalStream(StreamInfo stream, int captureChannels)
+    {
+        Info = stream.Clone(); CaptureChannels = captureChannels;
+        encoder = new(new()
+        {
+            Channels = stream.Audio.Mode == ChannelMode.ModeStereo ? 2 : 1,
+            FrameDurationMilliseconds = checked((int)stream.Audio.FrameMs), MaximumBandwidthHz = checked((int)stream.Audio.SampleRate),
+            Bitrate = checked((int)stream.Audio.BitrateBps), Complexity = checked((int)stream.Audio.Complexity),
+            ExpectedPacketLossPercent = checked((int)stream.Audio.ExpectedPacketLoss), ForwardErrorCorrection = stream.Audio.Fec,
+            DiscontinuousTransmission = stream.Audio.Dtx, DeepRedundancy = stream.Audio.Dred,
+            Application = stream.Audio.Application switch { OpusApplication.OpusAudio => VoiceCat.Codec.OpusApplication.Audio, OpusApplication.OpusLowdelay => VoiceCat.Codec.OpusApplication.LowDelay, _ => VoiceCat.Codec.OpusApplication.Voip }
+        });
+        try { left = new(); } catch { encoder.Dispose(); throw; }
+        try { right = new(); } catch { left.Dispose(); encoder.Dispose(); throw; }
+    }
+
+    internal void Process(AudioEngine engine, EncodedVoiceSender sender)
+    {
+        var input = capture.AsSpan(0, 960 * CaptureChannels);
+        if (Input.Count < input.Length) { Level = 0; Talking = false; buffered = 0; wasTransmitting = false; return; }
+        while (Input.Count > input.Length * 6) Input.Read(input);
+        if (buffered == 0) timestamp = engine.SampleClock;
+        Input.Read(input);
+        bool mic = Info.Kind == StreamKind.StreamMic;
+        if (mic && engine.InputNoiseReduction)
+        {
+            if (CaptureChannels == 1) left.Process(input);
+            else
+            {
+                for (int i = 0; i < 960; i++) mono[i] = input[2 * i]; left.Process(mono);
+                for (int i = 0; i < 960; i++) input[2 * i] = mono[i];
+                for (int i = 0; i < 960; i++) mono[i] = input[2 * i + 1]; right.Process(mono);
+                for (int i = 0; i < 960; i++) input[2 * i + 1] = mono[i];
+            }
+        }
+        float gain = mic ? engine.InputGain : 1;
+        double energy = 0;
+        for (int i = 0; i < input.Length; i++) { input[i] = (short)Math.Clamp((int)(input[i] * gain), short.MinValue, short.MaxValue); energy += (double)input[i] * input[i]; }
+        Level = (float)(Math.Sqrt(energy / input.Length) / 32768);
+        vad.Threshold = engine.VadThreshold;
+        bool transmit = !mic || !engine.MicMuted && engine.InputMode switch
+        {
+            AudioInputMode.AlwaysOn => true, AudioInputMode.PushToTalk => engine.PushToTalk,
+            _ => vad.Process(input)
+        };
+        Talking = transmit && Level > 0.001f;
+        if (!transmit) { buffered = 0; wasTransmitting = false; return; }
+        if (!wasTransmitting) marker = true;
+        wasTransmitting = true;
+        int channels = encoder.Options.Channels;
+        for (int i = 0; i < 960; i++)
+        {
+            if (channels == 1) wire[buffered + i] = CaptureChannels == 1 ? input[i] : (short)(((int)input[2 * i] + input[2 * i + 1]) / 2);
+            else { wire[buffered + 2 * i] = input[i * CaptureChannels]; wire[buffered + 2 * i + 1] = input[i * CaptureChannels + CaptureChannels - 1]; }
+        }
+        buffered += 960 * channels;
+        int frame = encoder.Options.SamplesPerChannel * channels;
+        while (buffered >= frame)
+        {
+            int length = encoder.Encode(wire.AsSpan(0, frame), packet);
+            VoiceFrameFlags flags = (Info.Audio.Fec ? VoiceFrameFlags.FecPresent : VoiceFrameFlags.None) | (marker ? VoiceFrameFlags.Marker : VoiceFrameFlags.None);
+            sender(Info.Ssrc, timestamp, packet.AsSpan(0, length), flags); marker = false;
+            timestamp = unchecked(timestamp + (uint)encoder.Options.SamplesPerChannel);
+            buffered -= frame;
+            wire.AsSpan(frame, buffered).CopyTo(wire);
+        }
+    }
+    public void Dispose() { encoder.Dispose(); left.Dispose(); right.Dispose(); }
+}

dotnet/src/VoiceCat.Audio/PcmRing.cs

@@ -0,0 +1,34 @@
+namespace VoiceCat.Audio;
+
+// Single consumer, non-waiting producer gate. Whole writes either fit or drop, so
+// channels remain aligned and a capture thread never waits for a mixer/network owner.
+public sealed class PcmRing
+{
+    private readonly short[] samples;
+    private readonly int mask;
+    private int read, written, producer;
+    public PcmRing(int capacity = 32768)
+    {
+        if (capacity < 2 || (capacity & (capacity - 1)) != 0) throw new ArgumentOutOfRangeException(nameof(capacity));
+        samples = new short[capacity]; mask = capacity - 1;
+    }
+    public int Count => unchecked(Volatile.Read(ref written) - Volatile.Read(ref read));
+    public bool TryWrite(ReadOnlySpan<short> source)
+    {
+        if (Interlocked.CompareExchange(ref producer, 1, 0) != 0) return false;
+        try
+        {
+            int index = written;
+            if (source.Length > samples.Length - unchecked(index - Volatile.Read(ref read))) return false;
+            for (int i = 0; i < source.Length; i++) samples[(index + i) & mask] = source[i];
+            Volatile.Write(ref written, unchecked(index + source.Length)); return true;
+        }
+        finally { Volatile.Write(ref producer, 0); }
+    }
+    public int Read(Span<short> destination)
+    {
+        int index = read, count = Math.Min(destination.Length, unchecked(Volatile.Read(ref written) - index));
+        for (int i = 0; i < count; i++) destination[i] = samples[(index + i) & mask];
+        Volatile.Write(ref read, unchecked(index + count)); return count;
+    }
+}

dotnet/src/VoiceCat.Audio/ReceiveStream.cs

@@ -0,0 +1,163 @@
+using VoiceCat.Codec;
+using VoiceCat.Dsp;
+using VoiceCat.Protocol;
+using Voicecat.V1;
+
+namespace VoiceCat.Audio;
+
+internal sealed class ReceiveStream : IDisposable
+{
+    internal readonly uint UserId;
+    internal readonly StreamInfo Info;
+    internal volatile float Gain = 1;
+    internal volatile bool Muted, NoiseReduction;
+    private readonly OpusDecoder decoder;
+    private readonly OpusDeepRedundancy? dred;
+    private readonly RnnoiseProcessor left, right;
+    private readonly short[] pcm = new short[5760 * 2];
+    private readonly short[] mono = new short[960];
+    private readonly short[] block = new short[1920];
+    private readonly byte[][] packets = Enumerable.Range(0, 64).Select(_ => new byte[1275]).ToArray();
+    private readonly VoiceFrameHeader[] headers = new VoiceFrameHeader[64];
+    private readonly int[] lengths = new int[64];
+    private int read, written;
+    private readonly byte[][] jitter = Enumerable.Range(0, 6).Select(_ => new byte[1275]).ToArray();
+    private readonly uint[] timestamps = new uint[6];
+    private readonly int[] sizes = new int[6];
+    private int count, available, offset, missing, waiting;
+    private uint expected;
+    private bool started, hasTimestamp;
+    private bool hasMarker;
+    private uint lastMarker;
+    private readonly int channels, frameSamples, maximumDepth;
+    internal int Depth => count;
+    internal int ConcealedFrames { get; private set; }
+    internal int DredFrames { get; private set; }
+    internal int FecFrames { get; private set; }
+
+    internal ReceiveStream(uint userId, StreamInfo info)
+    {
+        if (info.Audio.FrameMs is not (5 or 10 or 20 or 40 or 60) || !Enum.IsDefined(info.Audio.Mode)) throw new ArgumentException("Unsupported remote audio configuration.", nameof(info));
+        UserId = userId; Info = info.Clone();
+        channels = info.Audio.Mode == ChannelMode.ModeStereo ? 2 : 1;
+        frameSamples = checked((int)info.Audio.FrameMs * 48);
+        maximumDepth = Math.Clamp(120 / (int)info.Audio.FrameMs, 2, 6);
+        decoder = new(48000, channels);
+        try { left = new(); } catch { decoder.Dispose(); throw; }
+        try { right = new(); } catch { left.Dispose(); decoder.Dispose(); throw; }
+        try { if (info.Audio.Dred) dred = new(); } catch { right.Dispose(); left.Dispose(); decoder.Dispose(); throw; }
+    }
+
+    // Only the network receive owner calls this; mixer alone consumes.
+    internal bool Enqueue(VoiceFrameHeader header, ReadOnlySpan<byte> payload)
+    {
+        int index = written;
+        if (payload.Length is < 1 or > 1275 || unchecked(index - Volatile.Read(ref read)) >= 64) return false;
+        int slot = index & 63; payload.CopyTo(packets[slot]); headers[slot] = header; lengths[slot] = payload.Length;
+        Volatile.Write(ref written, unchecked(index + 1)); return true;
+    }
+
+    private void Drain()
+    {
+        while (read != Volatile.Read(ref written))
+        {
+            int source = read & 63; uint timestamp = headers[source].Timestamp;
+            if (!hasTimestamp) { hasTimestamp = true; expected = timestamp; }
+            int delta = unchecked((int)(timestamp - expected));
+            if ((headers[source].Flags & VoiceFrameFlags.Marker) != 0 && (!hasMarker || unchecked((int)(timestamp - lastMarker)) > 0))
+            {
+                hasMarker = true; lastMarker = timestamp;
+                sizes.AsSpan().Clear(); count = available = offset = missing = waiting = 0;
+                expected = timestamp; started = false; delta = 0;
+            }
+            bool duplicate = false;
+            for (int i = 0; i < sizes.Length; i++) if (sizes[i] != 0 && timestamps[i] == timestamp) duplicate = true;
+            if ((!started || delta >= 0) && delta % frameSamples == 0 && !duplicate)
+            {
+                if (count >= maximumDepth)
+                {
+                    int oldest = Oldest(); sizes[oldest] = 0; count--;
+                }
+                int target = Array.IndexOf(sizes, 0);
+                timestamps[target] = timestamp; sizes[target] = lengths[source]; packets[source].AsSpan(0, lengths[source]).CopyTo(jitter[target]); count++;
+                int oldestRemaining = Oldest();
+                if (count >= maximumDepth && unchecked((int)(timestamps[oldestRemaining] - expected)) > 0) expected = timestamps[oldestRemaining];
+            }
+            Volatile.Write(ref read, unchecked(read + 1));
+        }
+    }
+
+    private int Oldest()
+    {
+        int oldest = -1;
+        for (int i = 0; i < sizes.Length; i++) if (sizes[i] != 0 && (oldest < 0 || unchecked((int)(timestamps[i] - timestamps[oldest])) < 0)) oldest = i;
+        return oldest;
+    }
+
+    private void Decode()
+    {
+        available = frameSamples; offset = 0;
+        int found = -1;
+        for (int i = 0; i < sizes.Length; i++) if (sizes[i] != 0 && timestamps[i] == expected) { found = i; break; }
+        bool decoded = false;
+        if (found >= 0)
+        {
+            decoded = decoder.TryDecode(jitter[found].AsSpan(0, sizes[found]), pcm, frameSamples, out int result) && result == frameSamples;
+            sizes[found] = 0; count--; missing = decoded ? 0 : missing + 1;
+        }
+        else
+        {
+            int next = Oldest(); missing++;
+            if (next >= 0 && unchecked((int)(timestamps[next] - expected)) == frameSamples)
+            {
+                var packet = jitter[next].AsSpan(0, sizes[next]);
+                if (dred?.TryRecover(decoder, packet, pcm, frameSamples) == true) { decoded = true; DredFrames++; }
+                else if (Info.Audio.Fec && decoder.TryDecode(packet, pcm, frameSamples, out int recovered, true) && recovered == frameSamples) { decoded = true; FecFrames++; }
+            }
+        }
+        int maximumConcealment = Math.Max(1, 200 / (int)Info.Audio.FrameMs);
+        if (!decoded && missing <= maximumConcealment)
+        {
+            decoded = decoder.TryDecode([], pcm, frameSamples, out _); ConcealedFrames++;
+        }
+        if (!decoded || missing > maximumConcealment) pcm.AsSpan(0, frameSamples * channels).Clear();
+        expected = unchecked(expected + (uint)frameSamples);
+    }
+
+    internal void Mix(Span<int> output, bool deafened, PcmStreamHandler? sink)
+    {
+        Drain();
+        if (!started)
+        {
+            waiting++;
+            if (!hasTimestamp || count < Math.Min(3, maximumDepth) && waiting < 3) return;
+            expected = timestamps[Oldest()]; started = true;
+        }
+        int copied = 0;
+        while (copied < 960)
+        {
+            if (available == 0) Decode();
+            int take = Math.Min(960 - copied, available);
+            var decoded = pcm.AsSpan(offset * channels, take * channels);
+            decoded.CopyTo(block.AsSpan(copied * channels));
+            available -= take; offset += take; copied += take;
+        }
+        var samples = block.AsSpan(0, 960 * channels);
+        if (NoiseReduction && Info.Kind == StreamKind.StreamMic)
+        {
+            if (channels == 1) left.Process(samples);
+            else
+            {
+                for (int i = 0; i < 960; i++) mono[i] = samples[2 * i]; left.Process(mono);
+                for (int i = 0; i < 960; i++) samples[2 * i] = mono[i];
+                for (int i = 0; i < 960; i++) mono[i] = samples[2 * i + 1]; right.Process(mono);
+                for (int i = 0; i < 960; i++) samples[2 * i + 1] = mono[i];
+            }
+        }
+        float gain = Muted || deafened ? 0 : Gain;
+        for (int i = 0; i < samples.Length; i++) samples[i] = (short)Math.Clamp((int)(samples[i] * gain), short.MinValue, short.MaxValue);
+        sink?.Invoke(UserId, Info.StreamId, samples, channels);
+        for (int i = 0; i < 960; i++) { output[i * 2] += samples[i * channels]; output[i * 2 + 1] += samples[i * channels + channels - 1]; }
+    }
+    public void Dispose() { decoder.Dispose(); dred?.Dispose(); left.Dispose(); right.Dispose(); }
+}

dotnet/src/VoiceCat.Audio/VoiceCat.Audio.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <ProjectReference Include="../VoiceCat.Codec/VoiceCat.Codec.csproj" />
+    <ProjectReference Include="../VoiceCat.Dsp/VoiceCat.Dsp.csproj" />
+    <ProjectReference Include="../VoiceCat.Protocol/VoiceCat.Protocol.csproj" />
+    <InternalsVisibleTo Include="VoiceCat.Tests" />
+  </ItemGroup>
+</Project>

dotnet/src/VoiceCat.Audio/packages.lock.json

@@ -0,0 +1,24 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    }
+  }
+}

dotnet/src/VoiceCat.Audio/packages.publish.win-x64.lock.json

@@ -0,0 +1,31 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    },
+    "net10.0/win-x64": {}
+  }
+}

dotnet/src/VoiceCat.Codec/OpusDecoder.cs

@@ -41,5 +41,17 @@ public sealed class OpusDecoder : IDisposable
             return OpusException.Check(NativeMethods.Decode(handle, input, packet.Length, output, samplesPerChannel, recoverPreviousFrame ? 1 : 0));
     }
 
+    public unsafe bool TryDecode(ReadOnlySpan<byte> packet, Span<short> pcm, int samplesPerChannel, out int decodedSamples, bool recoverPreviousFrame = false)
+    {
+        ValidateOutput(pcm, samplesPerChannel);
+        if (packet.Overlaps(MemoryMarshal.AsBytes(pcm))) throw new ArgumentException("Packet and PCM storage must not overlap.");
+        fixed (byte* input = packet)
+        fixed (short* output = pcm)
+        {
+            decodedSamples = NativeMethods.Decode(handle, input, packet.Length, output, samplesPerChannel, recoverPreviousFrame ? 1 : 0);
+            return decodedSamples >= 0;
+        }
+    }
+
     public void Dispose() => handle.Dispose();
 }

dotnet/src/VoiceCat.Codec/OpusDeepRedundancy.cs

@@ -40,11 +40,10 @@ public sealed class OpusDeepRedundancy : IDisposable
         fixed (byte* packet = nextPacket)
         fixed (short* output = pcm)
         {
-            int parsed = OpusException.Check(NativeMethods.DredParse(decoder, dred, packet, nextPacket.Length,
-                checked(samplesPerChannel + recoveryOffset), audioDecoder.SampleRate, out _));
-            if (parsed == 0) return false;
-            OpusException.Check(NativeMethods.DredDecode(audioDecoder.Handle, dred, recoveryOffset, output, samplesPerChannel));
-            return true;
+            int parsed = NativeMethods.DredParse(decoder, dred, packet, nextPacket.Length,
+                checked(samplesPerChannel + recoveryOffset), audioDecoder.SampleRate, out _);
+            if (parsed <= 0) return false;
+            return NativeMethods.DredDecode(audioDecoder.Handle, dred, recoveryOffset, output, samplesPerChannel) >= 0;
         }
     }
 

dotnet/src/VoiceCat.Codec/OpusOptions.cs

@@ -21,7 +21,7 @@ public sealed record OpusOptions
     {
         if (SampleRate is not (8000 or 12000 or 16000 or 24000 or 48000)) throw new ArgumentOutOfRangeException(nameof(SampleRate));
         if (Channels is not (1 or 2)) throw new ArgumentOutOfRangeException(nameof(Channels));
-        if (FrameDurationMilliseconds is not (10 or 20 or 40 or 60)) throw new ArgumentOutOfRangeException(nameof(FrameDurationMilliseconds));
+        if (FrameDurationMilliseconds is not (5 or 10 or 20 or 40 or 60)) throw new ArgumentOutOfRangeException(nameof(FrameDurationMilliseconds));
         if (Application == OpusApplication.LowDelay && FrameDurationMilliseconds > 20) throw new ArgumentException("Low-delay Opus requires frames of at most 20 ms.");
         if (!Enum.IsDefined(Application)) throw new ArgumentOutOfRangeException(nameof(Application));
         if (Bitrate is < 500 or > 512000) throw new ArgumentOutOfRangeException(nameof(Bitrate));

dotnet/src/VoiceCat.Codec/packages.publish.win-x64.lock.json

@@ -0,0 +1,14 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      }
+    },
+    "net10.0/win-x64": {}
+  }
+}

dotnet/src/VoiceCat.Core/ClientMediaTransport.cs

@@ -0,0 +1,128 @@
+using System.Net;
+using System.Net.Sockets;
+using VoiceCat.Protocol;
+using VoiceCat.Crypto;
+using VoiceCat.Transport;
+
+namespace VoiceCat.Core;
+
+public delegate void EncodedVoiceHandler(VoiceFrameHeader header, ReadOnlySpan<byte> payload);
+
+internal sealed class ClientMediaTransport : IAsyncDisposable
+{
+    private readonly Socket socket;
+    private readonly MediaSessionCrypto crypto;
+    private readonly CancellationTokenSource stop;
+    private readonly byte[] binding = new byte[VoiceFrameHeader.Size + 16];
+    private readonly byte[] keepalive = new byte[VoiceFrameHeader.Size];
+    private readonly PacketQueue packets = new();
+    private readonly Task sending;
+    private readonly Task receiving;
+    private readonly TaskCompletionSource bound = new(TaskCreationOptions.RunContinuationsAsynchronously);
+    internal event EncodedVoiceHandler? Received;
+    internal Task Bound => bound.Task;
+
+    internal ClientMediaTransport(IPEndPoint endpoint, ReadOnlySpan<byte> token, MediaSessionCrypto crypto, CancellationToken cancellationToken)
+    {
+        if (token.Length != 16) throw new IOException("Invalid UDP binding token.");
+        this.crypto = crypto;
+        stop = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        socket = new(endpoint.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
+        try { socket.Connect(endpoint); }
+        catch { socket.Dispose(); stop.Dispose(); throw; }
+        new VoiceFrameHeader(MediaFrameType.UdpBinding, 0, 0, 0, 0, 0).Write(binding);
+        token.CopyTo(binding.AsSpan(VoiceFrameHeader.Size));
+        new VoiceFrameHeader(MediaFrameType.Keepalive, 0, 0, 0, 0, 0).Write(keepalive);
+        receiving = ReceiveAsync();
+        sending = SendAsync();
+    }
+
+    internal bool TrySend(VoiceFrameHeader header, ReadOnlySpan<byte> payload) => packets.TryWrite(header, payload);
+
+    private async Task SendAsync()
+    {
+        byte[] plain = new byte[1275], packet = new byte[1275 + VoiceFrameHeader.Size + MediaEncryptor.TagSize];
+        long nextKeepalive = 0;
+        try
+        {
+            while (!stop.IsCancellationRequested)
+            {
+                if (Environment.TickCount64 >= nextKeepalive)
+                {
+                    if (!bound.Task.IsCompleted) await socket.SendAsync(binding, SocketFlags.None, stop.Token).ConfigureAwait(false);
+                    await socket.SendAsync(keepalive, SocketFlags.None, stop.Token).ConfigureAwait(false);
+                    nextKeepalive = Environment.TickCount64 + (bound.Task.IsCompleted ? 5000 : 250);
+                }
+                while (packets.TryRead(plain, out VoiceFrameHeader header, out int length))
+                {
+                    int size = crypto.Encryptor.Encrypt(header, plain.AsSpan(0, length), packet);
+                    await socket.SendAsync(packet.AsMemory(0, size), SocketFlags.None, stop.Token).ConfigureAwait(false);
+                }
+                await Task.Delay(5, stop.Token).ConfigureAwait(false);
+            }
+        }
+        catch (Exception exception) when (exception is OperationCanceledException or SocketException or ObjectDisposedException)
+        { if (!stop.IsCancellationRequested) bound.TrySetException(exception); }
+        finally { stop.Cancel(); }
+    }
+
+    private async Task ReceiveAsync()
+    {
+        byte[] packet = new byte[65535], plain = new byte[65535];
+        try
+        {
+            while (true)
+            {
+                int length;
+                try { length = await socket.ReceiveAsync(packet, SocketFlags.None, stop.Token).ConfigureAwait(false); }
+                catch (SocketException exception) when (exception.SocketErrorCode is SocketError.ConnectionReset or SocketError.MessageSize) { continue; }
+                if (!VoiceFrameHeader.TryRead(packet.AsSpan(0, length), out var candidate)) continue;
+                if (candidate.Type == MediaFrameType.Keepalive && length == VoiceFrameHeader.Size) { bound.TrySetResult(); continue; }
+                if (candidate.Type != MediaFrameType.Voice || candidate.Codec != 0 ||
+                    !crypto.Decryptor.TryDecrypt(packet.AsSpan(0, length), plain, out var header, out int size)) continue;
+                Received?.Invoke(header, plain.AsSpan(0, size));
+            }
+        }
+        catch (Exception exception) when (exception is OperationCanceledException or SocketException or ObjectDisposedException)
+        { if (!stop.IsCancellationRequested) bound.TrySetException(exception); }
+        finally { bound.TrySetCanceled(); stop.Cancel(); }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        stop.Cancel(); socket.Dispose();
+        try { await Task.WhenAll(sending, receiving).ConfigureAwait(false); }
+        finally { System.Security.Cryptography.CryptographicOperations.ZeroMemory(binding); stop.Dispose(); }
+    }
+
+    // A bounded, allocation-free packet handoff. A contending producer drops instead of
+    // waiting; the network owner alone consumes and encrypts. Audio never enters a Channel lock.
+    private sealed class PacketQueue
+    {
+        private readonly byte[][] payloads = Enumerable.Range(0, 64).Select(_ => new byte[1275]).ToArray();
+        private readonly VoiceFrameHeader[] headers = new VoiceFrameHeader[64];
+        private readonly int[] lengths = new int[64];
+        private int read, written, producer;
+        internal bool TryWrite(VoiceFrameHeader header, ReadOnlySpan<byte> payload)
+        {
+            if (payload.Length is < 1 or > 1275 || Interlocked.CompareExchange(ref producer, 1, 0) != 0) return false;
+            try
+            {
+                int index = written;
+                if (unchecked(index - Volatile.Read(ref read)) >= 64) return false;
+                int slot = index & 63;
+                payload.CopyTo(payloads[slot]); headers[slot] = header; lengths[slot] = payload.Length;
+                Volatile.Write(ref written, unchecked(index + 1)); return true;
+            }
+            finally { Volatile.Write(ref producer, 0); }
+        }
+        internal bool TryRead(Span<byte> payload, out VoiceFrameHeader header, out int length)
+        {
+            int index = read; header = default; length = 0;
+            if (index == Volatile.Read(ref written)) return false;
+            int slot = index & 63; header = headers[slot]; length = lengths[slot];
+            payloads[slot].AsSpan(0, length).CopyTo(payload);
+            Volatile.Write(ref read, unchecked(index + 1)); return true;
+        }
+    }
+}

dotnet/src/VoiceCat.Core/VoiceCat.Core.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <ProjectReference Include="../VoiceCat.Crypto/VoiceCat.Crypto.csproj" />
+    <ProjectReference Include="../VoiceCat.Audio/VoiceCat.Audio.csproj" />
+    <InternalsVisibleTo Include="VoiceCat.Tests" />
+  </ItemGroup>
+</Project>

dotnet/src/VoiceCat.Core/VoiceCatClient.cs

@@ -0,0 +1,292 @@
+using System.Collections.Concurrent;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading.Channels;
+using VoiceCat.Crypto;
+using VoiceCat.Transport;
+using VoiceCat.Protocol;
+using VoiceCat.Audio;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.Core;
+
+public enum ClientConnectionState { Disconnected, Connecting, VerifyingIdentity, Authenticating, Connected }
+public sealed record ServerIdentityChallenge(string Host, ushort Port, string CertificateFingerprint, TofuStatus Status);
+
+public sealed partial class VoiceCatClient : IAsyncDisposable
+{
+    private readonly string clientName;
+    private readonly string clientVersion;
+    private readonly TofuStore pins;
+    private readonly SemaphoreSlim lifecycle = new(1);
+    private readonly CancellationTokenSource disposed = new();
+    private readonly object stateGate = new();
+    private readonly ConcurrentDictionary<ulong, TaskCompletionSource<Envelope>> pending = new();
+    private readonly System.Threading.Channels.Channel<Envelope> events = System.Threading.Channels.Channel.CreateBounded<Envelope>(128);
+    private readonly Dictionary<uint, Channel> channels = [];
+    private readonly Dictionary<uint, User> users = [];
+    private readonly Dictionary<uint, StreamInfo> localStreams = [];
+    public AudioEngine Audio { get; }
+    public IReadOnlyList<StreamInfo> LocalStreams { get { lock (stateGate) return localStreams.Values.Select(s => s.Clone()).ToArray(); } }
+    private TlsControlConnection? control;
+    private MediaSessionCrypto? mediaCrypto;
+    private ClientMediaTransport? media;
+    private Task keepalive = Task.CompletedTask;
+    public event EncodedVoiceHandler? VoiceReceived;
+    private CancellationTokenSource? connectionLifetime;
+    private Task reader = Task.CompletedTask;
+    private long nextRequest;
+    private AuthResult? authentication;
+    private ServerHello? hello;
+    private ClientConnectionState state;
+
+    public event Action<ClientConnectionState>? ConnectionStateChanged;
+    public ClientConnectionState State { get { lock (stateGate) return state; } }
+    public Task Completion => reader;
+    public AuthResult? Authentication { get { lock (stateGate) return authentication?.Clone(); } }
+    public ServerHello? ServerHello { get { lock (stateGate) return hello?.Clone(); } }
+    public IReadOnlyList<Channel> Channels { get { lock (stateGate) return channels.Values.Select(c => c.Clone()).ToArray(); } }
+    public IReadOnlyList<User> Users { get { lock (stateGate) return users.Values.Select(u => u.Clone()).ToArray(); } }
+    public bool TryReadEvent(out Envelope? envelope) => events.Reader.TryRead(out envelope);
+    public IAsyncEnumerable<Envelope> ReadEventsAsync(CancellationToken cancellationToken = default) => events.Reader.ReadAllAsync(cancellationToken);
+
+    public VoiceCatClient(string clientName = "VoiceCat .NET", string clientVersion = "0.1.0", string? tofuStorePath = null)
+    {
+        this.clientName = clientName;
+        this.clientVersion = clientVersion;
+        pins = new(tofuStorePath ?? Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "VoiceCat", "tofu.txt"));
+        Audio = new(TrySendEncodedVoice);
+        VoiceReceived += Audio.Receive;
+    }
+
+    public async Task ConnectAsync(string host, ushort port, Func<ServerIdentityChallenge, CancellationToken, ValueTask<bool>>? confirmIdentity = null, CancellationToken cancellationToken = default)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(host);
+        ArgumentOutOfRangeException.ThrowIfZero(port);
+        await lifecycle.WaitAsync(cancellationToken).ConfigureAwait(false);
+        Socket? socket = null;
+        bool started = false;
+        try
+        {
+            ObjectDisposedException.ThrowIf(disposed.IsCancellationRequested, this);
+            if (control is not null) throw new InvalidOperationException("Disconnect before reconnecting.");
+            started = true;
+            connectionLifetime = CancellationTokenSource.CreateLinkedTokenSource(disposed.Token);
+            using var connecting = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, connectionLifetime.Token);
+            CancellationToken token = connecting.Token;
+            SetState(ClientConnectionState.Connecting);
+            socket = new(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
+            await socket.ConnectAsync(host, port, token).ConfigureAwait(false);
+            string? fingerprint = null;
+            control = new(socket, TlsSession.CreateClient(value => { fingerprint = value; return true; }), connectionLifetime.Token);
+            socket = null; // Transport owns it from here.
+            mediaCrypto = await control.TakeMediaCryptoAsync(token).ConfigureAwait(false);
+            string certificatePin = fingerprint ?? throw new IOException("TLS did not report a certificate fingerprint.");
+            TofuStatus pinStatus = pins.Check(host, port, certificatePin);
+            if (pinStatus != TofuStatus.Matched)
+            {
+                SetState(ClientConnectionState.VerifyingIdentity);
+                if (confirmIdentity is null || !await confirmIdentity(new(host, port, certificatePin, pinStatus), token).ConfigureAwait(false))
+                    throw new System.Security.Authentication.AuthenticationException("Server identity was rejected.");
+                pins.Pin(host, port, certificatePin);
+            }
+            reader = ReadAsync(control, connectionLifetime.Token);
+            Envelope response = await RequestAsync(new() { ClientHello = new() { ProtoVersion = 2, ClientName = clientName, ClientVersion = clientVersion } }, token).ConfigureAwait(false);
+            if (response.ServerHello?.ProtoVersion != 2) throw new IOException("Unsupported server protocol.");
+            lock (stateGate) hello = response.ServerHello.Clone();
+            keepalive = KeepaliveAsync(connectionLifetime.Token);
+            SetState(ClientConnectionState.Authenticating);
+        }
+        catch
+        {
+            socket?.Dispose();
+            if (started) await CloseAsync().ConfigureAwait(false);
+            throw;
+        }
+        finally { lifecycle.Release(); }
+    }
+
+    public Task<AuthResult> AuthenticateGuestAsync(string nickname, CancellationToken cancellationToken = default) =>
+        AuthenticateAsync(new() { Guest = new() { Nickname = nickname } }, cancellationToken);
+    public Task<AuthResult> AuthenticateUserAsync(string username, string password, CancellationToken cancellationToken = default) =>
+        AuthenticateAsync(new() { Password = new() { Username = username, Password = password } }, cancellationToken);
+
+    private async Task<AuthResult> AuthenticateAsync(AuthRequest request, CancellationToken cancellationToken)
+    {
+        if (State != ClientConnectionState.Authenticating) throw new InvalidOperationException("Authentication requires a connected TLS session.");
+        Envelope response = await RequestAsync(new() { AuthRequest = request }, cancellationToken).ConfigureAwait(false);
+        AuthResult result = response.AuthResult ?? throw new IOException("Unexpected authentication response.");
+        if (result.Ok)
+        {
+            var endpoint = (IPEndPoint)control!.RemoteEndPoint;
+            IPAddress address = endpoint.Address.IsIPv4MappedToIPv6 ? endpoint.Address.MapToIPv4() : endpoint.Address;
+            media = new(new(address, checked((int)ServerHello!.UdpPort)), result.UdpToken.Span, mediaCrypto!, connectionLifetime!.Token);
+            media.Received += (header, packet) => VoiceReceived?.Invoke(header, packet);
+            SetState(ClientConnectionState.Connected);
+        }
+        return result;
+    }
+
+    public async Task<VoiceSubscriptionResult> SubscribeVoiceAsync(bool subscribe = true, CancellationToken cancellationToken = default)
+    {
+        if (subscribe && media is not null) await media.Bound.WaitAsync(TimeSpan.FromSeconds(5), cancellationToken).ConfigureAwait(false);
+        return (await RequestAsync(subscribe ? new() { SubscribeVoice = new() } : new() { UnsubscribeVoice = new() }, cancellationToken).ConfigureAwait(false)).VoiceSubscriptionResult;
+    }
+
+    public bool TrySendEncodedVoice(uint ssrc, uint timestamp, ReadOnlySpan<byte> payload, VoiceFrameFlags flags = VoiceFrameFlags.None) =>
+        media?.TrySend(new(MediaFrameType.Voice, flags, 0, ssrc, 0, timestamp), payload) == true;
+
+    public async Task<StreamInfo> StartStreamAsync(StreamKind kind, string label = "", int captureChannels = 1, CancellationToken cancellationToken = default)
+    {
+        if (State != ClientConnectionState.Connected) throw new InvalidOperationException("Client is disconnected.");
+        var response = (await RequestAsync(new() { StreamAnnounce = new() { Kind = kind, Label = label } }, cancellationToken).ConfigureAwait(false)).StreamAnnounceResult;
+        if (!response.Ok) throw new InvalidOperationException(response.Error);
+        var info = new StreamInfo { StreamId = response.StreamId, Ssrc = response.Ssrc, Kind = kind, Audio = response.EffectiveAudio.Clone(), Label = label };
+        try
+        {
+            lock (stateGate) { if (State != ClientConnectionState.Connected) throw new InvalidOperationException("Client disconnected during stream negotiation."); Audio.AddLocalStream(info, captureChannels); localStreams[info.StreamId] = info; }
+            return info.Clone();
+        }
+        catch { if (State == ClientConnectionState.Connected) Send(new() { StreamStop = new() { StreamId = info.StreamId } }); throw; }
+    }
+
+    public void StopStream(uint streamId)
+    {
+        lock (stateGate) { localStreams.Remove(streamId); Audio.RemoveLocalStream(streamId); }
+        Send(new() { StreamStop = new() { StreamId = streamId } });
+    }
+
+    private async Task KeepaliveAsync(CancellationToken cancellationToken)
+    {
+        try
+        {
+            using var timer = new PeriodicTimer(TimeSpan.FromSeconds(10));
+            while (await timer.WaitForNextTickAsync(cancellationToken).ConfigureAwait(false)) Send(new() { Ping = new() { Nonce = checked((ulong)Environment.TickCount64) } });
+        }
+        catch (Exception exception) when (exception is OperationCanceledException or IOException or InvalidOperationException) { }
+    }
+
+    public async Task<Envelope> RequestAsync(Envelope request, CancellationToken cancellationToken = default)
+    {
+        TlsControlConnection connection = control ?? throw new InvalidOperationException("Client is disconnected.");
+        var completion = new TaskCompletionSource<Envelope>(TaskCreationOptions.RunContinuationsAsynchronously);
+        ulong id = checked((ulong)Interlocked.Increment(ref nextRequest));
+        Envelope outbound = request.Clone(); outbound.RequestId = id;
+        if (!pending.TryAdd(id, completion)) throw new InvalidOperationException("Request ids exhausted.");
+        try
+        {
+            if (!connection.TrySend(outbound)) throw new IOException("Control queue is full or closed.");
+            return await completion.Task.WaitAsync(TimeSpan.FromSeconds(15), cancellationToken).ConfigureAwait(false);
+        }
+        finally { pending.TryRemove(id, out _); }
+    }
+
+    public void Send(Envelope message)
+    {
+        TlsControlConnection connection = control ?? throw new InvalidOperationException("Client is disconnected.");
+        if (!connection.TrySend(message.Clone())) throw new IOException("Control queue is full or closed.");
+    }
+
+    private async Task ReadAsync(TlsControlConnection connection, CancellationToken cancellationToken)
+    {
+        Exception? failure = null;
+        try
+        {
+            await foreach (Envelope message in connection.ReadAsync(cancellationToken).ConfigureAwait(false))
+            {
+                Apply(message);
+                if (message.RequestId != 0 && pending.TryRemove(message.RequestId, out var completion)) completion.TrySetResult(message.Clone());
+                if (!events.Writer.TryWrite(message.Clone())) throw new IOException("Client event queue exhausted; consume events regularly.");
+                if (message.Disconnect is not null) { connection.CompleteWrites(); break; }
+            }
+        }
+        catch (Exception exception) when (exception is IOException or OperationCanceledException or SocketException or ObjectDisposedException) { failure = exception; }
+        finally
+        {
+            connectionLifetime?.Cancel();
+            foreach (var operation in pending.Values) operation.TrySetException(failure ?? new IOException("Connection closed."));
+            SetState(ClientConnectionState.Disconnected);
+        }
+    }
+
+    private void Apply(Envelope message)
+    {
+        lock (stateGate)
+        {
+            if (message.AuthResult?.Ok == true) authentication = message.AuthResult.Clone();
+            if (message.ServerState is not null)
+            {
+                channels.Clear(); users.Clear();
+                foreach (var channel in message.ServerState.Channels) channels[channel.Id] = channel.Clone();
+                foreach (var user in message.ServerState.Users) users[user.Id] = user.Clone();
+            }
+            if (message.ChannelEvent is not null)
+            {
+                if (message.ChannelEvent.Kind == ChannelEvent.Types.Kind.Deleted) channels.Remove(message.ChannelEvent.DeletedId);
+                else if (message.ChannelEvent.Channel is not null) channels[message.ChannelEvent.Channel.Id] = message.ChannelEvent.Channel.Clone();
+            }
+            if (message.UserEvent is not null)
+            {
+                if (message.UserEvent.Kind == UserEvent.Types.Kind.Left) users.Remove(message.UserEvent.LeftId);
+                else if (message.UserEvent.User is not null) users[message.UserEvent.User.Id] = message.UserEvent.User.Clone();
+            }
+            if (authentication is not null && (message.ServerState is not null || message.UserEvent is not null))
+            {
+                User self = users.GetValueOrDefault(authentication.Self.Id, authentication.Self);
+                Audio.SetRemoteStreams(users.Values.ToArray(), self.Id, self.ChannelId);
+                foreach (var id in localStreams.Keys.Where(id => !self.Streams.Any(s => s.StreamId == id)).ToArray())
+                { Audio.RemoveLocalStream(id); localStreams.Remove(id); }
+            }
+        }
+    }
+
+    private void SetState(ClientConnectionState value)
+    {
+        lock (stateGate) state = value;
+        ConnectionStateChanged?.Invoke(value);
+    }
+
+    public async Task DisconnectAsync()
+    {
+        connectionLifetime?.Cancel();
+        await lifecycle.WaitAsync().ConfigureAwait(false);
+        try { await CloseAsync().ConfigureAwait(false); }
+        finally { lifecycle.Release(); }
+    }
+
+    private async Task CloseAsync()
+    {
+        connectionLifetime?.Cancel();
+        try { await reader.ConfigureAwait(false); }
+        finally
+        {
+            try { await keepalive.ConfigureAwait(false); }
+            catch (Exception exception) when (exception is IOException or OperationCanceledException or SocketException or ObjectDisposedException) { }
+            try { if (media is not null) await media.DisposeAsync().ConfigureAwait(false); }
+            catch (Exception exception) when (exception is IOException or OperationCanceledException or SocketException or ObjectDisposedException) { }
+            try { if (control is not null) await control.DisposeAsync().ConfigureAwait(false); }
+            catch (Exception exception) when (exception is IOException or OperationCanceledException or SocketException or ObjectDisposedException) { }
+            control = null;
+                media = null;
+                mediaCrypto?.Dispose(); mediaCrypto = null;
+                connectionLifetime?.Dispose(); connectionLifetime = null;
+                lock (stateGate) { authentication = null; hello = null; channels.Clear(); users.Clear(); }
+                lock (stateGate)
+                {
+                    foreach (var id in localStreams.Keys) Audio.RemoveLocalStream(id);
+                    localStreams.Clear(); Audio.SetRemoteStreams([], 0, 0);
+                }
+            SetState(ClientConnectionState.Disconnected);
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (disposed.IsCancellationRequested) return;
+        disposed.Cancel();
+        await DisconnectAsync().ConfigureAwait(false);
+        events.Writer.TryComplete();
+        Audio.Dispose();
+    }
+}

dotnet/src/VoiceCat.Core/packages.lock.json

@@ -0,0 +1,44 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "BouncyCastle.Cryptography": {
+        "type": "Transitive",
+        "resolved": "2.6.2",
+        "contentHash": "7oWOcvnntmMKNzDLsdxAYqApt+AjpRpP2CShjMfIa3umZ42UQMvH0tl1qAliYPNYO6vTdcGMqnRrCPmsfzTI1w=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.crypto": {
+        "type": "Project",
+        "dependencies": {
+          "BouncyCastle.Cryptography": "[2.6.2, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    }
+  }
+}

dotnet/src/VoiceCat.Core/packages.publish.win-x64.lock.json

@@ -0,0 +1,51 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      },
+      "BouncyCastle.Cryptography": {
+        "type": "Transitive",
+        "resolved": "2.6.2",
+        "contentHash": "7oWOcvnntmMKNzDLsdxAYqApt+AjpRpP2CShjMfIa3umZ42UQMvH0tl1qAliYPNYO6vTdcGMqnRrCPmsfzTI1w=="
+      },
+      "Google.Protobuf": {
+        "type": "Transitive",
+        "resolved": "3.36.1",
+        "contentHash": "77AqPEoaY1ODE+syYBHti0jXiwQq0J/fUr/fRyYhNlc9oKtH5dZZEr/OLKtdKNVG83PRnCYB2r8B80ZrObzOGQ=="
+      },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.codec": {
+        "type": "Project"
+      },
+      "voicecat.crypto": {
+        "type": "Project",
+        "dependencies": {
+          "BouncyCastle.Cryptography": "[2.6.2, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
+      "voicecat.dsp": {
+        "type": "Project"
+      },
+      "voicecat.protocol": {
+        "type": "Project",
+        "dependencies": {
+          "Google.Protobuf": "[3.36.1, )"
+        }
+      }
+    },
+    "net10.0/win-x64": {}
+  }
+}

dotnet/src/VoiceCat.Crypto/Transport/MediaSessionCrypto.cs

@@ -1,6 +1,6 @@
 using VoiceCat.Crypto;
 
-namespace VoiceCat.Server.Transport;
+namespace VoiceCat.Transport;
 
 internal sealed class MediaSessionCrypto(MediaEncryptor encryptor, MediaDecryptor decryptor) : IDisposable
 {

dotnet/src/VoiceCat.Crypto/Transport/TlsControlConnection.cs

@@ -7,7 +7,7 @@ using VoiceCat.Crypto;
 using VoiceCat.Protocol;
 using Voicecat.V1;
 
-namespace VoiceCat.Server.Transport;
+namespace VoiceCat.Transport;
 
 internal sealed class TlsControlConnection : IAsyncDisposable
 {
@@ -25,6 +25,7 @@ internal sealed class TlsControlConnection : IAsyncDisposable
     private MediaSessionCrypto? mediaCrypto;
 
     public Task Completion { get; }
+    internal System.Net.EndPoint RemoteEndPoint => socket.RemoteEndPoint!;
     public CancellationToken CancellationToken => lifetime.Token;
 
     internal TlsControlConnection(Socket socket, TlsSession tls, CancellationToken cancellationToken, TimeSpan? handshakeTimeout = null)

dotnet/src/VoiceCat.Crypto/VoiceCat.Crypto.csproj

@@ -5,5 +5,7 @@
   </ItemGroup>
   <ItemGroup>
     <InternalsVisibleTo Include="VoiceCat.Tests" />
+    <InternalsVisibleTo Include="VoiceCat.Server" />
+    <InternalsVisibleTo Include="VoiceCat.Core" />
   </ItemGroup>
 </Project>

dotnet/src/VoiceCat.Dsp/packages.publish.win-x64.lock.json

@@ -0,0 +1,14 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.7, )",
+        "resolved": "10.0.7",
+        "contentHash": "AA/yhzFHNtQZXLdqjzujPy25G8EWwGWsAnxOE2zYSBoT/8QHP6ketN3CToD3DFreO653ipUwnKHo22B8AlBMCw=="
+      }
+    },
+    "net10.0/win-x64": {}
+  }
+}

dotnet/src/VoiceCat.Server/Transport/MediaRelay.cs

@@ -1,3 +1,4 @@
+using VoiceCat.Transport;
 using System.Collections.Concurrent;
 using System.Net;
 using System.Net.Sockets;

dotnet/src/VoiceCat.Server/VoiceServer.cs

@@ -1,3 +1,4 @@
+using VoiceCat.Transport;
 using System.Net;
 using System.Net.Sockets;
 using System.Security.Cryptography;

dotnet/tests/VoiceCat.Tests/AudioEngineTests.cs

@@ -0,0 +1,117 @@
+using VoiceCat.Audio;
+using VoiceCat.Codec;
+using VoiceCat.Protocol;
+using Voicecat.V1;
+
+namespace VoiceCat.Tests;
+
+public class AudioEngineTests
+{
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void LostFramesUseDredThenFecBeforeBoundedPlc(bool useDred)
+    {
+        using var receive = new ReceiveStream(2, Stream(dred: useDred));
+        using var encoder = new OpusEncoder(new() { DeepRedundancy = useDred, ForwardErrorCorrection = true, ExpectedPacketLossPercent = 30, Complexity = 10, Bitrate = 64000 });
+        byte[] packet = new byte[1275]; short[] tone = Tone(); int[] output = new int[1920];
+        for (uint i = 0; i < 40; i++)
+        {
+            CodecTests.FillTone(tone, 960, 1, 48000, (int)i);
+            int size = encoder.Encode(tone, packet);
+            if (i != 25 && i != 30 && i != 35) receive.Enqueue(new(MediaFrameType.Voice, 0, 0, 42, i, i * 960), packet.AsSpan(0, size));
+            output.AsSpan().Clear(); receive.Mix(output, false, null);
+        }
+        if (useDred) Assert.True(receive.DredFrames > 0); else Assert.True(receive.FecFrames > 0);
+        for (int i = 0; i < 20; i++) { output.AsSpan().Clear(); receive.Mix(output, false, null); }
+        Assert.True(receive.ConcealedFrames > 0); Assert.All(output, sample => Assert.Equal(0, sample));
+    }
+
+    [Fact]
+    public void PcmRingDropsWholeFramesWhenFullAndPreservesOrderAcrossWraps()
+    {
+        var ring = new PcmRing(8); short[] output = new short[8];
+        for (int i = 0; i < 100; i++)
+        {
+            Assert.True(ring.TryWrite([1, 2, 3, 4, 5, 6])); Assert.False(ring.TryWrite([7, 8, 9]));
+            Assert.Equal(4, ring.Read(output.AsSpan(0, 4))); Assert.Equal(new short[] { 1, 2, 3, 4 }, output[..4]);
+            Assert.True(ring.TryWrite([7, 8])); Assert.Equal(4, ring.Read(output)); Assert.Equal(new short[] { 5, 6, 7, 8 }, output[..4]); Assert.Equal(0, ring.Count);
+        }
+    }
+    internal static StreamInfo Stream(int frame = 20, bool stereo = false, bool dred = false) => new()
+    {
+        StreamId = 1, Ssrc = 42, Kind = StreamKind.StreamMic,
+        Audio = new() { SampleRate = 48000, BitrateBps = 32000, FrameMs = (uint)frame, Complexity = 5,
+            Mode = stereo ? ChannelMode.ModeStereo : ChannelMode.ModeMono, Fec = true, ExpectedPacketLoss = 20, Dred = dred }
+    };
+    private static short[] Tone(int channels = 1)
+    {
+        var pcm = new short[960 * channels];
+        for (int i = 0; i < 960; i++) for (int c = 0; c < channels; c++) pcm[i * channels + c] = (short)(Math.Sin(i * 2 * Math.PI * (c == 0 ? 440 : 660) / 48000) * 8000);
+        return pcm;
+    }
+
+    [Theory]
+    [InlineData(5, false)] [InlineData(10, false)] [InlineData(20, false)] [InlineData(40, false)] [InlineData(60, false)] [InlineData(20, true)]
+    public void ReframedEncodedPcmIsDecodedAndMixedForMonoAndStereo(int frame, bool stereo)
+    {
+        StreamInfo stream = Stream(frame, stereo);
+        using var receive = new AudioEngine((_, _, _, _) => true, false);
+        receive.SetRemoteStreams([new() { Id = 2, ChannelId = 1, Streams = { stream } }], 1, 1);
+        using var send = new AudioEngine((ssrc, timestamp, payload, flags) => { receive.Receive(new(MediaFrameType.Voice, flags, 0, ssrc, 0, timestamp), payload); return true; }, false);
+        send.InputMode = AudioInputMode.AlwaysOn; send.AddLocalStream(stream, stereo ? 2 : 1);
+        long energy = 0; int sinkChannels = 0;
+        receive.MixedPcm += pcm => { foreach (short sample in pcm) energy += Math.Abs((int)sample); };
+        receive.StreamPcm += (_, _, _, channels) => sinkChannels = channels;
+        short[] tone = Tone(stereo ? 2 : 1);
+        for (int i = 0; i < 30; i++) { Assert.True(send.FeedPcm(1, tone, stereo ? 2 : 1)); send.ProcessCycle(); receive.ProcessCycle(); }
+        Assert.True(energy > 100000); Assert.Equal(stereo ? 2 : 1, sinkChannels);
+        receive.SetRemotePlayback(2, 1, 1, true, false); energy = 0;
+        for (int i = 0; i < 5; i++) { send.FeedPcm(1, tone, stereo ? 2 : 1); send.ProcessCycle(); receive.ProcessCycle(); }
+        Assert.Equal(0, energy);
+    }
+
+    [Fact]
+    public void AudioCyclesAllocateZeroBytesWithEncodeDecodeStereoNoiseReductionAndMixing()
+    {
+        StreamInfo stream = Stream(20, true);
+        using var receive = new AudioEngine((_, _, _, _) => true, false);
+        receive.SetRemoteStreams([new() { Id = 2, ChannelId = 1, Streams = { stream } }], 1, 1);
+        receive.SetRemotePlayback(2, 1, 0.8f, false, true);
+        using var send = new AudioEngine((ssrc, timestamp, payload, flags) => { receive.Receive(new(MediaFrameType.Voice, flags, 0, ssrc, 0, timestamp), payload); return true; }, false);
+        send.InputMode = AudioInputMode.AlwaysOn; send.InputNoiseReduction = true; send.AddLocalStream(stream, 2);
+        short[] tone = Tone(2);
+        for (int i = 0; i < 30; i++) { send.FeedPcm(1, tone, 2); send.ProcessCycle(); receive.ProcessCycle(); }
+        long before = GC.GetAllocatedBytesForCurrentThread();
+        for (int i = 0; i < 100; i++) { send.FeedPcm(1, tone, 2); send.ProcessCycle(); receive.ProcessCycle(); }
+        Assert.Equal(0, GC.GetAllocatedBytesForCurrentThread() - before);
+    }
+
+    [Fact]
+    public void JitterBacklogIsBoundedAndPlcEventuallyBecomesSilence()
+    {
+        var info = Stream(); using var stream = new ReceiveStream(2, info); using var encoder = new OpusEncoder(new() { Bitrate = 32000 });
+        byte[] packet = new byte[1275]; int length = encoder.Encode(Tone(), packet); int[] output = new int[1920];
+        for (uint i = 0; i < 64; i++) stream.Enqueue(new(MediaFrameType.Voice, 0, 0, 42, i, i * 960), packet.AsSpan(0, length));
+        stream.Mix(output, false, null); Assert.InRange(stream.Depth, 0, 6);
+        for (int i = 0; i < 20; i++) { output.AsSpan().Clear(); stream.Mix(output, false, null); }
+        Assert.All(output, value => Assert.Equal(0, value)); Assert.InRange(stream.ConcealedFrames, 1, 10);
+    }
+
+    [Fact]
+    public void PttResumeAndCaptureChannelChangesKeepTimestampProgressAndAudio()
+    {
+        var info = Stream(60, true); using var receive = new AudioEngine((_, _, _, _) => true, false);
+        receive.SetRemoteStreams([new() { Id = 2, ChannelId = 1, Streams = { info } }], 1, 1);
+        using var send = new AudioEngine((ssrc, timestamp, payload, flags) => { receive.Receive(new(MediaFrameType.Voice, flags, 0, ssrc, 0, timestamp), payload); return true; }, false);
+        send.InputMode = AudioInputMode.PushToTalk; send.PushToTalk = true; send.AddLocalStream(info);
+        short[] mono = Tone(), stereo = Tone(2); long energy = 0;
+        receive.MixedPcm += pcm => { foreach (short value in pcm) energy += Math.Abs((int)value); };
+        for (int i = 0; i < 15; i++) { send.FeedPcm(1, mono, 1); send.ProcessCycle(); receive.ProcessCycle(); }
+        send.PushToTalk = false;
+        for (int i = 0; i < 16; i++) { send.FeedPcm(1, mono, 1); send.ProcessCycle(); receive.ProcessCycle(); }
+        send.SetCaptureChannels(1, 2); send.PushToTalk = true; energy = 0;
+        for (int i = 0; i < 15; i++) { send.FeedPcm(1, stereo, 2); send.ProcessCycle(); receive.ProcessCycle(); }
+        Assert.True(energy > 100000);
+    }
+}

dotnet/tests/VoiceCat.Tests/ManagedClientTests.cs

@@ -0,0 +1,80 @@
+using VoiceCat.Core;
+using VoiceCat.Crypto;
+using Voicecat.V1;
+using static VoiceCat.Tests.ServerTests;
+using static VoiceCat.Tests.MediaRelayTests;
+
+namespace VoiceCat.Tests;
+
+public class ManagedClientTests
+{
+    private static VoiceCatClient NewClient(ServerFixture fixture, string name) => new(name, "test", Path.Combine(fixture.Directory, name + ".pins"));
+    private static Task Connect(VoiceCatClient client, ServerFixture fixture) => client.ConnectAsync("127.0.0.1", (ushort)fixture.Server.EndPoint.Port, (_, _) => ValueTask.FromResult(true));
+    private static async Task<Envelope> Event(VoiceCatClient client, Func<Envelope, bool> predicate)
+    {
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        await foreach (Envelope message in client.ReadEventsAsync(timeout.Token)) if (predicate(message)) return message;
+        throw new IOException("Expected client event was not received.");
+    }
+
+    [Fact]
+    public async Task ManagedClientsAuthenticateChatAndCorrelateConcurrentRequests()
+    {
+        await using var fixture = new ServerFixture();
+        await using var alice = NewClient(fixture, "Alice"); await using var bob = NewClient(fixture, "Bob");
+        await Connect(alice, fixture); await Connect(bob, fixture);
+        Assert.True((await alice.AuthenticateGuestAsync("Alice")).Ok); Assert.True((await bob.AuthenticateGuestAsync("Bob")).Ok);
+        await Event(bob, e => e.ServerState is not null); await Event(alice, e => e.UserEvent?.User?.Nickname == "Bob");
+        Assert.Equal(2, alice.Users.Count);
+        var copy = alice.Users[0]; copy.Nickname = "Mutated"; Assert.DoesNotContain(alice.Users, u => u.Nickname == "Mutated");
+        alice.Send(new() { TextMessage = new() { Scope = TextScope.TextChannel, TargetId = 1, Body = "Managed conversation", ClientMsgId = "a1" } });
+        Assert.Equal("Managed conversation", (await Event(bob, e => e.TextMessage is not null)).TextMessage.Body);
+        var requests = Enumerable.Range(1, 20).Select(async i =>
+        {
+            Envelope response = await alice.RequestAsync(new() { Ping = new() { Nonce = (ulong)i } });
+            Assert.Equal((ulong)i, response.Pong.Nonce); return response.RequestId;
+        });
+        Assert.Equal(20, (await Task.WhenAll(requests)).Distinct().Count());
+        await Assert.ThrowsAsync<InvalidOperationException>(() => Connect(alice, fixture));
+        Assert.Equal(ClientConnectionState.Connected, alice.State);
+        await alice.DisconnectAsync();
+        await Event(bob, e => e.UserEvent?.Kind == UserEvent.Types.Kind.Left);
+        await Connect(alice, fixture); Assert.True((await alice.AuthenticateGuestAsync("Returned")).Ok);
+    }
+
+    [Fact]
+    public async Task TofuRequiresApprovalPinsAcceptedCertificateAndRejectsChanges()
+    {
+        await using var first = new ServerFixture(); await using var second = new ServerFixture();
+        await using var client = NewClient(first, "Tofu");
+        await Assert.ThrowsAsync<System.Security.Authentication.AuthenticationException>(() => client.ConnectAsync("127.0.0.1", (ushort)first.Server.EndPoint.Port));
+        await client.ConnectAsync("127.0.0.1", (ushort)first.Server.EndPoint.Port, (challenge, _) =>
+        { Assert.Equal(TofuStatus.FirstConnect, challenge.Status); return ValueTask.FromResult(true); });
+        await client.DisconnectAsync();
+        await client.ConnectAsync("127.0.0.1", (ushort)first.Server.EndPoint.Port); await client.DisconnectAsync();
+        // Pin the other server's certificate to this endpoint, simulating a changed server certificate.
+        using var credentials = ServerCredentials.LoadOrCreate(second.Directory, "VoiceCat Server");
+        new TofuStore(Path.Combine(first.Directory, "Other.pins")).Pin("127.0.0.1", (ushort)first.Server.EndPoint.Port, credentials.CertificateFingerprint);
+        await using var changed = new VoiceCatClient(tofuStorePath: Path.Combine(first.Directory, "Other.pins"));
+        await Assert.ThrowsAsync<System.Security.Authentication.AuthenticationException>(() => changed.ConnectAsync("127.0.0.1", (ushort)first.Server.EndPoint.Port,
+            (challenge, _) => { Assert.Equal(TofuStatus.Mismatch, challenge.Status); return ValueTask.FromResult(false); }));
+    }
+
+    [Fact]
+    public async Task ManagedClientSendsAndReceivesAuthenticatedEncodedVoice()
+    {
+        await using var fixture = new ServerFixture();
+        await using var managed = NewClient(fixture, "Managed"); await Connect(managed, fixture); await managed.AuthenticateGuestAsync("Managed");
+        Assert.True((await managed.SubscribeVoiceAsync()).Ok);
+        await using var peer = await VoicePeer.ConnectAsync(fixture, "Peer");
+        var remote = await peer.AnnounceAsync(StreamKind.StreamMic);
+        var local = (await managed.RequestAsync(new() { StreamAnnounce = new() { Kind = StreamKind.StreamMic } })).StreamAnnounceResult;
+        Assert.True(local.Ok);
+        var received = new TaskCompletionSource<byte[]>(TaskCreationOptions.RunContinuationsAsynchronously);
+        managed.VoiceReceived += (header, payload) => { Assert.Equal(remote.Ssrc, header.Ssrc); received.TrySetResult(payload.ToArray()); };
+        await peer.SendAsync(peer.Seal(remote.Ssrc, [1, 2, 3]));
+        Assert.Equal(new byte[] { 1, 2, 3 }, await received.Task.WaitAsync(TimeSpan.FromSeconds(5)));
+        Assert.True(managed.TrySendEncodedVoice(local.Ssrc, 960, [4, 5, 6]));
+        Assert.Equal(new byte[] { 4, 5, 6 }, (await peer.ReceiveVoiceAsync()).Payload);
+    }
+}

dotnet/tests/VoiceCat.Tests/MediaRelayTests.cs

@@ -1,3 +1,4 @@
+using VoiceCat.Transport;
 using System.Net;
 using System.Diagnostics;
 using System.Net.Sockets;

dotnet/tests/VoiceCat.Tests/ProductionServerTests.cs

@@ -1,3 +1,4 @@
+using VoiceCat.Transport;
 using System.Net;
 using System.Net.Sockets;
 using System.Text.Json;

dotnet/tests/VoiceCat.Tests/ServerTests.cs

@@ -1,3 +1,4 @@
+using VoiceCat.Transport;
 using System.Diagnostics;
 using System.Net;
 using System.Net.Sockets;

dotnet/tests/VoiceCat.Tests/VoiceCat.Tests.csproj

@@ -4,6 +4,8 @@
     <IsTestProject>true</IsTestProject>
   </PropertyGroup>
   <ItemGroup>
+    <ProjectReference Include="../../../clients/windows/VoiceCat.Managed/VoiceCat.Managed.csproj" />
+    <ProjectReference Include="../../src/VoiceCat.Core/VoiceCat.Core.csproj" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.1" PrivateAssets="all" />

dotnet/tests/VoiceCat.Tests/WindowsManagedClientTests.cs

@@ -0,0 +1,58 @@
+using VoiceCat.Interop;
+using VoiceCat.Server.Data;
+using Voicecat.V1;
+using static VoiceCat.Tests.ServerTests;
+using Client = VoiceCat.Interop.VoiceCatClient;
+
+namespace VoiceCat.Tests;
+
+public class WindowsManagedClientTests
+{
+    private static async Task Until(Client client, Func<bool> predicate)
+    {
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        do { client.PumpEvents(); if (predicate()) return; await Task.Delay(10, timeout.Token); } while (true);
+    }
+    private static async Task Login(Client client, ServerFixture fixture, bool admin = false)
+    {
+        client.EventReceived += e => { if (e.Type == VcEventType.ServerIdentity) client.ConfirmServerIdentity(true); };
+        Assert.Equal(VcResult.Ok, client.Connect("127.0.0.1", (ushort)fixture.Server.EndPoint.Port));
+        if (admin) client.AuthenticateUser("Admin", "secret"); else client.AuthenticateGuest("Guest");
+        await Until(client, () => client.ListUsers().Count > 0);
+    }
+    [Fact]
+    public async Task ShippedWindowsFacadeChatsExchangesPcmAndKeepsCaptureIdsAcrossChannelMoves()
+    {
+        await using var fixture = new ServerFixture();
+        using (var accounts = new AccountStore(Path.Combine(fixture.Directory, "voicecat.db"))) await accounts.CreateAccountAsync("Admin", "secret", true);
+        using var alice = new Client("Alice", "test", tofuStorePath: Path.Combine(fixture.Directory, "alice.pins"));
+        using var bob = new Client("Bob", "test", tofuStorePath: Path.Combine(fixture.Directory, "bob.pins"));
+        await Login(alice, fixture, true); await Login(bob, fixture);
+        Assert.True(alice.GetPermissions().IsAdmin);
+        string? body = null; bob.EventReceived += e => { if (e.Type == VcEventType.TextMessage) body = e.Text; };
+        Assert.Equal(VcResult.Ok, alice.SendText(VcTextScope.Channel, 1, "Managed Windows chat"));
+        await Until(bob, () => body is not null); Assert.Equal("Managed Windows chat", body);
+        Assert.Equal(VcResult.Ok, alice.JoinVoice()); Assert.Equal(VcResult.Ok, bob.JoinVoice());
+        alice.SetInputMode(VcInputMode.AlwaysOn); bob.SetInputMode(VcInputMode.AlwaysOn);
+        var a = alice.StartStreamExternalFeed(VcStreamKind.Mic, "Mic"); var b = bob.StartStreamExternalFeed(VcStreamKind.Mic, "Mic");
+        Assert.Equal(VcResult.Ok, a.Result); Assert.Equal(VcResult.Ok, b.Result);
+        await Until(bob, () => bob.ManagedClient.Users.Any(u => u.Streams.Count > 0 && u.Id != bob.ManagedClient.Authentication!.Self.Id));
+        long aliceEnergy = 0, bobEnergy = 0;
+        alice.ManagedClient.Audio.MixedPcm += pcm => { long sum = 0; foreach (short sample in pcm) sum += Math.Abs((int)sample); Interlocked.Add(ref aliceEnergy, sum); };
+        bob.ManagedClient.Audio.MixedPcm += pcm => { long sum = 0; foreach (short sample in pcm) sum += Math.Abs((int)sample); Interlocked.Add(ref bobEnergy, sum); };
+        short[] tone = Enumerable.Range(0, 960).Select(i => (short)(8000 * Math.Sin(i * Math.PI * 880 / 48000))).ToArray();
+        for (int i = 0; i < 40; i++) { alice.StreamFeedPcm(a.StreamId, tone, 960, 1); bob.StreamFeedPcm(b.StreamId, tone, 960, 1); alice.PumpEvents(); bob.PumpEvents(); await Task.Delay(20); }
+        Assert.True(Interlocked.Read(ref aliceEnergy) > 100000); Assert.True(Interlocked.Read(ref bobEnergy) > 100000);
+        uint oldId = alice.ManagedClient.LocalStreams.Single().StreamId;
+        await alice.ManagedClient.RequestAsync(new() { CreateChannel = new() { Channel = new() { Name = "Stereo", ParentId = 1, Audio = AudioEngineTests.Stream(20, true).Audio } } });
+        await Until(alice, () => alice.ListChannels().Any(c => c.Name == "Stereo"));
+        uint channel = alice.ListChannels().Single(c => c.Name == "Stereo").Id;
+        Assert.Equal(VcResult.Ok, alice.JoinChannel(channel));
+        await Until(alice, () => alice.ManagedClient.LocalStreams.Any(s => s.StreamId != oldId));
+        Assert.Equal(a.StreamId, Assert.Single(alice.ListUserStreams(alice.ManagedClient.Authentication!.Self.Id)).StreamId);
+        Assert.True(alice.GetStreamAudioConfig(alice.ManagedClient.Authentication!.Self.Id, a.StreamId).Config!.Stereo);
+        Assert.Equal(VcResult.Ok, alice.StreamFeedPcm(a.StreamId, tone, 960, 1));
+        Assert.Equal(VcResult.Ok, alice.StopStream(a.StreamId));
+        Assert.Empty(alice.ManagedClient.LocalStreams);
+    }
+}

dotnet/tests/VoiceCat.Tests/packages.lock.json

@@ -146,9 +146,24 @@
           "xunit.extensibility.core": "[2.9.3]"
         }
       },
+      "voicecat.audio": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Codec": "[1.0.0, )",
+          "VoiceCat.Dsp": "[1.0.0, )",
+          "VoiceCat.Protocol": "[1.0.0, )"
+        }
+      },
       "voicecat.codec": {
         "type": "Project"
       },
+      "voicecat.core": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Audio": "[1.0.0, )",
+          "VoiceCat.Crypto": "[1.0.0, )"
+        }
+      },
       "voicecat.crypto": {
         "type": "Project",
         "dependencies": {
@@ -159,6 +174,12 @@
       "voicecat.dsp": {
         "type": "Project"
       },
+      "voicecat.managed": {
+        "type": "Project",
+        "dependencies": {
+          "VoiceCat.Core": "[1.0.0, )"
+        }
+      },
       "voicecat.protocol": {
         "type": "Project",
         "dependencies": {