Try to fix background glitching over long periods of time

The screen-audio pump opened and disposed a memory mapping plus its container
lookup and path strings on every 5 ms tick - about 200 mapping pairs per
second of steady allocation that churned the GC under long calls. The producer
opens the ring with O_CREAT and never replaces it, so the pump now keeps one
mapping across ticks and rebuilds it only when the ring file disappears or a
drain fails.

.clang-format

@@ -1,15 +0,0 @@
-# VoiceCat C++ style. Keep formatting boring and consistent.
-BasedOnStyle: Google
-Language: Cpp
-Standard: c++20
-ColumnLimit: 100
-IndentWidth: 4
-TabWidth: 4
-UseTab: Never
-AccessModifierOffset: -2
-PointerAlignment: Left
-DerivePointerAlignment: false
-AllowShortFunctionsOnASingleLine: Inline
-AllowShortIfStatementsOnASingleLine: false
-SortIncludes: CaseInsensitive
-IncludeBlocks: Regroup

.dockerignore

@@ -0,0 +1,26 @@
+# Git history — large and never needed inside the build context
+.git/
+
+# Previous build outputs
+build/
+artifacts/
+**/bin/
+**/obj/
+
+# Native GUI client code (Swift/Xcode, C#/WinForms) — server build doesn't need these
+clients/
+
+# Documentation and prose — not compiled
+docs/
+*.md
+AGENTS.md
+PROGRESS.md
+CLAUDE.md
+
+# Editor / tooling config
+.vscode/
+.idea/
+
+# OS noise
+.DS_Store
+Thumbs.db

.editorconfig

@@ -0,0 +1,7 @@
+root = true
+
+[*.cs]
+indent_style = space
+indent_size = 4
+csharp_style_namespace_declarations = file_scoped:warning
+dotnet_sort_system_directives_first = true

.github/workflows/dotnet.yml

@@ -0,0 +1,52 @@
+name: Build and test
+
+on:
+  push:
+    paths: ['src/**', 'tests/**', 'clients/**', 'native/**', 'proto/**', 'assets/**', 'scripts/**', '*.slnx', '*.props', '*.targets', 'global.json', 'Dockerfile', '.github/workflows/dotnet.yml']
+  pull_request:
+    paths: ['src/**', 'tests/**', 'clients/**', 'native/**', 'proto/**', 'assets/**', 'scripts/**', '*.slnx', '*.props', '*.targets', 'global.json', 'Dockerfile', '.github/workflows/dotnet.yml']
+  workflow_dispatch:
+
+jobs:
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [windows-latest, ubuntu-24.04, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-dotnet@v4
+        with:
+          global-json-file: global.json
+          cache: true
+          cache-dependency-path: '**/packages.lock.json'
+      - name: Build and stage native codec/DSP
+        shell: pwsh
+        run: ./scripts/build-native.ps1
+      - run: dotnet restore VoiceCat.slnx --locked-mode
+      - run: dotnet build VoiceCat.slnx -c Release --no-restore
+      - run: dotnet test VoiceCat.slnx -c Release --no-build
+      - shell: pwsh
+        run: ./scripts/check-licenses.ps1
+
+  apple-client:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-dotnet@v4
+        with:
+          global-json-file: global.json
+          cache: true
+          cache-dependency-path: '**/packages.lock.json'
+      - name: Install Apple workloads
+        run: dotnet workload install macos ios --version 10.0.401
+      - name: Build and stage native codec/DSP
+        shell: pwsh
+        run: ./scripts/build-native.ps1
+      - name: Build and stage static iOS codec/DSP
+        run: ./scripts/build-native-ios.sh
+      - name: Restore managed Apple clients
+        run: dotnet restore clients/apple/VoiceCat.Apple.slnx
+      - name: Build managed AppKit and UIKit clients
+        run: dotnet build clients/apple/VoiceCat.Apple.slnx -c Debug --no-restore

.gitignore

@@ -1,6 +1,13 @@
 # Build output
+**/bin/
+**/obj/
+**/TestResults/
+/artifacts/
 /build/
 /out/
+
+# Staged distribution artifacts (scripts/build-*.sh output)
+/dist/
 *.o
 *.obj
 *.a
@@ -11,9 +18,7 @@
 *.exe
 *.pdb
 
-# vcpkg
+# vcpkg (bundled as a submodule at /vcpkg — see docs/building.md §2)
-/vcpkg_installed/
-/vcpkg/
 
 # Generated protobuf
 *.pb.cc
@@ -33,8 +38,18 @@
 .DS_Store
 Thumbs.db
 
-# Apple / Windows client build artifacts (added in M4)
+# Apple / Windows client build artifacts
 clients/apple/**/build/
+clients/apple/**/bin/
+clients/apple/**/obj/
 clients/apple/**/*.xcodeproj/xcuserdata/
+clients/apple/**/*.xcodeproj/project.xcworkspace/
+clients/apple/**/*.xcframework/
 clients/windows/**/bin/
 clients/windows/**/obj/
+# SwiftPM build artifacts
+
+# Test artifacts: TOFU pin store written by vc_client during headless tests
+voicecat_tofu_pins.txt
+
+# Python bytecode cache (e.g. scripts/asc_api.py)

AGENTS.md

@@ -1,94 +1,52 @@
-# AGENTS.md — working method
+# VoiceCat working method
 
-This file is the **working method** for a developer or AI agent picking up VoiceCat. Companion
+Start with `CLAUDE.md` for commands and architecture and `PROGRESS.md` for the current handoff.
-files:
+The supported product is the .NET 10 implementation.
 
-- [`CLAUDE.md`](CLAUDE.md) — the hub: build/test commands, architecture at a glance, doc map.
+## Definition of done
-- [`PROGRESS.md`](PROGRESS.md) — living tracker: what's done, what's next. **Update it as you work.**
-- [`docs/`](docs/) — the **source of truth** for all design.
 
-Read those, then use the method below.
+A clean compile is the floor. Changes are done when their observable behavior is covered by a
+test or, for hardware/accessibility/release behavior, by a clearly recorded manual gate.
 
-## What this repo is right now
+For implementation work:
 
-A complete **design** ([`docs/`](docs/)) plus an **M0 skeleton**: it compiles and links, but
+1. Read the relevant code and current contract document.
-`libvoicecat`'s subsystems are stubs that return `VC_ERR_NOT_IMPLEMENTED`. Your job is to turn
+2. Add or adjust the smallest behavior test that demonstrates the requested result.
-the design into working software, one milestone at a time.
+3. Implement the change without weakening encryption, real-time safety, or accessibility.
+4. Build and run the affected tests, then the full managed test suite when practical.
+5. Update concise current documentation and `PROGRESS.md` if the handoff changed.
 
-## The working method (important)
+## Supported layout
 
-**A clean compile is the floor, not the goal.** Do not treat "make the compiler errors go
+| Path | Purpose |
-away" as done. Each milestone in [`docs/roadmap.md`](docs/roadmap.md) has an **exit
+|---|---|
-criterion stated as observable behavior** — that is what "done" means. Examples:
+| `proto/voicecat.proto` | Control-plane wire schema |
+| `src/` | Managed server, core, protocol, crypto, audio, codec/DSP, and CLI |
+| `tests/VoiceCat.Tests/` | Managed behavior tests |
+| `clients/windows/` | Supported WinForms client |
+| `clients/apple/` | Supported AppKit and UIKit clients |
+| `native/media/` | Required narrow Opus/RNNoise C ABI |
+| `native/rnnoise/` | Vendored RNNoise source/model |
+| `native/apple/broadcast/` | Required ReplayKit extension and shared-memory producer |
 
-- M1 done = *two `vccli` instances actually chat through a real server over TLS*, not "it builds".
+## Core verification
-- M2 done = *you can talk between two clients in a channel and hear loss concealment work*.
-
-So the loop is:
-
-1. Pick the current milestone in `docs/roadmap.md`. Read the relevant design doc section.
-2. Write the smallest test (CTest, or a `vccli` interaction) that encodes the exit behavior.
-3. Implement the subsystem until that test passes — not just until it compiles.
-4. Keep the build green and the existing tests passing on every commit.
-
-Every commit must compile and pass `ctest`. Behavior tests are how you know you're actually
-making progress.
-
-## Build
-
-Skeleton (no third-party deps — works immediately):
 
 ```bash
-cmake --preset dev
+./scripts/build-native.ps1
-cmake --build --preset dev
+dotnet restore VoiceCat.slnx --locked-mode
-ctest --preset dev
+dotnet build VoiceCat.slnx -c Release --no-restore
+dotnet test VoiceCat.slnx -c Release --no-build
+./scripts/check-licenses.ps1
 ```
 
-When a subsystem needs real libraries, turn on vcpkg deps:
+Apple builds additionally use `./scripts/build-native-ios.sh` and
+`clients/apple/VoiceCat.Apple.slnx` on macOS.
 
-```bash
+## Hard rules
-export VCPKG_ROOT=/path/to/vcpkg     # bootstrap vcpkg first; cross-platform
-cmake --preset server-release        # installs deps pinned in vcpkg.json
-cmake --build --preset server-release
-```
 
-`vcpkg.json` currently has a placeholder `builtin-baseline` — set it to a real vcpkg commit
+- Encryption is mandatory: TLS control plus authenticated encrypted UDP media.
-SHA the first time you enable `VOICECAT_USE_VCPKG_DEPS`.
+- Never introduce GPL/LGPL dependencies.
-
+- Real-time audio callbacks never allocate, lock, block, or perform I/O.
-## Where each subsystem lives (and its doc)
+- Preserve accessible names, keyboard operation, and curated screen-reader announcements.
-
+- Wire, database, and shared-ring changes are deliberate versioned changes.
-| Path | Subsystem | Design |
+- Keep `PROGRESS.md` short. Use Git history rather than accumulating completed-work prose.
-|------|-----------|--------|
-| `core/include/voicecat.h` | The C ABI every client/server calls | docs/architecture.md §4 |
-| `core/proto/voicecat.proto` | Control-plane wire format | docs/protocol.md |
-| `core/src/net/` | Asio TCP/UDP transport, framing | docs/architecture.md, docs/protocol.md §1 |
-| `core/src/crypto/` | TLS 1.3 (mbedTLS), media AEAD (libsodium), anti-replay | docs/security.md |
-| `core/src/codec/` | Opus encode/decode, FEC/DTX | docs/voice.md §3–4 |
-| `core/src/protocol/` | Envelope (de)serialize, state machine, routing | docs/protocol.md |
-| `core/src/session/` | Channels, users, streams, permissions, text | docs/protocol.md §5 |
-| `core/src/audio/` | Capture/playback (miniaudio), APM DSP, jitter buffer, mixer | docs/voice.md §8–11 |
-| `server/` | Connection mgr, session registry, SFU relay, SQLite | docs/architecture.md §5 |
-| `tools/vccli/` | Headless client to drive/verify the protocol | — |
-
-## Suggested first steps (M1 spine)
-
-1. **Wire protobuf + framing** (`net/` + `protocol/`): build, then generate C++ from
-   `voicecat.proto`, implement the `[u32 length][Envelope]` framing over a plain TCP socket
-   (TLS can come right after). Test: round-trip an `Envelope` through the framer.
-2. **TLS 1.3 via mbedTLS** (`crypto/`): wrap the TCP channel. Test: `vccli` completes a TLS
-   handshake against `voicecat-server` and exchanges a `ClientHello`/`ServerHello`.
-3. **Auth + state** (`session/`): guest + admin-provisioned accounts (Argon2id/SQLite),
-   channel tree snapshot/deltas, ephemeral text relay. Test: two `vccli` chat.
-
-Then proceed to M2 (UDP media) per the roadmap.
-
-## House rules
-
-- **No GPL/LGPL dependencies, ever** (closed-source redistribution is a goal). See
-  docs/tech-stack.md §5. CI should fail on a copyleft transitive dep.
-- **Encryption is mandatory** — never add a plaintext transport path. docs/security.md.
-- **Real-time audio threads** never allocate, lock, or block. docs/architecture.md §3.
-- Keep `docs/` and code in sync. If you change a wire format or the C ABI, update the doc in
-  the same commit.
-- The C ABI is the contract for the Swift/C# clients — treat changes to `voicecat.h` and
-  `voicecat.proto` as deliberate, versioned events (docs/protocol.md §8).

CLAUDE.md

@@ -1,143 +1,49 @@
-# CLAUDE.md — agent hub for VoiceCat
+# VoiceCat developer guide
 
-Auto-loaded each session. This is the **map**: build commands, architecture at a glance, and
+VoiceCat is a self-hosted encrypted voice and text chat system. The supported implementation
-where everything is. For the *working method* read [`AGENTS.md`](AGENTS.md); for *what's done
+is .NET 10. Read `AGENTS.md` for working rules and `PROGRESS.md` for the current short status.
-and what's next* read [`PROGRESS.md`](PROGRESS.md); for *design* read [`docs/`](docs/).
 
-> **One-line status:** M2 voice/media plane is complete and verified through the real client
+## Build and test
-> library, not just a raw-socket harness (`ctest --test-dir build/m1-dev` green — 10/10 tests,
-> including `test_voice_client_abi` driving two real `vc_client`s end-to-end, and `vccli
-> --voice` manually verified live). Next up is **M3** (multi-stream, per-channel tuning,
-> listener-side NR). See [`PROGRESS.md`](PROGRESS.md).
-
-VoiceCat = self-hosted native voice & text chat (TeamSpeak/Mumble-style). Plain TCP (control)
-+ UDP (media), no WebRTC, encrypted by default. A shared C++ core (`libvoicecat`) drives
-native clients (Swift on macOS/iOS, C# on Windows) and the server.
-
----
-
-## Build & test commands
-
-The **M0 skeleton builds with no third-party dependencies** — just CMake + Ninja + a C++20
-compiler. Deps (vcpkg) are off until a subsystem needs them.
 
 ```bash
-# Configure + build the skeleton (default; no vcpkg needed)
+./scripts/build-native.ps1
-cmake --preset dev
+dotnet restore VoiceCat.slnx --locked-mode
-cmake --build --preset dev
+dotnet build VoiceCat.slnx -c Release --no-restore
-
+dotnet test VoiceCat.slnx -c Release --no-build
-# Run the tests (behavior smoke test today; grows per milestone)
+./scripts/check-licenses.ps1
-ctest --preset dev                      # or: ctest --test-dir build/dev --output-on-failure
-
-# Run the binaries (Windows adds .exe; Linux/macOS no extension)
-./build/dev/bin/vccli                    # headless test client
-./build/dev/bin/voicecat-server --help
-./build/dev/bin/voicecat-server --name "My Server"
-
-# Build a single target / be verbose
-cmake --build --preset dev --target vccli
-cmake --build --preset dev --verbose
-
-# Clean
-rm -rf build/dev                         # nuke; or:
-cmake --build --preset dev --target clean
 ```
 
-When you start a subsystem that needs real libraries (mbedTLS, libsodium, opus, protobuf, …),
+Apple client builds require macOS, Xcode, and the .NET macOS/iOS workloads:
-turn vcpkg deps on:
 
 ```bash
-# one-time: git clone https://github.com/microsoft/vcpkg && ./vcpkg/bootstrap-vcpkg.sh  (.bat on Windows)
+./scripts/build-native-ios.sh
-export VCPKG_ROOT=/path/to/vcpkg         # works on Linux / macOS / Windows
+dotnet restore clients/apple/VoiceCat.Apple.slnx
-cmake --preset server-release            # auto-installs deps pinned in vcpkg.json
+dotnet build clients/apple/VoiceCat.Apple.slnx -c Debug --no-restore
-cmake --build --preset server-release
 ```
 
-Other useful toggles (pass with `-D` at configure time):
+Windows publishing uses `clients/windows/publish-client.ps1`. Server publishing uses
+`scripts/publish-server.ps1`.
 
-```bash
+## Current architecture
-cmake --preset dev -DVOICECAT_BUILD_SHARED=ON     # build libvoicecat as a .dll/.so/.dylib (for the C# client)
-cmake --preset dev -DVOICECAT_BUILD_SERVER=OFF     # core + tools only
-cmake --preset dev -DVOICECAT_BUILD_TESTS=OFF
-```
 
-Formatting: `clang-format` config is `.clang-format` (Google base, 100 cols, 4-space).
+- `proto/voicecat.proto` is the control-plane wire schema.
+- `src/VoiceCat.Protocol` owns protobuf framing and generated types.
+- `src/VoiceCat.Crypto` owns TLS, TOFU, media AEAD, identity, and password hashing.
+- `src/VoiceCat.Server` owns the TLS/UDP server and SQLite state.
+- `src/VoiceCat.Core` owns client connection and protocol state.
+- `src/VoiceCat.Audio`, `.Codec`, and `.Dsp` own voice processing.
+- `src/VoiceCat.Cli` is the supported headless client.
+- `clients/windows` is the WinForms client.
+- `clients/apple` contains the AppKit and UIKit clients.
+- `native/media` and `native/rnnoise` are the required Opus/RNNoise native boundary.
+- `native/apple/broadcast` is the required Swift ReplayKit extension.
 
-```bash
+## Invariants
-git ls-files '*.cpp' '*.h' | xargs clang-format -i
-```
 
----
+- TLS control and encrypted UDP media are mandatory; do not add plaintext transports.
-
+- No GPL or LGPL dependencies.
-## Architecture at a glance
+- Audio callbacks must not allocate, lock, block, or perform network I/O.
-
+- Treat `proto/voicecat.proto`, persisted database formats, and the ReplayKit ring layout as
-Full detail: [`docs/architecture.md`](docs/architecture.md). The short version:
+  explicit versioned contracts.
-
+- A passing build is not enough: add or update behavior tests for observable changes.
-```
+- Keep `PROGRESS.md` concise; do not append a historical changelog.
- Swift (macOS/iOS)  ─┐                                    ┌─ C# (Windows)
-                     ├──▶  libvoicecat  (C ABI: voicecat.h) ◀──┤
- voicecat-server  ───┘   net · crypto · codec · protocol ·     └─ all UIs are thin
-   (links core)          session · audio                          the core owns audio
-```
-
-- **One core, many faces.** Protocol, Opus, crypto, networking, jitter buffer, and mixing
-  live once in C++. Clients call the **C ABI** (`core/include/voicecat.h`); the server links
-  the same core, so framing/crypto never drift between ends.
-- **Two transports.** TCP + **TLS 1.3** (control, protobuf `Envelope`) and UDP + **exported-key
-  ChaCha20-Poly1305 AEAD** (media, fixed binary voice frame). Encryption is mandatory.
-- **Threading.** Real-time audio threads never allocate/lock/block; they exchange data with
-  the net thread via lock-free ring buffers; a worker pool absorbs blocking work.
-
-### Subsystem map (code ↔ design doc)
-
-| Path | Subsystem | Design |
-|------|-----------|--------|
-| `core/include/voicecat.h` | The C ABI (client/server contract) | architecture.md §4 |
-| `core/proto/voicecat.proto` | Control-plane wire format (source of truth) | protocol.md |
-| `core/src/net/` | Asio TCP/UDP transport, `[u32 len][payload]` framing | protocol.md §1, voice.md §2 |
-| `core/src/crypto/` | TLS 1.3 (mbedTLS), media AEAD (libsodium), anti-replay | security.md |
-| `core/src/codec/` | Opus encode/decode, FEC/DTX | voice.md §3–4 |
-| `core/src/protocol/` | Envelope (de)serialize, request/response, dispatch | protocol.md |
-| `core/src/session/` | Channels, users, streams, permissions, ephemeral text | protocol.md §5 |
-| `core/src/audio/` | miniaudio I/O, APM DSP, jitter buffer, mixer | voice.md §8–11 |
-| `core/src/core/` | `vc_client` — the handle behind the C ABI | architecture.md §4 |
-| `server/` | Connection mgr, session registry, SFU relay, SQLite | architecture.md §5 |
-| `tools/vccli/` | Headless client that drives/verifies the protocol | — |
-| `clients/apple/`, `clients/windows/` | Native GUIs (M4) | architecture.md §4 |
-
----
-
-## Documentation index (source of truth)
-
-Read [`docs/`](docs/) before changing behavior. Order:
-
-1. [docs/README.md](docs/README.md) — overview, locked decisions, glossary
-2. [docs/architecture.md](docs/architecture.md) — core, C ABI, threading, server
-3. [docs/protocol.md](docs/protocol.md) — control plane, Envelope, message catalog
-4. [docs/voice.md](docs/voice.md) — UDP media, Opus, multi-stream, two-sided NR, VAD/PTT
-5. [docs/security.md](docs/security.md) — mandatory encryption, TLS+AEAD, accounts, threat model
-6. [docs/tech-stack.md](docs/tech-stack.md) — libraries, permissive-license rule, tooling
-7. [docs/deployment.md](docs/deployment.md) — zero-config self-host (Docker / binary / source)
-8. [docs/roadmap.md](docs/roadmap.md) — milestones + resolved decisions
-
----
-
-## Keeping track of progress
-
-**[`PROGRESS.md`](PROGRESS.md) is the living status file.** When you finish a task, check it
-off there and note the next step, so the next agent can pick up instantly. Treat it as part of
-the work, not an afterthought — update it in the same commit as the code.
-
----
-
-## House rules (hard constraints)
-
-- **A clean compile is the floor, not the goal.** "Done" = the milestone's observable exit
-  criterion in [`docs/roadmap.md`](docs/roadmap.md) passes (e.g. M1 = two `vccli` actually chat
-  over TLS). Encode it as a test. See [`AGENTS.md`](AGENTS.md).
-- **No GPL/LGPL dependencies, ever** (closed-source redistribution is a goal). docs/tech-stack.md §5.
-- **Encryption is mandatory** — never add a plaintext transport path. docs/security.md.
-- **Real-time audio threads** never allocate, lock, or block. docs/architecture.md §3.
-- **Keep docs + code in sync.** Changing a wire format (`voicecat.proto`) or the C ABI
-  (`voicecat.h`) is a deliberate, versioned act — update the doc in the same commit (protocol.md §8).
-- Every commit must build (`cmake --build --preset dev`) and pass `ctest --preset dev`.

CMakeLists.txt

@@ -1,53 +0,0 @@
-cmake_minimum_required(VERSION 3.25)
-
-project(voicecat
-    VERSION 0.0.1
-    DESCRIPTION "Self-hosted native voice & text chat (see docs/)"
-    LANGUAGES CXX)
-
-# ── Options ───────────────────────────────────────────────────────────────────
-# The M0 skeleton compiles with NO third-party dependencies: every subsystem is a
-# stub that returns VC_ERR_NOT_IMPLEMENTED. As each subsystem is built out, flip
-# VOICECAT_USE_VCPKG_DEPS=ON so CMake pulls the real libraries (mbedTLS, libsodium,
-# opus, protobuf, ...) via the vcpkg toolchain (see vcpkg.json / docs/tech-stack.md).
-option(VOICECAT_USE_VCPKG_DEPS "Link real third-party deps via vcpkg" OFF)
-option(VOICECAT_BUILD_SERVER   "Build voicecat-server"                ON)
-option(VOICECAT_BUILD_TOOLS    "Build the vccli headless test client" ON)
-option(VOICECAT_BUILD_TESTS    "Build tests"                          ON)
-option(VOICECAT_BUILD_SHARED   "Build libvoicecat as a shared library" OFF)
-
-# ── Global settings ───────────────────────────────────────────────────────────
-set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_CXX_EXTENSIONS OFF)
-
-if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-    set(CMAKE_BUILD_TYPE Debug CACHE STRING "" FORCE)
-endif()
-
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
-set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-
-# ── Targets ───────────────────────────────────────────────────────────────────
-add_subdirectory(core)
-
-if(VOICECAT_BUILD_SERVER)
-    add_subdirectory(server)
-endif()
-
-if(VOICECAT_BUILD_TOOLS)
-    add_subdirectory(tools/vccli)
-    if(VOICECAT_USE_VCPKG_DEPS)
-        add_subdirectory(tools/voicecat-admin)
-    endif()
-endif()
-
-if(VOICECAT_BUILD_TESTS)
-    enable_testing()
-    add_subdirectory(tests)
-endif()
-
-message(STATUS "VoiceCat ${PROJECT_VERSION} configured "
-        "(vcpkg deps: ${VOICECAT_USE_VCPKG_DEPS}, "
-        "server: ${VOICECAT_BUILD_SERVER}, tools: ${VOICECAT_BUILD_TOOLS})")

CMakePresets.json

@@ -1,77 +0,0 @@
-{
-  "version": 6,
-  "cmakeMinimumRequired": { "major": 3, "minor": 25, "patch": 0 },
-  "configurePresets": [
-    {
-      "name": "dev",
-      "displayName": "Dev (skeleton, no third-party deps)",
-      "description": "Builds the stub skeleton with just a compiler. Works out of the box; no vcpkg required.",
-      "generator": "Ninja",
-      "binaryDir": "${sourceDir}/build/dev",
-      "cacheVariables": {
-        "CMAKE_BUILD_TYPE": "Debug",
-        "VOICECAT_USE_VCPKG_DEPS": "OFF"
-      }
-    },
-    {
-      "name": "vcpkg-base",
-      "hidden": true,
-      "description": "Shared base for presets that link real deps via vcpkg. Requires VCPKG_ROOT in the environment.",
-      "generator": "Ninja",
-      "toolchainFile": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake",
-      "cacheVariables": { "VOICECAT_USE_VCPKG_DEPS": "ON" }
-    },
-    {
-      "name": "m1-dev",
-      "inherits": "vcpkg-base",
-      "displayName": "M1 Dev (TLS control plane, deps via vcpkg)",
-      "description": "Active development preset for M1+. Requires VCPKG_ROOT env var pointing to a bootstrapped vcpkg. Set VCPKG_ROOT=D:\\code\\nvgt\\vcpkg\\bin (or wherever your vcpkg is).",
-      "binaryDir": "${sourceDir}/build/m1-dev",
-      "cacheVariables": {
-        "CMAKE_BUILD_TYPE": "Debug",
-        "VOICECAT_USE_VCPKG_DEPS": "ON",
-        "VOICECAT_BUILD_TOOLS": "ON",
-        "VOICECAT_BUILD_TESTS": "ON",
-        "VCPKG_TARGET_TRIPLET": "x64-mingw-static",
-        "VCPKG_HOST_TRIPLET": "x64-mingw-static"
-      }
-    },
-    {
-      "name": "m2-dev",
-      "inherits": "vcpkg-base",
-      "displayName": "M2 Dev (voice + media, deps via vcpkg)",
-      "description": "Active development preset for M2+. Requires VCPKG_ROOT env var pointing to a bootstrapped vcpkg. Set VCPKG_ROOT=D:\\code\\nvgt\\vcpkg\\bin (or wherever your vcpkg is).",
-      "binaryDir": "${sourceDir}/build/m2-dev",
-      "cacheVariables": {
-        "CMAKE_BUILD_TYPE": "Debug",
-        "VOICECAT_USE_VCPKG_DEPS": "ON",
-        "VOICECAT_BUILD_TOOLS": "ON",
-        "VOICECAT_BUILD_TESTS": "ON",
-        "VCPKG_TARGET_TRIPLET": "x64-mingw-static",
-        "VCPKG_HOST_TRIPLET": "x64-mingw-static"
-      }
-    },
-    {
-      "name": "server-release",
-      "inherits": "vcpkg-base",
-      "displayName": "Server (release, real deps)",
-      "binaryDir": "${sourceDir}/build/server-release",
-      "cacheVariables": {
-        "CMAKE_BUILD_TYPE": "Release",
-        "VOICECAT_BUILD_TOOLS": "ON",
-        "VCPKG_TARGET_TRIPLET": "x64-mingw-static"
-      }
-    }
-  ],
-  "buildPresets": [
-    { "name": "dev",            "configurePreset": "dev" },
-    { "name": "m1-dev",         "configurePreset": "m1-dev" },
-    { "name": "m2-dev",         "configurePreset": "m2-dev" },
-    { "name": "server-release", "configurePreset": "server-release" }
-  ],
-  "testPresets": [
-    { "name": "dev",    "configurePreset": "dev",    "output": { "outputOnFailure": true } },
-    { "name": "m1-dev", "configurePreset": "m1-dev", "output": { "outputOnFailure": true } },
-    { "name": "m2-dev", "configurePreset": "m2-dev", "output": { "outputOnFailure": true } }
-  ]
-}

Directory.Build.props

@@ -0,0 +1,14 @@
+<Project>
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <AnalysisLevel>latest</AnalysisLevel>
+    <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VoiceCatIosStatic)' == 'true'">
+    <RuntimeIdentifiers>ios-arm64;iossimulator-arm64</RuntimeIdentifiers>
+    <NuGetLockFilePath>packages.ios.lock.json</NuGetLockFilePath>
+  </PropertyGroup>
+</Project>

Directory.Build.targets

@@ -0,0 +1,13 @@
+<Project>
+  <PropertyGroup>
+    <VoiceCatNativeRid Condition="'$(VoiceCatNativeRid)' == '' and '$(RuntimeIdentifier)' != ''">$(RuntimeIdentifier)</VoiceCatNativeRid>
+    <VoiceCatNativeRid Condition="'$(VoiceCatNativeRid)' == ''">$(NETCoreSdkRuntimeIdentifier)</VoiceCatNativeRid>
+    <VoiceCatNativeDirectory Condition="'$(VoiceCatNativeDirectory)' == ''">$(MSBuildThisFileDirectory)artifacts/native/runtimes/$(VoiceCatNativeRid)/native</VoiceCatNativeDirectory>
+  </PropertyGroup>
+  <ItemGroup Condition="'$(MSBuildProjectName)' != 'VoiceCat.Server' and '$(MSBuildProjectName)' != 'VoiceCat.Crypto' and '$(MSBuildProjectName)' != 'VoiceCat.Protocol'">
+    <None Include="$(MSBuildThisFileDirectory)artifacts/native/licenses/*.txt" Link="licenses/%(Filename)%(Extension)" CopyToOutputDirectory="PreserveNewest" CopyToPublishDirectory="PreserveNewest" />
+    <None Include="$(VoiceCatNativeDirectory)/voicecat_media.dll" Condition="Exists('$(VoiceCatNativeDirectory)/voicecat_media.dll')" Link="%(Filename)%(Extension)" CopyToOutputDirectory="PreserveNewest" CopyToPublishDirectory="PreserveNewest" />
+    <None Include="$(VoiceCatNativeDirectory)/libvoicecat_media.so" Condition="Exists('$(VoiceCatNativeDirectory)/libvoicecat_media.so')" Link="%(Filename)%(Extension)" CopyToOutputDirectory="PreserveNewest" CopyToPublishDirectory="PreserveNewest" />
+    <None Include="$(VoiceCatNativeDirectory)/libvoicecat_media.dylib" Condition="Exists('$(VoiceCatNativeDirectory)/libvoicecat_media.dylib')" Link="%(Filename)%(Extension)" CopyToOutputDirectory="PreserveNewest" CopyToPublishDirectory="PreserveNewest" />
+  </ItemGroup>
+</Project>

Dockerfile

@@ -0,0 +1,27 @@
+# syntax=docker/dockerfile:1.7
+FROM mcr.microsoft.com/dotnet/sdk:10.0.203-noble AS build
+WORKDIR /src
+COPY global.json Directory.Build.props Directory.Build.targets ./
+COPY proto/voicecat.proto proto/voicecat.proto
+COPY src/ src/
+RUN dotnet restore src/VoiceCat.Server/VoiceCat.Server.csproj -r linux-x64 --locked-mode -p:NuGetLockFilePath=packages.publish.linux-x64.lock.json
+RUN dotnet publish src/VoiceCat.Server/VoiceCat.Server.csproj -c Release -r linux-x64 --self-contained true --no-restore \
+    -p:PublishSingleFile=true -p:PublishTrimmed=false -p:IncludeNativeLibrariesForSelfExtract=true -o /out \
+    && mkdir /empty-data
+
+FROM scratch AS export
+COPY --from=build /out/VoiceCat.Server /VoiceCat.Server
+
+FROM mcr.microsoft.com/dotnet/runtime-deps:10.0.10-noble-chiseled-extra AS runtime
+WORKDIR /app
+COPY --from=build --chown=1654:1654 /out/ ./
+COPY --from=build --chown=1654:1654 /empty-data/ /data/
+USER 1654:1654
+VOLUME ["/data"]
+EXPOSE 8384/tcp
+EXPOSE 8384/udp
+ENV VOICECAT_DATA_DIR=/data \
+    VOICECAT_BIND_ADDRESS=0.0.0.0 \
+    VOICECAT_BIND_PORT=8384
+HEALTHCHECK --interval=30s --timeout=6s --start-period=10s --retries=3 CMD ["/app/VoiceCat.Server", "--health-check", "127.0.0.1:8384"]
+ENTRYPOINT ["/app/VoiceCat.Server"]

PROGRESS.md

@@ -1,250 +1,59 @@
-# PROGRESS — VoiceCat
+# VoiceCat status
 
-Living status. **Update this file in the same commit as your work** so the next agent picks
+Updated: 2026-09-22
-up instantly. Newest status at the top.
 
-- **Date convention:** ISO (YYYY-MM-DD).
+## Current state
-- Statuses: `[ ]` not started · `[~]` in progress · `[x]` done.
 
----
+VoiceCat's supported implementation is .NET 10. The managed protocol, crypto, TLS, server,
+CLI, client state, audio engine, Windows client, macOS client, and iOS client are implemented.
+Retired implementations and compatibility projects have been removed; this tree contains only
+the supported product and its required native media boundaries.
 
-## ▶ Where we left off / next action
+The source-of-truth layout is:
 
-- **Done:** **M3 — multi-stream & per-channel tuning** ✓ complete (2026-06-16). See the M3
+- `proto/voicecat.proto` — wire schema.
-  section below for the full file-by-file change list. `ctest --test-dir build/m1-dev` —
+- `src/` — protocol, crypto, codec/DSP bindings, server, client core, audio, and CLI.
-  **11/11 tests** green (3 consecutive full-suite runs), including the new
+- `tests/VoiceCat.Tests/` — managed behavior and integration tests.
-  `test_m3_multistream` (real `vc_client`s, not raw sockets — same lesson as M2: ABI-level
+- `clients/windows/` — WinForms application over the managed core.
-  coverage is what proves the client library, not just the wire protocol).
+- `clients/apple/` — AppKit and UIKit applications over the managed core.
-  **Two items intentionally still open** (carried forward, not silently dropped):
+- `native/media/` and `native/rnnoise/` — required Opus/RNNoise shim and vendored RNNoise.
-  - `vc_set_input_device`/`vc_set_input_mode`/`vc_set_push_to_talk`/`vc_list_devices`
+- `native/apple/broadcast/` — required ReplayKit upload extension and shared ring producer.
-    (device enumeration + VAD/PTT input gate) remain `VC_ERR_NOT_IMPLEMENTED` — explicitly
-    scoped out of this M3 pass; revisit in a future milestone.
-  - Stereo Opus is now wire-correct end-to-end (a channel configured `MODE_STEREO` really
-    encodes/decodes 2-channel Opus packets), but `AudioEngine`'s playback mixer/output device
-    stays mono internally — stereo streams are downmixed (avg L/R) immediately after decode,
-    before mixing. True stereo *playback output* is a follow-up, not part of M3.
-- **Next:** **M4 — native clients** (Windows C#, macOS/iOS Swift). See `docs/roadmap.md §M4`.
 
----
+The physical-device iOS voice path now supports ReplayKit fallback, stable Apple VPIO voice-chat
+capture using a paced 20 ms handoff, and true built-in stereo microphone capture. Stereo was
+verified on an iPhone 16 Pro Max with a two-channel AVAudioEngine input and distinct left/right
+samples; the managed Apple binding requires native use of its otherwise-unmapped stereo polar
+pattern constant.
 
-## Milestones (see [docs/roadmap.md](docs/roadmap.md) for full detail)
+The iOS user list now opens a remote-user detail view with independent tuning for each active
+audio stream. Private messages are grouped into per-user conversations with direct access to the
+same user and audio controls.
 
-- [x] **M0 — Scaffolding** ✓ complete
+SQLite schema v4 persists DRED and the channel packet-loss mode. Manual loss remains the default;
-- [x] **M1 — Control plane** ✓ complete (2026-06-15)
+automatic Fast/Balanced/Stable modes measure each sender's authenticated UDP uplink at the server,
-- [x] **M2 — Voice, single stream** ✓ complete (2026-06-16)
+cap the applied Opus hint at 30%, and feed it back over TLS.
-- [x] **M3 — Multi-stream & per-channel tuning** ✓ complete (2026-06-16)
-- [ ] **M4 — Native clients** (Windows C#, macOS/iOS Swift) ← next
-- [ ] **M5 — Moderation, polish, beyond** (perms, bans, DRED; then file transfer, E2EE, …)
 
----
+## Release gates
 
-## M0 — Scaffolding ✓ (completed)
+- Run real multi-person calls on Windows, macOS, and physical iOS hardware, including adaptive
+  20/40/60 ms buffering, duration-aware DRED/FEC, automatic packet-loss feedback, and mismatched
+  input/output endpoints.
+- Complete NVDA and VoiceOver navigation/announcement passes.
+- Verify iOS remote-user tuning and private-conversation navigation with VoiceOver, including
+  multiple streams, users without active streams, and users who disconnect while a view is open.
+- Exercise iOS background/lock, interruption, Bluetooth, route-change, ReplayKit, and iOS 27
+  ScreenCaptureKit paths on devices. The background/lock gate keeps a call active for 15+ minutes
+  backgrounded and screen-locked with no periodic glitches and flat `VC_AUDIO` `feedDrops`/`starved`
+  counters (the render callback now paces the mix and the 20 ms capture handoff, and a watchdog
+  rebuilds a graph that stops calling back). Take a Siri or phone-call interruption while
+  backgrounded and confirm audio resumes without foregrounding. Complete a
+  30-minute iOS call and Wi-Fi/cellular switching with voice restoration, plus extended
+  mono/stereo/voice-chat switching while joined. Verify Windows desktop/per-app stereo sharing.
+- Complete Developer ID signing/notarization. The iOS host and ReplayKit extension have been
+  distribution-signed and packaged locally; upload the IPA for Apple's server-side validation.
+- Run the published Linux container and a 30-minute-or-longer server soak.
 
-- [x] Repo layout (`core/ server/ tools/ clients/ tests/`), CMake + presets, vcpkg manifest.
+## Working rule
-- [x] C ABI header `core/include/voicecat.h` (full surface, stubbed).
-- [x] Protocol source-of-truth `core/proto/voicecat.proto` (matches docs/protocol.md).
-- [x] Core stubs for all six subsystems (net/crypto/codec/protocol/session/audio) + `vc_client`.
-- [x] `voicecat-server` (arg parsing, config, stub run) and `vccli` (drives the C ABI).
-- [x] CTest **smoke test** asserting the C ABI contract (not just "it compiles").
-- [x] `.gitattributes` (LF), `.gitignore`, `.clang-format`, onboarding docs.
-- **Verified:** `cmake --preset dev && cmake --build --preset dev && ctest --preset dev` → green.
 
----
+Keep this file short. It records only current state and open release gates. Git history is the
-
+implementation diary.
-## M1 — Control plane ✓ (completed 2026-06-15)
-
-**Exit criterion:** ✓ `test_m1_integration` — two clients authenticate over TLS 1.3 (guest
-+ Argon2id password), exchange channel and private text messages. Passes in ~1 s.
-
-- [x] vcpkg baseline + `m1-dev` preset; `find_package` for protobuf/mbedTLS/libsodium/asio/sqlite3.
-- [x] `FrameCodec` feed + emit; `encode_envelope` / `decode_envelope`.
-- [x] Asio TCP acceptor + `TcpServerConn` (TLS path: blocking handshake thread + `tls_read_loop`).
-- [x] `TlsContext` (mbedTLS 1.3, server cert/identity, ECDSA-P256 self-signed, TOFU on client).
-- [x] `WorkerPool` (3 threads, used for Argon2id).
-- [x] `Database` — SQLite, Argon2id via libsodium, `create_account` / `authenticate` / bootstrap admin.
-- [x] `voicecat-admin` — account add/reset/del/list against live DB file.
-- [x] `ServerIdentityManager` — generate/persist Ed25519 key + cert; fingerprint display.
-- [x] `ConnSession` — WaitingHello → WaitingAuth → Authenticated state machine; full protocol relay.
-- [x] `SessionRegistry` — channel tree, user map, broadcast, text routing.
-- [x] `vc_client` (`client.cpp`) — full M1 C ABI: connect/TLS/ClientHello/AuthRequest/text/disconnect.
-- [x] `Server::run()` — io_context, acceptor, worker pool, signal handling, `on_ready` callback.
-- [x] `test_m1_integration` — M1 exit criterion. Verified green 2026-06-15.
-
-**Key bug fixed:** double-framing in `ConnSession::send_envelope` — `encode_envelope` was
-pre-framing the protobuf, then `TcpServerConn::send_frame` re-framed it. Fixed by serializing
-raw protobuf bytes directly and letting `send_frame` add the single `[4-byte len]` prefix.
-
----
-
----
-
-## M2 — Voice, single stream ✓ (completed 2026-06-16)
-
-**Exit criterion:** ✓ `test_m2_voice` — two headless clients authenticate over TLS, bind UDP,
-announce a MIC stream, send 50 encrypted Opus frames; server SFU relay re-encrypts + forwards
-to the second client; B receives ≥ 25 frames and all decrypt correctly. Passes in ~4 s.
-
-- [x] `m2-dev` preset (inherits `vcpkg-base`, binaryDir `build/m2-dev`); `m1-dev` also builds all M2 code.
-- [x] `core/CMakeLists.txt` — `find_package(Opus)`, `find_path(MINIAUDIO_INCLUDE_DIR)`.
-- [x] `core/src/net/voice_frame.h` — 14-byte UDP header (type/flags/codec/ssrc/seq/ts), serialize/parse, `make_udp_binding_packet`.
-- [x] `SodiumMediaCrypto` — ChaCha20-Poly1305 AEAD; counter-nonce; 64-bit sliding-window anti-replay; `derive_send/recv` from TLS RFC 5705 exporter.
-- [x] `OpusEncoder` / `OpusDecoder` — libopus 1.6, FEC, DTX, PLC (free; nullptr → decoder extrapolates).
-- [x] `UdpMediaChannel` — async UDP socket (asio); thread-safe `send_to`; async recv loop.
-- [x] `JitterBuffer` — per-ssrc, EWMA jitter estimation, adaptive depth 20–200 ms, late-drop at 500 ms.
-- [x] `AudioEngine` — miniaudio capture+playback; `inject_capture()` bypass for headless tests; per-ssrc RemoteStream with OpusDecoder + JitterBuffer.
-- [x] `ApmProcessor` — `ApmPassthrough` stub (VAD always open); WebRTC APM deferred until M3.
-- [x] `on_tls_ready` callback in `TcpChannelCallbacks` — server derives and stores media AEAD keys immediately after TLS handshake.
-- [x] `ConnSession` M2 — `udp_token` generated at construction; included in `AuthResult`; `handle_udp_binding` (verifies token, TCP ack); `handle_stream_announce` (assigns SSRC via registry); `udp_media_port` in `ServerHello`.
-- [x] `SessionRegistry` M2 — `register_udp_token`, `find_by_udp_token`, `register_udp_endpoint`, `find_by_udp_endpoint`, `assign_ssrc`, `find_channel_sessions`, `user_channel`.
-- [x] `MediaRelay` — SFU UDP relay; `kFrameUdpBinding` → endpoint binding; `kFrameVoice` → decrypt/re-encrypt/forward to channel members.
-- [x] `Server::run()` — creates and binds `MediaRelay`; passes media port to `ConnSession`; wires `on_tls_ready` to derive per-connection media AEAD keys.
-- [x] `test_voice_frame` — header round-trip, big-endian layout, binding packet format.
-- [x] `test_media_aead` — seal/open round-trip, anti-replay, tamper detection, multi-packet sequence.
-- [x] `test_opus_codec` — encode/decode round-trip energy check (within 3 dB), PLC, frame-samples helper.
-- [x] `test_m2_voice` — M2 exit criterion (raw-socket harness). Verified green 2026-06-16.
-
-**Follow-up (same day):** the above made `test_m2_voice` pass, but `vc_client`'s public voice
-methods were still stubs — the *actual* M2 exit criterion ("two vccli/early-GUI clients talk")
-wasn't met. Closed the gap:
-
-- [x] `core/src/core/client.cpp` — real `stream_start`/`stream_stop`/`set_self_mute`/
-  `set_remote_stream`; UDP-binding handshake (`start_udp_binding`/`handle_udp_binding_ack`/
-  `finish_udp_binding`); media key derivation from `tls_` (RFC 5705 exporter); `run_udp_recv`
-  (AEAD-open → `JitterBuffer::Frame` → `audio_engine_.push_recv_frame`); `on_capture_frame`
-  (encode → seal → `sendto`); `sync_remote_streams` (diffs a `User` proto's `streams` against
-  `remote_streams_`, wiring up `OpusDecoder`s and emitting `STREAM_STARTED`/`STOPPED`).
-  `set_input_device`/`set_input_mode`/`set_push_to_talk`/`list_devices` remain
-  `VC_ERR_NOT_IMPLEMENTED` — no device-enumeration backend yet; scoped to M3 (VAD/PTT).
-- [x] `core/src/session/session.cpp/h` — `SessionModel::find_user`, `find_user_by_ssrc`,
-  `Stream{stream_id, ssrc, kind, label, sample_rate, frame_ms}`.
-- [x] `server/src/conn_session.cpp/h` — `handle_stream_announce`/`handle_stream_stop` now
-  broadcast via `SessionRegistry::set_user_stream`/`clear_user_stream` → `UserEvent::UPDATED`.
-- [x] `server/src/session_registry.cpp/h` — `set_user_stream`/`clear_user_stream` (mutate a
-  user's `StreamInfo` list, return the updated `User` proto for broadcast).
-- [x] `tests/test_voice_client_abi.cpp` — drives two real `vc_client` instances through
-  `vc_connect`/`vc_authenticate_guest`/`vc_stream_start`/`vc_stream_stop`; asserts client B
-  observes client A's `STREAM_STARTED`/`STOPPED` events. Verified green 2026-06-16.
-- [x] `tools/vccli/src/main.cpp` — argv parsing (`--host/--port/--nick/--channel/--voice/
-  --mute/--text`); `--voice` starts a MIC stream and blocks on SIGINT, printing `on_event`
-  callbacks live (unbuffered stdout — MinGW/MSVCRT treat `_IOLBF` as full buffering for
-  non-console streams). Dropped the originally-planned `--voice-loopback` and the
-  `tx=N rx=M lost=K jitter=J` stats line: `voicecat.h` exposes no PCM-injection hook or
-  jitter/loss stats getter publicly, only `on_event` + `on_level` (RMS). Manually verified:
-  two `vccli --voice` instances see each other's stream start in real time.
-
----
-
-## M3 — Multi-stream & per-channel tuning ✓ (completed 2026-06-16)
-
-**Exit criterion:** ✓ `test_m3_multistream` — a real `vc_client` (A) runs two concurrent local
-streams (MIC + SCREEN_AUDIO) with distinct stream ids; a second client (B) sees both as
-separate `STREAM_STARTED` events and a `VC_EVENT_TALK_STATE` talking edge for A's MIC stream;
-B independently sets gain/mute/noise-reduction on each of A's streams without one call
-affecting the other; A then joins "Music Room" (channel 2: stereo/128kbps/`OPUS_AUDIO`/no
-DTX) and announces a fresh MIC stream there, while B stays in "Lobby" (channel 1: mono/24kbps/
-`OPUS_VOIP`/DTX on) — `vc_get_stream_audio_config` shows their effective Opus config differs
-exactly as the server enforces per channel. Passes in ~2.4s; verified across 8 consecutive
-standalone runs + 3 consecutive full-suite runs with no flakes.
-
-Exploration before implementing turned up several bugs/gaps where the wire format already
-supported this milestone but the client/server logic didn't — these were fixed as part of M3,
-not treated as pre-existing-and-out-of-scope:
-
-- [x] **Server `stream_id` bug** — `handle_stream_announce` always wrote `stream_id=1`, so a
-  second stream from the same user silently overwrote the first in
-  `SessionRegistry::set_user_stream`'s replace-by-id logic. Fixed with a per-session counter
-  (`ConnSession::next_stream_id_`) + `announced_stream_ids_` (also now validated in
-  `handle_stream_stop`, rejecting stops for ids the session never announced).
-- [x] **Per-channel `AudioConfig` was modeled but never populated/enforced.**
-  `SessionRegistry::init_default_channels()` now seeds Lobby (id=1: mono, 24kbps, `OPUS_VOIP`,
-  FEC+DTX on) and a new "Music Room" (id=2: stereo, 128kbps, `OPUS_AUDIO`, FEC+DTX off) with
-  real `AudioConfig`s; new `SessionRegistry::channel_audio_config(channel_id)` accessor (there
-  was no per-id channel getter before, only `channel_snapshot()`). `handle_stream_announce`
-  now treats the channel's config as authoritative (mode/frame_ms/application/fec/dtx/
-  complexity), clamping (not overriding) `bitrate_bps` to the channel's ceiling.
-- [x] **Client silently dropped `mode`/`dtx`/`complexity`/`application` from `effective_audio`**
-  even for the single M2 stream — `handle_stream_announce_result` and `sync_remote_streams`
-  only copied `sample_rate`/`bitrate_bps`/`frame_ms`/`fec` into `OpusParams`. New shared
-  `opus_params_from_audio_config()` helper (`client.cpp`) fixes both the send and receive
-  paths.
-- [x] `core/src/codec/opus_codec.h/.cpp` — new `OpusApplication` enum + `OpusParams::application`
-  field; `OpusEncoder::init` now honors it instead of hardcoding `OPUS_APPLICATION_VOIP`.
-- [x] `core/src/session/session.h/.cpp` — `Stream` struct extended with the full `AudioConfig`
-  (mode/bitrate_bps/application/fec/expected_packet_loss/dtx/complexity), not just
-  sample_rate/frame_ms; `copy_streams()` now copies all of it.
-- [x] `core/src/core/client.h/.cpp` — local-stream state is now a `std::unordered_map<int,
-  LocalStream>` keyed by `vc_stream_kind` (one active stream per kind — MIC/SCREEN_AUDIO/
-  AUX_DEVICE are each singletons for a client), replacing the M2 single-stream fields.
-  `StreamAnnounce`/`StreamAnnounceResult` round-trips are now correlated by `request_id`
-  (already round-tripped on the wire; just wasn't read) via `pending_announce_kind_`, so
-  multiple concurrent announces from one client resolve to the right `LocalStream`.
-  `on_capture_frame` takes a `kind` parameter and upmixes mono capture to stereo (duplicate
-  L=R) when a stream's channel config calls for it. `vc_set_self_mute`'s `mic_muted` only
-  gates the `MIC` kind — a concurrent `SCREEN_AUDIO` share keeps playing while muted.
-  `set_remote_stream` now actually wires `noise_reduction` through (previously parsed and
-  discarded). New `run_talk_timer()` (a small dedicated thread, started alongside the UDP
-  media path, never the miniaudio callback thread) polls both remote talk-state edges
-  (`AudioEngine::poll_talk_transitions()`) and local capture-activity edges, emitting
-  `VC_EVENT_TALK_STATE`.
-- [x] **Fixed a thread-join race in `teardown_voice()`** — it's called both from `run_io()`'s
-  own cleanup and from `disconnect()`, on different threads; without serialization both could
-  see `udp_thread_`/`talk_timer_thread_` as `joinable()` simultaneously and race to `join()`
-  the same `std::thread` (UB; surfaced as an intermittent `std::system_error: No such process`
-  under `ctest`). Added a `teardown_mu_` guard around the whole function. This pre-existed for
-  `udp_thread_` alone (likely the same root cause as the `test_m1_integration`/`test_m2_voice`
-  cleanup-path flake noted in the M2 section above) — adding `talk_timer_thread_`'s join just
-  made it surface more often, so it was fixed properly here rather than carried forward again.
-- [x] `core/src/audio/audio_engine.h/.cpp` — `CaptureCallback` gained a `kind` parameter
-  (the real miniaudio capture device is always tagged `kind=0`/MIC; a second concurrent local
-  stream is fed via its own `inject_capture(kind, ...)` ring buffer — `inject_taps_`, keyed by
-  kind — since there is only one real hardware capture device in M3). Fixed a buffer-sizing
-  bug in `on_playback`'s per-stream decode (`opus_decode`'s `frame_size` parameter is
-  samples-*per-channel*, not total samples — the old code passed `frames * params_.channels`,
-  which would have overflowed the decode buffer for any stereo stream). Stereo decoder output
-  is downmixed (avg L/R) into the engine's mono mix accumulator immediately after decode.
-  `RemoteStream` gained `recv_ns`/`noise_reduction_enabled` (lazy `ApmProcessor` instantiation
-  — freed on disable, so no separate instance cap is needed per the roadmap's guidance) and
-  `last_voice_ms`/`talking` (talk-indicator edge state, updated in `push_recv_frame`); new
-  `set_stream_noise_reduction()` and `poll_talk_transitions()`. Note: until `VOICECAT_HAS_APM`
-  is wired to a real WebRTC APM build, the NS toggle is plumbed end-to-end but behaviorally a
-  passthrough no-op (`ApmPassthrough` doesn't touch PCM) — same situation send-side APM has
-  been in since M2; M3's job was the plumbing, not the DSP backend.
-- [x] **New C ABI surface** (`core/include/voicecat.h`, additive only):
-  `vc_audio_config` struct + `vc_get_stream_audio_config(c, user_id, stream_id, out)` — the
-  effective Opus config for a stream you own or a peer's, reading from the (now richer)
-  `LocalStream`/`session::Stream`. `vc_test_inject_capture(c, stream_id, pcm, samples)` —
-  clearly-marked **test-only**, forwards to `AudioEngine::inject_capture`, so
-  `test_m3_multistream` can drive two concurrent synthetic-audio streams through the real ABI
-  without a microphone.
-- [x] `tests/test_m3_multistream.cpp` — the M3 exit criterion (ABI-level, mirrors
-  `test_voice_client_abi.cpp`'s approach per the M2 lesson). Registered in `tests/CMakeLists.txt`.
-
-**Explicitly out of scope for this pass** (confirmed with the user before implementing):
-- `vc_set_input_device`/`vc_set_input_mode`/`vc_set_push_to_talk`/`vc_list_devices` (device
-  enumeration + VAD/PTT input gate) — still `VC_ERR_NOT_IMPLEMENTED`. These were mentioned as
-  "scoped to M3" in the M2 follow-up notes above, but docs/roadmap.md's M3 bullets never
-  actually listed them — deferred again, now tracked explicitly rather than implicitly.
-- Real WASAPI desktop-audio loopback capture for `SCREEN_AUDIO` — the engine now supports
-  feeding a second concurrent local stream via `inject_capture`, but only synthetic PCM is
-  wired up; a real loopback capture device is a follow-up.
-- True stereo *playback output* — `AudioEngine`'s mixer/output device stays mono; stereo
-  streams are downmixed after decode (see above). The Opus wire format itself is fully
-  stereo-correct.
-
----
-
-## Decisions log
-
-All architecture/scope decisions are settled and recorded in
-[docs/roadmap.md §2 "Resolved decisions"](docs/roadmap.md) and reflected across `docs/`.
-If you make a *new* decision, record it there and link it here.
-
----
-
-## How to update this file
-
-1. Check off tasks as you complete them; flip a milestone to `[x]` only when its **exit
-   criterion test** passes.
-2. Keep the **"Where we left off / next action"** block at the top accurate — it's the first
-   thing the next agent reads.
-3. When you start a milestone, copy its task list from `docs/roadmap.md` into a section here.

README.md

@@ -1,58 +1,42 @@
 # VoiceCat
 
-Self-hosted, native voice & text chat in the spirit of classic TeamSpeak / Mumble —
+VoiceCat is a self-hosted, channel-based voice and text chat system built on .NET 10. It uses
-channel-based voice, channel + private text, one server you run yourself. Plain **TCP**
+TLS 1.3 for protobuf control traffic and authenticated encrypted UDP for Opus media. There is
-(control) and **UDP** (media), no WebRTC. Encrypted by default. A shared **C++ core**
+no WebRTC, central directory, or plaintext mode.
-(`libvoicecat`) drives native clients (Swift on macOS/iOS, C# on Windows) and the server.
 
-> **Status: pre-implementation.** The design is complete in [`docs/`](docs/). The code is an
+The repository contains a managed server, CLI, shared client/audio core, and native Windows,
-> M0 **skeleton** — it compiles and links, but every subsystem is a stub. See
+macOS, and iOS user interfaces. A small C library supplies Opus/RNNoise, and a small Swift iOS
-> [`AGENTS.md`](AGENTS.md) to start building, and [`docs/roadmap.md`](docs/roadmap.md) for the
+extension captures ReplayKit application audio.
-> milestones.
 
-## Read the design first
+## Build
-
-The [`docs/`](docs/) folder is the source of truth. Start at [`docs/README.md`](docs/README.md),
-then `architecture` → `protocol` → `voice` → `security` → `tech-stack` → `deployment` →
-`roadmap`.
-
-## Build the skeleton (no dependencies needed yet)
-
-The M0 skeleton builds with just a C++20 compiler + CMake + Ninja — **no vcpkg, no
-third-party libraries**, because every subsystem is currently a stub.
 
 ```bash
-cmake --preset dev
+./scripts/build-native.ps1
-cmake --build --preset dev
+dotnet restore VoiceCat.slnx --locked-mode
-ctest --preset dev            # runs the smoke test (links the core, calls the C ABI)
+dotnet build VoiceCat.slnx -c Release --no-restore
+dotnet test VoiceCat.slnx -c Release --no-build
 ```
 
-Artifacts land in `build/dev/bin/` (`voicecat-server`, `vccli`).
+See [CLAUDE.md](CLAUDE.md) for the developer map, [docs/README.md](docs/README.md) for current
-
+contracts, and [PROGRESS.md](PROGRESS.md) for the short release handoff.
-When you start implementing a subsystem that needs real libraries, build with vcpkg deps:
-
-```bash
-# one-time: git clone https://github.com/microsoft/vcpkg && ./vcpkg/bootstrap-vcpkg.sh
-export VCPKG_ROOT=/path/to/vcpkg            # set VCPKG_ROOT (works on Linux/macOS/Windows)
-cmake --preset server-release               # auto-installs deps from vcpkg.json
-cmake --build --preset server-release
-```
 
 ## Layout
 
-```
+```text
-docs/         design spec (read this)
+proto/                    protobuf wire schema
-core/         libvoicecat — the shared C++ core
+src/                      managed protocol, crypto, server, client, audio, and CLI
-  include/    voicecat.h  (the C ABI all clients call)
+tests/                    managed behavior and integration tests
-  proto/      voicecat.proto  (control-plane wire format, source of truth)
+clients/windows/          WinForms client
-  src/        net/ crypto/ codec/ protocol/ session/ audio/  (stubs today)
+clients/apple/            AppKit and UIKit clients
-server/       voicecat-server (headless; links the core)
+native/media/             narrow Opus/RNNoise C shim
-tools/vccli/  headless test client — drives the protocol from M1 on
+native/rnnoise/           vendored RNNoise source and model
-clients/      apple/ (Swift, M4)   windows/ (C#, M4)   — placeholders for now
+native/apple/broadcast/   ReplayKit broadcast extension
-tests/        CTest targets
+docs/                     current contracts and operating documentation
 ```
 
-## License
+## Non-negotiable constraints
 
-Permissive-only dependencies (no GPL/LGPL) so the project can be redistributed freely,
+- Encryption is mandatory.
-including closed-source. Project license: TBD (see [`docs/tech-stack.md`](docs/tech-stack.md) §5).
+- No GPL or LGPL dependencies.
+- Real-time audio callbacks never allocate, lock, block, or perform I/O.
+- Accessibility is a release requirement on every client platform.

VoiceCat.slnx

@@ -0,0 +1,18 @@
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/VoiceCat.Protocol/VoiceCat.Protocol.csproj" />
+    <Project Path="src/VoiceCat.Crypto/VoiceCat.Crypto.csproj" />
+    <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" />
+    <Project Path="src/VoiceCat.Cli/VoiceCat.Cli.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/VoiceCat.Tests/VoiceCat.Tests.csproj" />
+  </Folder>
+  <Folder Name="/clients/">
+    <Project Path="clients/windows/VoiceCat.Windows/VoiceCat.Windows.csproj" />
+  </Folder>
+</Solution>

clients/apple/README.md

@@ -1,19 +1,45 @@
-# Apple client (macOS + iOS) — placeholder
+# Apple clients
 
-Built in **M4** (see [`docs/roadmap.md`](../../docs/roadmap.md)). Swift + SwiftUI, consuming
+`VoiceCat.Mac` and `VoiceCat.iOS` are .NET 10 AppKit and UIKit clients over the shared managed
-`libvoicecat` through the C ABI ([`core/include/voicecat.h`](../../core/include/voicecat.h)).
+core. The ReplayKit upload extension under `native/apple/broadcast` remains Swift because it
+runs under the extension memory limit and writes the versioned shared audio ring.
 
-Planned shape (see [`docs/architecture.md`](../../docs/architecture.md) §4 and
+Build on macOS with Xcode and the pinned .NET workloads:
-[`docs/tech-stack.md`](../../docs/tech-stack.md) §2):
 
-- A Swift Package wrapping the core as an **XCFramework** (macOS + iOS device + simulator).
+```bash
-- A module map exposing `voicecat.h` to Swift (Swift can also use C++ interop directly, but
+./scripts/build-native.ps1
-  the C ABI is the stable contract).
+./scripts/build-native-ios.sh
-- SwiftUI app target for macOS and iOS.
+dotnet restore clients/apple/VoiceCat.Apple.slnx
-- **iOS audio:** app owns `AVAudioSession` (`.playAndRecord` / `.voiceChat`), mic permission,
+dotnet build clients/apple/VoiceCat.Apple.slnx -c Debug --no-restore
-  interruption/route handling, calling `vc_audio_*` hooks on the core.
+```
-- **iOS screen/system audio (`SCREEN_AUDIO`):** a **ReplayKit Broadcast Upload Extension**
-  capturing `RPSampleBufferType.audioApp`, linking a minimal core slice, sharing session
-  state via an **App Group** ([`docs/voice.md`](../../docs/voice.md) §9).
 
-Nothing here yet — the core must reach M2 (working voice) before the GUI is worth building.
+Use `publish-macos.sh --dry-run` to validate a local ad-hoc macOS bundle. The dry-run build does
+not enable hardened runtime because ad-hoc signatures have no Team ID and cannot satisfy macOS
+library validation. The script normalizes nested signatures and installs the verified bundle at
+both `VoiceCat.Mac/bin/Release/net10.0-macos27.0/osx-arm64/VoiceCat.app` and
+`VoiceCat.Mac/bin/Release/distribution/VoiceCat.app`. Distribution builds remain hardened and
+require `VOICECAT_CODESIGN_IDENTITY`; optional notarization uses `APPLE_ID`, `APPLE_TEAM_ID`, and
+`APPLE_APP_PASSWORD`.
+
+For a physical iOS device, use `build-ios-device.sh` and `deploy-ios-device.sh`. The host and
+ReplayKit extension require signing profiles with App Group `group.me.iamtalon.voicecat`.
+Hardware validation must cover VoiceOver, background and lock behavior, interruptions, route
+changes, Bluetooth, ReplayKit, and iOS 27 ScreenCaptureKit audio.
+For iOS voice stability, leave a call joined with the microphone active for at least 30 minutes
+and confirm speech stays clear and `VC_AUDIO` reports no growing `feedDrops`. While still joined,
+toggle Wi-Fi off and on, switch between Wi-Fi and cellular, and confirm the app stays open,
+reconnects, and restores the voice session. Repeat with mono, stereo, and voice processing.
+
+The iOS remote-user manual gate must also cover Users → user detail → independent microphone and
+screen-audio gain/mute controls, microphone receive noise reduction, the no-active-stream state,
+and Private Chats → conversation → User/audio settings. Repeat the navigation with VoiceOver and
+disconnect the remote user while its detail and conversation views are open.
+
+App Store builds use the same device builder with `--configuration Release`. Set
+`VOICECAT_BUILD_NUMBER`, `VOICECAT_DISPLAY_VERSION`, `VOICECAT_DEVELOPMENT_TEAM`, the host
+`VOICECAT_CODESIGN_KEY`/`VOICECAT_CODESIGN_PROVISION` pair, and the extension
+`VOICECAT_BROADCAST_CODESIGN_KEY`/`VOICECAT_BROADCAST_CODESIGN_PROVISION` pair. The host and
+extension profiles must both be App Store Connect profiles and include the shared App Group.
+
+The complete TestFlight workflow is documented in `docs/apple-ios-release.md`. The shared ring
+contract is documented in `docs/broadcast-ring-format.md`.

clients/apple/VoiceCat.Apple.slnx

@@ -0,0 +1,14 @@
+<Solution>
+  <Folder Name="/apps/">
+    <Project Path="VoiceCat.Mac/VoiceCat.Mac.csproj" />
+    <Project Path="VoiceCat.iOS/VoiceCat.iOS.csproj" />
+  </Folder>
+  <Folder Name="/managed/">
+    <Project Path="../../src/VoiceCat.Protocol/VoiceCat.Protocol.csproj" />
+    <Project Path="../../src/VoiceCat.Crypto/VoiceCat.Crypto.csproj" />
+    <Project Path="../../src/VoiceCat.Codec/VoiceCat.Codec.csproj" />
+    <Project Path="../../src/VoiceCat.Dsp/VoiceCat.Dsp.csproj" />
+    <Project Path="../../src/VoiceCat.Audio/VoiceCat.Audio.csproj" />
+    <Project Path="../../src/VoiceCat.Core/VoiceCat.Core.csproj" />
+  </Folder>
+</Solution>

clients/apple/VoiceCat.Mac/AdministrationWindowController.cs

@@ -0,0 +1,166 @@
+using AppKit;
+using CoreGraphics;
+using VoiceCat.Core;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.Mac;
+
+internal sealed class AdministrationWindowController : NSWindowController
+{
+    private readonly VoiceCatClient client;
+    private readonly uint selfId;
+    private readonly NSPopUpButton users = new(new CGRect(25, 335, 310, 28), false);
+    private readonly NSPopUpButton channels = new(new CGRect(25, 175, 310, 28), false);
+    private readonly NSTextField status = NSTextField.CreateLabel("");
+
+    internal AdministrationWindowController(VoiceCatClient client, uint selfId) : base(new NSWindow(new CGRect(0, 0, 560, 420),
+        NSWindowStyle.Titled | NSWindowStyle.Closable, NSBackingStore.Buffered, false))
+    {
+        this.client = client; this.selfId = selfId; Window!.Title = "VoiceCat Administration"; Window.Center();
+        NSView view = Window.ContentView!;
+        AddLabel(view, "User moderation", 25, 375); view.AddSubview(users);
+        AddButton(view, "Move…", 350, 333, Move); AddButton(view, "Kick…", 440, 333, Kick);
+        AddButton(view, "Ban…", 350, 293, Ban); AddButton(view, "Permissions…", 440, 293, Permissions);
+        AddButton(view, "Server mute", 350, 253, ServerMute); AddButton(view, "Server deafen", 440, 253, ServerDeafen);
+        AddButton(view, "Audio tuning…", 25, 253, Tune);
+        AddLabel(view, "Channel administration", 25, 215); view.AddSubview(channels);
+        AddButton(view, "Create…", 350, 173, CreateChannel); AddButton(view, "Edit…", 440, 173, EditChannel);
+        AddButton(view, "Delete", 350, 133, DeleteChannel); AddButton(view, "Accounts…", 440, 133, Accounts);
+        var refresh = new NSButton(new CGRect(25, 75, 100, 32)) { Title = "Refresh" }; refresh.Activated += (_, _) => Refresh(); view.AddSubview(refresh);
+        status.Frame = new CGRect(25, 25, 510, 35); status.AccessibilityLabel = "Administration result"; view.AddSubview(status);
+        ((INSAccessibility)users).AccessibilityLabel = "User to administer"; ((INSAccessibility)channels).AccessibilityLabel = "Channel to administer";
+        Refresh(); ApplyPermissions();
+    }
+
+    private void Refresh()
+    {
+        uint selectedUser = Selected(users), selectedChannel = Selected(channels);
+        users.RemoveAllItems(); foreach (User user in client.Users.Where(user => user.Id != selfId).OrderBy(user => user.Nickname)) Add(users, user.Nickname, user.Id);
+        channels.RemoveAllItems(); foreach (Channel channel in client.Channels.OrderBy(channel => channel.Order).ThenBy(channel => channel.Name)) Add(channels, channel.Name, channel.Id);
+        Select(users, selectedUser); Select(channels, selectedChannel);
+    }
+
+    private void ApplyPermissions()
+    {
+        Permissions permissions = client.Permissions;
+        status.StringValue = permissions.IsAdmin ? "Connected as administrator" : "Only actions allowed by your server permissions will succeed.";
+    }
+
+    private async void Move(object? sender, EventArgs args)
+    {
+        uint userId = Selected(users); if (userId == 0) return;
+        string[] names = client.Channels.Select(channel => channel.Name).ToArray(); int index = PromptChoice("Move user", "Destination channel", names); if (index < 0) return;
+        Show(await client.MoveUserAsync(userId, client.Channels[index].Id));
+    }
+    private async void Kick(object? sender, EventArgs args) { uint id = Selected(users); string? reason = PromptText("Kick user", "Reason", "Kicked by moderator"); if (id != 0 && reason is not null) Show(await client.KickUserAsync(id, reason)); }
+    private async void Ban(object? sender, EventArgs args)
+    {
+        uint id = Selected(users); if (id == 0) return;
+        string? reason = PromptText("Ban user", "Reason (append @1h, @1d, or @permanent)", "Banned by moderator @1d"); if (reason is null) return;
+        ulong expiry = 0; string lowered = reason.ToLowerInvariant();
+        if (lowered.EndsWith("@1h")) expiry = checked((ulong)DateTimeOffset.UtcNow.AddHours(1).ToUnixTimeMilliseconds());
+        else if (lowered.EndsWith("@1d")) expiry = checked((ulong)DateTimeOffset.UtcNow.AddDays(1).ToUnixTimeMilliseconds());
+        Show(await client.BanUserAsync(id, reason.Replace("@1h", "", StringComparison.OrdinalIgnoreCase).Replace("@1d", "", StringComparison.OrdinalIgnoreCase).Replace("@permanent", "", StringComparison.OrdinalIgnoreCase).Trim(), expiry));
+    }
+    private async void Permissions(object? sender, EventArgs args)
+    {
+        uint id = Selected(users); if (id == 0) return;
+        Permissions? permissions = PermissionEditor.Run(); if (permissions is not null) Show(await client.SetPermissionsAsync(id, permissions));
+    }
+    private async void ServerMute(object? sender, EventArgs args) { User? user = User(); if (user is not null) Show(await client.SetServerMuteAsync(user.Id, !user.ServerMuted, user.ServerDeafened)); }
+    private async void ServerDeafen(object? sender, EventArgs args) { User? user = User(); if (user is not null) Show(await client.SetServerMuteAsync(user.Id, user.ServerMuted, !user.ServerDeafened)); }
+    private void Tune(object? sender, EventArgs args) { User? user = User(); if (user is not null) PerUserTuning.Run(client, user); }
+    private async void CreateChannel(object? sender, EventArgs args) { ChannelEdit? edit = ChannelEditor.Run(null, client.Channels, client.SupportsAdaptivePacketLoss); if (edit is not null) { Show(await client.CreateChannelAsync(edit.Channel, edit.Password)); Refresh(); } }
+    private async void EditChannel(object? sender, EventArgs args) { Channel? channel = Channel(); if (channel is null) return; ChannelEdit? edit = ChannelEditor.Run(channel, client.Channels, client.SupportsAdaptivePacketLoss); if (edit is not null) { Show(await client.EditChannelAsync(edit.Channel, edit.Password)); Refresh(); } }
+    private async void DeleteChannel(object? sender, EventArgs args)
+    {
+        Channel? channel = Channel(); if (channel is null || channel.Id == 1) return;
+        if (!Confirm("Delete channel?", channel.Name)) return; Show(await client.DeleteChannelAsync(channel.Id)); Refresh();
+    }
+    private async void Accounts(object? sender, EventArgs args) => await AccountEditor.RunAsync(client);
+
+    private User? User() => client.Users.FirstOrDefault(user => user.Id == Selected(users));
+    private Channel? Channel() => client.Channels.FirstOrDefault(channel => channel.Id == Selected(channels));
+    private void Show(GenericResult result) { status.StringValue = result.Ok ? result.Message.Length == 0 ? "Operation completed." : result.Message : result.Message; Refresh(); }
+    private static void Add(NSPopUpButton picker, string title, uint id) { picker.AddItem(title); picker.LastItem!.RepresentedObject = new Foundation.NSString(id.ToString()); }
+    private static uint Selected(NSPopUpButton picker) => uint.TryParse(picker.SelectedItem?.RepresentedObject?.ToString(), out uint id) ? id : 0;
+    private static void Select(NSPopUpButton picker, uint id) { for (nint i = 0; i < picker.ItemCount; i++) if (picker.ItemAtIndex(i)?.RepresentedObject?.ToString() == id.ToString()) { picker.SelectItem(i); break; } }
+    private static void AddLabel(NSView view, string value, double x, double y) { NSTextField label = NSTextField.CreateLabel(value); label.Frame = new CGRect(x, y, 300, 22); label.Font = NSFont.BoldSystemFontOfSize(13)!; view.AddSubview(label); }
+    private static void AddButton(NSView view, string title, double x, double y, EventHandler handler) { var button = new NSButton(new CGRect(x, y, 95, 32)) { Title = title }; button.Activated += handler; view.AddSubview(button); }
+
+    internal static string? PromptText(string title, string prompt, string value = "", bool secure = false)
+    {
+        NSTextField field = secure ? new NSSecureTextField(new CGRect(0, 0, 340, 26)) : new NSTextField(new CGRect(0, 0, 340, 26)); field.StringValue = value;
+        var alert = new NSAlert { MessageText = title, InformativeText = prompt, AccessoryView = field }; alert.AddButton("OK"); alert.AddButton("Cancel");
+        return alert.RunModal() == 1000 ? field.StringValue : null;
+    }
+    internal static int PromptChoice(string title, string prompt, string[] values)
+    {
+        var picker = new NSPopUpButton(new CGRect(0, 0, 340, 28), false); picker.AddItems(values);
+        var alert = new NSAlert { MessageText = title, InformativeText = prompt, AccessoryView = picker }; alert.AddButton("OK"); alert.AddButton("Cancel");
+        return alert.RunModal() == 1000 ? checked((int)picker.IndexOfSelectedItem) : -1;
+    }
+    internal static bool Confirm(string title, string detail) { var alert = new NSAlert { MessageText = title, InformativeText = detail, AlertStyle = NSAlertStyle.Warning }; alert.AddButton("Continue"); alert.AddButton("Cancel"); return alert.RunModal() == 1000; }
+}
+
+internal sealed record ChannelEdit(Channel Channel, string Password);
+
+internal static class PermissionEditor
+{
+    internal static Permissions? Run()
+    {
+        string[] labels = ["Create temporary channels", "Kick users", "Ban users", "Move users", "Manage accounts", "Full administrator"];
+        var view = new NSView(new CGRect(0, 0, 330, 160)); var checks = new List<NSButton>();
+        for (int i = 0; i < labels.Length; i++) { NSButton check = NSButton.CreateCheckbox(labels[i], () => { }); check.Frame = new CGRect(0, 135 - i * 25, 320, 22); view.AddSubview(check); checks.Add(check); }
+        var alert = new NSAlert { MessageText = "Set permissions", AccessoryView = view }; alert.AddButton("Save"); alert.AddButton("Cancel"); if (alert.RunModal() != 1000) return null;
+        return new() { CanCreateTempChannel = On(0), CanKick = On(1), CanBan = On(2), CanMoveUsers = On(3), CanAdminAccounts = On(4), IsAdmin = On(5) };
+        bool On(int i) => checks[i].State == NSCellStateValue.On;
+    }
+}
+
+internal static class PerUserTuning
+{
+    internal static void Run(VoiceCatClient client, User user)
+    {
+        if (user.Streams.Count == 0) { AdministrationWindowController.PromptText("Audio tuning", "This user has no active streams."); return; }
+        var stream = new NSPopUpButton(new CGRect(0, 95, 340, 28), false); stream.AddItems(user.Streams.Select(value => $"{value.Label} ({value.Kind})").ToArray());
+        var gain = new NSSlider(new CGRect(0, 60, 340, 24)) { MinValue = 0, MaxValue = 400, DoubleValue = 100 };
+        var muted = NSButton.CreateCheckbox("Mute this stream", () => { }); muted.Frame = new CGRect(0, 30, 160, 24);
+        var noise = NSButton.CreateCheckbox("Receive noise reduction", () => { }); noise.Frame = new CGRect(170, 30, 170, 24);
+        var view = new NSView(new CGRect(0, 0, 340, 130)); view.AddSubview(stream); view.AddSubview(gain); view.AddSubview(muted); view.AddSubview(noise);
+        void LoadSelected()
+        {
+            if (stream.IndexOfSelectedItem < 0) return;
+            StreamInfo selected = user.Streams[checked((int)stream.IndexOfSelectedItem)];
+            (float Gain, bool Muted, bool NoiseReduction)? state = client.Audio.GetRemotePlayback(user.Id, selected.StreamId);
+            gain.DoubleValue = (state?.Gain ?? 1) * 100; muted.State = state?.Muted == true ? NSCellStateValue.On : NSCellStateValue.Off;
+            noise.State = state?.NoiseReduction == true ? NSCellStateValue.On : NSCellStateValue.Off;
+        }
+        stream.Activated += (_, _) => LoadSelected(); LoadSelected();
+        var alert = new NSAlert { MessageText = $"Audio — {user.Nickname}", InformativeText = "Stream, volume, mute, and receive noise reduction", AccessoryView = view };
+        alert.AddButton("Apply"); alert.AddButton("Cancel"); if (alert.RunModal() != 1000) return;
+        StreamInfo selected = user.Streams[checked((int)stream.IndexOfSelectedItem)]; client.Audio.SetRemotePlayback(user.Id, selected.StreamId, (float)gain.DoubleValue / 100,
+            muted.State == NSCellStateValue.On, noise.State == NSCellStateValue.On);
+    }
+}
+
+internal static class AccountEditor
+{
+    internal static async Task RunAsync(VoiceCatClient client)
+    {
+        IReadOnlyList<AccountEntry> accounts = await client.ListAccountsAsync();
+        string[] actions = ["Create account", "Reset password", "Delete account", "Close"];
+        int action = AdministrationWindowController.PromptChoice("Server accounts", string.Join("\n", accounts.Select(a => $"{a.Username}{(a.IsAdmin ? " (admin)" : "")}")), actions);
+        if (action is < 0 or 3) return;
+        if (action == 0)
+        {
+            string? name = AdministrationWindowController.PromptText("Create account", "Username"); if (string.IsNullOrWhiteSpace(name)) return;
+            string? password = AdministrationWindowController.PromptText("Create account", "Password", secure: true); if (!string.IsNullOrEmpty(password)) await client.CreateAccountAsync(name.Trim(), password);
+            return;
+        }
+        int selected = AdministrationWindowController.PromptChoice(action == 1 ? "Reset password" : "Delete account", "Account", accounts.Select(a => a.Username).ToArray()); if (selected < 0) return;
+        if (action == 1) { string? password = AdministrationWindowController.PromptText("Reset password", "New password", secure: true); if (!string.IsNullOrEmpty(password)) await client.ResetPasswordAsync(accounts[selected].Username, password); }
+        else if (AdministrationWindowController.Confirm("Delete account?", accounts[selected].Username)) await client.DeleteAccountAsync(accounts[selected].Username);
+    }
+}

clients/apple/VoiceCat.Mac/AppDelegate.cs

@@ -0,0 +1,22 @@
+using AppKit;
+using Foundation;
+
+namespace VoiceCat.Mac;
+
+internal sealed class AppDelegate : NSApplicationDelegate
+{
+    private ConnectWindowController? connect;
+    public override void DidFinishLaunching(NSNotification notification)
+    {
+        NSApplication.SharedApplication.ActivationPolicy = NSApplicationActivationPolicy.Regular;
+        BuildMenu();
+        connect = new(); connect.ShowWindow(this);
+    }
+    public override bool ApplicationShouldTerminateAfterLastWindowClosed(NSApplication sender) => true;
+    private static void BuildMenu()
+    {
+        var menu = new NSMenu(); var root = new NSMenuItem(); menu.AddItem(root);
+        var application = new NSMenu(); application.AddItem(new NSMenuItem("Quit VoiceCat", "q", (_, _) => NSApplication.SharedApplication.Terminate(null)));
+        root.Submenu = application; NSApplication.SharedApplication.MainMenu = menu;
+    }
+}

clients/apple/VoiceCat.Mac/ChannelEditor.cs

@@ -0,0 +1,68 @@
+using AppKit;
+using CoreGraphics;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.Mac;
+
+internal static class ChannelEditor
+{
+    internal static ChannelEdit? Run(Channel? existing, IReadOnlyList<Channel> channels, bool supportsAdaptivePacketLoss)
+    {
+        var view = new NSView(new CGRect(0, 0, 520, 500));
+        var name = Field(existing?.Name ?? "", 360); var topic = Field(existing?.Topic ?? "", 330);
+        var parent = Picker(channels.Select(channel => channel.Name).Prepend("No parent").ToArray(), 300);
+        int parentIndex = existing is null ? 0 : channels.ToList().FindIndex(channel => channel.Id == existing.ParentId) + 1; parent.SelectItem(Math.Max(0, parentIndex));
+        var type = Picker(["Permanent", "Temporary"], 270); type.SelectItem(existing?.Type == ChannelType.ChannelTemporary ? 1 : 0);
+        var maximum = Field((existing?.MaxUsers ?? 0).ToString(), 240); var order = Field((existing?.Order ?? 0).ToString(), 210);
+        var password = new NSSecureTextField(new CGRect(155, 180, 345, 24)) { PlaceholderString = existing?.PasswordProtected == true ? "Leave blank to preserve" : "Optional" };
+        var mode = Picker(["Mono", "Stereo"], 150); mode.SelectItem(existing?.Audio?.Mode == ChannelMode.ModeStereo ? 1 : 0);
+        var rate = Picker(["8000", "12000", "16000", "24000", "48000"], 120); Select(rate, (existing?.Audio?.SampleRate ?? 48000).ToString());
+        var frame = Picker(["5", "10", "20", "40", "60"], 90); Select(frame, (existing?.Audio?.FrameMs ?? 20).ToString());
+        var application = Picker(["VoIP", "Audio", "Low delay"], 60); application.SelectItem((int)(existing?.Audio?.Application ?? OpusApplication.OpusVoip));
+        var bitrate = Field((existing?.Audio?.BitrateBps ?? 64000).ToString(), 30);
+        Add(view, "Name", name, 360); Add(view, "Topic", topic, 330); Add(view, "Parent", parent, 300); Add(view, "Type", type, 270);
+        Add(view, "Maximum users (0=none)", maximum, 240); Add(view, "Sort order", order, 210); Add(view, "Password", password, 180);
+        Add(view, "Mode", mode, 150); Add(view, "Sample rate", rate, 120); Add(view, "Frame ms", frame, 90); Add(view, "Application", application, 60); Add(view, "Bitrate", bitrate, 30);
+
+        var advanced = new NSView(new CGRect(0, 0, 520, 175));
+        var automaticLoss = Check("Automatic packet loss", existing?.Audio?.PacketLossMode != PacketLossMode.PacketLossManual, 155, 140);
+        automaticLoss.Frame = new CGRect(155, 140, 200, 24);
+        automaticLoss.Enabled = supportsAdaptivePacketLoss;
+        var lossSpeed = Picker(["Fast", "Balanced", "Stable"], 105);
+        lossSpeed.SelectItem(existing?.Audio?.PacketLossMode switch { PacketLossMode.PacketLossAutoFast => 0, PacketLossMode.PacketLossAutoStable => 2, _ => 1 });
+        var loss = Field((existing?.Audio?.ExpectedPacketLoss ?? 5).ToString(), 70); loss.Frame = new CGRect(155, 70, 100, 24);
+        var complexity = Field((existing?.Audio?.Complexity ?? 10).ToString(), 40); complexity.Frame = new CGRect(155, 40, 100, 24);
+        var fec = Check("In-band FEC", existing?.Audio?.Fec ?? true, 0, 10); var dtx = Check("DTX", existing?.Audio?.Dtx ?? true, 130, 10);
+        var dred = Check("Deep redundancy", existing?.Audio?.Dred ?? false, 230, 10);
+        void UpdateLossControls() { loss.Enabled = !On(automaticLoss); lossSpeed.Enabled = supportsAdaptivePacketLoss && On(automaticLoss); }
+        automaticLoss.Activated += (_, _) => UpdateLossControls(); UpdateLossControls();
+        advanced.AddSubview(automaticLoss); Add(advanced, "Adaptation speed", lossSpeed, 105); Add(advanced, "Packet loss %", loss, 70); Add(advanced, "Complexity 0–10", complexity, 40);
+        advanced.AddSubview(fec); advanced.AddSubview(dtx); advanced.AddSubview(dred);
+        var container = new NSView(new CGRect(0, 0, 520, 690)); view.Frame = new CGRect(0, 180, 520, 500); container.AddSubview(view); container.AddSubview(advanced);
+        var alert = new NSAlert { MessageText = existing is null ? "Create channel" : "Edit channel", AccessoryView = container };
+        alert.AddButton(existing is null ? "Create" : "Save"); alert.AddButton("Cancel"); if (alert.RunModal() != 1000) return null;
+        if (string.IsNullOrWhiteSpace(name.StringValue) || !uint.TryParse(maximum.StringValue, out uint max) || !int.TryParse(order.StringValue, out int sort) ||
+            !uint.TryParse(rate.TitleOfSelectedItem, out uint sampleRate) || !uint.TryParse(frame.TitleOfSelectedItem, out uint frameMs) ||
+            !uint.TryParse(bitrate.StringValue, out uint bitrateValue) || !uint.TryParse(loss.StringValue, out uint packetLoss) ||
+            !uint.TryParse(complexity.StringValue, out uint complexityValue) || packetLoss > 100 || complexityValue > 10) return null;
+        uint parentId = parent.IndexOfSelectedItem <= 0 ? 0 : channels[checked((int)parent.IndexOfSelectedItem - 1)].Id;
+        return new(new Channel
+        {
+            Id = existing?.Id ?? 0, ParentId = parentId, Name = name.StringValue.Trim(), Topic = topic.StringValue.Trim(), MaxUsers = max, Order = sort,
+            Type = type.IndexOfSelectedItem == 1 ? ChannelType.ChannelTemporary : ChannelType.ChannelPermanent,
+            Audio = new AudioConfig { Codec = 0, Mode = mode.IndexOfSelectedItem == 1 ? ChannelMode.ModeStereo : ChannelMode.ModeMono,
+                SampleRate = sampleRate, FrameMs = frameMs, Application = (OpusApplication)(int)application.IndexOfSelectedItem, BitrateBps = bitrateValue,
+                Fec = On(fec), Dtx = On(dtx), Dred = On(dred), ExpectedPacketLoss = packetLoss, Complexity = complexityValue,
+                PacketLossMode = On(automaticLoss) ? lossSpeed.IndexOfSelectedItem switch
+                { 0 => PacketLossMode.PacketLossAutoFast, 2 => PacketLossMode.PacketLossAutoStable, _ => PacketLossMode.PacketLossAutoBalanced } : PacketLossMode.PacketLossManual }
+        }, password.StringValue);
+    }
+
+    private static NSTextField Field(string value, double y) => new(new CGRect(155, y, 345, 24)) { StringValue = value };
+    private static NSPopUpButton Picker(string[] values, double y) { var picker = new NSPopUpButton(new CGRect(155, y, 345, 26), false); picker.AddItems(values); return picker; }
+    private static NSButton Check(string title, bool value, double x, double y) { NSButton check = NSButton.CreateCheckbox(title, () => { }); check.Frame = new CGRect(x, y, 125, 24); check.State = value ? NSCellStateValue.On : NSCellStateValue.Off; return check; }
+    private static bool On(NSButton value) => value.State == NSCellStateValue.On;
+    private static void Add(NSView view, string label, NSView control, double y) { var text = NSTextField.CreateLabel(label); text.Frame = new CGRect(0, y + 2, 145, 20); view.AddSubview(text); view.AddSubview(control); ((INSAccessibility)control).AccessibilityLabel = label; }
+    private static void Select(NSPopUpButton picker, string value) { for (nint i = 0; i < picker.ItemCount; i++) if (picker.ItemTitle(i) == value) { picker.SelectItem(i); return; } }
+}

clients/apple/VoiceCat.Mac/ConnectWindowController.cs

@@ -0,0 +1,217 @@
+using AppKit;
+using CoreGraphics;
+using VoiceCat.Core;
+using VoiceCat.Crypto;
+
+namespace VoiceCat.Mac;
+
+internal sealed class ConnectWindowController : NSWindowController
+{
+    private static readonly string SupportDirectory = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "VoiceCat");
+    private readonly ServerProfileStore profileStore = new(Path.Combine(SupportDirectory, "servers.json"));
+    private readonly MacKeychainPasswordStore keychain = new();
+    private readonly NSPopUpButton profiles = new(new CGRect(120, 315, 330, 28), false);
+    private readonly NSTextField host = new(new CGRect(120, 270, 330, 26)) { StringValue = "127.0.0.1:8384", PlaceholderString = "Host:port" };
+    private readonly NSPopUpButton authentication = new(new CGRect(120, 225, 180, 28), false);
+    private readonly NSTextField identity = new(new CGRect(120, 180, 330, 26)) { StringValue = Environment.UserName };
+    private readonly NSTextField identityLabel;
+    private readonly NSSecureTextField password = new(new CGRect(120, 135, 330, 26)) { PlaceholderString = "Password" };
+    private readonly NSButton rememberPassword = NSButton.CreateCheckbox("Remember in Keychain", () => { });
+    private readonly NSTextField status = NSTextField.CreateLabel("Ready to connect");
+    private readonly NSButton save = new(new CGRect(120, 75, 90, 32)) { Title = "Save" };
+    private readonly NSButton remove = new(new CGRect(220, 75, 90, 32)) { Title = "Remove" };
+    private readonly NSButton connect = new(new CGRect(360, 75, 90, 32)) { Title = "Connect", BezelStyle = NSBezelStyle.Rounded };
+    private List<ServerProfile> saved = [];
+    private Guid? editingId;
+    private VoiceCatClient? client;
+    private MainWindowController? main;
+
+    internal ConnectWindowController() : base(new NSWindow(new CGRect(0, 0, 570, 390), NSWindowStyle.Titled | NSWindowStyle.Closable,
+        NSBackingStore.Buffered, false))
+    {
+        Window!.Title = "Connect to VoiceCat"; Window.Center();
+        var view = Window.ContentView!;
+        AddLabel(view, "Saved server", 25, 320); AddLabel(view, "Server", 25, 275); AddLabel(view, "Authentication", 25, 230);
+        identityLabel = AddLabel(view, "Nickname", 25, 185); AddLabel(view, "Password", 25, 140);
+        authentication.AddItem("Guest"); authentication.AddItem("Account"); authentication.Activated += AuthenticationChanged;
+        profiles.Activated += ProfileChanged;
+        ((INSAccessibility)profiles).AccessibilityLabel = "Saved servers";
+        ((INSAccessibility)host).AccessibilityLabel = "Server hostname and port";
+        ((INSAccessibility)authentication).AccessibilityLabel = "Authentication mode";
+        ((INSAccessibility)identity).AccessibilityLabel = "Guest nickname";
+        ((INSAccessibility)password).AccessibilityLabel = "Account password";
+        rememberPassword.Frame = new CGRect(310, 225, 180, 24);
+        ((INSAccessibility)rememberPassword).AccessibilityLabel = "Remember account password in Keychain";
+        view.AddSubview(profiles); view.AddSubview(host); view.AddSubview(authentication); view.AddSubview(identity); view.AddSubview(password); view.AddSubview(rememberPassword);
+        status.Frame = new CGRect(25, 30, 520, 24); status.AccessibilityLabel = "Connection status"; view.AddSubview(status);
+        ((INSAccessibility)save).AccessibilityLabel = "Save server profile"; save.Activated += SaveProfile; view.AddSubview(save);
+        ((INSAccessibility)remove).AccessibilityLabel = "Remove server profile"; remove.Activated += RemoveProfile; view.AddSubview(remove);
+        ((INSAccessibility)connect).AccessibilityLabel = "Connect to server"; connect.Activated += Connect; view.AddSubview(connect);
+        Window.DefaultButtonCell = connect.Cell;
+        ReloadProfiles(); UpdateAuthentication();
+    }
+
+    private static NSTextField AddLabel(NSView view, string text, double x, double y)
+    {
+        var label = NSTextField.CreateLabel(text); label.Frame = new CGRect(x, y, 90, 20); view.AddSubview(label); return label;
+    }
+
+    private void ReloadProfiles(Guid? select = null)
+    {
+        saved = profileStore.Load().ToList();
+        profiles.RemoveAllItems(); profiles.AddItem("New server…");
+        foreach (ServerProfile profile in saved) profiles.AddItem(profile.DisplayName);
+        int index = select is null ? (saved.Count == 0 ? 0 : 1) : saved.FindIndex(item => item.Id == select) + 1;
+        profiles.SelectItem(Math.Max(0, index));
+        ApplySelectedProfile();
+    }
+
+    private void ProfileChanged(object? sender, EventArgs args) => ApplySelectedProfile();
+
+    private void ApplySelectedProfile()
+    {
+        int index = checked((int)profiles.IndexOfSelectedItem) - 1;
+        if (index < 0 || index >= saved.Count)
+        {
+            editingId = null; remove.Enabled = false; password.StringValue = "";
+            rememberPassword.State = NSCellStateValue.Off; UpdateAuthentication(); return;
+        }
+        ServerProfile profile = saved[index]; editingId = profile.Id; remove.Enabled = true;
+        host.StringValue = FormatEndpoint(profile.Host, profile.Port);
+        authentication.SelectItem(profile.Authentication == ServerAuthentication.Guest ? 0 : 1);
+        identity.StringValue = profile.Authentication == ServerAuthentication.Guest ? profile.Nickname ?? Environment.UserName : profile.Username ?? "";
+        string? storedPassword = profile.Authentication == ServerAuthentication.Account
+            ? keychain.Load(profile.Id) ?? keychain.LoadLegacy(profile.LegacyKeychainTag) : null;
+        password.StringValue = storedPassword ?? "";
+        rememberPassword.State = storedPassword is null ? NSCellStateValue.Off : NSCellStateValue.On;
+        UpdateAuthentication();
+    }
+
+    private void AuthenticationChanged(object? sender, EventArgs args) => UpdateAuthentication();
+
+    private void UpdateAuthentication()
+    {
+        bool account = authentication.IndexOfSelectedItem == 1;
+        identityLabel.StringValue = account ? "Username" : "Nickname";
+        identity.PlaceholderString = account ? "Username" : "Nickname";
+        ((INSAccessibility)identity).AccessibilityLabel = account ? "Account username" : "Guest nickname";
+        password.Enabled = account;
+        rememberPassword.Enabled = account && editingId is not null;
+    }
+
+    private void SaveProfile(object? sender, EventArgs args)
+    {
+        try
+        {
+            ServerProfile profile = ReadProfile();
+            string pendingPassword = password.StringValue;
+            bool shouldRemember = rememberPassword.State == NSCellStateValue.On;
+            int index = saved.FindIndex(item => item.Id == profile.Id);
+            if (index < 0) saved.Add(profile); else saved[index] = profile;
+            if (profile.Authentication == ServerAuthentication.Guest || !shouldRemember) keychain.Remove(profile.Id);
+            profileStore.Save(saved); ReloadProfiles(profile.Id);
+            if (profile.Authentication == ServerAuthentication.Account && shouldRemember)
+            {
+                password.StringValue = pendingPassword;
+                rememberPassword.State = NSCellStateValue.On;
+            }
+            status.StringValue = "Server profile saved. Passwords are stored only after successful login.";
+        }
+        catch (Exception exception) { status.StringValue = exception.Message; }
+    }
+
+    private void RemoveProfile(object? sender, EventArgs args)
+    {
+        if (editingId is not { } id) return;
+        ServerProfile? profile = saved.FirstOrDefault(item => item.Id == id); if (profile is null) return;
+        var alert = new NSAlert { MessageText = "Remove server?", InformativeText = profile.DisplayName, AlertStyle = NSAlertStyle.Warning };
+        alert.AddButton("Remove"); alert.AddButton("Cancel"); if (alert.RunModal() != 1000) return;
+        keychain.Remove(profile.Id); saved.Remove(profile); profileStore.Save(saved); editingId = null; ReloadProfiles(); status.StringValue = "Server profile removed.";
+    }
+
+    private async void Connect(object? sender, EventArgs args)
+    {
+        if (client is not null) return;
+        try
+        {
+            SetBusy(true); status.StringValue = "Connecting…";
+            ServerProfile profile = ReadProfile();
+            string pins = Path.Combine(SupportDirectory, "tofu_pins.txt");
+            client = new("VoiceCat macOS", "0.1.0", pins);
+            await client.ConnectAsync(profile.Host, profile.Port, ConfirmIdentity);
+            string accountPassword = password.StringValue;
+            if (profile.Authentication == ServerAuthentication.Account && accountPassword.Length == 0)
+                accountPassword = keychain.Load(profile.Id) ?? keychain.LoadLegacy(profile.LegacyKeychainTag) ?? "";
+            if (profile.Authentication == ServerAuthentication.Account && accountPassword.Length == 0) throw new ArgumentException("Enter the account password.");
+            password.StringValue = "";
+            var result = profile.Authentication == ServerAuthentication.Guest
+                ? await client.AuthenticateGuestAsync(profile.Nickname ?? Environment.UserName)
+                : await client.AuthenticateUserAsync(profile.Username!, accountPassword);
+            if (!result.Ok) throw new InvalidOperationException(result.Error);
+            try
+            {
+                if (profile.Authentication == ServerAuthentication.Account && rememberPassword.State == NSCellStateValue.On) keychain.Save(profile.Id, accountPassword);
+                else keychain.Remove(profile.Id);
+            }
+            catch (Exception exception) { ShowKeychainWarning(exception.Message); }
+            main = new(client, result.Self.Id, result.Self.Nickname);
+            client = null; main.ShowWindow(this); Window.Close();
+        }
+        catch (Exception exception)
+        {
+            if (client is not null) await client.DisposeAsync(); client = null;
+            status.StringValue = exception.Message; SetBusy(false);
+        }
+    }
+
+    private ServerProfile ReadProfile()
+    {
+        (string serverHost, ushort port) = ParseEndpoint(host.StringValue);
+        bool account = authentication.IndexOfSelectedItem == 1;
+        string name = identity.StringValue.Trim();
+        return ServerProfile.Create(serverHost, port, account ? ServerAuthentication.Account : ServerAuthentication.Guest,
+            username: account ? name : null, nickname: account ? null : name, id: editingId);
+    }
+
+    private void SetBusy(bool busy)
+    {
+        profiles.Enabled = host.Enabled = authentication.Enabled = identity.Enabled = save.Enabled = connect.Enabled = !busy;
+        remove.Enabled = !busy && editingId is not null;
+        password.Enabled = !busy && authentication.IndexOfSelectedItem == 1;
+        rememberPassword.Enabled = !busy && authentication.IndexOfSelectedItem == 1 && editingId is not null;
+    }
+
+    private ValueTask<bool> ConfirmIdentity(ServerIdentityChallenge challenge, CancellationToken cancellationToken)
+    {
+        var completion = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+        NSApplication.SharedApplication.InvokeOnMainThread(() =>
+        {
+            var alert = new NSAlert { MessageText = challenge.Status == TofuStatus.FirstConnect ? "Trust this VoiceCat server?" : "Server identity changed",
+                InformativeText = $"{challenge.Host}:{challenge.Port}\n\nCertificate SHA-256:\n{challenge.CertificateFingerprint}", AlertStyle = challenge.Status == TofuStatus.Mismatch ? NSAlertStyle.Critical : NSAlertStyle.Informational };
+            alert.AddButton("Trust and connect"); alert.AddButton("Cancel"); completion.TrySetResult(alert.RunModal() == 1000);
+        });
+        return new(completion.Task.WaitAsync(cancellationToken));
+    }
+
+    private static void ShowKeychainWarning(string message)
+    {
+        var alert = new NSAlert
+        {
+            MessageText = "Password storage failed",
+            InformativeText = message + " You are still signed in, but the Keychain setting was not changed.",
+            AlertStyle = NSAlertStyle.Warning
+        };
+        alert.RunModal();
+    }
+
+    private static (string Host, ushort Port) ParseEndpoint(string value)
+    {
+        int separator = value.LastIndexOf(':');
+        if (separator <= 0 || !ushort.TryParse(value[(separator + 1)..], out ushort port) || port == 0) throw new ArgumentException("Enter a server as host:port.");
+        string parsedHost = value[..separator].Trim().Trim('[', ']');
+        if (parsedHost.Length == 0) throw new ArgumentException("Enter a server as host:port.");
+        return (parsedHost, port);
+    }
+
+    private static string FormatEndpoint(string serverHost, ushort port) => serverHost.Contains(':') ? $"[{serverHost}]:{port}" : $"{serverHost}:{port}";
+}

clients/apple/VoiceCat.Mac/CoreAudioDevices.cs

@@ -0,0 +1,113 @@
+using System.Runtime.InteropServices;
+using Foundation;
+using ObjCRuntime;
+using VoiceCat.Audio;
+
+namespace VoiceCat.Mac;
+
+internal static class CoreAudioDevices
+{
+    private const string CoreAudio = "/System/Library/Frameworks/CoreAudio.framework/CoreAudio";
+    private const uint SystemObject = 1;
+    private const uint Devices = 0x64657623;                 // 'dev#'
+    private const uint DefaultInput = 0x64496e20;            // 'dIn '
+    private const uint DefaultOutput = 0x644f7574;           // 'dOut'
+    private const uint StreamConfiguration = 0x736c6179;     // 'slay'
+    private const uint ObjectName = 0x6c6e616d;              // 'lnam'
+    private const uint ScopeGlobal = 0x676c6f62;             // 'glob'
+    private const uint ScopeInput = 0x696e7074;              // 'inpt'
+    private const uint ScopeOutput = 0x6f757470;             // 'outp'
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct PropertyAddress(uint selector, uint scope)
+    {
+        public uint Selector = selector;
+        public uint Scope = scope;
+        public uint Element;
+    }
+
+    [DllImport(CoreAudio)]
+    private static extern int AudioObjectGetPropertyDataSize(uint objectId, ref PropertyAddress address,
+        uint qualifierDataSize, nint qualifierData, out uint dataSize);
+
+    [DllImport(CoreAudio)]
+    private static extern int AudioObjectGetPropertyData(uint objectId, ref PropertyAddress address,
+        uint qualifierDataSize, nint qualifierData, ref uint dataSize, nint data);
+
+    internal static IReadOnlyList<AudioDeviceInfo> List(bool input)
+    {
+        uint defaultId = ReadUInt(SystemObject, input ? DefaultInput : DefaultOutput, ScopeGlobal);
+        var devices = new List<AudioDeviceInfo>();
+        foreach (uint id in ReadUIntArray(SystemObject, Devices, ScopeGlobal))
+        {
+            if (ChannelCount(id, input ? ScopeInput : ScopeOutput) == 0) continue;
+            string name = ReadString(id, ObjectName, ScopeGlobal) ?? $"Core Audio device {id}";
+            devices.Add(new(id.ToString(System.Globalization.CultureInfo.InvariantCulture), name, id == defaultId));
+        }
+        return devices.OrderByDescending(device => device.IsDefault).ThenBy(device => device.Name, StringComparer.CurrentCultureIgnoreCase).ToArray();
+    }
+
+    internal static uint ParseId(string? value)
+    {
+        if (!uint.TryParse(value, System.Globalization.NumberStyles.None, System.Globalization.CultureInfo.InvariantCulture, out uint id) || id == 0)
+            throw new ArgumentException("The selected Core Audio device is no longer available.", nameof(value));
+        return id;
+    }
+
+    private static uint ReadUInt(uint objectId, uint selector, uint scope)
+    {
+        var address = new PropertyAddress(selector, scope);
+        uint size = sizeof(uint);
+        nint memory = Marshal.AllocHGlobal(sizeof(uint));
+        try { return AudioObjectGetPropertyData(objectId, ref address, 0, 0, ref size, memory) == 0 ? unchecked((uint)Marshal.ReadInt32(memory)) : 0; }
+        finally { Marshal.FreeHGlobal(memory); }
+    }
+
+    private static uint[] ReadUIntArray(uint objectId, uint selector, uint scope)
+    {
+        var address = new PropertyAddress(selector, scope);
+        if (AudioObjectGetPropertyDataSize(objectId, ref address, 0, 0, out uint size) != 0 || size < sizeof(uint)) return [];
+        nint memory = Marshal.AllocHGlobal(checked((int)size));
+        try
+        {
+            if (AudioObjectGetPropertyData(objectId, ref address, 0, 0, ref size, memory) != 0) return [];
+            var result = new uint[size / sizeof(uint)];
+            for (int i = 0; i < result.Length; i++) result[i] = unchecked((uint)Marshal.ReadInt32(memory, i * sizeof(uint)));
+            return result;
+        }
+        finally { Marshal.FreeHGlobal(memory); }
+    }
+
+    private static int ChannelCount(uint deviceId, uint scope)
+    {
+        var address = new PropertyAddress(StreamConfiguration, scope);
+        if (AudioObjectGetPropertyDataSize(deviceId, ref address, 0, 0, out uint size) != 0 || size < 8) return 0;
+        nint memory = Marshal.AllocHGlobal(checked((int)size));
+        try
+        {
+            if (AudioObjectGetPropertyData(deviceId, ref address, 0, 0, ref size, memory) != 0) return 0;
+            int count = Marshal.ReadInt32(memory);
+            int first = IntPtr.Size == 8 ? 8 : 4;
+            int stride = IntPtr.Size == 8 ? 16 : 12;
+            int channels = 0;
+            for (int i = 0; i < count && first + i * stride + sizeof(uint) <= size; i++)
+                channels += Marshal.ReadInt32(memory, first + i * stride);
+            return channels;
+        }
+        finally { Marshal.FreeHGlobal(memory); }
+    }
+
+    private static string? ReadString(uint objectId, uint selector, uint scope)
+    {
+        var address = new PropertyAddress(selector, scope);
+        uint size = checked((uint)IntPtr.Size);
+        nint memory = Marshal.AllocHGlobal(IntPtr.Size);
+        try
+        {
+            if (AudioObjectGetPropertyData(objectId, ref address, 0, 0, ref size, memory) != 0) return null;
+            nint handle = Marshal.ReadIntPtr(memory);
+            return handle == 0 ? null : Runtime.GetNSObject<NSString>(handle, owns: false)?.ToString();
+        }
+        finally { Marshal.FreeHGlobal(memory); }
+    }
+}

clients/apple/VoiceCat.Mac/EventFeedback.cs

@@ -0,0 +1,49 @@
+using AVFoundation;
+using Foundation;
+
+namespace VoiceCat.Mac;
+
+internal enum SoundEvent { ChannelJoin, ChannelLeave, ChannelReceived, ChannelSent, PrivateReceived, PrivateSent, Login, Logout, ConnectionLost, VoiceOn, VoiceOff, VoiceStart, VoiceStop, PushToTalk }
+
+internal sealed class EventFeedback : IDisposable
+{
+    private readonly MacSettings settings;
+    private readonly AVSpeechSynthesizer speech = new();
+    private readonly Dictionary<SoundEvent, AVAudioPlayer> players = [];
+
+    internal EventFeedback(MacSettings settings) => this.settings = settings;
+
+    internal void Play(SoundEvent sound)
+    {
+        if (!settings.EventSounds || settings.EventVolume <= 0 ||
+            (sound is SoundEvent.VoiceStart or SoundEvent.VoiceStop && !settings.SelfTalkSounds) ||
+            (sound == SoundEvent.PushToTalk && !settings.PushToTalkSound)) return;
+        if (!players.TryGetValue(sound, out AVAudioPlayer? player))
+        {
+            string path = Path.Combine(NSBundle.MainBundle.ResourcePath ?? "", "Sounds", FileName(sound) + ".wav");
+            if (!File.Exists(path)) return;
+            player = AVAudioPlayer.FromUrl(NSUrl.FromFilename(path));
+            if (player is null) return;
+            player.PrepareToPlay(); players[sound] = player;
+        }
+        player.Volume = settings.EventVolume; player.CurrentTime = 0; player.Play();
+    }
+
+    internal void Speak(string text)
+    {
+        if (!settings.SpokenEvents || string.IsNullOrWhiteSpace(text)) return;
+        speech.SpeakUtterance(new AVSpeechUtterance(text.Trim()));
+    }
+
+    private static string FileName(SoundEvent value) => value switch
+    {
+        SoundEvent.ChannelJoin => "channel_join", SoundEvent.ChannelLeave => "channel_leave",
+        SoundEvent.ChannelReceived => "channel_recv", SoundEvent.ChannelSent => "channel_sent",
+        SoundEvent.PrivateReceived => "pm_recv", SoundEvent.PrivateSent => "pm_sent",
+        SoundEvent.Login => "login", SoundEvent.Logout => "logout", SoundEvent.ConnectionLost => "connection_lost",
+        SoundEvent.VoiceOn => "voice_on", SoundEvent.VoiceOff => "voice_off", SoundEvent.VoiceStart => "va_start",
+        SoundEvent.VoiceStop => "va_stop", _ => "ptt"
+    };
+
+    public void Dispose() { foreach (AVAudioPlayer player in players.Values) player.Dispose(); speech.Dispose(); }
+}

clients/apple/VoiceCat.Mac/Info.plist

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>CFBundleDisplayName</key><string>VoiceCat</string>
+  <key>CFBundleIdentifier</key><string>net.iamtalon.voicecat</string>
+  <key>CFBundleName</key><string>VoiceCat</string>
+  <key>CFBundleVersion</key><string>1</string>
+  <key>CFBundleShortVersionString</key><string>0.1.0</string>
+  <key>LSMinimumSystemVersion</key><string>14.0</string>
+  <key>NSMicrophoneUsageDescription</key><string>VoiceCat uses the microphone when you join voice and enable a microphone stream.</string>
+  <key>NSScreenCaptureUsageDescription</key><string>VoiceCat uses ScreenCaptureKit only when you share desktop or application audio.</string>
+  <key>NSPrincipalClass</key><string>NSApplication</string>
+</dict></plist>

clients/apple/VoiceCat.Mac/MacAudioBackend.cs

@@ -0,0 +1,243 @@
+using System.Runtime.InteropServices;
+using AudioUnit;
+using AVFoundation;
+using Foundation;
+using VoiceCat.Audio;
+
+namespace VoiceCat.Mac;
+
+internal sealed class MacAudioBackend : IAudioDeviceBackend
+{
+    private Exception? failure;
+
+    internal Exception? Failure => Volatile.Read(ref failure);
+
+    public IReadOnlyList<AudioDeviceInfo> Enumerate(bool input) => CoreAudioDevices.List(input);
+
+    public IAudioCapture OpenCapture(string? deviceId, bool loopback, CapturePcmHandler pcm)
+    {
+        if (loopback) throw new NotSupportedException("Screen audio uses ScreenCaptureKit, not microphone capture.");
+        return new Capture(deviceId, pcm, ReportFailure);
+    }
+
+    public IAudioPlayback OpenPlayback(string? deviceId = null)
+    {
+        return new Playback(deviceId, ReportFailure);
+    }
+
+    private void ReportFailure(Exception exception) => Interlocked.CompareExchange(ref failure, exception, null);
+
+    private sealed class Capture : IAudioCapture
+    {
+        private readonly CapturePcmHandler handler;
+        private readonly AVAudioEngine engine = new();
+        private readonly AVAudioFormat outputFormat;
+        private readonly AVAudioConverter converter;
+        private readonly AVAudioPcmBuffer converted;
+        private readonly AVAudioConverterInputHandler inputProvider;
+        private readonly Action<Exception> reportFailure;
+        private AVAudioPcmBuffer? pendingInput;
+        private bool inputProvided;
+        private int disposed;
+
+        internal Capture(string? deviceId, CapturePcmHandler handler, Action<Exception> reportFailure)
+        {
+            this.handler = handler;
+            this.reportFailure = reportFailure;
+            AVAudioInputNode input = engine.InputNode;
+            if (!string.IsNullOrEmpty(deviceId))
+            {
+                AudioUnitStatus status = input.AudioUnit!.SetCurrentDevice(CoreAudioDevices.ParseId(deviceId), AudioUnitScopeType.Global, 0);
+                if (status != AudioUnitStatus.NoError) throw new InvalidOperationException($"Core Audio input selection failed ({status}).");
+            }
+            AVAudioFormat inputFormat = input.GetBusOutputFormat(0);
+            uint channels = Math.Clamp(inputFormat.ChannelCount, 1u, 2u);
+            outputFormat = new(AVAudioCommonFormat.PCMInt16, 48_000, channels, true);
+            converter = new(inputFormat, outputFormat);
+            uint outputCapacity = checked((uint)Math.Ceiling(4_096 * 48_000 / inputFormat.SampleRate) + 64);
+            converted = new(outputFormat, outputCapacity);
+            inputProvider = ProvideInput;
+            NSError? tapError = null;
+            if (OperatingSystem.IsMacOSVersionAtLeast(27))
+                input.InstallTapOnBus(0, 960, inputFormat, out tapError, Convert);
+            else
+                input.InstallTapOnBus(0, 960, inputFormat, Convert);
+            if (tapError is not null)
+            {
+                converted.Dispose();
+                converter.Dispose();
+                outputFormat.Dispose();
+                engine.Dispose();
+                throw new InvalidOperationException("Core Audio capture tap could not be installed: " + tapError.LocalizedDescription);
+            }
+            engine.Prepare();
+            if (!engine.StartAndReturnError(out var error))
+            {
+                input.RemoveTapOnBus(0);
+                converted.Dispose();
+                converter.Dispose();
+                outputFormat.Dispose();
+                engine.Dispose();
+                throw new InvalidOperationException("Core Audio capture could not start: " + error.LocalizedDescription);
+            }
+        }
+
+        private unsafe void Convert(AVAudioPcmBuffer input, AVAudioTime _time)
+        {
+            try
+            {
+                pendingInput = input;
+                inputProvided = false;
+                converted.FrameLength = 0;
+                AVAudioConverterOutputStatus result = converter.ConvertToBuffer(converted, out NSError? error, inputProvider);
+                if (result == AVAudioConverterOutputStatus.Error)
+                {
+                    reportFailure(new InvalidOperationException("Core Audio input conversion failed: " + error?.LocalizedDescription));
+                    return;
+                }
+                if (converted.FrameLength == 0) return;
+                nint samples = Marshal.ReadIntPtr(converted.Int16ChannelData);
+                if (samples == 0) return;
+                int channels = checked((int)outputFormat.ChannelCount);
+                int remainingFrames = checked((int)converted.FrameLength);
+                var pcm = new ReadOnlySpan<short>((void*)samples, checked(remainingFrames * channels));
+                while (remainingFrames > 0)
+                {
+                    int frames = Math.Min(960, remainingFrames);
+                    handler(pcm[..(frames * channels)], channels);
+                    pcm = pcm[(frames * channels)..];
+                    remainingFrames -= frames;
+                }
+            }
+            catch (Exception exception) { reportFailure(exception); }
+            finally { pendingInput = null; }
+        }
+
+        private AVAudioBuffer ProvideInput(uint _, out AVAudioConverterInputStatus status)
+        {
+            if (!inputProvided && pendingInput is { } input)
+            {
+                inputProvided = true;
+                status = AVAudioConverterInputStatus.HaveData;
+                return input;
+            }
+            status = AVAudioConverterInputStatus.NoDataNow;
+            return null!;
+        }
+
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref disposed, 1) != 0) return;
+            engine.InputNode.RemoveTapOnBus(0);
+            engine.Stop();
+            converted.Dispose();
+            converter.Dispose();
+            outputFormat.Dispose();
+            engine.Dispose();
+        }
+    }
+
+    private sealed class Playback : IAudioPlayback
+    {
+        private readonly AdaptivePcmBuffer pcm = new(2);
+        private readonly short[] renderScratch = new short[8_192];
+        private readonly AVAudioEngine engine = new();
+        private readonly AVAudioFormat format;
+        private readonly AVAudioSourceNode source;
+        private readonly Action<Exception> reportFailure;
+        private int callbackFailed;
+        private int disposed;
+
+        internal Playback(string? deviceId, Action<Exception> reportFailure)
+        {
+            this.reportFailure = reportFailure;
+            if (!string.IsNullOrEmpty(deviceId))
+            {
+                AudioUnitStatus status = engine.OutputNode.AudioUnit!.SetCurrentDevice(CoreAudioDevices.ParseId(deviceId), AudioUnitScopeType.Global, 0);
+                if (status != AudioUnitStatus.NoError) throw new InvalidOperationException($"Core Audio output selection failed ({status}).");
+            }
+            // AVAudioEngine's native mixer path is planar Float32. Convert from the managed
+            // Int16 ring directly in this allocation-free callback, avoiding an extra graph
+            // converter and matching the established Swift/VPIO renderer.
+            format = new(AVAudioCommonFormat.PCMFloat32, 48_000, 2, false);
+            source = new(format, Render);
+            engine.AttachNode(source);
+            NSError? connectionError = null;
+            if (OperatingSystem.IsMacOSVersionAtLeast(27))
+                engine.Connect(source, engine.MainMixerNode, format, out connectionError);
+            else
+                engine.Connect(source, engine.MainMixerNode, format);
+            if (connectionError is not null)
+            {
+                engine.DetachNode(source);
+                source.Dispose();
+                format.Dispose();
+                engine.Dispose();
+                throw new InvalidOperationException("Core Audio playback could not be connected: " + connectionError.LocalizedDescription);
+            }
+            engine.Prepare();
+            if (!engine.StartAndReturnError(out var error))
+            {
+                engine.DetachNode(source);
+                source.Dispose();
+                format.Dispose();
+                engine.Dispose();
+                throw new InvalidOperationException("Core Audio playback could not start: " + error.LocalizedDescription);
+            }
+        }
+
+        public void Write(ReadOnlySpan<short> stereoPcm) => pcm.TryWrite(stereoPcm);
+        public int BufferMilliseconds { get => pcm.BufferMilliseconds; set => pcm.BufferMilliseconds = value; }
+
+        private unsafe int Render(IntPtr isSilence, IntPtr _, uint frameCount, IntPtr outputData)
+        {
+            try
+            {
+                int bufferCount = Marshal.ReadInt32(outputData);
+                int firstBuffer = IntPtr.Size == 8 ? 8 : 4;
+                const int bufferStride64 = 16;
+                int stride = IntPtr.Size == 8 ? bufferStride64 : 12;
+                int frames = checked((int)frameCount);
+                int requested = checked(frames * 2);
+                if (bufferCount != 2 || requested > renderScratch.Length) return Fail("Core Audio returned an invalid planar stereo playback buffer.");
+                Span<short> source = renderScratch.AsSpan(0, requested);
+                int read = pcm.Read(source);
+                source[read..].Clear();
+                for (int channel = 0; channel < 2; channel++)
+                {
+                    int offset = firstBuffer + channel * stride;
+                    int channels = Marshal.ReadInt32(outputData, offset);
+                    int byteCount = Marshal.ReadInt32(outputData, offset + 4);
+                    nint data = Marshal.ReadIntPtr(outputData, offset + 8);
+                    if (channels != 1 || data == 0 || byteCount < frames * sizeof(float)) return Fail("Core Audio returned an invalid Float32 playback channel.");
+                    var output = new Span<float>((void*)data, frames);
+                    for (int frame = 0; frame < frames; frame++) output[frame] = source[frame * 2 + channel] * (1.0f / 32_768.0f);
+                }
+                if (isSilence != IntPtr.Zero) Marshal.WriteByte(isSilence, read == 0 ? (byte)1 : (byte)0);
+                return 0;
+            }
+            catch (Exception exception)
+            {
+                if (Interlocked.Exchange(ref callbackFailed, 1) == 0) reportFailure(exception);
+                return -1;
+            }
+        }
+
+        private int Fail(string message)
+        {
+            if (Interlocked.Exchange(ref callbackFailed, 1) == 0) reportFailure(new InvalidOperationException(message));
+            return -1;
+        }
+
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref disposed, 1) != 0) return;
+            engine.Stop();
+            engine.DetachNode(source);
+            source.Dispose();
+            format.Dispose();
+            engine.Dispose();
+        }
+    }
+
+}

clients/apple/VoiceCat.Mac/MacKeychainPasswordStore.cs

@@ -0,0 +1,72 @@
+using System.Security.Cryptography;
+using System.Text;
+using Foundation;
+using Security;
+
+namespace VoiceCat.Mac;
+
+internal sealed class MacKeychainPasswordStore
+{
+    private const string Service = "net.iamtalon.voicecat";
+
+    internal string? Load(Guid profileId)
+    {
+        using var query = Query(profileId);
+        using SecRecord? result = SecKeyChain.QueryAsRecord(query, out SecStatusCode status);
+        if (status != SecStatusCode.Success || result?.ValueData is not { } data) return null;
+        byte[] encoded = data.ToArray();
+        try { return Encoding.UTF8.GetString(encoded); }
+        finally { CryptographicOperations.ZeroMemory(encoded); }
+    }
+
+    internal string? LoadLegacy(string? keychainTag)
+    {
+        if (string.IsNullOrWhiteSpace(keychainTag)) return null;
+        using var query = new SecRecord(SecKind.GenericPassword) { Service = "cat.voice.VoiceCatMac", Account = keychainTag };
+        using SecRecord? result = SecKeyChain.QueryAsRecord(query, out SecStatusCode status);
+        if (status != SecStatusCode.Success || result?.ValueData is not { } data) return null;
+        byte[] encoded = data.ToArray();
+        try { return Encoding.UTF8.GetString(encoded); }
+        finally { CryptographicOperations.ZeroMemory(encoded); }
+    }
+
+    internal void Save(Guid profileId, string password)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(password);
+        byte[] encoded = Encoding.UTF8.GetBytes(password);
+        try
+        {
+            using var data = NSData.FromArray(encoded);
+            using var query = Query(profileId);
+            using var attributes = new SecRecord
+            {
+                Label = "VoiceCat server password",
+                Accessible = SecAccessible.WhenUnlocked,
+                ValueData = data
+            };
+            SecStatusCode status = SecKeyChain.Update(query, attributes);
+            if (status == SecStatusCode.ItemNotFound)
+            {
+                using var record = Query(profileId);
+                record.Label = attributes.Label; record.Accessible = attributes.Accessible; record.ValueData = data;
+                status = SecKeyChain.Add(record);
+            }
+            if (status != SecStatusCode.Success) throw new InvalidOperationException($"Keychain save failed ({status}).");
+        }
+        finally { CryptographicOperations.ZeroMemory(encoded); }
+    }
+
+    internal void Remove(Guid profileId)
+    {
+        using var query = Query(profileId);
+        SecStatusCode status = SecKeyChain.Remove(query);
+        if (status is not (SecStatusCode.Success or SecStatusCode.ItemNotFound))
+            throw new InvalidOperationException($"Keychain removal failed ({status}).");
+    }
+
+    private static SecRecord Query(Guid profileId) => new(SecKind.GenericPassword)
+    {
+        Service = Service,
+        Account = profileId.ToString("D")
+    };
+}

clients/apple/VoiceCat.Mac/MacSettings.cs

@@ -0,0 +1,71 @@
+using Foundation;
+using VoiceCat.Audio;
+
+namespace VoiceCat.Mac;
+
+internal sealed class MacSettings
+{
+    private readonly NSUserDefaults values = NSUserDefaults.StandardUserDefaults;
+
+    internal AudioInputMode InputMode { get; set; } = AudioInputMode.VoiceActivation;
+    internal float VadThreshold { get; set; } = 0.05f;
+    internal float InputGain { get; set; } = 1f;
+    internal float OutputGain { get; set; } = 0.8f;
+    internal bool InputNoiseReduction { get; set; }
+    internal bool StereoMicrophone { get; set; }
+    internal ushort PushToTalkKeyCode { get; set; } = 0x60;
+    internal string? InputDeviceId { get; set; }
+    internal string? OutputDeviceId { get; set; }
+    internal bool AuxiliaryEnabled { get; set; }
+    internal string? AuxiliaryDeviceId { get; set; }
+    internal float AuxiliaryGain { get; set; } = 1f;
+    internal int AudioBufferMilliseconds { get; set; } = 40;
+    internal bool EventSounds { get; set; } = true;
+    internal bool SpokenEvents { get; set; }
+    internal float EventVolume { get; set; } = 1f;
+    internal bool SelfTalkSounds { get; set; }
+    internal bool PushToTalkSound { get; set; }
+
+    internal void Load()
+    {
+        NSString[] keys = [(NSString)"voice.inputMode", (NSString)"voice.vadThreshold", (NSString)"voice.inputGain", (NSString)"voice.outputGain",
+            (NSString)"voice.pttKeyCode", (NSString)"voice.auxGain", (NSString)"voice.audioBufferMs", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
+        NSObject[] defaults = [NSNumber.FromInt32((int)AudioInputMode.VoiceActivation), NSNumber.FromFloat(0.05f),
+            NSNumber.FromFloat(1f), NSNumber.FromFloat(0.8f), NSNumber.FromInt32(0x60), NSNumber.FromFloat(1f), NSNumber.FromInt32(40),
+            NSNumber.FromBoolean(true), NSNumber.FromFloat(1f)];
+        values.RegisterDefaults(new NSDictionary<NSString, NSObject>(keys, defaults));
+        InputMode = Enum.IsDefined(typeof(AudioInputMode), (int)values.IntForKey("voice.inputMode"))
+            ? (AudioInputMode)(int)values.IntForKey("voice.inputMode") : AudioInputMode.VoiceActivation;
+        VadThreshold = Math.Clamp(values.FloatForKey("voice.vadThreshold"), 0f, 1f);
+        InputGain = Math.Clamp(values.FloatForKey("voice.inputGain"), 0f, 4f);
+        OutputGain = Math.Clamp(values.FloatForKey("voice.outputGain"), 0f, 1f);
+        InputNoiseReduction = values.BoolForKey("voice.inputNoiseReduction");
+        StereoMicrophone = values.BoolForKey("voice.stereoMic");
+        PushToTalkKeyCode = checked((ushort)Math.Clamp(values.IntForKey("voice.pttKeyCode"), 0, ushort.MaxValue));
+        InputDeviceId = EmptyToNull(values.StringForKey("voice.inputDevice"));
+        OutputDeviceId = EmptyToNull(values.StringForKey("voice.outputDevice"));
+        AuxiliaryEnabled = values.BoolForKey("voice.auxEnabled");
+        AuxiliaryDeviceId = EmptyToNull(values.StringForKey("voice.auxDeviceUID"));
+        AuxiliaryGain = Math.Clamp(values.FloatForKey("voice.auxGain"), 0f, 4f);
+        int audioBuffer = checked((int)values.IntForKey("voice.audioBufferMs")); AudioBufferMilliseconds = audioBuffer is 20 or 40 or 60 ? audioBuffer : 40;
+        EventSounds = values.BoolForKey("feedback.sounds");
+        SpokenEvents = values.BoolForKey("feedback.speech");
+        EventVolume = Math.Clamp(values.FloatForKey("feedback.volume"), 0f, 1f);
+        SelfTalkSounds = values.BoolForKey("feedback.selfTalk");
+        PushToTalkSound = values.BoolForKey("feedback.ptt");
+    }
+
+    internal void Save()
+    {
+        values.SetInt((int)InputMode, "voice.inputMode"); values.SetFloat(VadThreshold, "voice.vadThreshold");
+        values.SetFloat(InputGain, "voice.inputGain"); values.SetFloat(OutputGain, "voice.outputGain");
+        values.SetBool(InputNoiseReduction, "voice.inputNoiseReduction"); values.SetBool(StereoMicrophone, "voice.stereoMic");
+        values.SetInt(PushToTalkKeyCode, "voice.pttKeyCode"); Set("voice.inputDevice", InputDeviceId); Set("voice.outputDevice", OutputDeviceId);
+        values.SetBool(AuxiliaryEnabled, "voice.auxEnabled"); Set("voice.auxDeviceUID", AuxiliaryDeviceId); values.SetFloat(AuxiliaryGain, "voice.auxGain"); values.SetInt(AudioBufferMilliseconds, "voice.audioBufferMs");
+        values.SetBool(EventSounds, "feedback.sounds"); values.SetBool(SpokenEvents, "feedback.speech"); values.SetFloat(EventVolume, "feedback.volume");
+        values.SetBool(SelfTalkSounds, "feedback.selfTalk"); values.SetBool(PushToTalkSound, "feedback.ptt"); values.Synchronize();
+    }
+
+    private void Set(string key, string? value) { if (value is null) values.RemoveObject(key); else values.SetString(value, key); }
+    private static string? EmptyToNull(string? value) => string.IsNullOrWhiteSpace(value) ? null : value;
+}

clients/apple/VoiceCat.Mac/MainWindowController.cs

@@ -0,0 +1,486 @@
+using AppKit;
+using AVFoundation;
+using CoreGraphics;
+using Foundation;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+using Voicecat.V1;
+
+namespace VoiceCat.Mac;
+
+internal sealed class MainWindowController : NSWindowController
+{
+    private readonly VoiceCatClient client;
+    private readonly MacAudioBackend audioBackend = new();
+    private readonly uint selfId;
+    private readonly NSPopUpButton channels = new(new CGRect(20, 515, 245, 28), false);
+    private readonly NSPopUpButton inputDevice = new(new CGRect(275, 515, 165, 28), false);
+    private readonly NSPopUpButton outputDevice = new(new CGRect(450, 515, 165, 28), false);
+    private readonly NSTextView users = new(new CGRect(0, 0, 190, 430)) { Editable = false, Selectable = true };
+    private readonly NSTextView chat = new(new CGRect(0, 0, 510, 390)) { Editable = false, Selectable = true };
+    private readonly NSPopUpButton messageTarget = new(new CGRect(230, 55, 160, 28), false);
+    private readonly NSTextField compose = new(new CGRect(400, 55, 230, 28)) { PlaceholderString = "Message" };
+    private readonly NSButton send = new(new CGRect(640, 53, 90, 32)) { Title = "Send" };
+    private readonly NSButton voice = new(new CGRect(630, 510, 100, 32)) { Title = "Join voice" };
+    private readonly NSButton settingsButton = new(new CGRect(740, 510, 90, 32)) { Title = "Settings" };
+    private readonly NSButton screenAudioButton = new(new CGRect(840, 510, 130, 32)) { Title = "Share audio" };
+    private readonly NSButton administrationButton = new(new CGRect(840, 20, 130, 28)) { Title = "Administration" };
+    private readonly NSButton privateMessageButton = new(new CGRect(700, 20, 130, 28)) { Title = "Private chat" };
+    private readonly NSButton muteButton = NSButton.CreateCheckbox("Mute", () => { });
+    private readonly NSButton deafenButton = NSButton.CreateCheckbox("Deafen", () => { });
+    private readonly NSTextField status = NSTextField.CreateLabel("Connected");
+    private readonly MacSettings settings = new();
+    private readonly EventFeedback feedback;
+    private readonly NSTimer timer;
+    private uint currentChannel = 1;
+    private uint microphoneStreamId;
+    private uint auxiliaryStreamId;
+    private uint screenAudioStreamId;
+    private bool joinedVoice;
+    private bool changingChannel;
+    private IAudioCapture? microphone;
+    private IAudioCapture? auxiliary;
+    private IAudioPlayback? playback;
+    private ScreenAudioCapture? screenAudio;
+    private ScreenAudioSelection screenAudioSelection = ScreenAudioSelection.Default;
+    private SettingsWindowController? settingsWindow;
+    private AdministrationWindowController? administrationWindow;
+    private readonly Dictionary<uint, PrivateMessageWindowController> privateWindows = [];
+    private readonly HashSet<uint> talkingUsers = [];
+    private bool lastTalking;
+    private string? activeInputDevice;
+    private string? activeOutputDevice;
+    private string? activeAuxiliaryDevice;
+    private bool activeStereo;
+    private NSObject? pushToTalkMonitor;
+    private bool pushToTalkEngaged;
+    private long lastRemoteAudioTick;
+
+    internal MainWindowController(VoiceCatClient client, uint selfId, string nickname) : base(new NSWindow(new CGRect(0, 0, 1000, 570),
+        NSWindowStyle.Titled | NSWindowStyle.Closable | NSWindowStyle.Resizable | NSWindowStyle.Miniaturizable, NSBackingStore.Buffered, false))
+    {
+        this.client = client; this.selfId = selfId; settings.Load(); feedback = new(settings);
+        Window!.Title = $"VoiceCat — {nickname}"; Window.Center(); Window.MinSize = new CGSize(680, 480);
+        var content = Window.ContentView!;
+        ((INSAccessibility)channels).AccessibilityLabel = "Channel"; channels.Activated += ChangeChannel; content.AddSubview(channels);
+        PopulateAudioDevices(inputDevice, true); PopulateAudioDevices(outputDevice, false);
+        ((INSAccessibility)inputDevice).AccessibilityLabel = "Microphone input device"; inputDevice.Activated += ChangeAudioDevice; content.AddSubview(inputDevice);
+        ((INSAccessibility)outputDevice).AccessibilityLabel = "Audio output device"; outputDevice.Activated += ChangeAudioDevice; content.AddSubview(outputDevice);
+        ((INSAccessibility)voice).AccessibilityLabel = "Join or leave voice"; voice.Activated += ToggleVoice; content.AddSubview(voice);
+        ((INSAccessibility)settingsButton).AccessibilityLabel = "Open audio and notification settings"; settingsButton.Activated += OpenSettings; content.AddSubview(settingsButton);
+        ((INSAccessibility)screenAudioButton).AccessibilityLabel = "Start or stop sharing screen audio"; screenAudioButton.Activated += ToggleScreenAudio; content.AddSubview(screenAudioButton);
+        ((INSAccessibility)administrationButton).AccessibilityLabel = "Open server moderation and administration"; administrationButton.Activated += OpenAdministration; content.AddSubview(administrationButton);
+        ((INSAccessibility)privateMessageButton).AccessibilityLabel = "Open a private conversation with the selected message recipient"; privateMessageButton.Activated += OpenPrivateMessage; content.AddSubview(privateMessageButton);
+        muteButton.Frame = new CGRect(275, 490, 75, 22); deafenButton.Frame = new CGRect(355, 490, 85, 22);
+        ((INSAccessibility)muteButton).AccessibilityLabel = "Mute microphone"; ((INSAccessibility)deafenButton).AccessibilityLabel = "Deafen playback";
+        muteButton.Activated += SelfAudioChanged; deafenButton.Activated += SelfAudioChanged; content.AddSubview(muteButton); content.AddSubview(deafenButton);
+        var userScroll = new NSScrollView(new CGRect(20, 90, 190, 410)) { HasVerticalScroller = true, DocumentView = users }; userScroll.AccessibilityLabel = "Users in channel"; content.AddSubview(userScroll);
+        var chatScroll = new NSScrollView(new CGRect(230, 90, 500, 410)) { HasVerticalScroller = true, DocumentView = chat }; chatScroll.AccessibilityLabel = "Channel messages"; content.AddSubview(chatScroll);
+        ((INSAccessibility)messageTarget).AccessibilityLabel = "Message recipient"; content.AddSubview(messageTarget);
+        ((INSAccessibility)compose).AccessibilityLabel = "Message"; compose.Activated += Send; content.AddSubview(compose);
+        ((INSAccessibility)send).AccessibilityLabel = "Send message"; send.Activated += Send; content.AddSubview(send);
+        status.Frame = new CGRect(20, 22, 660, 22); status.AccessibilityLabel = "Connection status"; content.AddSubview(status);
+        timer = NSTimer.CreateRepeatingScheduledTimer(TimeSpan.FromMilliseconds(50), _ => Pump());
+        ApplyEngineSettings(); feedback.Play(SoundEvent.Login); feedback.Speak("Connected");
+        pushToTalkMonitor = NSEvent.AddLocalMonitorForEventsMatchingMask(NSEventMask.KeyDown | NSEventMask.KeyUp, value => HandlePushToTalk(value)!);
+        RefreshState();
+    }
+    private NSEvent? HandlePushToTalk(NSEvent value)
+    {
+        if (settings.InputMode != AudioInputMode.PushToTalk || value.KeyCode != settings.PushToTalkKeyCode) return value;
+        bool engaged = value.Type == NSEventType.KeyDown;
+        client.Audio.PushToTalk = engaged;
+        if (engaged && !pushToTalkEngaged) feedback.Play(SoundEvent.PushToTalk);
+        pushToTalkEngaged = engaged; return null;
+    }
+
+    private void Pump()
+    {
+        while (client.TryReadEvent(out Envelope? envelope))
+        {
+            if (envelope!.TextMessage is { } text)
+            {
+                if (text.Scope == TextScope.TextPrivate)
+                {
+                    uint other = text.SenderId == selfId ? text.TargetId : text.SenderId;
+                    GetPrivateWindow(other).Append(text, Name(text.SenderId));
+                    feedback.Play(text.SenderId == selfId ? SoundEvent.PrivateSent : SoundEvent.PrivateReceived);
+                    if (text.SenderId != selfId) feedback.Speak($"Private message from {Name(text.SenderId)}: {text.Body}");
+                }
+                else { Append(FormatMessage(text)); feedback.Play(text.SenderId == selfId ? SoundEvent.ChannelSent : SoundEvent.ChannelReceived); }
+            }
+            if (envelope.StreamState is { } streamState)
+            {
+                if (streamState.Talking) talkingUsers.Add(streamState.UserId); else talkingUsers.Remove(streamState.UserId);
+                RefreshState();
+            }
+            if (envelope.UserEvent is { } userEvent)
+            {
+                string name = userEvent.User?.Nickname ?? Name(userEvent.LeftId);
+                if (userEvent.Kind == UserEvent.Types.Kind.Joined && userEvent.User?.ChannelId == currentChannel && userEvent.User.Id != selfId)
+                { AppendActivity($"{name} joined the channel"); feedback.Play(SoundEvent.ChannelJoin); feedback.Speak($"{name} joined"); }
+                else if (userEvent.Kind == UserEvent.Types.Kind.Left)
+                { talkingUsers.Remove(userEvent.LeftId); AppendActivity($"{name} left the server"); feedback.Play(SoundEvent.ChannelLeave); }
+            }
+            if (envelope.ServerState is not null || envelope.ChannelEvent is not null || envelope.UserEvent is not null) RefreshState();
+            if (envelope.Disconnect is { } disconnected)
+            {
+                StopAudioDevices(); joinedVoice = false; voice.Title = "Join voice";
+                status.StringValue = "Disconnected: " + disconnected.Reason; voice.Enabled = send.Enabled = messageTarget.Enabled = false;
+                feedback.Play(SoundEvent.ConnectionLost); feedback.Speak("Connection lost"); Announce(status.StringValue);
+            }
+        }
+        if (client.Audio.Failure is { } failure) { status.StringValue = "Audio stopped: " + failure.Message; return; }
+        if (audioBackend.Failure is { } deviceFailure) { status.StringValue = "Audio device stopped: " + deviceFailure.Message; return; }
+        if (joinedVoice)
+        {
+            (float level, bool talking) = client.Audio.GetLocalLevel(microphoneStreamId);
+            if (talking != lastTalking)
+            {
+                lastTalking = talking; client.PublishStreamState(microphoneStreamId, talking);
+                feedback.Play(talking ? SoundEvent.VoiceStart : SoundEvent.VoiceStop);
+            }
+            bool receiving = Environment.TickCount64 - Volatile.Read(ref lastRemoteAudioTick) < 1_000;
+            status.StringValue = $"Voice connected · Mic {(talking ? "sending" : "idle")} {level:P0} · Remote audio {(receiving ? "active" : "idle")}";
+        }
+    }
+    private void OpenSettings(object? sender, EventArgs args)
+    {
+        settingsWindow ??= new(this, settings, audioBackend);
+        settingsWindow.ShowWindow(this); settingsWindow.Window?.MakeKeyAndOrderFront(this);
+    }
+    private void OpenAdministration(object? sender, EventArgs args)
+    {
+        administrationWindow ??= new(client, selfId); administrationWindow.ShowWindow(this); administrationWindow.Window?.MakeKeyAndOrderFront(this);
+    }
+    private void OpenPrivateMessage(object? sender, EventArgs args)
+    {
+        uint target = uint.TryParse(messageTarget.SelectedItem?.RepresentedObject?.ToString(), out uint selected) ? selected : 0;
+        if (target == 0) { status.StringValue = "Choose a private message recipient first."; return; }
+        PrivateMessageWindowController window = GetPrivateWindow(target); window.ShowWindow(this); window.Window?.MakeKeyAndOrderFront(this);
+    }
+    private PrivateMessageWindowController GetPrivateWindow(uint userId)
+    {
+        if (privateWindows.TryGetValue(userId, out PrivateMessageWindowController? existing)) return existing;
+        var created = new PrivateMessageWindowController(client, userId, selfId, Name(userId)); privateWindows[userId] = created; return created;
+    }
+
+    private void SelfAudioChanged(object? sender, EventArgs args)
+    {
+        bool muted = muteButton.State == NSCellStateValue.On;
+        bool deafened = deafenButton.State == NSCellStateValue.On;
+        client.SetSelfAudioState(muted, deafened);
+        status.StringValue = deafened ? "Deafened" : muted ? "Microphone muted" : "Voice active";
+    }
+
+    private async void ToggleScreenAudio(object? sender, EventArgs args)
+    {
+        try
+        {
+            screenAudioButton.Enabled = false;
+            if (screenAudioStreamId != 0) { StopScreenAudio(); return; }
+            if (!joinedVoice) throw new InvalidOperationException("Join voice before sharing screen audio.");
+            ScreenAudioSelection? selection = await ScreenAudioPicker.ChooseAsync(screenAudioSelection);
+            if (selection is null) return;
+            screenAudioSelection = selection;
+            StreamInfo stream = await client.StartStreamAsync(StreamKind.StreamScreenAudio, "Desktop audio", 2);
+            screenAudioStreamId = stream.StreamId;
+            int channelCount = stream.Audio.Mode == ChannelMode.ModeStereo ? 2 : 1;
+            var capture = new ScreenAudioCapture(channelCount, screenAudioSelection,
+                (pcm, channels) => { uint id = screenAudioStreamId; if (id != 0) client.Audio.FeedPcm(id, pcm, channels); });
+            capture.Failed += exception => NSApplication.SharedApplication.InvokeOnMainThread(() => { status.StringValue = exception.Message; StopScreenAudio(); });
+            screenAudio = capture; await capture.StartAsync(); screenAudioButton.Title = "Stop sharing";
+            status.StringValue = "Sharing desktop audio";
+        }
+        catch (Exception exception) { StopScreenAudio(); status.StringValue = exception.Message; }
+        finally { screenAudioButton.Enabled = true; }
+    }
+
+    private void StopScreenAudio()
+    {
+        Interlocked.Exchange(ref screenAudio, null)?.Dispose();
+        uint id = screenAudioStreamId; screenAudioStreamId = 0;
+        TryStopStream(id);
+        screenAudioButton.Title = "Share audio";
+    }
+
+    private void ApplyEngineSettings()
+    {
+        client.Audio.InputMode = settings.InputMode; client.Audio.VadThreshold = settings.VadThreshold;
+        if (settings.InputMode != AudioInputMode.PushToTalk) { client.Audio.PushToTalk = false; pushToTalkEngaged = false; }
+        client.Audio.InputGain = settings.InputGain; client.Audio.OutputGain = settings.OutputGain;
+        client.Audio.InputNoiseReduction = settings.InputNoiseReduction;
+        client.Audio.DeviceBufferMilliseconds = settings.AudioBufferMilliseconds;
+        if (playback is not null) playback.BufferMilliseconds = settings.AudioBufferMilliseconds;
+        if (auxiliaryStreamId != 0) client.Audio.SetLocalGain(auxiliaryStreamId, settings.AuxiliaryGain);
+    }
+
+    internal async Task ApplySettingsAsync()
+    {
+        ApplyEngineSettings();
+        if (!joinedVoice) return;
+        bool restart = activeInputDevice != settings.InputDeviceId || activeOutputDevice != settings.OutputDeviceId || activeStereo != settings.StereoMicrophone;
+        if (restart) { await LeaveVoice(); await JoinVoice(); return; }
+        if (settings.AuxiliaryEnabled && auxiliaryStreamId == 0) await StartAuxiliaryAsync();
+        else if (!settings.AuxiliaryEnabled && auxiliaryStreamId != 0) StopAuxiliary();
+        else if (settings.AuxiliaryEnabled && activeAuxiliaryDevice != settings.AuxiliaryDeviceId) { StopAuxiliary(); await StartAuxiliaryAsync(); }
+    }
+    private void RefreshState()
+    {
+        uint previousTarget = uint.TryParse(messageTarget.SelectedItem?.RepresentedObject?.ToString(), out uint selectedTarget) ? selectedTarget : 0;
+        channels.RemoveAllItems();
+        IReadOnlyList<(Channel Channel, int Depth)> hierarchy = FlattenChannels(client.Channels);
+        foreach ((Channel channel, int depth) in hierarchy)
+        {
+            int members = client.Users.Count(user => user.ChannelId == channel.Id);
+            channels.AddItem(new string(' ', depth * 3) + channel.Name + $" ({members})" + (channel.PasswordProtected ? " [password]" : ""));
+            channels.LastItem!.RepresentedObject = new NSString(channel.Id.ToString());
+            channels.LastItem!.ToolTip = channel.Topic;
+        }
+        currentChannel = client.Users.FirstOrDefault(u => u.Id == selfId)?.ChannelId ?? currentChannel;
+        int selectedIndex = hierarchy.ToList().FindIndex(item => item.Channel.Id == currentChannel); if (selectedIndex >= 0) channels.SelectItem(selectedIndex);
+        users.Value = string.Join("\n", client.Users.Where(u => u.ChannelId == currentChannel).OrderBy(u => u.Nickname).Select(u =>
+            (talkingUsers.Contains(u.Id) ? "Speaking — " : "") + (u.Id == selfId ? "You — " : "") + u.Nickname +
+            (u.ServerDeafened ? " [server deafened]" : u.ServerMuted ? " [server muted]" : u.SelfDeafened ? " [deafened]" : u.SelfMicMuted ? " [muted]" : "")));
+        messageTarget.RemoveAllItems(); messageTarget.AddItem("Current channel"); messageTarget.LastItem!.RepresentedObject = new NSString("0");
+        foreach (var user in client.Users.Where(user => user.Id != selfId).OrderBy(user => user.Nickname))
+        {
+            messageTarget.AddItem("Private: " + user.Nickname);
+            messageTarget.LastItem!.RepresentedObject = new NSString(user.Id.ToString());
+        }
+        int targetIndex = client.Users.Where(user => user.Id != selfId).OrderBy(user => user.Nickname).ToList().FindIndex(user => user.Id == previousTarget) + 1;
+        messageTarget.SelectItem(Math.Max(0, targetIndex));
+        status.StringValue = $"Connected · {client.Users.Count} users";
+    }
+    private static IReadOnlyList<(Channel Channel, int Depth)> FlattenChannels(IReadOnlyList<Channel> values)
+    {
+        var result = new List<(Channel, int)>(); var visited = new HashSet<uint>();
+        void AddChildren(uint parent, int depth)
+        {
+            foreach (Channel channel in values.Where(channel => channel.ParentId == parent).OrderBy(channel => channel.Order).ThenBy(channel => channel.Name))
+                if (visited.Add(channel.Id)) { result.Add((channel, depth)); AddChildren(channel.Id, depth + 1); }
+        }
+        AddChildren(0, 0);
+        foreach (Channel channel in values.Where(channel => !visited.Contains(channel.Id)).OrderBy(channel => channel.Order).ThenBy(channel => channel.Name)) result.Add((channel, 0));
+        return result;
+    }
+    private async void ChangeChannel(object? sender, EventArgs args)
+    {
+        if (changingChannel || !uint.TryParse(channels.SelectedItem?.RepresentedObject?.ToString(), out uint id) || id == currentChannel) return;
+        var channel = client.Channels.FirstOrDefault(item => item.Id == id);
+        if (channel is null) { RefreshState(); return; }
+        string? password = channel.PasswordProtected ? PromptForChannelPassword(channel.Name) : "";
+        if (password is null) { RefreshState(); return; }
+        bool resumeVoice = joinedVoice;
+        try
+        {
+            changingChannel = true; channels.Enabled = false;
+            if (resumeVoice) await LeaveVoice();
+            var result = (await client.RequestAsync(new() { JoinChannel = new() { ChannelId = id, Password = password } })).JoinChannelResult;
+            if (result.Ok) currentChannel = id;
+            if (resumeVoice) await JoinVoice();
+            RefreshState();
+            status.StringValue = result.Ok ? $"Joined {channel.Name}" : result.Error;
+        }
+        catch (Exception exception)
+        {
+            string message = exception.Message;
+            if (resumeVoice && !joinedVoice)
+            {
+                try { await JoinVoice(); }
+                catch (Exception restoreException) { message += " Voice could not be restored: " + restoreException.Message; }
+            }
+            RefreshState(); status.StringValue = message;
+        }
+        finally { changingChannel = false; channels.Enabled = true; }
+    }
+
+    private string? PromptForChannelPassword(string channelName)
+    {
+        var field = new NSSecureTextField(new CGRect(0, 0, 320, 26)) { PlaceholderString = "Channel password" };
+        ((INSAccessibility)field).AccessibilityLabel = $"Password for {channelName}";
+        var alert = new NSAlert
+        {
+            MessageText = $"Join {channelName}",
+            InformativeText = "Enter the channel password.",
+            AlertStyle = NSAlertStyle.Informational,
+            AccessoryView = field
+        };
+        alert.AddButton("Join"); alert.AddButton("Cancel");
+        if (alert.RunModal() != 1000) { field.StringValue = ""; return null; }
+        string value = field.StringValue; field.StringValue = ""; return value;
+    }
+    private void Send(object? sender, EventArgs args)
+    {
+        string body = compose.StringValue.Trim(); if (body.Length == 0) return;
+        uint target = uint.TryParse(messageTarget.SelectedItem?.RepresentedObject?.ToString(), out uint selectedTarget) ? selectedTarget : 0;
+        try { client.Send(new() { TextMessage = new() { Scope = target == 0 ? TextScope.TextChannel : TextScope.TextPrivate, TargetId = target == 0 ? currentChannel : target, Body = body, ClientMsgId = Guid.NewGuid().ToString("N") } }); compose.StringValue = ""; }
+        catch (Exception exception) { status.StringValue = exception.Message; }
+    }
+    private async void ToggleVoice(object? sender, EventArgs args)
+    {
+        try
+        {
+            voice.Enabled = false;
+            if (!joinedVoice) await JoinVoice();
+            else await LeaveVoice();
+        }
+        catch (Exception exception) { status.StringValue = exception.Message; }
+        finally { voice.Enabled = true; }
+    }
+
+    private void PopulateAudioDevices(NSPopUpButton menu, bool input)
+    {
+        IReadOnlyList<AudioDeviceInfo> devices = audioBackend.Enumerate(input);
+        foreach (AudioDeviceInfo device in devices)
+        {
+            menu.AddItem(device.Name + (device.IsDefault ? " (default)" : ""));
+            menu.LastItem!.RepresentedObject = new NSString(device.Id);
+        }
+        int selected = devices.ToList().FindIndex(device => device.IsDefault);
+        if (selected >= 0) menu.SelectItem(selected);
+        menu.Enabled = devices.Count > 0;
+    }
+
+    private async void ChangeAudioDevice(object? sender, EventArgs args)
+    {
+        if (!joinedVoice) return;
+        try { await LeaveVoice(); await JoinVoice(); }
+        catch (Exception exception) { status.StringValue = exception.Message; }
+    }
+
+    private async Task JoinVoice()
+    {
+        AVAuthorizationStatus permission = AVCaptureDevice.GetAuthorizationStatus(AVAuthorizationMediaType.Audio);
+        if (permission == AVAuthorizationStatus.NotDetermined)
+        {
+            bool granted = await AVCaptureDevice.RequestAccessForMediaTypeAsync(AVAuthorizationMediaType.Audio);
+            permission = granted ? AVAuthorizationStatus.Authorized : AVAuthorizationStatus.Denied;
+        }
+        if (permission != AVAuthorizationStatus.Authorized)
+            throw new UnauthorizedAccessException("Microphone access is disabled. Enable VoiceCat in System Settings → Privacy & Security → Microphone, then join voice again.");
+
+        var result = await client.SubscribeVoiceAsync();
+        if (!result.Ok) throw new InvalidOperationException(result.Error);
+        try
+        {
+            ApplyEngineSettings();
+            activeInputDevice = settings.InputDeviceId ?? SelectedDevice(inputDevice);
+            activeOutputDevice = settings.OutputDeviceId ?? SelectedDevice(outputDevice);
+            activeStereo = settings.StereoMicrophone;
+            playback = audioBackend.OpenPlayback(activeOutputDevice);
+            playback.BufferMilliseconds = settings.AudioBufferMilliseconds;
+            client.Audio.MixedPcm += PlayMixedPcm;
+            StreamInfo stream = await client.StartStreamAsync(StreamKind.StreamMic, "Microphone", settings.StereoMicrophone ? 2 : 1);
+            microphoneStreamId = stream.StreamId;
+            microphone = audioBackend.OpenCapture(activeInputDevice, false, FeedMicrophone);
+            if (settings.AuxiliaryEnabled) await StartAuxiliaryAsync();
+            joinedVoice = true; voice.Title = "Leave voice"; status.StringValue = "Voice connected";
+            feedback.Play(SoundEvent.VoiceOn);
+        }
+        catch
+        {
+            try { if (microphoneStreamId != 0) client.StopStream(microphoneStreamId); } catch { }
+            StopAudioDevices();
+            try { await client.SubscribeVoiceAsync(false); } catch { }
+            throw;
+        }
+    }
+
+    private async Task LeaveVoice()
+    {
+        uint streamId = microphoneStreamId;
+        joinedVoice = false; voice.Title = "Join voice";
+        StopAudioDevices();
+        if (streamId != 0) client.StopStream(streamId);
+        await client.SubscribeVoiceAsync(false);
+        status.StringValue = "Voice disconnected";
+        feedback.Play(SoundEvent.VoiceOff);
+    }
+
+    private async Task StartAuxiliaryAsync()
+    {
+        if (auxiliaryStreamId != 0) return;
+        StreamInfo stream = await client.StartStreamAsync(StreamKind.StreamAuxDevice, "Aux device", 2);
+        auxiliaryStreamId = stream.StreamId; client.Audio.SetLocalGain(stream.StreamId, settings.AuxiliaryGain);
+        try { activeAuxiliaryDevice = settings.AuxiliaryDeviceId; auxiliary = audioBackend.OpenCapture(activeAuxiliaryDevice, false, FeedAuxiliary); }
+        catch { client.StopStream(auxiliaryStreamId); auxiliaryStreamId = 0; throw; }
+    }
+
+    private void StopAuxiliary()
+    {
+        Interlocked.Exchange(ref auxiliary, null)?.Dispose();
+        activeAuxiliaryDevice = null;
+        uint id = auxiliaryStreamId; auxiliaryStreamId = 0;
+        TryStopStream(id);
+    }
+
+    private void FeedAuxiliary(ReadOnlySpan<short> pcm, int channels)
+    {
+        uint id = auxiliaryStreamId; if (id != 0) client.Audio.FeedPcm(id, pcm, channels);
+    }
+
+    private void FeedMicrophone(ReadOnlySpan<short> pcm, int channels)
+    {
+        uint streamId = microphoneStreamId;
+        if (streamId != 0) client.Audio.FeedPcm(streamId, pcm, channels);
+    }
+
+    private static string? SelectedDevice(NSPopUpButton menu) => menu.SelectedItem?.RepresentedObject?.ToString();
+
+    private void PlayMixedPcm(ReadOnlySpan<short> pcm)
+    {
+        bool signal = false;
+        foreach (short sample in pcm)
+            if (sample is > 64 or < -64) { signal = true; break; }
+        if (signal) Volatile.Write(ref lastRemoteAudioTick, Environment.TickCount64);
+        Volatile.Read(ref playback)?.Write(pcm);
+    }
+
+    private void StopAudioDevices()
+    {
+        StopScreenAudio();
+        StopAuxiliary();
+        microphoneStreamId = 0;
+        Volatile.Write(ref lastRemoteAudioTick, 0);
+        Interlocked.Exchange(ref microphone, null)?.Dispose();
+        client.Audio.MixedPcm -= PlayMixedPcm;
+        Interlocked.Exchange(ref playback, null)?.Dispose();
+        activeInputDevice = activeOutputDevice = null; lastTalking = false;
+    }
+    private void TryStopStream(uint id)
+    {
+        if (id == 0 || client.State != ClientConnectionState.Connected) return;
+        try { client.StopStream(id); }
+        catch (InvalidOperationException) { }
+        catch (IOException) { }
+    }
+    private string Name(uint id) => client.Users.FirstOrDefault(u => u.Id == id)?.Nickname ?? $"User {id}";
+    private string FormatMessage(TextMessage text)
+    {
+        string prefix = text.Scope switch
+        {
+            TextScope.TextPrivate => $"[private: {Name(text.SenderId == selfId ? text.TargetId : text.SenderId)}] ",
+            TextScope.TextServer => "[server] ",
+            _ => ""
+        };
+        return $"[{DateTime.Now:t}] {prefix}{Name(text.SenderId)}: {text.Body}";
+    }
+    private void Append(string line)
+    {
+        chat.Value = chat.Value.Length == 0 ? line : chat.Value + "\n" + line;
+        chat.ScrollRangeToVisible(new NSRange(chat.Value.Length, 0));
+    }
+    private void AppendActivity(string line) => Append($"[{DateTime.Now:t}] — {line}");
+    private void Announce(string value)
+    {
+        NSString[] keys = [NSAccessibilityNotificationUserInfoKeys.AnnouncementKey, NSAccessibilityNotificationUserInfoKeys.PriorityKey];
+        NSObject[] values = [(NSString)value, NSNumber.FromInt32(1)];
+        NSAccessibility.PostNotification(status, NSView.AnnouncementRequestedNotification, new NSDictionary<NSString, NSObject>(keys, values));
+    }
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing) { timer.Invalidate(); if (pushToTalkMonitor is not null) NSEvent.RemoveMonitor(pushToTalkMonitor); client.Audio.PushToTalk = false; settingsWindow?.Close(); administrationWindow?.Close(); foreach (PrivateMessageWindowController window in privateWindows.Values) window.Close(); privateWindows.Clear(); StopAudioDevices(); feedback.Dispose(); client.DisposeAsync().AsTask().GetAwaiter().GetResult(); }
+        base.Dispose(disposing);
+    }
+}

clients/apple/VoiceCat.Mac/PrivateMessageWindowController.cs

@@ -0,0 +1,43 @@
+using AppKit;
+using CoreGraphics;
+using VoiceCat.Core;
+using Voicecat.V1;
+
+namespace VoiceCat.Mac;
+
+internal sealed class PrivateMessageWindowController : NSWindowController
+{
+    private readonly VoiceCatClient client;
+    private readonly uint otherUserId;
+    private readonly uint selfId;
+    private readonly NSTextView transcript = new(new CGRect(0, 0, 430, 300)) { Editable = false, Selectable = true };
+    private readonly NSTextField compose = new(new CGRect(20, 20, 350, 28)) { PlaceholderString = "Private message" };
+
+    internal PrivateMessageWindowController(VoiceCatClient client, uint otherUserId, uint selfId, string nickname) : base(new NSWindow(
+        new CGRect(0, 0, 480, 400), NSWindowStyle.Titled | NSWindowStyle.Closable | NSWindowStyle.Resizable,
+        NSBackingStore.Buffered, false))
+    {
+        this.client = client; this.otherUserId = otherUserId; this.selfId = selfId;
+        Window!.Title = $"Private message — {nickname}"; Window.Center();
+        NSView view = Window.ContentView!;
+        var scroll = new NSScrollView(new CGRect(20, 65, 440, 315)) { DocumentView = transcript, HasVerticalScroller = true };
+        scroll.AccessibilityLabel = $"Private conversation with {nickname}"; view.AddSubview(scroll);
+        ((INSAccessibility)compose).AccessibilityLabel = $"Message to {nickname}"; compose.Activated += Send; view.AddSubview(compose);
+        var button = new NSButton(new CGRect(380, 18, 80, 32)) { Title = "Send" }; button.Activated += Send; view.AddSubview(button);
+    }
+
+    private void Send(object? sender, EventArgs args)
+    {
+        string value = compose.StringValue.Trim(); if (value.Length == 0) return;
+        client.Send(new() { TextMessage = new() { Scope = TextScope.TextPrivate, TargetId = otherUserId, Body = value, ClientMsgId = Guid.NewGuid().ToString("N") } });
+        compose.StringValue = "";
+    }
+
+    internal void Append(TextMessage message, string sender)
+    {
+        string line = $"[{DateTime.Now:t}] {(message.SenderId == selfId ? "You" : sender)}: {message.Body}";
+        transcript.Value = transcript.Value.Length == 0 ? line : transcript.Value + "\n" + line;
+        transcript.ScrollRangeToVisible(new Foundation.NSRange(transcript.Value.Length, 0));
+        Window?.MakeKeyAndOrderFront(this);
+    }
+}

clients/apple/VoiceCat.Mac/Program.cs

@@ -0,0 +1,5 @@
+using AppKit;
+
+NSApplication.Init();
+NSApplication.SharedApplication.Delegate = new VoiceCat.Mac.AppDelegate();
+NSApplication.SharedApplication.Run();

clients/apple/VoiceCat.Mac/ScreenAudioCapture.cs

@@ -0,0 +1,156 @@
+using System.Runtime.InteropServices;
+using CoreFoundation;
+using CoreMedia;
+using Foundation;
+using ObjCRuntime;
+using ScreenCaptureKit;
+using VoiceCat.Audio;
+
+namespace VoiceCat.Mac;
+
+internal enum ScreenAudioScope { EntireDesktop, OnlyApplications, AllExceptApplications }
+internal sealed record ScreenAudioSelection(ScreenAudioScope Scope, IReadOnlySet<string> BundleIdentifiers, bool ExcludeScreenReader)
+{
+    internal static ScreenAudioSelection Default { get; } = new(ScreenAudioScope.EntireDesktop, new HashSet<string>(), false);
+}
+
+internal sealed class ScreenAudioCapture : NSObject, ISCStreamOutput
+{
+    private static readonly HashSet<string> ScreenReaders = ["com.apple.VoiceOver", "com.apple.VoiceOver4", "com.apple.speech.speechsynthesisd"];
+    private readonly int channels;
+    private readonly CapturePcmHandler onPcm;
+    private readonly ScreenAudioSelection selection;
+    private readonly DispatchQueue queue = new("net.iamtalon.voicecat.screen-audio");
+    private readonly CaptureDelegate streamDelegate;
+    private SCStream? stream;
+    private int disposed;
+
+    internal ScreenAudioCapture(int channels, ScreenAudioSelection selection, CapturePcmHandler onPcm)
+    {
+        this.channels = Math.Clamp(channels, 1, 2); this.selection = selection; this.onPcm = onPcm;
+        streamDelegate = new(error => Failed?.Invoke(error));
+    }
+
+    internal event Action<Exception>? Failed;
+
+    internal static async Task<IReadOnlyList<ScreenApplication>> GetApplicationsAsync(CancellationToken cancellationToken = default)
+    {
+        SCShareableContent content = await GetContentAsync(cancellationToken).ConfigureAwait(false);
+        return content.Applications.Where(application => !string.IsNullOrWhiteSpace(application.BundleIdentifier) &&
+                !ScreenReaders.Contains(application.BundleIdentifier) && application.BundleIdentifier != NSBundle.MainBundle.BundleIdentifier)
+            .GroupBy(application => application.BundleIdentifier, StringComparer.Ordinal).Select(group => group.First())
+            .Select(application => new ScreenApplication(string.IsNullOrWhiteSpace(application.ApplicationName) ? application.BundleIdentifier : application.ApplicationName,
+                application.BundleIdentifier)).OrderBy(application => application.Name, StringComparer.CurrentCultureIgnoreCase).ToArray();
+    }
+
+    internal async Task StartAsync(CancellationToken cancellationToken = default)
+    {
+        SCShareableContent content = await GetContentAsync(cancellationToken).ConfigureAwait(false);
+        SCDisplay display = content.Displays.FirstOrDefault() ?? throw new InvalidOperationException("No display is available for screen audio capture.");
+        SCRunningApplication[] matching = content.Applications.Where(application => Included(application.BundleIdentifier)).ToArray();
+        SCContentFilterOption option = selection.Scope == ScreenAudioScope.OnlyApplications ? SCContentFilterOption.Include : SCContentFilterOption.Exclude;
+        var filter = new SCContentFilter(display, matching, [], option);
+        var configuration = new SCStreamConfiguration
+        {
+            CapturesAudio = true, ExcludesCurrentProcessAudio = true, SampleRate = 48_000,
+            ChannelCount = channels, Width = 2, Height = 2, QueueDepth = 6,
+            MinimumFrameInterval = new CMTime(1, 1)
+        };
+        var created = new SCStream(filter, configuration, streamDelegate);
+        if (!created.AddStreamOutput(this, SCStreamOutputType.Audio, queue, out NSError? outputError))
+            throw new InvalidOperationException(outputError?.LocalizedDescription ?? "Could not attach the screen-audio output.");
+        stream = created;
+        var started = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        created.StartCapture(error => { if (error is null) started.TrySetResult(); else started.TrySetException(new InvalidOperationException(error.LocalizedDescription)); });
+        await started.Task.WaitAsync(TimeSpan.FromSeconds(15), cancellationToken).ConfigureAwait(false);
+    }
+
+    private bool Included(string bundleIdentifier)
+    {
+        bool selected = selection.BundleIdentifiers.Contains(bundleIdentifier);
+        bool reader = selection.ExcludeScreenReader && ScreenReaders.Contains(bundleIdentifier);
+        return selection.Scope switch
+        {
+            ScreenAudioScope.OnlyApplications => selected,
+            ScreenAudioScope.AllExceptApplications => selected || reader,
+            _ => reader
+        };
+    }
+
+    [Export("stream:didOutputSampleBuffer:ofType:")]
+    public unsafe void DidOutputSampleBuffer(SCStream captureStream, CMSampleBuffer sampleBuffer, SCStreamOutputType type)
+    {
+        if (type != SCStreamOutputType.Audio || !sampleBuffer.DataIsReady || disposed != 0) return;
+        int frames = checked((int)sampleBuffer.NumSamples);
+        if (frames <= 0 || frames > 8192) return;
+        Span<byte> listStorage = stackalloc byte[40];
+        fixed (byte* list = listStorage)
+        {
+            int status = CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer.Handle, out _, (IntPtr)list,
+                (nuint)listStorage.Length, IntPtr.Zero, IntPtr.Zero, 0, out IntPtr blockBuffer);
+            if (status != 0) return;
+            try
+            {
+                uint count = *(uint*)list;
+                if (count is 0 or > 2) return;
+                Span<short> converted = stackalloc short[frames * channels];
+                NativeAudioBuffer* first = (NativeAudioBuffer*)(list + 8);
+                bool planar = count > 1;
+                int sourceChannels = planar ? checked((int)count) : checked((int)Math.Max(1, first->Channels));
+                for (int frame = 0; frame < frames; frame++)
+                {
+                    float left = planar ? ((float*)first[0].Data)[frame] : ((float*)first[0].Data)[frame * sourceChannels];
+                    float right = sourceChannels > 1
+                        ? planar ? ((float*)first[1].Data)[frame] : ((float*)first[0].Data)[frame * sourceChannels + 1]
+                        : left;
+                    if (channels == 1) converted[frame] = ToInt16(sourceChannels > 1 ? (left + right) * 0.5f : left);
+                    else { converted[frame * 2] = ToInt16(left); converted[frame * 2 + 1] = ToInt16(right); }
+                }
+                onPcm(converted, channels);
+            }
+            finally { if (blockBuffer != IntPtr.Zero) CFRelease(blockBuffer); }
+        }
+    }
+
+    private static short ToInt16(float value) => (short)Math.Clamp((int)MathF.Round(Math.Clamp(value, -1, 1) * 32767), short.MinValue, short.MaxValue);
+
+    private static Task<SCShareableContent> GetContentAsync(CancellationToken cancellationToken)
+    {
+        var completion = new TaskCompletionSource<SCShareableContent>(TaskCreationOptions.RunContinuationsAsynchronously);
+        SCShareableContent.GetShareableContent((content, error) =>
+        {
+            if (error is not null) completion.TrySetException(new UnauthorizedAccessException(error.LocalizedDescription));
+            else if (content is null) completion.TrySetException(new InvalidOperationException("ScreenCaptureKit returned no shareable content."));
+            else completion.TrySetResult(content);
+        });
+        cancellationToken.Register(() => completion.TrySetCanceled(cancellationToken));
+        return completion.Task;
+    }
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing && Interlocked.Exchange(ref disposed, 1) == 0)
+        {
+            SCStream? previous = Interlocked.Exchange(ref stream, null);
+            if (previous is null) { streamDelegate.Dispose(); queue.Dispose(); }
+            else previous.StopCapture(_ => { previous.Dispose(); streamDelegate.Dispose(); queue.Dispose(); });
+        }
+        base.Dispose(disposing);
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct NativeAudioBuffer { internal uint Channels, DataByteSize; internal IntPtr Data; }
+
+    private sealed class CaptureDelegate(Action<Exception> failed) : SCStreamDelegate
+    {
+        public override void DidStop(SCStream stream, NSError error) => failed(new IOException(error.LocalizedDescription));
+    }
+
+    [DllImport("/System/Library/Frameworks/CoreMedia.framework/CoreMedia")]
+    private static extern int CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(IntPtr sampleBuffer,
+        out nuint bufferListSizeNeeded, IntPtr bufferList, nuint bufferListSize, IntPtr structureAllocator,
+        IntPtr blockAllocator, uint flags, out IntPtr blockBuffer);
+
+    [DllImport("/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation")]
+    private static extern void CFRelease(IntPtr value);
+}

clients/apple/VoiceCat.Mac/ScreenAudioPicker.cs

@@ -0,0 +1,49 @@
+using AppKit;
+using CoreGraphics;
+using Foundation;
+using ScreenCaptureKit;
+
+namespace VoiceCat.Mac;
+
+internal sealed record ScreenApplication(string Name, string BundleIdentifier);
+
+internal static class ScreenAudioPicker
+{
+    internal static async Task<ScreenAudioSelection?> ChooseAsync(ScreenAudioSelection initial, CancellationToken cancellationToken = default)
+    {
+        IReadOnlyList<ScreenApplication> applications = await ScreenAudioCapture.GetApplicationsAsync(cancellationToken);
+        var mode = new NSPopUpButton(new CGRect(0, 270, 390, 28), false);
+        mode.AddItems(["Everything", "Only selected applications", "All except selected applications"]);
+        mode.SelectItem((int)initial.Scope);
+        ((INSAccessibility)mode).AccessibilityLabel = "Screen audio sharing mode";
+
+        var source = new ApplicationSource(applications);
+        var table = new NSTableView(new CGRect(0, 0, 390, 225)) { DataSource = source, Delegate = source, AllowsMultipleSelection = true, HeaderView = null };
+        table.AddColumn(new NSTableColumn("application") { Title = "Application", Width = 370 });
+        ((INSAccessibility)table).AccessibilityLabel = "Applications to include or exclude";
+        uint[] selected = applications.Select((application, index) => initial.BundleIdentifiers.Contains(application.BundleIdentifier) ? (uint?)index : null)
+            .Where(index => index.HasValue).Select(index => index!.Value).ToArray();
+        if (selected.Length > 0) table.SelectRows(NSIndexSet.FromArray(selected), false);
+        var scroll = new NSScrollView(new CGRect(0, 38, 390, 225)) { DocumentView = table, HasVerticalScroller = true, BorderType = NSBorderType.BezelBorder };
+        var exclude = NSButton.CreateCheckbox("Exclude VoiceOver and speech-synthesis audio", () => { });
+        exclude.Frame = new CGRect(0, 5, 390, 24); exclude.State = initial.ExcludeScreenReader ? NSCellStateValue.On : NSCellStateValue.Off;
+        ((INSAccessibility)exclude).AccessibilityLabel = "Exclude screen reader audio";
+        var accessory = new NSView(new CGRect(0, 0, 390, 305)); accessory.AddSubview(mode); accessory.AddSubview(scroll); accessory.AddSubview(exclude);
+        var alert = new NSAlert { MessageText = "Choose screen audio", InformativeText = "Select what other people will hear.", AccessoryView = accessory };
+        alert.AddButton("Share"); alert.AddButton("Cancel");
+        if (alert.RunModal() != 1000) return null;
+        var bundleIdentifiers = table.SelectedRows.ToArray().Select(index => applications[checked((int)index)].BundleIdentifier).ToHashSet(StringComparer.Ordinal);
+        return new((ScreenAudioScope)(int)mode.IndexOfSelectedItem, bundleIdentifiers, exclude.State == NSCellStateValue.On);
+    }
+
+    private sealed class ApplicationSource(IReadOnlyList<ScreenApplication> applications) : NSTableViewDataSource, INSTableViewDelegate
+    {
+        public override nint GetRowCount(NSTableView tableView) => applications.Count;
+        [Export("tableView:viewForTableColumn:row:")]
+        public NSView GetViewForItem(NSTableView tableView, NSTableColumn? tableColumn, nint row)
+        {
+            var value = NSTextField.CreateLabel(applications[checked((int)row)].Name);
+            value.LineBreakMode = AppKit.NSLineBreakMode.TruncatingTail; return value;
+        }
+    }
+}

clients/apple/VoiceCat.Mac/SettingsWindowController.cs

@@ -0,0 +1,126 @@
+using AppKit;
+using CoreGraphics;
+using VoiceCat.Audio;
+
+namespace VoiceCat.Mac;
+
+internal sealed class SettingsWindowController : NSWindowController
+{
+    private readonly MainWindowController owner;
+    private readonly MacSettings settings;
+    private readonly MacAudioBackend audio;
+    private readonly NSPopUpButton mode = new(new CGRect(160, 455, 260, 28), false);
+    private readonly NSSlider vad = new(new CGRect(160, 415, 260, 24)) { MinValue = 0, MaxValue = 100 };
+    private readonly NSSlider inputGain = new(new CGRect(160, 375, 260, 24)) { MinValue = 0, MaxValue = 400 };
+    private readonly NSButton noiseReduction = NSButton.CreateCheckbox("Noise reduction (RNNoise)", () => { });
+    private readonly NSButton stereo = NSButton.CreateCheckbox("Stereo microphone", () => { });
+    private readonly NSPopUpButton input = new(new CGRect(160, 285, 260, 28), false);
+    private readonly NSPopUpButton output = new(new CGRect(160, 245, 260, 28), false);
+    private readonly NSSlider outputGain = new(new CGRect(160, 205, 260, 24)) { MinValue = 0, MaxValue = 100 };
+    private readonly NSButton auxiliary = NSButton.CreateCheckbox("Aux input stream", () => { });
+    private readonly NSPopUpButton auxiliaryDevice = new(new CGRect(160, 125, 260, 28), false);
+    private readonly NSSlider auxiliaryGain = new(new CGRect(160, 85, 260, 24)) { MinValue = 0, MaxValue = 400 };
+    private readonly NSButton sounds = NSButton.CreateCheckbox("Event sounds", () => { });
+    private readonly NSButton speech = NSButton.CreateCheckbox("Speak events", () => { });
+    private readonly NSButton selfTalk = NSButton.CreateCheckbox("Own voice-activity sounds", () => { });
+    private readonly NSButton pttSound = NSButton.CreateCheckbox("Push-to-talk cue", () => { });
+    private readonly NSButton pttKey = new(new CGRect(220, 12, 200, 32)) { Title = "Change PTT key…" };
+    private readonly NSSlider eventVolume = new(new CGRect(160, 505, 260, 24)) { MinValue = 0, MaxValue = 100 };
+    private readonly NSPopUpButton audioBuffer = new(new CGRect(160, 545, 260, 28), false);
+
+    internal SettingsWindowController(MainWindowController owner, MacSettings settings, MacAudioBackend audio) : base(
+        new NSWindow(new CGRect(0, 0, 460, 660), NSWindowStyle.Titled | NSWindowStyle.Closable,
+            NSBackingStore.Buffered, false))
+    {
+        this.owner = owner; this.settings = settings; this.audio = audio;
+        Window!.Title = "VoiceCat Settings"; Window.Center();
+        NSView view = Window.ContentView!;
+        mode.AddItems(["Voice activation", "Push to talk", "Always on"]);
+        audioBuffer.AddItems(["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"]);
+        Add(view, "Audio buffering", audioBuffer, 555);
+        Add(view, "Sound volume", eventVolume, 515);
+        Add(view, "Input mode", mode, 465); Add(view, "VAD sensitivity", vad, 425); Add(view, "Microphone volume", inputGain, 385);
+        noiseReduction.Frame = new CGRect(160, 340, 260, 24); stereo.Frame = new CGRect(160, 315, 260, 24);
+        view.AddSubview(noiseReduction); view.AddSubview(stereo);
+        Add(view, "Input device", input, 295); Add(view, "Output device", output, 255); Add(view, "Output volume", outputGain, 215);
+        auxiliary.Frame = new CGRect(160, 165, 260, 24); view.AddSubview(auxiliary);
+        Add(view, "Aux device", auxiliaryDevice, 135); Add(view, "Aux volume", auxiliaryGain, 95);
+        sounds.Frame = new CGRect(25, 45, 110, 24); speech.Frame = new CGRect(145, 45, 110, 24);
+        selfTalk.Frame = new CGRect(265, 45, 180, 24); pttSound.Frame = new CGRect(25, 18, 180, 24);
+        view.AddSubview(sounds); view.AddSubview(speech); view.AddSubview(selfTalk); view.AddSubview(pttSound); view.AddSubview(pttKey);
+        foreach (NSControl control in new NSControl[] { mode, vad, inputGain, noiseReduction, stereo, input, output,
+            outputGain, auxiliary, auxiliaryDevice, auxiliaryGain, sounds, speech, selfTalk, pttSound, eventVolume, audioBuffer }) control.Activated += Changed;
+        pttKey.Activated += CapturePushToTalkKey;
+        Populate(input, true, settings.InputDeviceId); Populate(output, false, settings.OutputDeviceId); Populate(auxiliaryDevice, true, settings.AuxiliaryDeviceId);
+        LoadValues(); SetAccessibility();
+    }
+
+    private static void Add(NSView view, string label, NSView control, double y)
+    {
+        NSTextField text = NSTextField.CreateLabel(label); text.Frame = new CGRect(25, y, 125, 22); view.AddSubview(text); view.AddSubview(control);
+    }
+
+    private void Populate(NSPopUpButton picker, bool capture, string? selected)
+    {
+        picker.RemoveAllItems(); IReadOnlyList<AudioDeviceInfo> devices = audio.Enumerate(capture);
+        foreach (AudioDeviceInfo device in devices) { picker.AddItem(device.Name + (device.IsDefault ? " (default)" : "")); picker.LastItem!.RepresentedObject = new Foundation.NSString(device.Id); }
+        int index = devices.ToList().FindIndex(device => device.Id == selected);
+        if (index < 0) index = devices.ToList().FindIndex(device => device.IsDefault);
+        if (index >= 0) picker.SelectItem(index); picker.Enabled = devices.Count > 0;
+    }
+
+    private void LoadValues()
+    {
+        mode.SelectItem((int)settings.InputMode); vad.DoubleValue = settings.VadThreshold * 100;
+        inputGain.DoubleValue = settings.InputGain * 100; outputGain.DoubleValue = settings.OutputGain * 100;
+        noiseReduction.State = State(settings.InputNoiseReduction); stereo.State = State(settings.StereoMicrophone);
+        auxiliary.State = State(settings.AuxiliaryEnabled); auxiliaryGain.DoubleValue = settings.AuxiliaryGain * 100;
+        sounds.State = State(settings.EventSounds); speech.State = State(settings.SpokenEvents);
+        eventVolume.DoubleValue = settings.EventVolume * 100;
+        selfTalk.State = State(settings.SelfTalkSounds); pttSound.State = State(settings.PushToTalkSound);
+        pttKey.Title = $"PTT key code: {settings.PushToTalkKeyCode}";
+        audioBuffer.SelectItem(settings.AudioBufferMilliseconds switch { 20 => 0, 60 => 2, _ => 1 });
+        UpdateEnabled();
+    }
+
+    private void CapturePushToTalkKey(object? sender, EventArgs args)
+    {
+        var alert = new NSAlert { MessageText = "Set push-to-talk key", InformativeText = "Press the key to use while VoiceCat is focused." };
+        alert.AddButton("Cancel"); NSObject? monitor = null;
+        monitor = NSEvent.AddLocalMonitorForEventsMatchingMask(NSEventMask.KeyDown, value =>
+        {
+            settings.PushToTalkKeyCode = value.KeyCode; settings.Save(); pttKey.Title = $"PTT key code: {value.KeyCode}";
+            NSApplication.SharedApplication.AbortModal(); return null!;
+        });
+        try { alert.RunModal(); }
+        finally { if (monitor is not null) NSEvent.RemoveMonitor(monitor); }
+    }
+
+    private async void Changed(object? sender, EventArgs args)
+    {
+        settings.InputMode = (AudioInputMode)mode.IndexOfSelectedItem; settings.VadThreshold = (float)vad.DoubleValue / 100;
+        settings.InputGain = (float)inputGain.DoubleValue / 100; settings.OutputGain = (float)outputGain.DoubleValue / 100;
+        settings.InputNoiseReduction = On(noiseReduction); settings.StereoMicrophone = On(stereo);
+        settings.InputDeviceId = Selected(input); settings.OutputDeviceId = Selected(output);
+        settings.AuxiliaryEnabled = On(auxiliary); settings.AuxiliaryDeviceId = Selected(auxiliaryDevice);
+        settings.AuxiliaryGain = (float)auxiliaryGain.DoubleValue / 100; settings.EventSounds = On(sounds);
+        settings.EventVolume = (float)eventVolume.DoubleValue / 100; settings.SpokenEvents = On(speech);
+        settings.SelfTalkSounds = On(selfTalk); settings.PushToTalkSound = On(pttSound);
+        settings.AudioBufferMilliseconds = audioBuffer.IndexOfSelectedItem switch { 0 => 20, 2 => 60, _ => 40 };
+        settings.Save(); UpdateEnabled(); await owner.ApplySettingsAsync();
+    }
+
+    private void UpdateEnabled() { vad.Enabled = settings.InputMode == AudioInputMode.VoiceActivation; auxiliaryDevice.Enabled = auxiliaryGain.Enabled = settings.AuxiliaryEnabled; }
+    private void SetAccessibility()
+    {
+        ((INSAccessibility)mode).AccessibilityLabel = "Microphone input mode"; ((INSAccessibility)vad).AccessibilityLabel = "Voice activation sensitivity";
+        ((INSAccessibility)inputGain).AccessibilityLabel = "Microphone volume"; ((INSAccessibility)input).AccessibilityLabel = "Microphone device";
+        ((INSAccessibility)output).AccessibilityLabel = "Output device"; ((INSAccessibility)outputGain).AccessibilityLabel = "Output volume";
+        ((INSAccessibility)auxiliaryDevice).AccessibilityLabel = "Auxiliary input device"; ((INSAccessibility)auxiliaryGain).AccessibilityLabel = "Auxiliary input volume";
+        ((INSAccessibility)eventVolume).AccessibilityLabel = "Event sound volume";
+        ((INSAccessibility)audioBuffer).AccessibilityLabel = "Audio buffering";
+    }
+    private static bool On(NSButton button) => button.State == NSCellStateValue.On;
+    private static NSCellStateValue State(bool value) => value ? NSCellStateValue.On : NSCellStateValue.Off;
+    private static string? Selected(NSPopUpButton picker) => picker.SelectedItem?.RepresentedObject?.ToString();
+}

clients/apple/VoiceCat.Mac/VoiceCat.Mac.csproj

@@ -0,0 +1,46 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0-macos27.0</TargetFramework>
+    <RuntimeIdentifier>osx-arm64</RuntimeIdentifier>
+    <SupportedOSPlatformVersion>14.0</SupportedOSPlatformVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <ApplicationTitle>VoiceCat</ApplicationTitle>
+    <ApplicationId>net.iamtalon.voicecat</ApplicationId>
+    <UseHardenedRuntime Condition="'$(Configuration)' == 'Release'">true</UseHardenedRuntime>
+    <UseHardenedRuntime Condition="'$(Configuration)' != 'Release'">false</UseHardenedRuntime>
+    <ApplicationManifest>Info.plist</ApplicationManifest>
+    <CodesignEntitlements>VoiceCat.Mac.entitlements</CodesignEntitlements>
+    <NoWarn>$(NoWarn);XCODE_27_0_PREVIEW</NoWarn>
+    <VoiceCatNativeMediaPath>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)../../../artifacts/native/runtimes/osx-arm64/native/libvoicecat_media.dylib'))</VoiceCatNativeMediaPath>
+    <VoiceCatNativeLicenseDirectory>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)../../../artifacts/native/licenses'))</VoiceCatNativeLicenseDirectory>
+    <_ComputePublishLocationDependsOn>VoiceCatPrepareNativeAssets;$(_ComputePublishLocationDependsOn)</_ComputePublishLocationDependsOn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../../../src/VoiceCat.Core/VoiceCat.Core.csproj" />
+    <BundleResource Include="../../../assets/sounds/*.wav" Link="Sounds/%(Filename)%(Extension)" />
+  </ItemGroup>
+
+  <!-- Every managed media project stages the same dylib for ordinary .NET consumers.
+       The macOS bundler preserves those transitive items separately and otherwise runs
+       install_name_tool against the same temporary file concurrently. Collapse them to
+       the single native reference the application actually ships. -->
+  <Target Name="VoiceCatPrepareNativeAssets">
+    <ItemGroup>
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'libvoicecat_media.dylib'" />
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'NOTICE.txt' or '%(Filename)%(Extension)' == 'Opus.txt' or '%(Filename)%(Extension)' == 'RNNoise.txt'" />
+      <ResolvedFileToPublish Include="$(VoiceCatNativeMediaPath)" Condition="Exists('$(VoiceCatNativeMediaPath)')">
+        <RelativePath>libvoicecat_media.dylib</RelativePath>
+        <PublishFolderType>DynamicLibrary</PublishFolderType>
+        <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
+      </ResolvedFileToPublish>
+      <ResolvedFileToPublish Include="$(VoiceCatNativeLicenseDirectory)/*.txt">
+        <RelativePath>licenses/%(Filename)%(Extension)</RelativePath>
+        <PublishFolderType>Assembly</PublishFolderType>
+        <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
+      </ResolvedFileToPublish>
+    </ItemGroup>
+  </Target>
+</Project>

clients/apple/VoiceCat.Mac/VoiceCat.Mac.entitlements

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>com.apple.security.app-sandbox</key><true/>
+  <key>com.apple.security.cs.allow-jit</key><true/>
+  <key>com.apple.security.network.client</key><true/>
+  <key>com.apple.security.device.audio-input</key><true/>
+  <key>com.apple.security.files.user-selected.read-write</key><true/>
+</dict></plist>

clients/apple/VoiceCat.Mac/packages.lock.json

@@ -0,0 +1,58 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0-macos27.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.12, )",
+        "resolved": "10.0.12",
+        "contentHash": "xi+BDjFpW+Sb+MHFHaH6Y/gV9I8BluFwRXc1QyCdoZbIK26eNiBeFuMTe/FMwc33G1wdHCyDg7CVTmb8OdQrMQ=="
+      },
+      "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-macos27.0/osx-arm64": {}
+  }
+}

clients/apple/VoiceCat.iOS/AdministrationControllers.cs

@@ -0,0 +1,150 @@
+using UIKit;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed class UsersController : UITableViewController
+{
+    private readonly AppModel model; private IReadOnlyList<User> Visible => model.CurrentChannelId == 0 ? model.Users : model.Users.Where(user => user.ChannelId == model.CurrentChannelId).ToArray();
+    internal UsersController(AppModel model) { this.model = model; Title = "Users"; model.Changed += () => TableView.ReloadData(); }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "user"); }
+    public override nint RowsInSection(UITableView tableView, nint section) => Visible.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        User user = Visible[indexPath.Row]; UITableViewCell cell = tableView.DequeueReusableCell("user", indexPath); var content = cell.DefaultContentConfiguration;
+        content.Text = user.Nickname + (user.Id == model.SelfUserId ? " (you)" : "");
+        content.SecondaryText = user.ServerDeafened ? "server deafened" : user.ServerMuted ? "server muted" : user.SelfDeafened ? "deafened" : user.SelfMicMuted ? "muted" : user.IsGuest ? "guest" : "account";
+        content.Image = UIImage.GetSystemImage(user.ServerMuted || user.SelfMicMuted ? "mic.slash.fill" : "mic.fill"); cell.ContentConfiguration = content; cell.AccessibilityLabel = $"{content.Text}, {content.SecondaryText}";
+        cell.Accessory = user.Id == model.SelfUserId ? UITableViewCellAccessory.None : UITableViewCellAccessory.DisclosureIndicator;
+        if (user.Id != model.SelfUserId) cell.AccessibilityCustomActions =
+        [
+            new("Open user details", (Func<UIAccessibilityCustomAction, bool>)(_ => { Open(user.Id); return true; })),
+            new("Private message", (Func<UIAccessibilityCustomAction, bool>)(_ => { NavigationController?.PushViewController(new PrivateConversationController(model, user.Id, user.Nickname), true); return true; }))
+        ];
+        return cell;
+    }
+    public override void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        User user = Visible[indexPath.Row]; tableView.DeselectRow(indexPath, true); if (user.Id == model.SelfUserId) return;
+        Open(user.Id);
+    }
+    private void Open(uint userId) => NavigationController?.PushViewController(new UserDetailController(model, userId), true);
+}
+
+internal sealed class UserDetailController : FormController
+{
+    private readonly AppModel model; private readonly uint userId;
+    private User? User => model.Users.FirstOrDefault(value => value.Id == userId);
+    private IReadOnlyList<(string Title, Action Run, bool Destructive)> AdminActions
+    {
+        get
+        {
+        User? user = User; if (user is null) return [];
+        Permissions permissions = model.Client?.Permissions ?? new(); var result = new List<(string, Action, bool)>();
+        if (permissions.CanKick || permissions.IsAdmin) result.Add(("Kick", () => PromptReason(user, false), true));
+        if (permissions.CanBan || permissions.IsAdmin) result.Add(("Ban", () => NavigationController?.PushViewController(new BanUserController(model, user), true), true));
+        if (permissions.CanMoveUsers || permissions.IsAdmin) result.Add(("Move to channel", () => NavigationController?.PushViewController(new MoveUserController(model, user), true), false));
+        if (permissions.IsAdmin)
+        {
+            result.Add((user.ServerMuted ? "Server unmute" : "Server mute", () => Run(() => model.Client!.SetServerMuteAsync(user.Id, !user.ServerMuted, user.ServerDeafened)), false));
+            result.Add((user.ServerDeafened ? "Server undeafen" : "Server deafen", () => Run(() => model.Client!.SetServerMuteAsync(user.Id, user.ServerMuted, !user.ServerDeafened)), false));
+            result.Add(("Permissions", () => NavigationController?.PushViewController(new PermissionsController(model, user), true), false));
+        }
+        return result;
+        }
+    }
+    internal UserDetailController(AppModel model, uint userId) : base(model.Users.FirstOrDefault(value => value.Id == userId)?.Nickname ?? $"User {userId}")
+    { this.model = model; this.userId = userId; model.Changed += Reload; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "detail"); Reload(); }
+    public override nint NumberOfSections(UITableView tableView) => AdminActions.Count == 0 ? 2 : 3;
+    public override nint RowsInSection(UITableView tableView, nint section) => section switch
+    { 0 => Math.Max(User?.Streams.Count ?? 0, 1), 1 => 1, _ => AdminActions.Count };
+    public override string? TitleForHeader(UITableView tableView, nint section) => section switch { 0 => "Audio streams", 1 => "Conversation", _ => "Administration" };
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        User? user = User;
+        if (indexPath.Section == 0)
+        {
+            if (user is null || user.Streams.Count == 0)
+            {
+                UITableViewCell empty = TextCell(tableView, indexPath, "detail", user is null ? "User is offline" : "No active audio streams");
+                empty.SelectionStyle = UITableViewCellSelectionStyle.None; empty.AccessibilityTraits |= UIAccessibilityTrait.NotEnabled; return empty;
+            }
+            StreamInfo stream = user.Streams[indexPath.Row]; string kind = stream.Kind == StreamKind.StreamMic ? "Microphone" : "Screen audio";
+            (float Gain, bool Muted, bool NoiseReduction)? state = model.Client?.Audio.GetRemotePlayback(userId, stream.StreamId);
+            string status = state is null ? kind : $"{kind} · {state.Value.Gain:P0}{(state.Value.Muted ? " · muted" : "")}{(state.Value.NoiseReduction && stream.Kind == StreamKind.StreamMic ? " · noise reduction" : "")}";
+            string displayName = string.IsNullOrWhiteSpace(stream.Label) ? kind : stream.Label; UITableViewCell cell = TextCell(tableView, indexPath, "detail", displayName, status);
+            cell.Accessory = UITableViewCellAccessory.DisclosureIndicator; cell.AccessibilityLabel = $"{displayName}, {status}"; return cell;
+        }
+        if (indexPath.Section == 1)
+        {
+            UITableViewCell cell = TextCell(tableView, indexPath, "detail", "Private message", user is null ? "User is offline" : null);
+            cell.Accessory = UITableViewCellAccessory.DisclosureIndicator; cell.UserInteractionEnabled = user is not null; if (user is null) cell.AccessibilityTraits |= UIAccessibilityTrait.NotEnabled; return cell;
+        }
+        (string title, _, bool destructive) = AdminActions[indexPath.Row]; UITableViewCell action = TextCell(tableView, indexPath, "detail", title);
+        if (destructive) { UIListContentConfiguration content = action.DefaultContentConfiguration; content.TextProperties.Color = UIColor.SystemRed; action.ContentConfiguration = content; } return action;
+    }
+    public override void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        tableView.DeselectRow(indexPath, true); User? user = User; if (user is null) return;
+        if (indexPath.Section == 0 && user.Streams.Count > indexPath.Row)
+            NavigationController?.PushViewController(new PerUserTuningController(model, user.Id, user.Streams[indexPath.Row].StreamId), true);
+        else if (indexPath.Section == 1) NavigationController?.PushViewController(new PrivateConversationController(model, user.Id, user.Nickname), true);
+        else if (indexPath.Section == 2) AdminActions[indexPath.Row].Run();
+    }
+    private void Reload() { Title = User?.Nickname ?? $"User {userId}"; if (IsViewLoaded) TableView.ReloadData(); }
+    private void PromptReason(User user, bool ban) { UIAlertController prompt = UIAlertController.Create(ban ? "Ban user" : "Kick user", "Reason (optional)", UIAlertControllerStyle.Alert); prompt.AddTextField(field => field.AccessibilityLabel = "Reason"); prompt.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); prompt.AddAction(UIAlertAction.Create(ban ? "Ban" : "Kick", UIAlertActionStyle.Destructive, _ => Run(() => model.Client!.KickUserAsync(user.Id, prompt.TextFields?[0].Text ?? "")))); PresentViewController(prompt, true, null); }
+    private async void Run(Func<Task<GenericResult>> command) { try { GenericResult result = await model.RunAdminAsync(_ => command()); if (!result.Ok) throw new InvalidOperationException(result.Message); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+}
+
+internal abstract class FormController : UITableViewController
+{
+    protected FormController(string title) : base(UITableViewStyle.InsetGrouped) { Title = title; }
+    protected static UITableViewCell TextCell(UITableView table, NSIndexPath path, string id, string text, string? detail = null)
+    { UITableViewCell cell = table.DequeueReusableCell(id, path); var content = cell.DefaultContentConfiguration; content.Text = text; content.SecondaryText = detail; cell.ContentConfiguration = content; return cell; }
+    protected static UISwitch Switch(bool value, string label, EventHandler handler) { var toggle = new UISwitch { On = value, AccessibilityLabel = label }; toggle.ValueChanged += handler; return toggle; }
+}
+
+internal sealed class PermissionsController : FormController
+{
+    private readonly AppModel model; private readonly User user; private readonly string[] names = ["Create temporary channels", "Kick users", "Ban users", "Move users", "Manage accounts", "Administrator"];
+    private readonly bool[] values = new bool[6];
+    internal PermissionsController(AppModel model, User user) : base($"Permissions — {user.Nickname}") { this.model = model; this.user = user; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "permission"); NavigationItem.RightBarButtonItem = new("Save", UIBarButtonItemStyle.Done, async (_, _) => await Save()); }
+    public override nint RowsInSection(UITableView tableView, nint section) => names.Length;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath) { UITableViewCell cell = TextCell(tableView, indexPath, "permission", names[indexPath.Row]); int row = indexPath.Row; cell.AccessoryView = Switch(values[row], names[row], (_, _) => values[row] = ((UISwitch)cell.AccessoryView!).On); return cell; }
+    private async Task Save() { try { var permissions = new Permissions { CanCreateTempChannel = values[0], CanKick = values[1], CanBan = values[2], CanMoveUsers = values[3], CanAdminAccounts = values[4], IsAdmin = values[5] }; GenericResult result = await model.RunAdminAsync(client => client.SetPermissionsAsync(user.Id, permissions)); if (!result.Ok) throw new InvalidOperationException(result.Message); NavigationController?.PopViewController(true); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+}
+
+internal sealed class MoveUserController : FormController
+{
+    private readonly AppModel model; private readonly User user; private uint selected;
+    internal MoveUserController(AppModel model, User user) : base($"Move {user.Nickname}") { this.model = model; this.user = user; selected = user.ChannelId; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "channel"); NavigationItem.RightBarButtonItem = new("Move", UIBarButtonItemStyle.Done, async (_, _) => await Move()); }
+    public override nint RowsInSection(UITableView tableView, nint section) => model.Channels.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath) { Channel channel = model.Channels[indexPath.Row]; UITableViewCell cell = TextCell(tableView, indexPath, "channel", channel.Name); cell.Accessory = channel.Id == selected ? UITableViewCellAccessory.Checkmark : UITableViewCellAccessory.None; cell.AccessibilityLabel = channel.Name + (channel.Id == selected ? ", selected" : ""); return cell; }
+    public override void RowSelected(UITableView tableView, NSIndexPath indexPath) { selected = model.Channels[indexPath.Row].Id; tableView.ReloadData(); }
+    private async Task Move() { try { GenericResult result = await model.RunAdminAsync(client => client.MoveUserAsync(user.Id, selected)); if (!result.Ok) throw new InvalidOperationException(result.Message); NavigationController?.PopViewController(true); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+}
+
+internal sealed class BanUserController : UIViewController
+{
+    private readonly AppModel model; private readonly User user; private readonly UITextField reason = UiHelpers.Field("Reason (optional)"); private readonly UISegmentedControl duration = new(["Permanent", "1 hour", "1 day", "1 week"]);
+    internal BanUserController(AppModel model, User user) { this.model = model; this.user = user; Title = $"Ban {user.Nickname}"; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemGroupedBackground; duration.SelectedSegment = 0; duration.AccessibilityLabel = "Ban duration"; UIStackView stack = new([reason, duration]) { Axis = UILayoutConstraintAxis.Vertical, Spacing = 16, TranslatesAutoresizingMaskIntoConstraints = false }; View.AddSubview(stack); NSLayoutConstraint.ActivateConstraints([stack.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor, 24), stack.LeadingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.LeadingAnchor), stack.TrailingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.TrailingAnchor)]); NavigationItem.RightBarButtonItem = new("Ban", UIBarButtonItemStyle.Done, async (_, _) => await Ban()); }
+    private async Task Ban() { try { ulong expires = duration.SelectedSegment switch { 1 => (ulong)DateTimeOffset.UtcNow.AddHours(1).ToUnixTimeMilliseconds(), 2 => (ulong)DateTimeOffset.UtcNow.AddDays(1).ToUnixTimeMilliseconds(), 3 => (ulong)DateTimeOffset.UtcNow.AddDays(7).ToUnixTimeMilliseconds(), _ => 0 }; GenericResult result = await model.RunAdminAsync(client => client.BanUserAsync(user.Id, reason.Text ?? "", expires)); if (!result.Ok) throw new InvalidOperationException(result.Message); NavigationController?.PopViewController(true); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+}
+
+internal sealed class PerUserTuningController : FormController
+{
+    private readonly AppModel model; private readonly uint userId, streamId; private readonly UISlider gain = new() { MinValue = 0, MaxValue = 4, Value = 1 };
+    private bool muted, noise;
+    private User? User => model.Users.FirstOrDefault(value => value.Id == userId);
+    private StreamInfo? Stream => User?.Streams.FirstOrDefault(value => value.StreamId == streamId);
+    internal PerUserTuningController(AppModel model, uint userId, uint streamId) : base("Audio tuning") { this.model = model; this.userId = userId; this.streamId = streamId; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "tuning"); StreamInfo? stream = Stream; Title = stream?.Label ?? "Audio tuning"; gain.AccessibilityLabel = $"Volume gain for {User?.Nickname ?? $"User {userId}"}, {stream?.Label ?? "stream"}"; gain.ValueChanged += (_, _) => Apply(); if (model.Client?.Audio.GetRemotePlayback(userId, streamId) is { } state) { gain.Value = state.Gain; muted = state.Muted; noise = state.NoiseReduction; } }
+    public override nint RowsInSection(UITableView tableView, nint section) => Stream?.Kind == StreamKind.StreamMic ? 3 : 2;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath) { string title = indexPath.Row switch { 0 => "Gain", 1 => "Mute", _ => "Noise reduction" }; UITableViewCell cell = TextCell(tableView, indexPath, "tuning", title); if (indexPath.Row == 0) cell.AccessoryView = gain; else { int row = indexPath.Row; cell.AccessoryView = Switch(row == 1 ? muted : noise, title, (_, _) => { bool value = ((UISwitch)cell.AccessoryView!).On; if (row == 1) muted = value; else noise = value; Apply(); }); } return cell; }
+    private void Apply() { if (model.Client is not { } client || Stream is null) return; client.Audio.SetRemotePlayback(userId, streamId, gain.Value, muted, noise); }
+}

clients/apple/VoiceCat.iOS/AppDelegate.cs

@@ -0,0 +1,18 @@
+using Foundation;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+[Register("AppDelegate")]
+internal sealed class AppDelegate : UIApplicationDelegate
+{
+    public override bool FinishedLaunching(UIApplication application, NSDictionary? launchOptions)
+    {
+        AppModel.Shared.Load();
+        return true;
+    }
+
+    public override UISceneConfiguration GetConfiguration(UIApplication application, UISceneSession connectingSceneSession,
+        UISceneConnectionOptions options) => new("Default Configuration", connectingSceneSession.Role)
+        { DelegateType = typeof(SceneDelegate) };
+}

clients/apple/VoiceCat.iOS/AppModel.cs

@@ -0,0 +1,375 @@
+using UIKit;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed record ChatEntry(DateTime Timestamp, uint SenderId, uint PeerUserId, string Sender, string Peer, string Text, bool Private);
+internal sealed record ActivityEntry(DateTime Timestamp, string Text);
+
+internal sealed class AppModel
+{
+    internal static AppModel Shared { get; } = new();
+    private readonly IosStorage storage = new();
+    private readonly List<ServerProfile> profiles = [];
+    private readonly List<ChatEntry> messages = [];
+    private readonly List<ActivityEntry> activity = [];
+    private readonly IosSettings settings = new();
+    private readonly EventFeedback feedback;
+    private CancellationTokenSource? lifetime;
+    private VoiceCatClient? client;
+    private TaskCompletionSource<bool>? identityDecision;
+    private ServerProfile? connectedProfile;
+    private int reconnectAttempt;
+    private bool explicitDisconnect;
+    private uint microphoneStream;
+    private BroadcastAudioPump? broadcast;
+    private Timer? levelTimer;
+    private bool lastTalking;
+    private bool restoringVoice;
+    private uint restoreChannel;
+    private bool restoreMuted;
+    private bool restoreDeafened;
+    private bool backgrounded;
+    private int diagnosticPolls;
+
+    internal event Action? Changed;
+    internal event Action<ServerIdentityChallenge>? IdentityRequested;
+    internal IReadOnlyList<ServerProfile> Profiles => profiles;
+    internal IReadOnlyList<ChatEntry> Messages => messages;
+    internal IReadOnlyList<ActivityEntry> Activity => activity;
+    internal IosSettings Settings => settings;
+    internal VoiceCatClient? Client => client;
+    internal bool IsConnected => client?.State == ClientConnectionState.Connected;
+    internal bool SupportsAdaptivePacketLoss => client?.SupportsAdaptivePacketLoss == true;
+    internal bool IsConnecting { get; private set; }
+    internal bool VoiceJoined => microphoneStream != 0;
+    internal bool ScreenSharing => broadcast?.IsActive == true;
+    internal bool IsBackgrounded => backgrounded;
+    internal float MicrophoneLevel { get; private set; }
+    internal string Status { get; private set; } = "Not connected";
+    internal uint CurrentChannelId { get; private set; }
+    internal uint SelfUserId => client?.Authentication?.Self.Id ?? 0;
+    internal IReadOnlyList<Channel> Channels => client?.Channels ?? [];
+    internal IReadOnlyList<User> Users => client?.Users ?? [];
+
+    private AppModel() { feedback = new(settings); }
+    internal void Load() { profiles.Clear(); profiles.AddRange(storage.LoadProfiles()); settings.Load(); IosAudioRouter.Shared.Load(); Notify(); }
+    internal void Save() { storage.SaveProfiles(profiles); settings.Save(); }
+
+    internal void DidEnterBackground()
+    {
+        backgrounded = true; Save();
+        // Do not stop or rebuild AVAudioEngine here. With the `audio` background mode and an
+        // active PlayAndRecord session, capture, playback, media UDP, and screen-ring draining
+        // remain live while the scene is backgrounded or the device is locked.
+    }
+
+    internal void WillEnterForeground()
+    {
+        backgrounded = false;
+        IosAudioRouter.Shared.ResumeForeground();
+    }
+
+    internal void DidBecomeActive()
+    {
+        backgrounded = false;
+        IosAudioRouter.Shared.EnsureAudio("active scene");
+        Notify();
+    }
+
+    internal void UpsertProfile(ServerProfile profile, string? password)
+    {
+        int index = profiles.FindIndex(item => item.Id == profile.Id);
+        if (index < 0) profiles.Add(profile); else profiles[index] = profile;
+        if (!string.IsNullOrEmpty(password)) storage.SavePassword(profile.Id, password);
+        Save(); Notify();
+    }
+
+    internal void RemoveProfile(ServerProfile profile)
+    {
+        storage.RemovePassword(profile.Id); profiles.RemoveAll(item => item.Id == profile.Id); Save(); Notify();
+    }
+
+    internal async Task ConnectAsync(ServerProfile profile, string? suppliedPassword = null, bool restoring = false)
+    {
+        if (IsConnecting || IsConnected) return;
+        explicitDisconnect = false; IsConnecting = true; connectedProfile = profile;
+        Status = restoring ? "Reconnecting…" : "Connecting…"; Notify();
+        lifetime?.Cancel(); lifetime?.Dispose(); lifetime = new();
+        // The AVAudioSourceNode render callback drives Audio.RunCycle and the 20 ms capture
+        // handoff; a sleep-paced audio worker stalls when iOS coalesces backgrounded wakeups and
+        // the call glitches after several minutes in the background.
+        VoiceCatClient next = new("VoiceCat-iOS", "0.0.1", storage.TofuPath, deviceClockedAudio: true);
+        next.ConnectionStateChanged += state =>
+        {
+            if (state == ClientConnectionState.Disconnected && next.ConnectionFailure is { } failure)
+                Console.Error.WriteLine($"VoiceCat control connection failed: {failure}");
+            if (state == ClientConnectionState.Disconnected)
+                UIApplication.SharedApplication.BeginInvokeOnMainThread(async () =>
+                {
+                    try { await HandleConnectionLostAsync(next); }
+                    catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Reconnect cleanup failed: {exception}"); }
+                });
+        };
+        client = next;
+        try
+        {
+            await next.ConnectAsync(profile.Host, profile.Port, ConfirmIdentityAsync, lifetime.Token);
+            AuthResult auth = profile.Authentication == ServerAuthentication.Guest
+                ? await next.AuthenticateGuestAsync(profile.Nickname ?? "iOS User", lifetime.Token)
+                : await next.AuthenticateUserAsync(profile.Username!, suppliedPassword ?? storage.LoadPassword(profile) ?? "", lifetime.Token);
+            if (!auth.Ok) throw new InvalidOperationException(auth.Error);
+            CurrentChannelId = auth.Self.ChannelId; reconnectAttempt = 0; IsConnecting = false; Status = "Connected";
+            ApplyAudioSettings(next);
+            IosAudioEngine.Shared.StartListening(next);
+            broadcast = new(); broadcast.Changed += BroadcastChanged; broadcast.Start(next);
+            _ = PumpEventsAsync(next, lifetime.Token);
+            levelTimer?.Dispose(); levelTimer = new(_ =>
+                UIApplication.SharedApplication.BeginInvokeOnMainThread(PollAudio), null, 50, 50);
+            feedback.Play(SoundEvent.Login); feedback.Speak(restoring ? "Reconnected" : "Connected");
+            if (restoring && restoreChannel != 0) await RestoreSessionAsync(next);
+            Notify();
+        }
+        catch (Exception exception)
+        {
+            System.Diagnostics.Debug.WriteLine($"Connection failed: {exception}");
+            IsConnecting = false; Status = exception.Message;
+            if (ReferenceEquals(client, next)) { client = null; await StopSessionResourcesAsync(); }
+            await next.DisposeAsync();
+            Notify();
+            if (restoring && !explicitDisconnect) ScheduleReconnect();
+            else throw;
+        }
+    }
+
+    private ValueTask<bool> ConfirmIdentityAsync(ServerIdentityChallenge challenge, CancellationToken token)
+    {
+        identityDecision = new(TaskCreationOptions.RunContinuationsAsynchronously);
+        token.Register(() => identityDecision.TrySetCanceled(token));
+        UIApplication.SharedApplication.BeginInvokeOnMainThread(() => IdentityRequested?.Invoke(challenge));
+        return new(identityDecision.Task);
+    }
+
+    internal void ResolveIdentity(bool accepted) { identityDecision?.TrySetResult(accepted); identityDecision = null; }
+
+    private async Task PumpEventsAsync(VoiceCatClient owner, CancellationToken token)
+    {
+        try
+        {
+            await foreach (Envelope envelope in owner.ReadEventsAsync(token))
+            {
+                if (envelope.JoinChannelResult?.Ok == true) CurrentChannelId = envelope.JoinChannelResult.ChannelId;
+                if (envelope.JoinChannelResult is { Ok: false } joinFailure) AddActivity("Join failed: " + joinFailure.Error);
+                if (envelope.TextMessage is { } text)
+                {
+                    User? sender = owner.Users.FirstOrDefault(user => user.Id == text.SenderId);
+                    bool privateMessage = text.Scope == TextScope.TextPrivate;
+                    uint peerUserId = privateMessage ? text.SenderId == SelfUserId ? text.TargetId : text.SenderId : 0;
+                    User? peer = privateMessage ? owner.Users.FirstOrDefault(user => user.Id == peerUserId) : null;
+                    messages.Add(new(DateTime.Now, text.SenderId, peerUserId, sender?.Nickname ?? $"User {text.SenderId}", peer?.Nickname ?? $"User {peerUserId}", text.Body, privateMessage));
+                    if (messages.Count > 500) messages.RemoveAt(0);
+                    bool self = text.SenderId == SelfUserId;
+                    feedback.Play(text.Scope == TextScope.TextPrivate
+                        ? self ? SoundEvent.PrivateSent : SoundEvent.PrivateReceived
+                        : self ? SoundEvent.ChannelSent : SoundEvent.ChannelReceived);
+                    if (!self) feedback.Speak(text.Scope == TextScope.TextPrivate ? $"Private message from {sender?.Nickname}: {text.Body}" : $"{sender?.Nickname}: {text.Body}");
+                }
+                if (envelope.UserEvent is { } userEvent) HandleUserEvent(owner, userEvent);
+                if (envelope.StreamState is { } streamState) AddActivity($"{Name(owner, streamState.UserId)} {(streamState.Talking ? "started" : "stopped")} talking");
+                if (envelope.StreamAnnounceResult?.Ok == false) AddActivity("Stream failed: " + envelope.StreamAnnounceResult.Error);
+                if (envelope.GenericResult is { Ok: false } result) AddActivity("Operation failed: " + result.Message);
+                if (envelope.Disconnect is { } disconnected) AddActivity("Disconnected: " + disconnected.Reason);
+                UIApplication.SharedApplication.BeginInvokeOnMainThread(Notify);
+            }
+        }
+        catch (OperationCanceledException) { }
+        finally
+        {
+            await HandleConnectionLostAsync(owner);
+        }
+    }
+
+    private async Task HandleConnectionLostAsync(VoiceCatClient owner)
+    {
+        if (!ReferenceEquals(client, owner) || IsConnecting || explicitDisconnect) return;
+        // A failed TLS reader changes State but leaves the event channel open until disposal.
+        // Handle that state change directly so a Wi-Fi transition cannot strand this session.
+        CaptureRestoreState(owner);
+        client = null; Status = "Connection lost";
+        try { await StopSessionResourcesAsync(); }
+        catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Audio cleanup failed: {exception}"); }
+        try { await owner.DisposeAsync(); }
+        catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Connection cleanup failed: {exception}"); }
+        feedback.Play(SoundEvent.ConnectionLost); feedback.Speak("Connection lost, reconnecting"); Notify();
+        ScheduleReconnect();
+    }
+
+    internal async Task JoinChannelAsync(uint channelId, string password = "")
+    {
+        VoiceCatClient active = client ?? throw new InvalidOperationException("Not connected.");
+        Envelope response = await active.RequestAsync(new() { JoinChannel = new() { ChannelId = channelId, Password = password } });
+        if (response.JoinChannelResult?.Ok != true) throw new InvalidOperationException(response.JoinChannelResult?.Error ?? "Join failed.");
+        CurrentChannelId = channelId; Notify();
+    }
+
+    internal void SendText(string body, uint targetUser = 0)
+    {
+        if (string.IsNullOrWhiteSpace(body)) return;
+        (client ?? throw new InvalidOperationException("Not connected.")).Send(new()
+        {
+            TextMessage = new() { Scope = targetUser == 0 ? TextScope.TextChannel : TextScope.TextPrivate,
+                TargetId = targetUser == 0 ? CurrentChannelId : targetUser, Body = body.Trim(), ClientMsgId = Guid.NewGuid().ToString("N") }
+        });
+    }
+
+    internal async Task ToggleVoiceAsync()
+    {
+        VoiceCatClient active = client ?? throw new InvalidOperationException("Not connected.");
+        if (microphoneStream != 0)
+        {
+            IosAudioEngine.Shared.StopMicrophone(); active.StopStream(microphoneStream); microphoneStream = 0;
+            await active.SubscribeVoiceAsync(false); MicrophoneLevel = 0; feedback.Play(SoundEvent.VoiceOff); Notify(); return;
+        }
+        if (AVFoundation.AVCaptureDevice.GetAuthorizationStatus(AVFoundation.AVAuthorizationMediaType.Audio) == AVFoundation.AVAuthorizationStatus.NotDetermined)
+            await AVFoundation.AVCaptureDevice.RequestAccessForMediaTypeAsync(AVFoundation.AVAuthorizationMediaType.Audio);
+        VoiceSubscriptionResult subscribed = await active.SubscribeVoiceAsync();
+        if (!subscribed.Ok) throw new InvalidOperationException(subscribed.Error);
+        int channels = IosAudioRouter.Shared.CaptureChannels;
+        StreamInfo stream = await active.StartStreamAsync(StreamKind.StreamMic, "Microphone", channels);
+        microphoneStream = stream.StreamId; IosAudioEngine.Shared.StartMicrophone(stream.StreamId, channels); feedback.Play(SoundEvent.VoiceOn); Notify();
+    }
+
+    internal void ToggleScreenAudio()
+    {
+        if (!OperatingSystem.IsIOSVersionAtLeast(27)) throw new PlatformNotSupportedException("Use the ReplayKit broadcast picker on this iOS version.");
+        if (ScreenSharing) { IosScreenCapture.Stop(); broadcast?.RequestStop(); }
+        else
+        {
+            if (!IsConnected || CurrentChannelId == 0) throw new InvalidOperationException("Connect and join a channel before sharing screen audio.");
+            IosScreenCapture.Present();
+        }
+    }
+
+    internal void SetSelfAudio(bool muted, bool deafened) { client?.SetSelfAudioState(muted, deafened); Notify(); }
+    internal void SetPushToTalk(bool active)
+    {
+        if (client is null) return; client.Audio.PushToTalk = active;
+        if (active) feedback.Play(SoundEvent.PushToTalk); Notify();
+    }
+    internal void ApplyVoiceSettings()
+    {
+        if (client is { } active) ApplyAudioSettings(active); settings.Save(); Notify();
+    }
+
+    internal async Task<GenericResult> RunAdminAsync(Func<VoiceCatClient, Task<GenericResult>> action)
+    {
+        GenericResult result = await action(client ?? throw new InvalidOperationException("Not connected."));
+        AddActivity(result.Ok ? (string.IsNullOrEmpty(result.Message) ? "Operation completed." : result.Message) : "Operation failed: " + result.Message);
+        Notify(); return result;
+    }
+
+    internal async Task DisconnectAsync()
+    {
+        explicitDisconnect = true; lifetime?.Cancel(); await StopSessionResourcesAsync();
+        VoiceCatClient? old = client; client = null; microphoneStream = 0; IsConnecting = false; Status = "Not connected"; Notify();
+        if (old is not null) await old.DisposeAsync(); feedback.Play(SoundEvent.Logout); feedback.Speak("Disconnected");
+    }
+
+    private void ScheduleReconnect()
+    {
+        ServerProfile? profile = connectedProfile; if (profile is null || explicitDisconnect) return;
+        int delay = Math.Min(1 << Math.Min(reconnectAttempt++, 5), 30);
+        CancellationToken token = lifetime?.Token ?? default;
+        _ = Task.Run(async () =>
+        {
+            try { await Task.Delay(TimeSpan.FromSeconds(delay), token); }
+            catch (OperationCanceledException) { return; }
+            UIApplication.SharedApplication.BeginInvokeOnMainThread(async () =>
+            {
+                if (token.IsCancellationRequested || explicitDisconnect) return;
+                try { await ConnectAsync(profile, restoring: true); }
+                catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Reconnect failed: {exception}"); }
+            });
+        });
+    }
+
+    private void Notify() => Changed?.Invoke();
+
+    private void ApplyAudioSettings(VoiceCatClient owner)
+    {
+        owner.Audio.InputMode = settings.InputMode; owner.Audio.VadThreshold = settings.VadThreshold;
+        owner.Audio.InputGain = settings.InputGain; owner.Audio.OutputGain = settings.OutputGain;
+        owner.Audio.InputNoiseReduction = settings.InputNoiseReduction;
+        owner.Audio.DeviceBufferMilliseconds = settings.AudioBufferMilliseconds;
+        IosAudioEngine.Shared.BufferMilliseconds = settings.AudioBufferMilliseconds;
+    }
+
+    private void PollAudio()
+    {
+        VoiceCatClient? owner = client; uint stream = microphoneStream;
+        if (owner is null || owner.State != ClientConnectionState.Connected || stream == 0) return;
+        (float level, bool talking) = owner.Audio.GetLocalLevel(stream); MicrophoneLevel = level;
+        if (++diagnosticPolls >= 20)
+        {
+            diagnosticPolls = 0;
+            LocalAudioDiagnostics audio = owner.Audio.GetLocalDiagnostics(stream);
+            Console.Error.WriteLine($"VC_AUDIO {IosAudioEngine.Shared.CaptureDiagnostics()} cycles={audio.Cycles} starved={audio.StarvedCycles} " +
+                $"encoded={audio.EncodedPackets} packetDrops={audio.RejectedPackets} queued={audio.BufferedFrames}");
+        }
+        if (talking != lastTalking)
+        {
+            try { owner.PublishStreamState(stream, talking); }
+            catch (Exception exception) when (exception is IOException or InvalidOperationException or ObjectDisposedException) { return; }
+            lastTalking = talking; feedback.Play(talking ? SoundEvent.VoiceStart : SoundEvent.VoiceStop);
+        }
+        Notify();
+    }
+
+    private void HandleUserEvent(VoiceCatClient owner, UserEvent value)
+    {
+        string name = value.User?.Nickname ?? Name(owner, value.LeftId);
+        if (value.Kind == UserEvent.Types.Kind.Joined && value.User?.ChannelId == CurrentChannelId && value.User.Id != SelfUserId)
+        { AddActivity($"{name} joined"); feedback.Play(SoundEvent.ChannelJoin); feedback.Speak($"{name} joined"); }
+        else if (value.Kind == UserEvent.Types.Kind.Left)
+        { AddActivity($"{name} left"); feedback.Play(SoundEvent.ChannelLeave); feedback.Speak($"{name} left"); }
+        User? self = owner.Users.FirstOrDefault(user => user.Id == SelfUserId); if (self is not null) CurrentChannelId = self.ChannelId;
+    }
+
+    private void AddActivity(string text) { activity.Add(new(DateTime.Now, text)); if (activity.Count > 500) activity.RemoveAt(0); }
+    private static string Name(VoiceCatClient owner, uint id) => owner.Users.FirstOrDefault(user => user.Id == id)?.Nickname ?? $"User {id}";
+    private void BroadcastChanged()
+    {
+        UIApplication.SharedApplication.BeginInvokeOnMainThread(() =>
+        {
+            // Presenting either system picker can replace or interrupt the app's audio session.
+            // Rebuild after the producer becomes active so playback and an existing mic tap are
+            // attached to the session that will remain in use for the broadcast.
+            if (ScreenSharing) IosAudioRouter.Shared.Recover("screen sharing started");
+            Notify();
+        });
+    }
+
+    private void CaptureRestoreState(VoiceCatClient owner)
+    {
+        restoreChannel = CurrentChannelId; restoringVoice = microphoneStream != 0;
+        restoreMuted = owner.Audio.MicMuted; restoreDeafened = owner.Audio.Deafened;
+    }
+
+    private async Task RestoreSessionAsync(VoiceCatClient owner)
+    {
+        Envelope joined = await owner.RequestAsync(new() { JoinChannel = new() { ChannelId = restoreChannel } });
+        if (joined.JoinChannelResult?.Ok != true) { AddActivity("Could not restore the previous channel."); return; }
+        CurrentChannelId = restoreChannel;
+        if (restoringVoice) await ToggleVoiceAsync();
+        owner.SetSelfAudioState(restoreMuted, restoreDeafened); AddActivity($"Restored to channel {restoreChannel}{(restoringVoice ? " with voice" : "")}");
+    }
+
+    private async Task StopSessionResourcesAsync()
+    {
+        levelTimer?.Dispose(); levelTimer = null; IosAudioEngine.Shared.Stop(); microphoneStream = 0; MicrophoneLevel = 0; lastTalking = false;
+        if (broadcast is { } pump) { broadcast = null; pump.Changed -= BroadcastChanged; await pump.DisposeAsync(); }
+    }
+}

clients/apple/VoiceCat.iOS/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,14 @@
+{
+  "images" : [
+    {
+      "filename" : "AppIcon-1024.png",
+      "idiom" : "universal",
+      "platform" : "ios",
+      "size" : "1024x1024"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

clients/apple/VoiceCat.iOS/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

clients/apple/VoiceCat.iOS/BroadcastAudioPump.cs

@@ -0,0 +1,136 @@
+using System.IO.MemoryMappedFiles;
+using VoiceCat.Core;
+using Voicecat.V1;
+
+namespace VoiceCat.iOS;
+
+internal sealed class BroadcastAudioPump : IAsyncDisposable
+{
+    private const uint Magic = 0x56434252, Version = 1;
+    private const int Header = 64, Capacity = 96_000, Frame = 960;
+    private readonly CancellationTokenSource stop = new();
+    private readonly short[] scratch = new short[Frame * 2];
+    private Thread? worker;
+    private VoiceCatClient? client;
+    private MemoryMappedFile? map;
+    private MemoryMappedViewAccessor? view;
+    private string? path;
+    private uint streamId;
+    private bool active;
+    private int generation;
+
+    internal event Action? Changed;
+    internal bool IsActive => active;
+
+    internal void Start(VoiceCatClient owner)
+    {
+        client = owner;
+        worker = new Thread(Run) { IsBackground = true, Name = "VoiceCat iOS screen audio", Priority = ThreadPriority.AboveNormal };
+        worker.Start();
+    }
+
+    private void Run()
+    {
+        CancellationToken token = stop.Token;
+        try
+        {
+            while (!token.IsCancellationRequested)
+            {
+                try { DrainAsync(token).GetAwaiter().GetResult(); }
+                catch (Exception exception) when (exception is IOException or UnauthorizedAccessException or InvalidDataException or OperationCanceledException) { CloseMapping(); }
+                if (!token.IsCancellationRequested) Thread.Sleep(5);
+            }
+        }
+        finally { CloseMapping(); }
+    }
+
+    private async Task DrainAsync(CancellationToken token)
+    {
+        if (!OpenMapping()) return;
+        MemoryMappedViewAccessor pages = view!;
+        bool active = pages.ReadUInt32(16) != 0;
+        if (!active) { StopStream(); SetActive(false); return; }
+        VoiceCatClient owner = client ?? throw new IOException("Client disconnected.");
+        if (streamId == 0)
+        {
+            int startGeneration = Volatile.Read(ref generation);
+            StreamInfo stream = await owner.StartStreamAsync(StreamKind.StreamScreenAudio, "Screen audio", 2, token).ConfigureAwait(false);
+            if (startGeneration != Volatile.Read(ref generation) || pages.ReadUInt32(16) == 0 || !ReferenceEquals(client, owner))
+            {
+                try { owner.StopStream(stream.StreamId); } catch (Exception exception) when (exception is IOException or InvalidOperationException) { }
+                return;
+            }
+            streamId = stream.StreamId; pages.Write(32, pages.ReadUInt64(24)); SetActive(true);
+        }
+        ulong write = pages.ReadUInt64(24), read = pages.ReadUInt64(32);
+        if (write - read > Capacity) read = write - Capacity;
+        while (write - read >= Frame * 2)
+        {
+            for (int sample = 0; sample < scratch.Length; sample++)
+            {
+                ulong index = (read + (ulong)sample) % Capacity;
+                scratch[sample] = pages.ReadInt16(Header + checked((long)index * sizeof(short)));
+            }
+            if (!owner.Audio.FeedPcm(streamId, scratch, 2)) break;
+            read += (ulong)scratch.Length;
+            pages.Write(32, read);
+        }
+    }
+
+    // The producer opens the ring with O_CREAT and never replaces it, so one mapping covers the
+    // pump's whole life. Creating and disposing a mapping (plus its container lookup and path
+    // strings) every 5 ms tick allocated steadily at 200 Hz and churned the GC under long calls;
+    // the mapping is now built on the ring's transitions and reused until the file disappears or
+    // a drain fails.
+    private bool OpenMapping()
+    {
+        path ??= ResolvePath();
+        if (path is null) return false;
+        bool present = File.Exists(path);
+        if (view is not null)
+        {
+            if (present) return true;
+            CloseMapping(); return false;
+        }
+        if (!present) return false;
+        MemoryMappedFile candidate = MemoryMappedFile.CreateFromFile(path, FileMode.Open, null, Header + Capacity * sizeof(short), MemoryMappedFileAccess.ReadWrite);
+        try
+        {
+            MemoryMappedViewAccessor pages = candidate.CreateViewAccessor(0, Header + Capacity * sizeof(short), MemoryMappedFileAccess.ReadWrite);
+            if (pages.ReadUInt32(0) != Magic || pages.ReadUInt32(4) != Version)
+            {
+                pages.Dispose(); throw new InvalidDataException("Unsupported broadcast ring.");
+            }
+            map = candidate; view = pages; return true;
+        }
+        catch { candidate.Dispose(); throw; }
+    }
+
+    private static string? ResolvePath()
+    {
+        NSUrl? root = NSFileManager.DefaultManager.GetContainerUrl(IosConstants.AppGroup);
+        return root?.Path is null ? null : Path.Combine(root.Path, "voicecat", "broadcast_audio.ring");
+    }
+
+    private void CloseMapping()
+    {
+        view?.Dispose(); view = null;
+        map?.Dispose(); map = null;
+    }
+
+    private void StopStream()
+    {
+        uint id = streamId; streamId = 0; if (id == 0 || client?.State != ClientConnectionState.Connected) return;
+        try { client.StopStream(id); } catch (Exception exception) when (exception is IOException or InvalidOperationException) { }
+    }
+
+    internal void RequestStop() { Interlocked.Increment(ref generation); SetActive(false); }
+
+    private void SetActive(bool value) { if (active == value) return; active = value; Changed?.Invoke(); }
+
+    public ValueTask DisposeAsync()
+    {
+        stop.Cancel(); Interlocked.Increment(ref generation); worker?.Join(); worker = null;
+        StopStream(); SetActive(false); stop.Dispose(); return ValueTask.CompletedTask;
+    }
+}

clients/apple/VoiceCat.iOS/ChannelEditorController.cs

@@ -0,0 +1,57 @@
+using UIKit;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed class ChannelEditorController : UIViewController
+{
+    private readonly AppModel model; private readonly Channel? existing;
+    private readonly UITextField name = UiHelpers.Field("Channel name"), topic = UiHelpers.Field("Topic (optional)"), maximum = UiHelpers.Field("Maximum users, 0 is unlimited"), order = UiHelpers.Field("Sort order"), password = UiHelpers.Field("Password; blank preserves existing", true), bitrate = UiHelpers.Field("Bitrate in bits per second"), loss = UiHelpers.Field("Expected packet loss percent"), complexity = UiHelpers.Field("Complexity 0 through 10");
+    private readonly UISegmentedControl type = new(["Permanent", "Temporary"]), mode = new(["Mono", "Stereo"]), application = new(["VoIP", "Audio", "Low delay"]);
+    private readonly UIButton parent = UIButton.FromType(UIButtonType.System), sampleRate = UIButton.FromType(UIButtonType.System), frame = UIButton.FromType(UIButtonType.System);
+    private readonly UIButton lossSpeed = UIButton.FromType(UIButtonType.System);
+    private readonly UISwitch automaticLoss = new(), fec = new(), dtx = new(), dred = new(); private uint parentId;
+
+    internal ChannelEditorController(AppModel model, Channel? existing) { this.model = model; this.existing = existing; Title = existing is null ? "New Channel" : "Edit Channel"; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemGroupedBackground; UIScrollView scroll = new() { TranslatesAutoresizingMaskIntoConstraints = false }; UIStackView stack = new() { Axis = UILayoutConstraintAxis.Vertical, Spacing = 12, TranslatesAutoresizingMaskIntoConstraints = false };
+        View.AddSubview(scroll); scroll.AddSubview(stack); NSLayoutConstraint.ActivateConstraints([scroll.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor), scroll.BottomAnchor.ConstraintEqualTo(View.BottomAnchor), scroll.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor), scroll.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor), stack.TopAnchor.ConstraintEqualTo(scroll.ContentLayoutGuide.TopAnchor, 16), stack.BottomAnchor.ConstraintEqualTo(scroll.ContentLayoutGuide.BottomAnchor, -24), stack.LeadingAnchor.ConstraintEqualTo(scroll.FrameLayoutGuide.LeadingAnchor, 20), stack.TrailingAnchor.ConstraintEqualTo(scroll.FrameLayoutGuide.TrailingAnchor, -20)]);
+        foreach (UIView row in new UIView[] { name, topic, PickerRow("Parent channel", parent), PickerRow("Channel type", type), maximum, order, password, PickerRow("Channel mode", mode), PickerRow("Sample rate", sampleRate), PickerRow("Frame duration", frame), PickerRow("Opus application", application), bitrate, SwitchRow("Automatic packet loss", automaticLoss), PickerRow("Adaptation speed", lossSpeed), loss, complexity, SwitchRow("Forward error correction", fec), SwitchRow("Discontinuous transmission", dtx), SwitchRow("Deep redundancy", dred) }) stack.AddArrangedSubview(row);
+        maximum.KeyboardType = order.KeyboardType = bitrate.KeyboardType = loss.KeyboardType = complexity.KeyboardType = UIKeyboardType.NumberPad;
+        parent.Menu = UIMenu.Create(model.Channels.Where(channel => channel.Id != existing?.Id).OrderBy(channel => channel.Name).Select(channel => UIAction.Create(channel.Name, null, null, _ => { parentId = channel.Id; parent.SetTitle(channel.Name, UIControlState.Normal); })).Prepend(UIAction.Create("Root", null, null, _ => { parentId = 0; parent.SetTitle("Root", UIControlState.Normal); })).ToArray()); parent.ShowsMenuAsPrimaryAction = true;
+        sampleRate.Menu = Choice(sampleRate, ["48000"]); sampleRate.ShowsMenuAsPrimaryAction = true; frame.Menu = Choice(frame, ["5", "10", "20", "40", "60"]); frame.ShowsMenuAsPrimaryAction = true;
+        lossSpeed.Menu = Choice(lossSpeed, ["Fast", "Balanced", "Stable"]); lossSpeed.ShowsMenuAsPrimaryAction = true;
+        automaticLoss.Enabled = model.SupportsAdaptivePacketLoss;
+        automaticLoss.ValueChanged += (_, _) => UpdateLossControls();
+        Load(); NavigationItem.RightBarButtonItem = new("Save", UIBarButtonItemStyle.Done, async (_, _) => await Save());
+    }
+    private void Load()
+    {
+        Channel channel = existing ?? new Channel { Audio = new AudioConfig { SampleRate = 48000, BitrateBps = 64000, FrameMs = 20, Fec = true, Complexity = 10, ExpectedPacketLoss = 5 } };
+        name.Text = channel.Name; topic.Text = channel.Topic; maximum.Text = channel.MaxUsers.ToString(); order.Text = channel.Order.ToString(); parentId = channel.ParentId;
+        parent.SetTitle(model.Channels.FirstOrDefault(value => value.Id == parentId)?.Name ?? "Root", UIControlState.Normal); type.SelectedSegment = channel.Type == ChannelType.ChannelTemporary ? 1 : 0; mode.SelectedSegment = channel.Audio?.Mode == ChannelMode.ModeStereo ? 1 : 0;
+        sampleRate.SetTitle((channel.Audio?.SampleRate ?? 48000).ToString(), UIControlState.Normal); frame.SetTitle((channel.Audio?.FrameMs ?? 20).ToString(), UIControlState.Normal); application.SelectedSegment = (nint)(channel.Audio?.Application ?? OpusApplication.OpusVoip);
+        bitrate.Text = (channel.Audio?.BitrateBps ?? 64000).ToString(); loss.Text = (channel.Audio?.ExpectedPacketLoss ?? 5).ToString(); complexity.Text = (channel.Audio?.Complexity ?? 10).ToString(); fec.On = channel.Audio?.Fec ?? true; dtx.On = channel.Audio?.Dtx ?? false; dred.On = channel.Audio?.Dred ?? false;
+        automaticLoss.On = channel.Audio?.PacketLossMode != PacketLossMode.PacketLossManual;
+        lossSpeed.SetTitle(channel.Audio?.PacketLossMode switch { PacketLossMode.PacketLossAutoFast => "Fast", PacketLossMode.PacketLossAutoStable => "Stable", _ => "Balanced" }, UIControlState.Normal);
+        UpdateLossControls();
+    }
+    private async Task Save()
+    {
+        try
+        {
+            if (string.IsNullOrWhiteSpace(name.Text) || !uint.TryParse(maximum.Text, out uint max) || !int.TryParse(order.Text, out int sort) || !uint.TryParse(sampleRate.Title(UIControlState.Normal), out uint rate) || !uint.TryParse(frame.Title(UIControlState.Normal), out uint frameMs) || !uint.TryParse(bitrate.Text, out uint bits) || !uint.TryParse(loss.Text, out uint packetLoss) || !uint.TryParse(complexity.Text, out uint cpu) || packetLoss > 100 || cpu > 10) throw new ArgumentException("Enter valid channel and Opus settings.");
+            var channel = new Channel { Id = existing?.Id ?? 0, ParentId = parentId, Name = name.Text.Trim(), Topic = topic.Text?.Trim() ?? "", MaxUsers = max, Order = sort, Type = type.SelectedSegment == 1 ? ChannelType.ChannelTemporary : ChannelType.ChannelPermanent,
+                Audio = new AudioConfig { Codec = 0, Mode = mode.SelectedSegment == 1 ? ChannelMode.ModeStereo : ChannelMode.ModeMono, SampleRate = rate, FrameMs = frameMs, Application = (OpusApplication)(int)application.SelectedSegment, BitrateBps = bits, ExpectedPacketLoss = packetLoss, Complexity = cpu, Fec = fec.On, Dtx = dtx.On, Dred = dred.On,
+                    PacketLossMode = automaticLoss.On ? lossSpeed.Title(UIControlState.Normal) switch { "Fast" => PacketLossMode.PacketLossAutoFast, "Stable" => PacketLossMode.PacketLossAutoStable, _ => PacketLossMode.PacketLossAutoBalanced } : PacketLossMode.PacketLossManual } };
+            GenericResult result = await model.RunAdminAsync(client => existing is null ? client.CreateChannelAsync(channel, password.Text ?? "") : client.EditChannelAsync(channel, password.Text ?? "")); if (!result.Ok) throw new InvalidOperationException(result.Message); NavigationController?.PopViewController(true);
+        }
+        catch (Exception exception) { UiHelpers.ShowError(this, exception); }
+    }
+    private void UpdateLossControls() { loss.Enabled = !automaticLoss.On; lossSpeed.Enabled = model.SupportsAdaptivePacketLoss && automaticLoss.On; }
+    private static UIView PickerRow(string label, UIView control) { var row = new UIStackView { Axis = UILayoutConstraintAxis.Horizontal, Distribution = UIStackViewDistribution.FillEqually, Spacing = 8 }; var text = new UILabel { Text = label }; control.AccessibilityLabel = label; row.AddArrangedSubview(text); row.AddArrangedSubview(control); return row; }
+    private static UIView SwitchRow(string label, UISwitch toggle) { var row = new UIStackView { Axis = UILayoutConstraintAxis.Horizontal, Distribution = UIStackViewDistribution.EqualSpacing }; row.AddArrangedSubview(new UILabel { Text = label }); toggle.AccessibilityLabel = label; row.AddArrangedSubview(toggle); return row; }
+    private static UIMenu Choice(UIButton button, string[] values) => UIMenu.Create(values.Select(value => UIAction.Create(value, null, null, _ => button.SetTitle(value, UIControlState.Normal))).ToArray());
+}

clients/apple/VoiceCat.iOS/Entitlements.plist

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>com.apple.security.application-groups</key><array><string>group.me.iamtalon.voicecat</string></array>
+</dict></plist>

clients/apple/VoiceCat.iOS/EventFeedback.cs

@@ -0,0 +1,49 @@
+using AVFoundation;
+using Foundation;
+
+namespace VoiceCat.iOS;
+
+internal enum SoundEvent { ChannelJoin, ChannelLeave, ChannelReceived, ChannelSent, PrivateReceived, PrivateSent, Login, Logout, ConnectionLost, VoiceOn, VoiceOff, VoiceStart, VoiceStop, PushToTalk }
+
+internal sealed class EventFeedback : IDisposable
+{
+    private readonly IosSettings settings;
+    private readonly AVSpeechSynthesizer speech = new();
+    private readonly Dictionary<SoundEvent, AVAudioPlayer> players = [];
+
+    internal EventFeedback(IosSettings settings) => this.settings = settings;
+
+    internal void Play(SoundEvent sound)
+    {
+        if (!settings.EventSounds || settings.EventVolume <= 0 ||
+            (sound is SoundEvent.VoiceStart or SoundEvent.VoiceStop && !settings.SelfTalkSounds) ||
+            (sound == SoundEvent.PushToTalk && !settings.PushToTalkSound)) return;
+        if (!players.TryGetValue(sound, out AVAudioPlayer? player))
+        {
+            string path = Path.Combine(NSBundle.MainBundle.ResourcePath ?? "", "Sounds", FileName(sound) + ".wav");
+            if (!File.Exists(path)) return;
+            player = AVAudioPlayer.FromUrl(NSUrl.FromFilename(path));
+            if (player is null) return;
+            player.PrepareToPlay(); players[sound] = player;
+        }
+        player.Volume = settings.EventVolume; player.CurrentTime = 0; player.Play();
+    }
+
+    internal void Speak(string text)
+    {
+        if (!settings.SpokenEvents || string.IsNullOrWhiteSpace(text)) return;
+        speech.SpeakUtterance(new AVSpeechUtterance(text.Trim()));
+    }
+
+    private static string FileName(SoundEvent value) => value switch
+    {
+        SoundEvent.ChannelJoin => "channel_join", SoundEvent.ChannelLeave => "channel_leave",
+        SoundEvent.ChannelReceived => "channel_recv", SoundEvent.ChannelSent => "channel_sent",
+        SoundEvent.PrivateReceived => "pm_recv", SoundEvent.PrivateSent => "pm_sent",
+        SoundEvent.Login => "login", SoundEvent.Logout => "logout", SoundEvent.ConnectionLost => "connection_lost",
+        SoundEvent.VoiceOn => "voice_on", SoundEvent.VoiceOff => "voice_off", SoundEvent.VoiceStart => "va_start",
+        SoundEvent.VoiceStop => "va_stop", _ => "ptt"
+    };
+
+    public void Dispose() { foreach (AVAudioPlayer player in players.Values) player.Dispose(); speech.Dispose(); }
+}

clients/apple/VoiceCat.iOS/Info.plist

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0"><dict>
+  <key>CFBundleDisplayName</key><string>VoiceCat</string>
+  <key>CFBundleIdentifier</key><string>me.iamtalon.voicecat</string>
+  <key>XSAppIconAssets</key><string>Assets.xcassets/AppIcon.appiconset</string>
+  <key>LSRequiresIPhoneOS</key><true/>
+  <key>NSMicrophoneUsageDescription</key><string>VoiceCat needs microphone access to transmit your voice in channels.</string>
+  <key>UIBackgroundModes</key><array><string>audio</string><string>screen-capture</string></array>
+  <key>UIRequiresFullScreen</key><false/>
+  <key>UIDeviceFamily</key><array><integer>1</integer><integer>2</integer></array>
+  <key>UILaunchScreen</key><dict/>
+  <key>UISupportedInterfaceOrientations</key><array><string>UIInterfaceOrientationPortrait</string><string>UIInterfaceOrientationLandscapeLeft</string><string>UIInterfaceOrientationLandscapeRight</string></array>
+  <key>UISupportedInterfaceOrientations~ipad</key><array><string>UIInterfaceOrientationPortrait</string><string>UIInterfaceOrientationPortraitUpsideDown</string><string>UIInterfaceOrientationLandscapeLeft</string><string>UIInterfaceOrientationLandscapeRight</string></array>
+  <key>UIApplicationSceneManifest</key><dict>
+    <key>UIApplicationSupportsMultipleScenes</key><false/>
+    <key>UISceneConfigurations</key><dict><key>UIWindowSceneSessionRoleApplication</key><array><dict>
+      <key>UISceneConfigurationName</key><string>Default Configuration</string>
+      <key>UISceneDelegateClassName</key><string>VoiceCat.iOS.SceneDelegate</string>
+    </dict></array></dict>
+  </dict>
+</dict></plist>

clients/apple/VoiceCat.iOS/IosAudioEngine.cs

@@ -0,0 +1,268 @@
+using System.Runtime.InteropServices;
+using AVFoundation;
+using UIKit;
+using VoiceCat.Audio;
+using VoiceCat.Core;
+
+namespace VoiceCat.iOS;
+
+internal sealed class IosAudioEngine
+{
+    // InstallTapOnBus bufferSize is only a request. Physical iOS hardware can deliver 4,800
+    // frames per callback (observed with the voice-processing graph), so conversion storage
+    // must cover substantially more than the requested 960 frames without allocating in Capture.
+    private const int MaximumCaptureCallbackFrames = 16_384;
+    internal static IosAudioEngine Shared { get; } = new();
+    private readonly AdaptivePcmBuffer playbackRing = new(2, capacityFrames: 65_536);
+    private readonly short[] renderScratch = new short[16_384];
+    private AVAudioEngine? engine;
+    private Foundation.NSObject? engineConfigurationObserver;
+    private AVAudioSourceNode? source;
+    private AVAudioFormat? outputFormat;
+    private VoiceCatClient? client;
+    private sealed class MicrophoneRoute(uint streamId, int channels)
+    {
+        internal readonly uint StreamId = streamId;
+        internal readonly int Channels = channels;
+        // Capture hardware and the managed 20 ms sender have independent clocks. Correct
+        // their small rate difference before the queue eventually reaches its hard edge.
+        // RemoteIO can deliver capture in 100 ms bursts, so retain one burst of headroom.
+        internal readonly AdaptivePcmBuffer Ring = new(channels, 120, 65_536);
+    }
+    private MicrophoneRoute? microphone;
+    private readonly short[] microphoneFrame = new short[960 * 2];
+    private int microphoneCredit;
+    private AVAudioFormat? microphoneFormat;
+    private AVAudioConverter? microphoneConverter;
+    private AVAudioPcmBuffer? convertedMicrophone;
+    private AVAudioPcmBuffer? pendingInput;
+    private AVAudioConverterInputHandler? inputProvider;
+    private bool inputProvided;
+    private bool tapInstalled;
+    private long captureCallbacks, capturedFrames, convertedFrames, rejectedFeeds, converterFailures, stereoFrames, stereoDifferentFrames;
+    private long renderCallbacks, lastRenderTimestamp;
+    internal bool IsConnected { get; private set; }
+    internal bool IsRunning => engine?.Running == true;
+    // The watchdog compares this across ticks: a graph that stops calling back while it still
+    // reports Running leaves the whole device-clocked pipeline frozen until it is rebuilt.
+    internal long RenderCallbacks => Interlocked.Read(ref renderCallbacks);
+    internal int BufferMilliseconds { get => playbackRing.BufferMilliseconds; set => playbackRing.BufferMilliseconds = value; }
+
+    internal void StartListening(VoiceCatClient owner)
+    {
+        Stop(); client = owner; IsConnected = true; owner.Audio.MixedPcm += ReceiveMixedPcm; Rebuild();
+    }
+
+    internal void StartMicrophone(uint streamId, int channels)
+    {
+        Volatile.Write(ref microphone, CreateMicrophoneRoute(streamId, channels)); Rebuild();
+    }
+
+    internal void StopMicrophone() { Volatile.Write(ref microphone, null); Rebuild(); }
+    internal void Reconfigure()
+    {
+        if (!IsConnected) return;
+        MicrophoneRoute? current = Volatile.Read(ref microphone);
+        int channels = IosAudioRouter.Shared.CaptureChannels;
+        if (current is not null)
+        {
+            // Stop the old tap before publishing a route with a different sample width. Otherwise
+            // an in-flight callback could interpret its old converter buffer using the new width.
+            DestroyGraph();
+            if (current.Channels != channels) client!.Audio.SetCaptureChannels(current.StreamId, channels);
+            Volatile.Write(ref microphone, CreateMicrophoneRoute(current.StreamId, channels));
+        }
+        Rebuild();
+    }
+
+    private static MicrophoneRoute CreateMicrophoneRoute(uint streamId, int channels)
+    {
+        return new MicrophoneRoute(streamId, Math.Clamp(channels, 1, 2));
+    }
+    internal bool EnsureRunning()
+    {
+        if (!IsConnected || engine?.Running == true) return true;
+        Rebuild(); return engine?.Running == true;
+    }
+
+    private void Rebuild()
+    {
+        DestroyGraph(); MicrophoneRoute? route = Volatile.Read(ref microphone); IosAudioRouter.Shared.Apply(route is not null);
+        var next = new AVAudioEngine();
+        AVAudioInputNode? input = null;
+        if (route is not null)
+        {
+            // Enabling voice processing rebuilds both sides of AVAudioEngine. Do it before any
+            // formats are queried or nodes are connected so the graph is built from the final IO.
+            input = next.InputNode;
+            if (!input.SetVoiceProcessingEnabled(IosAudioRouter.Shared.UsesVoiceProcessing, out NSError? processingError))
+                throw new InvalidOperationException(processingError.LocalizedDescription);
+            if (IosAudioRouter.Shared.UsesVoiceProcessing) input.VoiceProcessingAgcEnabled = IosAudioRouter.Shared.AutomaticGainControl;
+        }
+        outputFormat = new(AVAudioCommonFormat.PCMFloat32, 48_000, 2, false);
+        source = new(outputFormat, Render);
+        next.AttachNode(source);
+        NSError? connectionError = null;
+        if (OperatingSystem.IsIOSVersionAtLeast(27)) next.Connect(source, next.MainMixerNode, outputFormat, out connectionError);
+        else next.Connect(source, next.MainMixerNode, outputFormat);
+        if (connectionError is not null) throw new InvalidOperationException(connectionError.LocalizedDescription);
+        if (route is not null)
+        {
+            AVAudioFormat inputFormat = input!.GetBusOutputFormat(0);
+            Console.Error.WriteLine($"VC_GRAPH vpio={IosAudioRouter.Shared.UsesVoiceProcessing} requestedCh={route.Channels} " +
+                $"inputCh={inputFormat.ChannelCount} inputRate={inputFormat.SampleRate}");
+            microphoneFormat = new(AVAudioCommonFormat.PCMInt16, 48_000, (uint)route.Channels, true);
+            microphoneConverter = new(inputFormat, microphoneFormat);
+            uint capacity = checked((uint)Math.Ceiling(MaximumCaptureCallbackFrames * 48_000 / inputFormat.SampleRate) + 64);
+            convertedMicrophone = new(microphoneFormat, capacity);
+            inputProvider = ProvideInput;
+            NSError? tapError = null;
+            if (OperatingSystem.IsIOSVersionAtLeast(27)) input.InstallTapOnBus(0, 960, inputFormat, out tapError, Capture);
+            else input.InstallTapOnBus(0, 960, inputFormat, Capture);
+            if (tapError is not null) throw new InvalidOperationException(tapError.LocalizedDescription);
+            tapInstalled = true;
+        }
+        next.Prepare();
+        if (!next.StartAndReturnError(out NSError? error)) { next.Dispose(); throw new InvalidOperationException(error.LocalizedDescription); }
+        engine = next;
+        engineConfigurationObserver = Foundation.NSNotificationCenter.DefaultCenter.AddObserver(
+            AVAudioEngine.ConfigurationChangeNotification, notification =>
+            {
+                if (!ReferenceEquals(notification.Object, next)) return;
+                UIApplication.SharedApplication.BeginInvokeOnMainThread(() =>
+                {
+                    if (IsConnected && ReferenceEquals(engine, next) && !next.Running) Rebuild();
+                });
+            }, next);
+    }
+
+    private unsafe void Capture(AVAudioPcmBuffer buffer, AVAudioTime time)
+    {
+        Interlocked.Increment(ref captureCallbacks);
+        Interlocked.Add(ref capturedFrames, buffer.FrameLength);
+        VoiceCatClient? owner = client; MicrophoneRoute? route = Volatile.Read(ref microphone);
+        if (owner is null || route is null || buffer.FrameLength == 0) return;
+        AVAudioConverter? converter = microphoneConverter;
+        AVAudioPcmBuffer? converted = convertedMicrophone;
+        AVAudioConverterInputHandler? provider = inputProvider;
+        if (converter is null || converted is null || provider is null) return;
+        pendingInput = buffer; inputProvided = false; converted.FrameLength = 0;
+        converter.ConvertToBuffer(converted, out NSError? conversionError, provider);
+        if (conversionError is not null) Interlocked.Increment(ref converterFailures);
+        if (converted.FrameLength == 0) return;
+        Interlocked.Add(ref convertedFrames, converted.FrameLength);
+        nint samples = Marshal.ReadIntPtr(converted.Int16ChannelData);
+        if (samples != 0 && ReferenceEquals(route, Volatile.Read(ref microphone)))
+        {
+            var pcm = new ReadOnlySpan<short>((void*)samples, checked((int)converted.FrameLength * route.Channels));
+            if (route.Channels == 2)
+            {
+                Interlocked.Add(ref stereoFrames, converted.FrameLength);
+                long different = 0;
+                for (int frame = 0; frame < converted.FrameLength; frame++)
+                    if (pcm[frame * 2] != pcm[frame * 2 + 1]) different++;
+                Interlocked.Add(ref stereoDifferentFrames, different);
+            }
+            if (!route.Ring.TryWrite(pcm)) Interlocked.Increment(ref rejectedFeeds);
+        }
+        pendingInput = null;
+    }
+
+    internal string CaptureDiagnostics()
+    {
+        return $"callbacks={Interlocked.Exchange(ref captureCallbacks, 0)} input={Interlocked.Exchange(ref capturedFrames, 0)} " +
+            $"converted={Interlocked.Exchange(ref convertedFrames, 0)} feedDrops={Interlocked.Exchange(ref rejectedFeeds, 0)} " +
+            $"converterErrors={Interlocked.Exchange(ref converterFailures, 0)} stereo={Interlocked.Exchange(ref stereoDifferentFrames, 0)}/" +
+            $"{Interlocked.Exchange(ref stereoFrames, 0)}";
+    }
+
+    private AVAudioBuffer ProvideInput(uint _, out AVAudioConverterInputStatus status)
+    {
+        if (!inputProvided && pendingInput is { } input) { inputProvided = true; status = AVAudioConverterInputStatus.HaveData; return input; }
+        status = AVAudioConverterInputStatus.NoDataNow; return null!;
+    }
+
+    // One paced 20 ms handoff from the capture ring into the encoder. The render callback calls
+    // this at its demand rate: the ring absorbs RemoteIO's burst pattern and the small capture vs
+    // output clock difference, so the sender sees a steady 20 ms feed without a sleep-paced pacer
+    // thread to stall when iOS coalesces a backgrounded app's wakeups.
+    private void PumpMicrophoneChunk(VoiceCatClient owner)
+    {
+        MicrophoneRoute? route = Volatile.Read(ref microphone);
+        if (route is null) return;
+        int required = 960 * route.Channels;
+        if (route.Ring.Read(microphoneFrame.AsSpan(0, required)) == required &&
+            ReferenceEquals(route, Volatile.Read(ref microphone)) &&
+            !owner.Audio.FeedPcm(route.StreamId, microphoneFrame.AsSpan(0, required), route.Channels))
+            Interlocked.Increment(ref rejectedFeeds);
+    }
+
+    private void ReceiveMixedPcm(ReadOnlySpan<short> pcm) => playbackRing.TryWrite(pcm);
+
+    private unsafe int Render(IntPtr isSilence, IntPtr timestamp, uint frameCount, IntPtr outputData)
+    {
+        int frames = checked((int)frameCount), requested = checked(frames * 2);
+        if (requested > renderScratch.Length) return -1;
+        // This callback is the cadence iOS keeps exact while the app is backgrounded or the device
+        // is locked, so it owns both managed 20 ms hands-offs: capture into the sender and one mix
+        // cycle per 20 ms of render demand. Both run allocation-free and without locks or I/O.
+        Interlocked.Increment(ref renderCallbacks);
+        long now = System.Diagnostics.Stopwatch.GetTimestamp(), previous = lastRenderTimestamp;
+        lastRenderTimestamp = now;
+        VoiceCatClient? owner = Volatile.Read(ref client);
+        if (owner is null || !IsConnected) microphoneCredit = 0;
+        else
+        {
+            if (previous != 0 && (now - previous) * 1000.0 / System.Diagnostics.Stopwatch.Frequency > 100)
+            {
+                Volatile.Read(ref microphone)?.Ring.Resynchronize();
+                playbackRing.Resynchronize(); owner.Audio.ResynchronizeInputs(); microphoneCredit = 0;
+            }
+            microphoneCredit += frames;
+            while (microphoneCredit >= 960) { microphoneCredit -= 960; PumpMicrophoneChunk(owner); }
+            // Top the mix ring up to cover this callback plus its configured target so the read
+            // below never starves and the buffer keeps its chosen buffering latency. Catch-up is
+            // capped at one extra cycle so a refill cannot overrun this callback's deadline.
+            int deficit = Math.Min(frames + playbackRing.TargetFrames - playbackRing.CountFrames, frames + 960);
+            for (int produced = 0; produced < deficit; produced += 960) owner.Audio.RunCycle();
+        }
+        Span<short> input = renderScratch.AsSpan(0, requested);
+        int read = playbackRing.Read(input); input[read..].Clear();
+        int count = Marshal.ReadInt32(outputData), first = IntPtr.Size == 8 ? 8 : 4, stride = IntPtr.Size == 8 ? 16 : 12;
+        if (count != 2) return -1;
+        for (int channel = 0; channel < 2; channel++)
+        {
+            nint data = Marshal.ReadIntPtr(outputData, first + channel * stride + 8);
+            var output = new Span<float>((void*)data, frames);
+            for (int frame = 0; frame < frames; frame++) output[frame] = input[frame * 2 + channel] / 32768f;
+        }
+        if (isSilence != IntPtr.Zero) Marshal.WriteByte(isSilence, read == 0 ? (byte)1 : (byte)0);
+        return 0;
+    }
+
+    internal void Stop()
+    {
+        IsConnected = false; Volatile.Write(ref microphone, null);
+        if (client is { } owner) owner.Audio.MixedPcm -= ReceiveMixedPcm;
+        DestroyGraph(); client = null; IosAudioRouter.Shared.Deactivate();
+    }
+
+    private void DestroyGraph()
+    {
+        if (engineConfigurationObserver is { } observer)
+        {
+            Foundation.NSNotificationCenter.DefaultCenter.RemoveObserver(observer);
+            observer.Dispose(); engineConfigurationObserver = null;
+        }
+        if (engine is { } old)
+        {
+            if (tapInstalled) old.InputNode.RemoveTapOnBus(0);
+            old.Stop(); if (source is not null) old.DetachNode(source); old.Dispose();
+        }
+        tapInstalled = false; pendingInput = null; inputProvider = null; lastRenderTimestamp = 0; microphoneCredit = 0;
+        convertedMicrophone?.Dispose(); convertedMicrophone = null;
+        microphoneConverter?.Dispose(); microphoneConverter = null;
+        microphoneFormat?.Dispose(); microphoneFormat = null;
+        source?.Dispose(); source = null; outputFormat?.Dispose(); outputFormat = null; engine = null;
+    }
+}

clients/apple/VoiceCat.iOS/IosAudioRouter.cs

@@ -0,0 +1,296 @@
+using AVFoundation;
+using Foundation;
+using ObjCRuntime;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal enum IosAudioPreset { VoiceChat, StereoMicrophone, MonoMicrophone, Advanced }
+internal enum IosBluetoothMode { HfpVoice, BuiltInMicA2dp, BuiltInMicSpeaker }
+internal enum IosMicMode { Standard, Raw }
+internal sealed record IosAudioPort(string Id, string Name, string Type);
+internal sealed record IosAudioDataSource(string Id, string Name, IReadOnlyList<AVAudioDataSourcePolarPattern> Patterns);
+
+internal sealed class IosAudioRouter
+{
+    private static readonly NativeHandle SupportedPolarPatternsSelector = Selector.GetHandle("supportedPolarPatterns");
+    private static readonly NativeHandle SetPreferredPolarPatternSelector = Selector.GetHandle("setPreferredPolarPattern:error:");
+    internal static IosAudioRouter Shared { get; } = new();
+    private readonly NSUserDefaults defaults = NSUserDefaults.StandardUserDefaults;
+    private bool applying;
+    private System.Threading.Timer? watchdog;
+    private long lastRenderCallbacks = -1;
+    private int watchdogMisses;
+    private bool watchdogTicking;
+    private bool interrupted;
+    internal event Action? Changed;
+    internal IosAudioPreset Preset { get; private set; } = IosAudioPreset.VoiceChat;
+    internal IosBluetoothMode BluetoothMode { get; private set; } = IosBluetoothMode.HfpVoice;
+    internal IosMicMode MicMode { get; private set; } = IosMicMode.Standard;
+    internal bool ForceSpeaker { get; private set; }
+    internal bool VoiceProcessing { get; private set; } = true;
+    internal bool AutomaticGainControl { get; private set; } = true;
+    internal int CaptureChannels { get; private set; } = 1;
+    internal string? SelectedInputId { get; private set; }
+    internal string? SelectedDataSourceId { get; private set; }
+    internal AVAudioDataSourcePolarPattern SelectedPolarPattern { get; private set; } = AVAudioDataSourcePolarPattern.Unknown;
+    internal IReadOnlyList<IosAudioPort> Inputs { get; private set; } = [];
+    internal IReadOnlyList<IosAudioPort> Outputs { get; private set; } = [];
+    internal bool VoiceProcessingAvailable => CaptureChannels == 1 && MicMode == IosMicMode.Standard && BluetoothMode != IosBluetoothMode.BuiltInMicA2dp;
+    internal bool UsesVoiceProcessing => VoiceProcessing && VoiceProcessingAvailable;
+
+    private IosAudioRouter()
+    {
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.RouteChangeNotification, HandleRouteChange);
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.InterruptionNotification, HandleInterruption);
+        NSNotificationCenter.DefaultCenter.AddObserver(AVAudioSession.MediaServicesWereResetNotification, _ => Recover("media services reset"));
+    }
+
+    internal void Load()
+    {
+        if (Enum.TryParse(defaults.StringForKey("cat.voice.audio.preset"), true, out IosAudioPreset preset)) Preset = preset;
+        if (Enum.TryParse(defaults.StringForKey("cat.voice.audio.bluetoothMode"), true, out IosBluetoothMode bluetooth)) BluetoothMode = bluetooth;
+        if (Enum.TryParse(defaults.StringForKey("cat.voice.audio.micMode"), true, out IosMicMode mic)) MicMode = mic;
+        ForceSpeaker = defaults.BoolForKey("cat.voice.audio.forceSpeaker");
+        VoiceProcessing = defaults.ValueForKey(new NSString("cat.voice.audio.voiceProcessing")) is null || defaults.BoolForKey("cat.voice.audio.voiceProcessing");
+        AutomaticGainControl = defaults.ValueForKey(new NSString("cat.voice.audio.agc")) is null || defaults.BoolForKey("cat.voice.audio.agc");
+        CaptureChannels = defaults.IntForKey("cat.voice.audio.captureChannels") == 2 ? 2 : Preset == IosAudioPreset.StereoMicrophone ? 2 : 1;
+        SelectedInputId = defaults.StringForKey("cat.voice.audio.inputPortId"); SelectedDataSourceId = defaults.StringForKey("cat.voice.audio.dataSourceId");
+        if (Enum.TryParse(defaults.StringForKey("cat.voice.audio.polarPattern"), true, out AVAudioDataSourcePolarPattern pattern)) SelectedPolarPattern = pattern;
+        RefreshRoutes();
+    }
+
+    internal void SelectPreset(IosAudioPreset preset)
+    {
+        Preset = preset;
+        if (preset != IosAudioPreset.Advanced)
+        {
+            CaptureChannels = preset == IosAudioPreset.StereoMicrophone ? 2 : 1; MicMode = IosMicMode.Standard;
+            BluetoothMode = preset == IosAudioPreset.VoiceChat ? IosBluetoothMode.HfpVoice : IosBluetoothMode.BuiltInMicA2dp;
+            if (preset is IosAudioPreset.StereoMicrophone or IosAudioPreset.MonoMicrophone)
+                SelectedInputId = AVAudioSession.SharedInstance().AvailableInputs?.FirstOrDefault(value => value.PortType == AVAudioSession.PortBuiltInMic)?.UID;
+            else SelectedInputId = null;
+            // Named presets never carry an Advanced capsule selection across transitions.
+            // Stereo derives its data source below; mono/voice chat must clear a stale stereo one.
+            SelectedDataSourceId = null; SelectedPolarPattern = AVAudioDataSourcePolarPattern.Unknown;
+            if (preset == IosAudioPreset.VoiceChat) ForceSpeaker = true;
+        }
+        SaveAndReconfigure();
+    }
+
+    internal void SetForceSpeaker(bool value) { ForceSpeaker = value; SaveAndReconfigure(); }
+    internal void SetVoiceProcessing(bool value) { VoiceProcessing = value; SaveAndReconfigure(); }
+    internal void SetAutomaticGainControl(bool value) { AutomaticGainControl = value; SaveAndReconfigure(); }
+    internal void SetCaptureChannels(int value) { CaptureChannels = value == 2 ? 2 : 1; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+    internal void SetBluetoothMode(IosBluetoothMode value) { BluetoothMode = value; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+    internal void SetMicMode(IosMicMode value) { MicMode = value; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+    internal void SelectInput(string? id) { SelectedInputId = string.IsNullOrEmpty(id) ? null : id; SelectedDataSourceId = null; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+    internal void SelectDataSource(string? id) { SelectedDataSourceId = string.IsNullOrEmpty(id) ? null : id; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+    internal void SelectPolarPattern(AVAudioDataSourcePolarPattern pattern) { SelectedPolarPattern = pattern; Preset = IosAudioPreset.Advanced; SaveAndReconfigure(); }
+
+    internal IReadOnlyList<IosAudioDataSource> DataSources()
+    {
+        AVAudioSessionPortDescription? port = AVAudioSession.SharedInstance().AvailableInputs?.FirstOrDefault(value => value.UID == SelectedInputId);
+        return port?.DataSources?.Select(value => new IosAudioDataSource(value.DataSourceID.ToString(), value.DataSourceName,
+            value.SupportedPolarPatterns?.ToArray() ?? [])).ToArray() ?? [];
+    }
+
+    internal void RefreshRoutes()
+    {
+        AVAudioSession session = AVAudioSession.SharedInstance();
+        Inputs = session.AvailableInputs?.Select(value => new IosAudioPort(value.UID, value.PortName, value.PortType.ToString())).ToArray() ?? [];
+        Outputs = session.CurrentRoute.Outputs.Select(value => new IosAudioPort(value.UID, value.PortName, value.PortType.ToString())).ToArray();
+        SelectedInputId ??= session.PreferredInput?.UID; Changed?.Invoke();
+    }
+
+    internal void Apply(bool configureInput)
+    {
+        if (applying) return; applying = true;
+        try
+        {
+            AVAudioSession session = AVAudioSession.SharedInstance(); AVAudioSessionCategoryOptions options = AVAudioSessionCategoryOptions.MixWithOthers;
+            if (BluetoothMode == IosBluetoothMode.HfpVoice) options |= AVAudioSessionCategoryOptions.AllowBluetooth | AVAudioSessionCategoryOptions.AllowBluetoothA2DP | AVAudioSessionCategoryOptions.AllowAirPlay;
+            if (BluetoothMode == IosBluetoothMode.BuiltInMicA2dp) options |= AVAudioSessionCategoryOptions.AllowBluetoothA2DP | AVAudioSessionCategoryOptions.AllowAirPlay;
+            if (BluetoothMode == IosBluetoothMode.BuiltInMicSpeaker || ForceSpeaker && BluetoothMode != IosBluetoothMode.BuiltInMicA2dp) options |= AVAudioSessionCategoryOptions.DefaultToSpeaker;
+            AVAudioSessionMode mode = CaptureChannels == 2 ? AVAudioSessionMode.Default : MicMode == IosMicMode.Raw ? AVAudioSessionMode.Measurement
+                : BluetoothMode == IosBluetoothMode.BuiltInMicA2dp ? AVAudioSessionMode.VideoRecording : AVAudioSessionMode.VoiceChat;
+            if (!session.SetCategory(AVAudioSessionCategory.PlayAndRecord, mode, options, out NSError? categoryError)) throw new InvalidOperationException(categoryError.LocalizedDescription);
+            session.SetPreferredSampleRate(48_000, out _); session.SetPreferredIOBufferDuration(0.02, out _);
+            if (configureInput) ApplyInputSelection(session);
+            if (!session.SetActive(true, AVAudioSessionSetActiveOptions.NotifyOthersOnDeactivation, out NSError? activeError)) throw new InvalidOperationException(activeError.LocalizedDescription);
+            Console.Error.WriteLine($"VC_ROUTE preset={Preset} requestedCh={CaptureChannels} sessionCh={session.InputNumberOfChannels} " +
+                $"preferred={session.PreferredInput?.PortName ?? "default"} dataSource={session.InputDataSource?.DataSourceName ?? "default"} " +
+                $"pattern={session.InputDataSource?.SelectedPolarPattern.ToString() ?? "default"}");
+            session.OverrideOutputAudioPort(ForceSpeaker && BluetoothMode != IosBluetoothMode.BuiltInMicA2dp ? AVAudioSessionPortOverride.Speaker : AVAudioSessionPortOverride.None, out _); RefreshRoutes();
+            ResetWatchdog(); EnsureWatchdog();
+        }
+        finally { applying = false; }
+    }
+
+    private void ApplyInputSelection(AVAudioSession session)
+    {
+        AVAudioSessionPortDescription? port = session.AvailableInputs?.FirstOrDefault(value => value.UID == SelectedInputId);
+        if (CaptureChannels == 2) port ??= session.AvailableInputs?.FirstOrDefault(value => value.PortType == AVAudioSession.PortBuiltInMic);
+        if (port is null) { if (CaptureChannels == 1) ClearStereoPolarPattern(session); return; }
+        if (CaptureChannels == 2)
+        {
+            // Polar-pattern discovery alone is insufficient on current iPhones: until a stereo
+            // orientation is requested, the built-in port can expose only its mono Bottom source
+            // and AVAudioEngine consequently binds a one-channel input node. This is Apple's
+            // dedicated switch for built-in stereo recording. Portrait matches this portrait UI;
+            // it also gives Core Audio an unambiguous left/right mapping before graph creation.
+            if (!session.SetPreferredInputOrientation(AVAudioStereoOrientation.Portrait, out NSError? orientationError))
+                throw new InvalidOperationException(orientationError?.LocalizedDescription ?? "Could not set the stereo microphone orientation.");
+        }
+        AVAudioSessionDataSourceDescription? source = CaptureChannels == 2
+            ? port.DataSources?.FirstOrDefault(SupportsStereoPolarPattern)
+            : port.DataSources?.FirstOrDefault(value => value.DataSourceID.ToString() == SelectedDataSourceId);
+        if (CaptureChannels == 1 && source is null) ClearStereoPolarPattern(session);
+        if (source is not null)
+        {
+            if (!port.SetPreferredDataSource(source, out NSError? portError)) throw new InvalidOperationException(portError.LocalizedDescription);
+            if (CaptureChannels == 2) SetStereoPolarPattern(source);
+            else if (SelectedPolarPattern != AVAudioDataSourcePolarPattern.Unknown &&
+                !source.SetPreferredPolarPattern(SelectedPolarPattern, out NSError? patternError))
+                throw new InvalidOperationException(patternError.LocalizedDescription);
+        }
+        if (!session.SetPreferredInput(port, out NSError? inputError)) throw new InvalidOperationException(inputError.LocalizedDescription);
+        // The working Swift client deliberately does not call
+        // SetPreferredInputNumberOfChannels: doing so disrupts stereo + A2DP routing. The stereo
+        // capsule and polar pattern above cause the input node to expose its two-channel format.
+        if (CaptureChannels == 2 && source is not null &&
+            !session.SetInputDataSource(source, out NSError? sourceError))
+            throw new InvalidOperationException(sourceError.LocalizedDescription);
+        Console.Error.WriteLine($"VC_ROUTE_SELECT port={port.PortName} source={source?.DataSourceName ?? "none"} " +
+            $"stereoPattern={source is not null && SupportsStereoPolarPattern(source)} " +
+            $"patterns={string.Join(',', source?.SupportedPolarPatterns?.Select(value => value.ToString()) ?? [])}");
+    }
+
+    // Microsoft.iOS 27 exposes AVAudioSessionPolarPatternStereo as an NSString constant but its
+    // AVAudioDataSourcePolarPattern smart enum still has no Stereo member. Reading the native
+    // NSArray and setting the native NSString avoids silently mapping Stereo to Unknown.
+    private static bool SupportsStereoPolarPattern(AVAudioSessionDataSourceDescription source)
+    {
+        NativeHandle handle = NativeMethods.GetObject(source.Handle, SupportedPolarPatternsSelector);
+        NSArray? patterns = Runtime.GetNSObject<NSArray>(handle);
+        if (patterns is null) return false;
+        for (nuint index = 0; index < patterns.Count; index++)
+            if (patterns.GetItem<NSString>(index)?.IsEqualTo(AVAudioSession.PolarPatternStereo.Handle) == true) return true;
+        return false;
+    }
+
+    private static void SetStereoPolarPattern(AVAudioSessionDataSourceDescription source)
+    {
+        NativeHandle error = NativeHandle.Zero;
+        if (NativeMethods.SetObject(source.Handle, SetPreferredPolarPatternSelector,
+            AVAudioSession.PolarPatternStereo.Handle, ref error) == 0)
+            throw new InvalidOperationException(Runtime.GetNSObject<NSError>(error)?.LocalizedDescription ?? "Could not enable stereo microphone capture.");
+    }
+
+    private static class NativeMethods
+    {
+        [System.Runtime.InteropServices.DllImport("/usr/lib/libobjc.dylib", EntryPoint = "objc_msgSend")]
+        internal static extern NativeHandle GetObject(NativeHandle receiver, NativeHandle selector);
+
+        [System.Runtime.InteropServices.DllImport("/usr/lib/libobjc.dylib", EntryPoint = "objc_msgSend")]
+        internal static extern byte SetObject(NativeHandle receiver, NativeHandle selector, NativeHandle value, ref NativeHandle error);
+    }
+
+    private static void ClearStereoPolarPattern(AVAudioSession session)
+    {
+        session.SetPreferredInputOrientation(AVAudioStereoOrientation.None, out _);
+        AVAudioSessionPortDescription? builtIn = session.AvailableInputs?.FirstOrDefault(value => value.PortType == AVAudioSession.PortBuiltInMic);
+        if (builtIn is null) return;
+        foreach (AVAudioSessionDataSourceDescription source in builtIn.DataSources ?? [])
+            if (source.SelectedPolarPattern == AVAudioDataSourcePolarPattern.Unknown && SupportsStereoPolarPattern(source))
+                source.SetPreferredPolarPattern(AVAudioDataSourcePolarPattern.Unknown, out _);
+    }
+
+    private void SaveAndReconfigure()
+    {
+        defaults.SetString(Preset.ToString(), "cat.voice.audio.preset"); defaults.SetString(BluetoothMode.ToString(), "cat.voice.audio.bluetoothMode");
+        defaults.SetString(MicMode.ToString(), "cat.voice.audio.micMode"); defaults.SetBool(ForceSpeaker, "cat.voice.audio.forceSpeaker");
+        defaults.SetBool(VoiceProcessing, "cat.voice.audio.voiceProcessing"); defaults.SetBool(AutomaticGainControl, "cat.voice.audio.agc"); defaults.SetInt(CaptureChannels, "cat.voice.audio.captureChannels");
+        Set("cat.voice.audio.inputPortId", SelectedInputId); Set("cat.voice.audio.dataSourceId", SelectedDataSourceId); defaults.SetString(SelectedPolarPattern.ToString(), "cat.voice.audio.polarPattern"); defaults.Synchronize();
+        if (IosAudioEngine.Shared.IsConnected) IosAudioEngine.Shared.Reconfigure(); Changed?.Invoke();
+    }
+
+    private void Set(string key, string? value) { if (value is null) defaults.RemoveObject(key); else defaults.SetString(value, key); }
+    internal void Deactivate()
+    {
+        watchdog?.Dispose(); watchdog = null; ResetWatchdog();
+        AVAudioSession.SharedInstance().SetActive(false, AVAudioSessionSetActiveOptions.NotifyOthersOnDeactivation, out _);
+    }
+    internal void EnsureAudio(string reason)
+    {
+        if (!IosAudioEngine.Shared.IsConnected || interrupted) return;
+        try { IosAudioEngine.Shared.EnsureRunning(); }
+        catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Audio recovery ({reason}) failed: {exception}"); }
+    }
+
+    internal void Recover(string reason)
+    {
+        RefreshRoutes();
+        if (!IosAudioEngine.Shared.IsConnected || interrupted) return;
+        UIApplication.SharedApplication.BeginInvokeOnMainThread(() =>
+        {
+            try { IosAudioEngine.Shared.Reconfigure(); }
+            catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Audio recovery ({reason}) failed: {exception}"); }
+        });
+    }
+
+    // The render callback is the only clock for the device-clocked pipeline, so a graph that
+    // stops while the app is backgrounded freezes capture, mix and send with no notification to
+    // recover from. Poll for that and rebuild; a failed rebuild is retried on the next tick.
+    private void EnsureWatchdog()
+    {
+        watchdog ??= new System.Threading.Timer(_ => UIApplication.SharedApplication.BeginInvokeOnMainThread(TickWatchdog),
+            null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
+    }
+
+    private void ResetWatchdog() { lastRenderCallbacks = -1; watchdogMisses = 0; }
+
+    // An interruption that ends while the app is suspended never delivers its Ended notification.
+    internal void ResumeForeground() { interrupted = false; ResetWatchdog(); Recover("foreground"); }
+
+    private void TickWatchdog()
+    {
+        if (watchdogTicking) return;
+        watchdogTicking = true;
+        try
+        {
+            if (!IosAudioEngine.Shared.IsConnected || interrupted || applying) { ResetWatchdog(); return; }
+            long callbacks = IosAudioEngine.Shared.RenderCallbacks;
+            bool stalled = !IosAudioEngine.Shared.IsRunning || callbacks == lastRenderCallbacks;
+            lastRenderCallbacks = callbacks;
+            if (!stalled) { watchdogMisses = 0; return; }
+            // One missed tick can be a route change already rebuilding the graph.
+            if (++watchdogMisses < 2) return;
+            ResetWatchdog();
+            try { IosAudioEngine.Shared.Reconfigure(); }
+            catch (Exception exception) { System.Diagnostics.Debug.WriteLine($"Audio watchdog rebuild failed: {exception}"); }
+        }
+        finally { watchdogTicking = false; }
+    }
+    private void HandleRouteChange(NSNotification note)
+    {
+        NSNumber? value = note.UserInfo?[new NSString("AVAudioSessionRouteChangeReasonKey")] as NSNumber;
+        AVAudioSessionRouteChangeReason reason = (AVAudioSessionRouteChangeReason)(value?.UInt32Value ?? 0);
+        RefreshRoutes();
+        if (reason is AVAudioSessionRouteChangeReason.CategoryChange
+            or AVAudioSessionRouteChangeReason.Override
+            or AVAudioSessionRouteChangeReason.RouteConfigurationChange)
+            return;
+        Recover($"route change ({reason})");
+    }
+    private void HandleInterruption(NSNotification note)
+    {
+        NSNumber? type = note.UserInfo?[new NSString("AVAudioSessionInterruptionTypeKey")] as NSNumber;
+        AVAudioSessionInterruptionType interruption = (AVAudioSessionInterruptionType)(type?.UInt32Value ?? 0);
+        // The system stops the graph on Began and SetActive fails until the interruption clears,
+        // so suppress recovery until Ended and let the watchdog retry if that rebuild fails.
+        if (interruption == AVAudioSessionInterruptionType.Began) { interrupted = true; ResetWatchdog(); return; }
+        if (interruption != AVAudioSessionInterruptionType.Ended) return;
+        interrupted = false; ResetWatchdog(); Recover("interruption ended");
+    }
+}

clients/apple/VoiceCat.iOS/IosConstants.cs

@@ -0,0 +1,8 @@
+namespace VoiceCat.iOS;
+
+internal static class IosConstants
+{
+    internal const string AppGroup = "group.me.iamtalon.voicecat";
+    internal const string BroadcastExtension = "me.iamtalon.voicecat.broadcast";
+    internal const string PasswordService = "me.iamtalon.voicecat.ios";
+}

clients/apple/VoiceCat.iOS/IosScreenCapture.cs

@@ -0,0 +1,25 @@
+using System.Runtime.InteropServices;
+using Foundation;
+
+namespace VoiceCat.iOS;
+
+internal static partial class IosScreenCapture
+{
+    internal static void Present()
+    {
+        if (!OperatingSystem.IsIOSVersionAtLeast(27)) return;
+        NSUrl? root = NSFileManager.DefaultManager.GetContainerUrl(IosConstants.AppGroup);
+        if (root?.Path is null) throw new InvalidOperationException("The VoiceCat App Group is unavailable.");
+        string path = Path.Combine(root.Path, "voicecat", "broadcast_audio.ring"); Directory.CreateDirectory(Path.GetDirectoryName(path)!);
+        if (!IsAvailable) throw new InvalidOperationException("Screen audio sharing is unavailable on this device."); PresentNative(path);
+    }
+
+    internal static bool IsAvailable => OperatingSystem.IsIOSVersionAtLeast(27) && Available() != 0;
+
+    [LibraryImport("__Internal", EntryPoint = "vc_ios_screen_capture_available")]
+    private static partial int Available();
+    [LibraryImport("__Internal", EntryPoint = "vc_ios_screen_capture_present", StringMarshalling = StringMarshalling.Utf8)]
+    private static partial void PresentNative(string ringPath);
+    [LibraryImport("__Internal", EntryPoint = "vc_ios_screen_capture_stop")]
+    internal static partial void Stop();
+}

clients/apple/VoiceCat.iOS/IosSettings.cs

@@ -0,0 +1,52 @@
+using Foundation;
+using VoiceCat.Audio;
+
+namespace VoiceCat.iOS;
+
+internal sealed class IosSettings
+{
+    private readonly NSUserDefaults values = NSUserDefaults.StandardUserDefaults;
+
+    internal AudioInputMode InputMode { get; set; } = AudioInputMode.VoiceActivation;
+    internal float VadThreshold { get; set; } = 0.025f;
+    internal float InputGain { get; set; } = 1f;
+    internal float OutputGain { get; set; } = 1f;
+    internal bool InputNoiseReduction { get; set; }
+    internal bool EventSounds { get; set; } = true;
+    internal bool SpokenEvents { get; set; }
+    internal float EventVolume { get; set; } = 1f;
+    internal bool SelfTalkSounds { get; set; }
+    internal bool PushToTalkSound { get; set; }
+    internal int AudioBufferMilliseconds { get; set; } = 40;
+
+    internal void Load()
+    {
+        NSString[] keys = [(NSString)"voice.inputMode", (NSString)"voice.vadThreshold", (NSString)"voice.inputGain",
+            (NSString)"voice.outputGain", (NSString)"voice.audioBufferMs", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
+        NSObject[] defaults = [NSNumber.FromInt32((int)AudioInputMode.VoiceActivation), NSNumber.FromFloat(0.025f),
+            NSNumber.FromFloat(1f), NSNumber.FromFloat(1f), NSNumber.FromInt32(40), NSNumber.FromBoolean(true), NSNumber.FromFloat(1f)];
+        values.RegisterDefaults(new NSDictionary<NSString, NSObject>(keys, defaults));
+        int inputMode = checked((int)values.IntForKey("voice.inputMode"));
+        InputMode = Enum.IsDefined(typeof(AudioInputMode), inputMode) ? (AudioInputMode)inputMode : AudioInputMode.VoiceActivation;
+        VadThreshold = Math.Clamp(values.FloatForKey("voice.vadThreshold"), 0.001f, 0.1f);
+        InputGain = Math.Clamp(values.FloatForKey("voice.inputGain"), 0f, 4f);
+        OutputGain = Math.Clamp(values.FloatForKey("voice.outputGain"), 0f, 1f);
+        InputNoiseReduction = values.BoolForKey("voice.inputNoiseReduction");
+        int audioBuffer = checked((int)values.IntForKey("voice.audioBufferMs")); AudioBufferMilliseconds = audioBuffer is 20 or 40 or 60 ? audioBuffer : 40;
+        EventSounds = values.BoolForKey("feedback.sounds");
+        SpokenEvents = values.BoolForKey("feedback.speech");
+        EventVolume = Math.Clamp(values.FloatForKey("feedback.volume"), 0f, 1f);
+        SelfTalkSounds = values.BoolForKey("feedback.selfTalk");
+        PushToTalkSound = values.BoolForKey("feedback.ptt");
+    }
+
+    internal void Save()
+    {
+        values.SetInt((int)InputMode, "voice.inputMode"); values.SetFloat(VadThreshold, "voice.vadThreshold");
+        values.SetFloat(InputGain, "voice.inputGain"); values.SetFloat(OutputGain, "voice.outputGain");
+        values.SetInt(AudioBufferMilliseconds, "voice.audioBufferMs");
+        values.SetBool(InputNoiseReduction, "voice.inputNoiseReduction"); values.SetBool(EventSounds, "feedback.sounds");
+        values.SetBool(SpokenEvents, "feedback.speech"); values.SetFloat(EventVolume, "feedback.volume");
+        values.SetBool(SelfTalkSounds, "feedback.selfTalk"); values.SetBool(PushToTalkSound, "feedback.ptt"); values.Synchronize();
+    }
+}

clients/apple/VoiceCat.iOS/IosStorage.cs

@@ -0,0 +1,90 @@
+using System.Security.Cryptography;
+using System.Text;
+using Foundation;
+using Security;
+using VoiceCat.Core;
+
+namespace VoiceCat.iOS;
+
+internal sealed class IosStorage
+{
+    private readonly string directory;
+    private readonly ServerProfileStore profiles;
+
+    internal IosStorage()
+    {
+        NSUrl? group = NSFileManager.DefaultManager.GetContainerUrl(IosConstants.AppGroup);
+        string root = group?.Path ?? Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        directory = Path.Combine(root, "voicecat");
+        profiles = new(Path.Combine(directory, "servers.json"));
+    }
+
+    internal string TofuPath => Path.Combine(directory, "tofu_pins.txt");
+    internal IReadOnlyList<ServerProfile> LoadProfiles()
+    {
+        MigrateLegacyFiles();
+        return profiles.Load();
+    }
+    internal void SaveProfiles(IEnumerable<ServerProfile> values) => profiles.Save(values);
+
+    private void MigrateLegacyFiles()
+    {
+        Directory.CreateDirectory(directory);
+        string legacy = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "voicecat");
+        if (Path.GetFullPath(legacy) == Path.GetFullPath(directory) || !Directory.Exists(legacy)) return;
+        foreach (string name in new[] { "servers.json", "tofu_pins.txt" })
+        {
+            string source = Path.Combine(legacy, name), destination = Path.Combine(directory, name);
+            if (File.Exists(source) && !File.Exists(destination)) File.Copy(source, destination);
+        }
+    }
+
+    internal string? LoadPassword(ServerProfile profile)
+    {
+        string? value = ReadPassword(IosConstants.PasswordService, profile.Id.ToString("D"), IosConstants.AppGroup);
+        return value ?? (profile.LegacyKeychainTag is { Length: > 0 } tag
+            ? ReadPassword("cat.voice.VoiceCatiOS", tag, IosConstants.AppGroup) ?? ReadPassword("cat.voice.VoiceCatiOS", tag, null)
+            : null);
+    }
+
+    internal void SavePassword(Guid id, string password)
+    {
+        byte[] encoded = Encoding.UTF8.GetBytes(password);
+        try
+        {
+            using var data = NSData.FromArray(encoded);
+            using var query = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+            using var attributes = new SecRecord { ValueData = data, Label = "VoiceCat server password", Accessible = SecAccessible.AfterFirstUnlock };
+            SecStatusCode status = SecKeyChain.Update(query, attributes);
+            if (status == SecStatusCode.ItemNotFound)
+            {
+                using var record = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+                record.ValueData = data; record.Label = attributes.Label; record.Accessible = attributes.Accessible;
+                status = SecKeyChain.Add(record);
+            }
+            if (status != SecStatusCode.Success) throw new InvalidOperationException($"Keychain save failed ({status}).");
+        }
+        finally { CryptographicOperations.ZeroMemory(encoded); }
+    }
+
+    internal void RemovePassword(Guid id)
+    {
+        using var query = PasswordQuery(IosConstants.PasswordService, id.ToString("D"), IosConstants.AppGroup);
+        SecStatusCode status = SecKeyChain.Remove(query);
+        if (status is not (SecStatusCode.Success or SecStatusCode.ItemNotFound))
+            throw new InvalidOperationException($"Keychain removal failed ({status}).");
+    }
+
+    private static string? ReadPassword(string service, string account, string? group)
+    {
+        using var query = PasswordQuery(service, account, group);
+        using SecRecord? result = SecKeyChain.QueryAsRecord(query, out SecStatusCode status);
+        if (status != SecStatusCode.Success || result?.ValueData is not { } data) return null;
+        byte[] bytes = data.ToArray();
+        try { return Encoding.UTF8.GetString(bytes); }
+        finally { CryptographicOperations.ZeroMemory(bytes); }
+    }
+
+    private static SecRecord PasswordQuery(string service, string account, string? group) => new(SecKind.GenericPassword)
+    { Service = service, Account = account, AccessGroup = group };
+}

clients/apple/VoiceCat.iOS/Main.cs

@@ -0,0 +1,3 @@
+using UIKit;
+
+UIApplication.Main(args, null, typeof(VoiceCat.iOS.AppDelegate));

clients/apple/VoiceCat.iOS/MainControllers.cs

@@ -0,0 +1,189 @@
+using UIKit;
+using VoiceCat.Audio;
+using Voicecat.V1;
+using Channel = Voicecat.V1.Channel;
+
+namespace VoiceCat.iOS;
+
+internal sealed class MainTabController : UITabBarController
+{
+    internal MainTabController(AppModel model)
+    {
+        UIViewController channels = Wrap(new ChannelsController(model), "Channels", "list.bullet.indent", 0);
+        UIViewController chat = Wrap(new ChatController(model), "Chat", "message", 1);
+        UIViewController settings = Wrap(new SettingsController(model), "Settings", "gear", 2);
+        ViewControllers = [channels, chat, settings];
+    }
+
+    private static UIViewController Wrap(UIViewController content, string title, string image, nint tag)
+    {
+        var root = new UIViewController(); UIView rootView = root.View!; rootView.BackgroundColor = UIColor.SystemBackground;
+        var navigation = new UINavigationController(content); UIView navigationView = navigation.View!; navigationView.TranslatesAutoresizingMaskIntoConstraints = false;
+        root.AddChildViewController(navigation); rootView.AddSubview(navigationView); navigation.DidMoveToParentViewController(root);
+        var voice = new VoiceControlsView(AppModel.Shared) { TranslatesAutoresizingMaskIntoConstraints = false }; rootView.AddSubview(voice);
+        NSLayoutConstraint.ActivateConstraints([navigationView.TopAnchor.ConstraintEqualTo(rootView.TopAnchor), navigationView.LeadingAnchor.ConstraintEqualTo(rootView.LeadingAnchor),
+            navigationView.TrailingAnchor.ConstraintEqualTo(rootView.TrailingAnchor), navigationView.BottomAnchor.ConstraintEqualTo(voice.TopAnchor),
+            voice.LeadingAnchor.ConstraintEqualTo(rootView.LeadingAnchor), voice.TrailingAnchor.ConstraintEqualTo(rootView.TrailingAnchor),
+            voice.BottomAnchor.ConstraintEqualTo(rootView.SafeAreaLayoutGuide.BottomAnchor), voice.HeightAnchor.ConstraintEqualTo(58)]);
+        root.TabBarItem = new(title, UIImage.GetSystemImage(image), tag); return root;
+    }
+}
+
+internal sealed class VoiceControlsView : UIView
+{
+    private readonly AppModel model; private readonly UIButton join = UIButton.FromType(UIButtonType.System);
+    private readonly UIButton ptt = UIButton.FromType(UIButtonType.System); private readonly UIButton mute = UIButton.FromType(UIButtonType.System);
+    private readonly UIButton deafen = UIButton.FromType(UIButtonType.System); private readonly UIProgressView level = new(UIProgressViewStyle.Default);
+    internal VoiceControlsView(AppModel model) { this.model = model; model.Changed += Refresh; Build(); }
+    private void Build()
+    {
+        BackgroundColor = UIColor.SecondarySystemBackground; join.TouchUpInside += async (_, _) => await Run(model.ToggleVoiceAsync);
+        ptt.TouchDown += (_, _) => model.SetPushToTalk(true); ptt.TouchUpInside += (_, _) => model.SetPushToTalk(false);
+        ptt.TouchUpOutside += (_, _) => model.SetPushToTalk(false); ptt.TouchCancel += (_, _) => model.SetPushToTalk(false);
+        mute.TouchUpInside += (_, _) => model.SetSelfAudio(!(model.Client?.Audio.MicMuted ?? false), model.Client?.Audio.Deafened ?? false);
+        deafen.TouchUpInside += (_, _) => model.SetSelfAudio(model.Client?.Audio.MicMuted ?? false, !(model.Client?.Audio.Deafened ?? false));
+        UIStackView stack = new([join, ptt, level, mute, deafen]) { Axis = UILayoutConstraintAxis.Horizontal, Alignment = UIStackViewAlignment.Center,
+            Distribution = UIStackViewDistribution.Fill, Spacing = 12, TranslatesAutoresizingMaskIntoConstraints = false };
+        AddSubview(stack); level.WidthAnchor.ConstraintEqualTo(65).Active = true;
+        NSLayoutConstraint.ActivateConstraints([stack.LeadingAnchor.ConstraintEqualTo(LeadingAnchor, 12), stack.TrailingAnchor.ConstraintEqualTo(TrailingAnchor, -12), stack.CenterYAnchor.ConstraintEqualTo(CenterYAnchor)]); Refresh();
+    }
+    private void Refresh()
+    {
+        join.SetTitle(model.VoiceJoined ? "Leave Voice" : "Join Voice", UIControlState.Normal); join.AccessibilityLabel = join.Title(UIControlState.Normal); join.Enabled = model.CurrentChannelId != 0;
+        ptt.SetTitle("Hold to Talk", UIControlState.Normal); ptt.AccessibilityLabel = "Push to talk, hold to transmit"; ptt.Hidden = model.Settings.InputMode != AudioInputMode.PushToTalk; ptt.Enabled = model.VoiceJoined;
+        bool muted = model.Client?.Audio.MicMuted == true, deafened = model.Client?.Audio.Deafened == true;
+        mute.SetImage(UIImage.GetSystemImage(muted ? "mic.slash.fill" : "mic.fill"), UIControlState.Normal); mute.AccessibilityLabel = muted ? "Unmute microphone" : "Mute microphone"; mute.Enabled = model.VoiceJoined;
+        deafen.SetImage(UIImage.GetSystemImage(deafened ? "headphones.slash" : "headphones"), UIControlState.Normal); deafen.AccessibilityLabel = deafened ? "Undeafen" : "Deafen"; deafen.Enabled = model.VoiceJoined;
+        level.Progress = Math.Clamp(model.MicrophoneLevel * 10, 0, 1); level.AccessibilityLabel = "Microphone level"; level.AccessibilityValue = $"{level.Progress:P0}";
+    }
+    private async Task Run(Func<Task> operation) { try { await operation(); } catch (Exception exception) { if (Window?.RootViewController is { } owner) UiHelpers.ShowError(owner, exception); } }
+}
+
+internal sealed class ChannelsController : UITableViewController
+{
+    private readonly AppModel model; private IReadOnlyList<(Channel Channel, int Depth)> Visible => Flatten();
+    internal ChannelsController(AppModel model) { this.model = model; Title = "Channels"; model.Changed += Reload; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "channel");
+        NavigationItem.RightBarButtonItems = [new("Users", UIBarButtonItemStyle.Plain, (_, _) => NavigationController?.PushViewController(new UsersController(model), true)),
+            new(UIBarButtonSystemItem.Add, (_, _) => NavigationController?.PushViewController(new ChannelEditorController(model, null), true))]; Reload();
+    }
+    private void Reload() { TableView.ReloadData(); NavigationItem.RightBarButtonItems![1].Enabled = model.Client?.Permissions is { } p && (p.IsAdmin || p.CanCreateTempChannel); }
+    public override nint RowsInSection(UITableView tableView, nint section) => Visible.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        (Channel channel, int depth) = Visible[indexPath.Row]; UITableViewCell cell = tableView.DequeueReusableCell("channel", indexPath);
+        int count = model.Users.Count(user => user.ChannelId == channel.Id); var content = cell.DefaultContentConfiguration;
+        content.Text = new string(' ', depth * 3) + channel.Name; content.SecondaryText = string.IsNullOrEmpty(channel.Topic) ? $"{count} users" : $"{channel.Topic} • {count} users";
+        content.Image = UIImage.GetSystemImage(channel.Id == model.CurrentChannelId ? "checkmark.circle.fill" : channel.PasswordProtected ? "lock.fill" : "bubble.left"); cell.ContentConfiguration = content;
+        cell.AccessibilityLabel = $"{channel.Name}{(channel.Id == model.CurrentChannelId ? ", current" : "")}{(channel.PasswordProtected ? ", password protected" : "")}, {count} users"; return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        Channel channel = Visible[indexPath.Row].Channel; tableView.DeselectRow(indexPath, true);
+        if (channel.PasswordProtected) { PromptPassword(channel); return; }
+        try { await model.JoinChannelAsync(channel.Id); } catch (Exception exception) { UiHelpers.ShowError(this, exception); }
+    }
+    public override UISwipeActionsConfiguration? GetTrailingSwipeActionsConfiguration(UITableView tableView, NSIndexPath indexPath)
+    {
+        if (model.Client?.Permissions.IsAdmin != true) return null; Channel channel = Visible[indexPath.Row].Channel;
+        UIContextualAction edit = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Normal, "Edit", (_, _, done) => { NavigationController?.PushViewController(new ChannelEditorController(model, channel), true); done(true); });
+        UIContextualAction delete = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Destructive, "Delete", (_, _, done) => { ConfirmDelete(channel); done(true); });
+        delete.BackgroundColor = UIColor.SystemRed; return UISwipeActionsConfiguration.FromActions(channel.Id == 1 ? [edit] : [delete, edit]);
+    }
+    private void PromptPassword(Channel channel)
+    {
+        UIAlertController prompt = UIAlertController.Create("Channel Password", channel.Name, UIAlertControllerStyle.Alert); prompt.AddTextField(field => { field.SecureTextEntry = true; field.AccessibilityLabel = "Channel password"; });
+        prompt.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); prompt.AddAction(UIAlertAction.Create("Join", UIAlertActionStyle.Default, async _ => { try { await model.JoinChannelAsync(channel.Id, prompt.TextFields?[0].Text ?? ""); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } })); PresentViewController(prompt, true, null);
+    }
+    private void ConfirmDelete(Channel channel)
+    {
+        UIAlertController alert = UIAlertController.Create("Delete channel?", channel.Name, UIAlertControllerStyle.Alert); alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null));
+        alert.AddAction(UIAlertAction.Create("Delete", UIAlertActionStyle.Destructive, async _ => { try { GenericResult result = await model.RunAdminAsync(client => client.DeleteChannelAsync(channel.Id)); if (!result.Ok) throw new InvalidOperationException(result.Message); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } })); PresentViewController(alert, true, null);
+    }
+    private IReadOnlyList<(Channel, int)> Flatten()
+    {
+        var result = new List<(Channel, int)>(); void Add(uint parent, int depth) { foreach (Channel value in model.Channels.Where(channel => channel.ParentId == parent).OrderBy(channel => channel.Order).ThenBy(channel => channel.Name)) { result.Add((value, depth)); Add(value.Id, depth + 1); } }
+        Add(0, 0); return result;
+    }
+}
+
+internal sealed class ChatController : UIViewController
+{
+    private readonly AppModel model; private readonly UITextView log = new(); private readonly UITextField compose = UiHelpers.Field("Message");
+    internal ChatController(AppModel model) { this.model = model; Title = "Chat"; model.Changed += Refresh; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemBackground; log.Editable = false; log.Font = UIFont.PreferredBody; log.AccessibilityLabel = "Chat and activity timeline"; log.TranslatesAutoresizingMaskIntoConstraints = false;
+        NavigationItem.RightBarButtonItem = new("Private Chats", UIBarButtonItemStyle.Plain, (_, _) => NavigationController?.PushViewController(new PrivateChatsController(model), true));
+        UIButton send = UIButton.FromType(UIButtonType.System); send.SetTitle("Send", UIControlState.Normal); send.AccessibilityLabel = "Send message"; send.TranslatesAutoresizingMaskIntoConstraints = false; send.TouchUpInside += (_, _) => { model.SendText(compose.Text ?? ""); compose.Text = ""; };
+        compose.TranslatesAutoresizingMaskIntoConstraints = false; View.AddSubviews(log, compose, send);
+        NSLayoutConstraint.ActivateConstraints([log.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor), log.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), log.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), compose.TopAnchor.ConstraintEqualTo(log.BottomAnchor, 8), compose.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), compose.BottomAnchor.ConstraintEqualTo(View.KeyboardLayoutGuide.TopAnchor, -8), send.LeadingAnchor.ConstraintEqualTo(compose.TrailingAnchor, 8), send.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), send.CenterYAnchor.ConstraintEqualTo(compose.CenterYAnchor), compose.WidthAnchor.ConstraintGreaterThanOrEqualTo(120)]); Refresh();
+    }
+    private void Refresh()
+    {
+        IEnumerable<(DateTime Time, string Text)> chat = model.Messages.Where(message => !message.Private).Select(message => (message.Timestamp, $"{message.Sender}: {message.Text}"));
+        IEnumerable<(DateTime Time, string Text)> activity = model.Activity.Select(value => (value.Timestamp, $"• {value.Text}"));
+        log.Text = string.Join("\n", chat.Concat(activity).OrderBy(value => value.Time).Select(value => $"[{value.Time:t}] {value.Text}")); if (log.Text.Length > 0) log.ScrollRangeToVisible(new(log.Text.Length - 1, 1));
+    }
+}
+
+internal sealed class PrivateChatsController : UITableViewController
+{
+    private readonly AppModel model;
+    private IReadOnlyList<(uint Id, string Name, ChatEntry? Latest, bool Online)> Peers
+    {
+        get
+        {
+            var online = model.Users.Where(user => user.Id != model.SelfUserId).ToDictionary(user => user.Id);
+            var history = model.Messages.Where(message => message.Private).GroupBy(message => message.PeerUserId).ToDictionary(group => group.Key, group => group.OrderByDescending(message => message.Timestamp).First());
+            return online.Keys.Concat(history.Keys).Distinct().Select(id =>
+            {
+                online.TryGetValue(id, out User? user); history.TryGetValue(id, out ChatEntry? latest);
+                string name = user?.Nickname ?? latest?.Peer ?? $"User {id}"; return (Id: id, Name: name, Latest: latest, Online: user is not null);
+            }).OrderByDescending(peer => peer.Latest?.Timestamp ?? DateTime.MinValue).ThenBy(peer => peer.Name).ToArray();
+        }
+    }
+    internal PrivateChatsController(AppModel model) { this.model = model; Title = "Private Chats"; model.Changed += Reload; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "private-peer"); Reload(); }
+    public override nint RowsInSection(UITableView tableView, nint section) => Peers.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        (uint _, string name, ChatEntry? latest, bool online) = Peers[indexPath.Row]; UITableViewCell cell = tableView.DequeueReusableCell("private-peer", indexPath); var content = cell.DefaultContentConfiguration;
+        content.Text = name; content.SecondaryText = latest?.Text ?? "Start a conversation"; content.Image = UIImage.GetSystemImage(online ? "person.crop.circle.fill" : "person.crop.circle.badge.xmark"); cell.ContentConfiguration = content;
+        cell.Accessory = UITableViewCellAccessory.DisclosureIndicator; cell.AccessibilityLabel = $"{name}, {(online ? "online" : "offline")}, {content.SecondaryText}"; return cell;
+    }
+    public override void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        (uint id, string name, _, _) = Peers[indexPath.Row]; tableView.DeselectRow(indexPath, true); NavigationController?.PushViewController(new PrivateConversationController(model, id, name), true);
+    }
+    private void Reload() { if (IsViewLoaded) { TableView.ReloadData(); TableView.BackgroundView = Peers.Count == 0 ? new UILabel { Text = "No other users or private conversations", TextAlignment = UITextAlignment.Center, AccessibilityLabel = "No other users or private conversations" } : null; } }
+}
+
+internal sealed class PrivateConversationController : UIViewController
+{
+    private readonly AppModel model; private readonly uint peerUserId; private readonly string fallbackName;
+    private readonly UITextView transcript = new(); private readonly UITextField compose = UiHelpers.Field("Private message"); private readonly UIButton send = UIButton.FromType(UIButtonType.System);
+    private User? Peer => model.Users.FirstOrDefault(user => user.Id == peerUserId);
+    internal PrivateConversationController(AppModel model, uint peerUserId, string fallbackName)
+    { this.model = model; this.peerUserId = peerUserId; this.fallbackName = fallbackName; Title = fallbackName; model.Changed += Refresh; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemBackground; transcript.Editable = false; transcript.Font = UIFont.PreferredBody; transcript.AccessibilityLabel = $"Private conversation with {fallbackName}"; transcript.TranslatesAutoresizingMaskIntoConstraints = false;
+        compose.AccessibilityLabel = $"Message to {fallbackName}"; compose.TranslatesAutoresizingMaskIntoConstraints = false;
+        send.SetTitle("Send", UIControlState.Normal); send.AccessibilityLabel = $"Send message to {fallbackName}"; send.TranslatesAutoresizingMaskIntoConstraints = false; send.TouchUpInside += (_, _) => Send();
+        NavigationItem.RightBarButtonItem = new("User", UIBarButtonItemStyle.Plain, (_, _) => NavigationController?.PushViewController(new UserDetailController(model, peerUserId), true)) { AccessibilityLabel = $"Audio and user settings for {fallbackName}" };
+        View.AddSubviews(transcript, compose, send);
+        NSLayoutConstraint.ActivateConstraints([transcript.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor), transcript.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), transcript.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), compose.TopAnchor.ConstraintEqualTo(transcript.BottomAnchor, 8), compose.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor, 12), compose.BottomAnchor.ConstraintEqualTo(View.KeyboardLayoutGuide.TopAnchor, -8), send.LeadingAnchor.ConstraintEqualTo(compose.TrailingAnchor, 8), send.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor, -12), send.CenterYAnchor.ConstraintEqualTo(compose.CenterYAnchor), compose.WidthAnchor.ConstraintGreaterThanOrEqualTo(120)]); Refresh();
+    }
+    private void Send() { string text = compose.Text ?? ""; if (string.IsNullOrWhiteSpace(text) || Peer is null) return; model.SendText(text, peerUserId); compose.Text = ""; }
+    private void Refresh()
+    {
+        if (!IsViewLoaded) return; string name = Peer?.Nickname ?? fallbackName; Title = name;
+        IEnumerable<ChatEntry> messages = model.Messages.Where(message => message.Private && message.PeerUserId == peerUserId).OrderBy(message => message.Timestamp);
+        transcript.Text = string.Join("\n", messages.Select(message => $"[{message.Timestamp:t}] {(message.SenderId == model.SelfUserId ? "You" : message.Sender)}: {message.Text}"));
+        if (transcript.Text.Length > 0) transcript.ScrollRangeToVisible(new(transcript.Text.Length - 1, 1));
+        bool online = Peer is not null; compose.Enabled = online; send.Enabled = online; NavigationItem.RightBarButtonItem!.Enabled = online;
+    }
+}

clients/apple/VoiceCat.iOS/RootViewController.cs

@@ -0,0 +1,31 @@
+using VoiceCat.Core;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal sealed class RootViewController : UIViewController
+{
+    private readonly AppModel model;
+    private UIViewController? current;
+    internal RootViewController(AppModel model) { this.model = model; model.Changed += Refresh; model.IdentityRequested += ShowIdentity; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemBackground; Refresh(); }
+
+    private void Refresh()
+    {
+        bool main = model.IsConnected;
+        if (current is MainTabController && main || current is UINavigationController && !main) return;
+        UIViewController next = main ? new MainTabController(model) : new UINavigationController(new ServerListController(model));
+        if (current is not null) { current.WillMoveToParentViewController(null); current.View!.RemoveFromSuperview(); current.RemoveFromParentViewController(); }
+        UIView rootView = View!, nextView = next.View!;
+        AddChildViewController(next); nextView.Frame = rootView.Bounds; nextView.AutoresizingMask = UIViewAutoresizing.All; rootView.AddSubview(nextView); next.DidMoveToParentViewController(this); current = next;
+    }
+
+    private void ShowIdentity(ServerIdentityChallenge challenge)
+    {
+        UIAlertController alert = UIAlertController.Create(challenge.Status == VoiceCat.Crypto.TofuStatus.Mismatch ? "Server Identity Changed" : "New Server Identity",
+            $"{challenge.Host}:{challenge.Port}\n\nSHA-256\n{challenge.CertificateFingerprint}", UIAlertControllerStyle.Alert);
+        alert.AddAction(UIAlertAction.Create("Reject", UIAlertActionStyle.Destructive, _ => model.ResolveIdentity(false)));
+        alert.AddAction(UIAlertAction.Create("Trust", UIAlertActionStyle.Default, _ => model.ResolveIdentity(true)));
+        PresentViewController(alert, true, null);
+    }
+}

clients/apple/VoiceCat.iOS/SceneDelegate.cs

@@ -0,0 +1,28 @@
+using Foundation;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+[Register("SceneDelegate")]
+internal sealed class SceneDelegate : UIResponder, IUIWindowSceneDelegate
+{
+    [Export("window")]
+    public UIWindow? Window { get; set; }
+
+    [Export("scene:willConnectToSession:options:")]
+    public void WillConnect(UIScene scene, UISceneSession session, UISceneConnectionOptions options)
+    {
+        if (scene is not UIWindowScene windowScene) return;
+        Window = new(windowScene) { RootViewController = new RootViewController(AppModel.Shared) };
+        Window.MakeKeyAndVisible();
+    }
+
+    [Export("sceneDidEnterBackground:")]
+    public void DidEnterBackground(UIScene scene) => AppModel.Shared.DidEnterBackground();
+
+    [Export("sceneWillEnterForeground:")]
+    public void WillEnterForeground(UIScene scene) => AppModel.Shared.WillEnterForeground();
+
+    [Export("sceneDidBecomeActive:")]
+    public void DidBecomeActive(UIScene scene) => AppModel.Shared.DidBecomeActive();
+}

clients/apple/VoiceCat.iOS/ServerListController.cs

@@ -0,0 +1,67 @@
+using VoiceCat.Core;
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal sealed class ServerListController : UITableViewController
+{
+    private readonly AppModel model;
+    internal ServerListController(AppModel model) { this.model = model; Title = "Servers"; TabBarItem = new(UITabBarSystemItem.Favorites, 0); }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "server");
+        NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Add, (_, _) => PresentEditor(null)); model.Changed += Reload;
+    }
+    public override nint RowsInSection(UITableView tableView, nint section) => model.Profiles.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
+    {
+        UITableViewCell cell = tableView.DequeueReusableCell("server", indexPath);
+        ServerProfile p = model.Profiles[indexPath.Row];
+        var content = cell.DefaultContentConfiguration; content.Text = p.DisplayName; content.SecondaryText = p.Authentication.ToString(); cell.ContentConfiguration = content;
+        cell.Accessory = UITableViewCellAccessory.DisclosureIndicator; return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath indexPath)
+    {
+        tableView.DeselectRow(indexPath, true); try { await model.ConnectAsync(model.Profiles[indexPath.Row]); } catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+    public override UISwipeActionsConfiguration GetTrailingSwipeActionsConfiguration(UITableView tableView, NSIndexPath indexPath)
+    {
+        ServerProfile profile = model.Profiles[indexPath.Row];
+        UIContextualAction edit = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Normal, "Edit", (_, _, done) => { PresentEditor(profile); done(true); });
+        UIContextualAction delete = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Destructive, "Delete", (_, _, done) => { model.RemoveProfile(profile); done(true); });
+        return UISwipeActionsConfiguration.FromActions([delete, edit]);
+    }
+    private void PresentEditor(ServerProfile? profile) => PresentViewController(new UINavigationController(new ServerEditorController(model, profile)), true, null);
+    private void Reload() { TableView.ReloadData(); NavigationItem.Prompt = model.IsConnecting ? model.Status : null; }
+}
+
+internal sealed class ServerEditorController : UIViewController
+{
+    private readonly AppModel model; private readonly ServerProfile? existing;
+    private readonly UITextField host = UiHelpers.Field("Hostname or IP address");
+    private readonly UITextField port = UiHelpers.Field("Port");
+    private readonly UISegmentedControl mode = new(["Guest", "Account"]);
+    private readonly UITextField name = UiHelpers.Field("Nickname or username");
+    private readonly UITextField password = UiHelpers.Field("Password (optional)", true);
+    internal ServerEditorController(AppModel model, ServerProfile? existing) { this.model = model; this.existing = existing; Title = existing is null ? "Add Server" : "Edit Server"; }
+    public override void ViewDidLoad()
+    {
+        base.ViewDidLoad(); View!.BackgroundColor = UIColor.SystemGroupedBackground; port.KeyboardType = UIKeyboardType.NumberPad;
+        UIStackView stack = new([host, port, mode, name, password]) { Axis = UILayoutConstraintAxis.Vertical, Spacing = 12, TranslatesAutoresizingMaskIntoConstraints = false };
+        View.AddSubview(stack); NSLayoutConstraint.ActivateConstraints([stack.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor, 24), stack.LeadingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.LeadingAnchor), stack.TrailingAnchor.ConstraintEqualTo(View.LayoutMarginsGuide.TrailingAnchor)]);
+        mode.SelectedSegment = existing?.Authentication == ServerAuthentication.Account ? 1 : 0; host.Text = existing?.Host; port.Text = (existing?.Port ?? 8384).ToString(); name.Text = existing?.Username ?? existing?.Nickname;
+        NavigationItem.LeftBarButtonItem = new(UIBarButtonSystemItem.Cancel, (_, _) => DismissViewController(true, null));
+        NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Save, (_, _) => Save());
+    }
+    private void Save()
+    {
+        try
+        {
+            if (!ushort.TryParse(port.Text, out ushort number)) throw new ArgumentException("Enter a valid port.");
+            ServerAuthentication auth = mode.SelectedSegment == 1 ? ServerAuthentication.Account : ServerAuthentication.Guest;
+            ServerProfile p = ServerProfile.Create(host.Text ?? "", number, auth, auth == ServerAuthentication.Account ? name.Text : null, auth == ServerAuthentication.Guest ? name.Text : null, existing?.Id);
+            model.UpsertProfile(p, password.Text); DismissViewController(true, null);
+        }
+        catch (Exception e) { UiHelpers.ShowError(this, e); }
+    }
+}

clients/apple/VoiceCat.iOS/SettingsController.cs

@@ -0,0 +1,99 @@
+using AVFoundation;
+using AVKit;
+using ReplayKit;
+using UIKit;
+using VoiceCat.Audio;
+using Voicecat.V1;
+
+namespace VoiceCat.iOS;
+
+internal sealed class SettingsController : UITableViewController
+{
+    private readonly AppModel model;
+    internal SettingsController(AppModel model) : base(UITableViewStyle.InsetGrouped) { this.model = model; Title = "Settings"; model.Changed += Reload; IosAudioRouter.Shared.Changed += Reload; }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "setting"); }
+    private void Reload() => TableView.ReloadData();
+    public override nint NumberOfSections(UITableView tableView) => 5;
+    public override nint RowsInSection(UITableView tableView, nint section) => section switch { 0 => 5, 1 => 4, 2 => 5, 3 => model.Client?.Permissions is { } p && (p.IsAdmin || p.CanAdminAccounts) ? 1 : 0, _ => 2 };
+    public override string? TitleForHeader(UITableView tableView, nint section) => section switch { 0 => "Audio", 1 => "Voice", 2 => "Notifications", 3 => "Administration", _ => "Server" };
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath path)
+    {
+        UITableViewCell cell = tableView.DequeueReusableCell("setting", path); cell.AccessoryView = null; cell.Accessory = UITableViewCellAccessory.None;
+        string title = path.Section switch
+        {
+            0 => path.Row switch { 0 => "Audio preset", 1 => "Speaker output", 2 => "Advanced audio", 3 => "Audio buffering", _ => model.ScreenSharing ? "Stop sharing screen audio" : "Share screen audio" },
+            1 => path.Row switch { 0 => "Input mode", 1 => $"VAD threshold: {model.Settings.VadThreshold:0.000}", 2 => $"Microphone volume: {model.Settings.InputGain:P0}", _ => "Microphone noise reduction" },
+            2 => path.Row switch { 0 => "Event sounds", 1 => $"Sound volume: {model.Settings.EventVolume:P0}", 2 => "Speak events", 3 => "Own voice activity sounds", _ => "Push-to-talk cue" },
+            3 => "Manage accounts", _ => path.Row == 0 ? "Disconnect" : "VoiceCat 0.0.1"
+        };
+        var content = cell.DefaultContentConfiguration; content.Text = title; content.SecondaryText = path.Section == 0 && path.Row == 0 ? IosAudioRouter.Shared.Preset.ToString() : path.Section == 1 && path.Row == 0 ? model.Settings.InputMode.ToString() : path.Section == 0 && path.Row == 3 ? $"{model.Settings.AudioBufferMilliseconds} ms" : path.Section == 0 && path.Row == 4 && model.ScreenSharing ? "Sharing" : null; cell.ContentConfiguration = content; cell.AccessibilityLabel = title + (content.SecondaryText is null ? "" : ", " + content.SecondaryText);
+        if (path.Section == 0 && path.Row == 1) cell.AccessoryView = Toggle(IosAudioRouter.Shared.ForceSpeaker, "Speaker output", (_, _) => IosAudioRouter.Shared.SetForceSpeaker(((UISwitch)cell.AccessoryView!).On));
+        else if (path.Section == 1 && path.Row == 3) cell.AccessoryView = Toggle(model.Settings.InputNoiseReduction, title, (_, _) => { model.Settings.InputNoiseReduction = ((UISwitch)cell.AccessoryView!).On; model.ApplyVoiceSettings(); });
+        else if (path.Section == 2 && path.Row is 0 or 2 or 3 or 4) { bool value = path.Row switch { 0 => model.Settings.EventSounds, 2 => model.Settings.SpokenEvents, 3 => model.Settings.SelfTalkSounds, _ => model.Settings.PushToTalkSound }; int row = path.Row; cell.AccessoryView = Toggle(value, title, (_, _) => { bool on = ((UISwitch)cell.AccessoryView!).On; if (row == 0) model.Settings.EventSounds = on; else if (row == 2) model.Settings.SpokenEvents = on; else if (row == 3) model.Settings.SelfTalkSounds = on; else model.Settings.PushToTalkSound = on; model.Save(); }); }
+        else if (path.Section == 0 && path.Row is 2 or 3 || path.Section == 3) cell.Accessory = UITableViewCellAccessory.DisclosureIndicator;
+        return cell;
+    }
+    public override async void RowSelected(UITableView tableView, NSIndexPath path)
+    {
+        tableView.DeselectRow(path, true); try
+        {
+            if (path.Section == 0 && path.Row == 0) Choice("Audio preset", Enum.GetValues<IosAudioPreset>().Select(value => value.ToString()).ToArray(), index => IosAudioRouter.Shared.SelectPreset(Enum.GetValues<IosAudioPreset>()[index]));
+            else if (path.Section == 0 && path.Row == 2) NavigationController?.PushViewController(new AdvancedAudioController(), true);
+            else if (path.Section == 0 && path.Row == 3) Choice("Audio buffering", ["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"], index => { model.Settings.AudioBufferMilliseconds = index switch { 0 => 20, 2 => 60, _ => 40 }; model.ApplyVoiceSettings(); });
+            else if (path.Section == 0 && path.Row == 4) ShowScreenSharing();
+            else if (path.Section == 1 && path.Row == 0) Choice("Input mode", ["Voice activation", "Push to talk", "Always on"], index => { model.Settings.InputMode = (AudioInputMode)index; model.ApplyVoiceSettings(); });
+            else if (path.Section == 1 && path.Row == 1) Slider("Voice activation threshold", 0.001f, 0.1f, model.Settings.VadThreshold, value => { model.Settings.VadThreshold = value; model.ApplyVoiceSettings(); });
+            else if (path.Section == 1 && path.Row == 2) Slider("Microphone volume", 0, 4, model.Settings.InputGain, value => { model.Settings.InputGain = value; model.ApplyVoiceSettings(); });
+            else if (path.Section == 2 && path.Row == 1) Slider("Sound volume", 0, 1, model.Settings.EventVolume, value => { model.Settings.EventVolume = value; model.Save(); });
+            else if (path.Section == 3) NavigationController?.PushViewController(new AccountsController(model), true);
+            else if (path.Section == 4 && path.Row == 0) await model.DisconnectAsync();
+        }
+        catch (Exception exception) { UiHelpers.ShowError(this, exception); }
+    }
+    private static UISwitch Toggle(bool value, string label, EventHandler changed) { var toggle = new UISwitch { On = value, AccessibilityLabel = label }; toggle.ValueChanged += changed; return toggle; }
+    private void Choice(string title, string[] values, Action<int> selected) { UIAlertController alert = UIAlertController.Create(title, null, UIAlertControllerStyle.ActionSheet); for (int i = 0; i < values.Length; i++) { int index = i; alert.AddAction(UIAlertAction.Create(values[i], UIAlertActionStyle.Default, _ => selected(index))); } alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); alert.PopoverPresentationController!.SourceView = View!; PresentViewController(alert, true, null); }
+    private void Slider(string title, float minimum, float maximum, float current, Action<float> changed) { var slider = new UISlider(new CoreGraphics.CGRect(16, 48, 238, 28)) { MinValue = minimum, MaxValue = maximum, Value = current, AccessibilityLabel = title }; UIAlertController alert = UIAlertController.Create(title, null, UIAlertControllerStyle.Alert); alert.View!.AddSubview(slider); alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); alert.AddAction(UIAlertAction.Create("Apply", UIAlertActionStyle.Default, _ => changed(slider.Value))); PresentViewController(alert, true, null); }
+    private void ShowScreenSharing()
+    {
+        // ScreenCaptureKit is the preferred iOS 27 path, but `IsAvailable` also reflects
+        // policy restrictions and transient OS state. Keep the bundled ReplayKit provider as
+        // a compatibility path instead of reporting that capable hardware is unsupported.
+        if (IosScreenCapture.IsAvailable) { model.ToggleScreenAudio(); return; }
+#pragma warning disable CA1422
+        var picker = new RPSystemBroadcastPickerView(new CoreGraphics.CGRect(0, 0, 60, 60)) { PreferredExtension = IosConstants.BroadcastExtension, ShowsMicrophoneButton = false };
+#pragma warning restore CA1422
+        foreach (UIView view in picker.Subviews) view.AccessibilityLabel = model.ScreenSharing ? "Stop sharing screen audio" : "Share screen audio";
+        UIAlertController alert = UIAlertController.Create("Screen Audio", "Tap the broadcast button, then choose Start Broadcast.", UIAlertControllerStyle.Alert); UIView alertView = alert.View!; alertView.AddSubview(picker); picker.Center = new(alertView.Bounds.GetMidX(), 110); alert.AddAction(UIAlertAction.Create("Done", UIAlertActionStyle.Cancel, null)); PresentViewController(alert, true, null);
+    }
+}
+
+internal sealed class AdvancedAudioController : UITableViewController
+{
+    private readonly IosAudioRouter router = IosAudioRouter.Shared;
+    internal AdvancedAudioController() : base(UITableViewStyle.InsetGrouped) { Title = "Advanced Audio"; router.Changed += () => TableView.ReloadData(); }
+    public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "audio"); router.RefreshRoutes(); }
+    public override nint RowsInSection(UITableView tableView, nint section) => 8;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath path)
+    {
+        string title = path.Row switch { 0 => "Input port", 1 => "Microphone orientation", 2 => "Polar pattern", 3 => "Microphone mode", 4 => "Capture channels", 5 => "Bluetooth mode", 6 => "Voice processing and AGC", _ => "Current outputs" };
+        UITableViewCell cell = tableView.DequeueReusableCell("audio", path); var content = cell.DefaultContentConfiguration; content.Text = title; content.SecondaryText = path.Row switch { 0 => router.Inputs.FirstOrDefault(value => value.Id == router.SelectedInputId)?.Name ?? "Default", 1 => router.DataSources().FirstOrDefault(value => value.Id == router.SelectedDataSourceId)?.Name ?? "Default", 2 => router.SelectedPolarPattern.ToString(), 3 => router.MicMode.ToString(), 4 => router.CaptureChannels == 2 ? "Stereo" : "Mono", 5 => router.BluetoothMode.ToString(), 6 => router.UsesVoiceProcessing ? "AEC/NS on" + (router.AutomaticGainControl ? ", AGC on" : ", AGC off") : "Unavailable or off", _ => string.Join(", ", router.Outputs.Select(value => value.Name)) }; cell.ContentConfiguration = content; cell.AccessibilityLabel = title + ", " + content.SecondaryText; cell.Accessory = path.Row < 7 ? UITableViewCellAccessory.DisclosureIndicator : UITableViewCellAccessory.None; return cell;
+    }
+    public override void RowSelected(UITableView tableView, NSIndexPath path) { tableView.DeselectRow(path, true); if (path.Row == 0) Menu("Input port", router.Inputs.Select(value => value.Name).Prepend("Default").ToArray(), index => router.SelectInput(index == 0 ? null : router.Inputs[index - 1].Id)); else if (path.Row == 1) { var values = router.DataSources(); Menu("Microphone orientation", values.Select(value => value.Name).Prepend("Default").ToArray(), index => router.SelectDataSource(index == 0 ? null : values[index - 1].Id)); } else if (path.Row == 2) Menu("Polar pattern", Enum.GetValues<AVAudioDataSourcePolarPattern>().Select(value => value.ToString()).ToArray(), index => router.SelectPolarPattern(Enum.GetValues<AVAudioDataSourcePolarPattern>()[index])); else if (path.Row == 3) Menu("Microphone mode", Enum.GetValues<IosMicMode>().Select(value => value.ToString()).ToArray(), index => router.SetMicMode(Enum.GetValues<IosMicMode>()[index])); else if (path.Row == 4) Menu("Capture channels", ["Mono", "Stereo"], index => router.SetCaptureChannels(index + 1)); else if (path.Row == 5) Menu("Bluetooth mode", Enum.GetValues<IosBluetoothMode>().Select(value => value.ToString()).ToArray(), index => router.SetBluetoothMode(Enum.GetValues<IosBluetoothMode>()[index])); else if (path.Row == 6) Menu("Voice processing", ["Off", "On without AGC", "On with AGC"], index => { router.SetVoiceProcessing(index != 0); router.SetAutomaticGainControl(index == 2); }); }
+    private void Menu(string title, string[] values, Action<int> selected) { UIAlertController alert = UIAlertController.Create(title, null, UIAlertControllerStyle.ActionSheet); for (int i = 0; i < values.Length; i++) { int index = i; alert.AddAction(UIAlertAction.Create(values[i], UIAlertActionStyle.Default, _ => selected(index))); } alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); alert.PopoverPresentationController!.SourceView = View!; PresentViewController(alert, true, null); }
+}
+
+internal sealed class AccountsController : UITableViewController
+{
+    private readonly AppModel model; private IReadOnlyList<AccountEntry> accounts = [];
+    internal AccountsController(AppModel model) { this.model = model; Title = "Accounts"; }
+    public override async void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "account"); NavigationItem.RightBarButtonItem = new(UIBarButtonSystemItem.Add, (_, _) => PromptCreate()); await Refresh(); }
+    public override nint RowsInSection(UITableView tableView, nint section) => accounts.Count;
+    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath path) { AccountEntry account = accounts[path.Row]; UITableViewCell cell = tableView.DequeueReusableCell("account", path); var content = cell.DefaultContentConfiguration; content.Text = account.Username; content.SecondaryText = $"{(account.IsAdmin ? "Administrator" : "Account")} • created {DateTimeOffset.FromUnixTimeMilliseconds((long)account.CreatedAtUnixMs):d}"; cell.ContentConfiguration = content; cell.AccessibilityLabel = content.Text + ", " + content.SecondaryText; return cell; }
+    public override UISwipeActionsConfiguration GetTrailingSwipeActionsConfiguration(UITableView tableView, NSIndexPath path) { AccountEntry account = accounts[path.Row]; UIContextualAction reset = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Normal, "Reset password", (_, _, done) => { PromptReset(account); done(true); }); UIContextualAction delete = UIContextualAction.FromContextualActionStyle(UIContextualActionStyle.Destructive, "Delete", (_, _, done) => { ConfirmDelete(account); done(true); }); return UISwipeActionsConfiguration.FromActions([delete, reset]); }
+    private async Task Refresh() { try { accounts = await model.Client!.ListAccountsAsync(); TableView.ReloadData(); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+    private void PromptCreate() => Credentials("Create Account", "Create", async (name, password) => await Execute(client => client.CreateAccountAsync(name, password)));
+    private void PromptReset(AccountEntry account) => Credentials($"Reset {account.Username}", "Reset", async (_, password) => await Execute(client => client.ResetPasswordAsync(account.Username, password)), account.Username, false);
+    private void ConfirmDelete(AccountEntry account) { UIAlertController alert = UIAlertController.Create("Delete account?", account.Username, UIAlertControllerStyle.Alert); alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); alert.AddAction(UIAlertAction.Create("Delete", UIAlertActionStyle.Destructive, async _ => await Execute(client => client.DeleteAccountAsync(account.Username)))); PresentViewController(alert, true, null); }
+    private void Credentials(string title, string action, Func<string, string, Task> run, string username = "", bool editName = true) { UIAlertController prompt = UIAlertController.Create(title, null, UIAlertControllerStyle.Alert); prompt.AddTextField(field => { field.Placeholder = "Username"; field.Text = username; field.Enabled = editName; field.AccessibilityLabel = "Username"; }); prompt.AddTextField(field => { field.Placeholder = "Password"; field.SecureTextEntry = true; field.AccessibilityLabel = "New password"; }); prompt.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null)); prompt.AddAction(UIAlertAction.Create(action, UIAlertActionStyle.Default, async _ => await run(prompt.TextFields?[0].Text ?? "", prompt.TextFields?[1].Text ?? ""))); PresentViewController(prompt, true, null); }
+    private async Task Execute(Func<VoiceCat.Core.VoiceCatClient, Task<GenericResult>> operation) { try { GenericResult result = await model.RunAdminAsync(operation); if (!result.Ok) throw new InvalidOperationException(result.Message); await Refresh(); } catch (Exception exception) { UiHelpers.ShowError(this, exception); } }
+}

clients/apple/VoiceCat.iOS/UiHelpers.cs

@@ -0,0 +1,20 @@
+using UIKit;
+
+namespace VoiceCat.iOS;
+
+internal static class UiHelpers
+{
+    internal static void ShowError(UIViewController owner, Exception exception) => ShowMessage(owner, "VoiceCat", exception.Message);
+    internal static void ShowMessage(UIViewController owner, string title, string message)
+    {
+        UIAlertController alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
+        alert.AddAction(UIAlertAction.Create("OK", UIAlertActionStyle.Default, null)); owner.PresentViewController(alert, true, null);
+    }
+
+    internal static UITextField Field(string placeholder, bool secure = false)
+    {
+        var field = new UITextField { Placeholder = placeholder, BorderStyle = UITextBorderStyle.RoundedRect,
+            SecureTextEntry = secure, TranslatesAutoresizingMaskIntoConstraints = false };
+        field.AccessibilityLabel = placeholder; return field;
+    }
+}

clients/apple/VoiceCat.iOS/VoiceCat.iOS.csproj

@@ -0,0 +1,65 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0-ios27.0</TargetFramework>
+    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == ''">iossimulator-arm64</RuntimeIdentifier>
+    <SupportedOSPlatformVersion>18.0</SupportedOSPlatformVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <ApplicationTitle>VoiceCat</ApplicationTitle>
+    <ApplicationId>me.iamtalon.voicecat</ApplicationId>
+    <ApplicationVersion>1</ApplicationVersion>
+    <ApplicationDisplayVersion>0.0.1</ApplicationDisplayVersion>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <ApplicationManifest>Info.plist</ApplicationManifest>
+    <TrimMode Condition="'$(Configuration)' == 'Release'">full</TrimMode>
+    <NoWarn>$(NoWarn);XCODE_27_0_PREVIEW</NoWarn>
+    <WarningsNotAsErrors>$(WarningsNotAsErrors);IL2104</WarningsNotAsErrors>
+    <VoiceCatIosStatic>true</VoiceCatIosStatic>
+    <VoiceCatNativeRid Condition="$([System.String]::Copy('$(RuntimeIdentifier)').StartsWith('iossimulator'))">iossimulator-arm64</VoiceCatNativeRid>
+    <VoiceCatNativeRid Condition="'$(VoiceCatNativeRid)' == ''">ios-arm64</VoiceCatNativeRid>
+    <VoiceCatNativeMediaPath>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)../../../artifacts/native/runtimes/$(VoiceCatNativeRid)/native/libvoicecat_media.a'))</VoiceCatNativeMediaPath>
+    <VoiceCatBroadcastSdk Condition="$([System.String]::Copy('$(RuntimeIdentifier)').StartsWith('iossimulator'))">iphonesimulator</VoiceCatBroadcastSdk>
+    <VoiceCatBroadcastSdk Condition="'$(VoiceCatBroadcastSdk)' == ''">iphoneos</VoiceCatBroadcastSdk>
+    <VoiceCatBroadcastArch>arm64</VoiceCatBroadcastArch>
+    <VoiceCatBroadcastOutput>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)obj/$(Configuration)/$(TargetFramework)/$(RuntimeIdentifier)/broadcast'))</VoiceCatBroadcastOutput>
+    <VoiceCatIosCaptureOutput>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)obj/$(Configuration)/$(TargetFramework)/$(RuntimeIdentifier)/capture'))</VoiceCatIosCaptureOutput>
+    <_ComputePublishLocationDependsOn>VoiceCatPrepareIosNativeAssets;$(_ComputePublishLocationDependsOn)</_ComputePublishLocationDependsOn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../../../src/VoiceCat.Core/VoiceCat.Core.csproj" AdditionalProperties="VoiceCatIosStatic=true" />
+    <NativeReference Include="$(VoiceCatNativeMediaPath)" Condition="Exists('$(VoiceCatNativeMediaPath)')">
+      <Kind>Static</Kind>
+      <ForceLoad>true</ForceLoad>
+    </NativeReference>
+    <LinkerArgument Include="-Wl,-force_load,$(VoiceCatNativeMediaPath)" Condition="Exists('$(VoiceCatNativeMediaPath)')" />
+    <ReferenceNativeSymbol Include="vcm_opus_version;vcm_opus_error;vcm_encoder_create;vcm_encoder_destroy;vcm_encoder_set;vcm_encoder_get_dred;vcm_encode;vcm_decoder_create;vcm_decoder_destroy;vcm_decode;vcm_dred_decoder_create;vcm_dred_decoder_destroy;vcm_dred_create;vcm_dred_destroy;vcm_dred_parse;vcm_dred_decode;vcm_rnnoise_create;vcm_rnnoise_destroy;vcm_rnnoise_process">
+      <SymbolType>Function</SymbolType>
+    </ReferenceNativeSymbol>
+    <NativeReference Include="$(VoiceCatIosCaptureOutput)/libvoicecat_ios_capture.a">
+      <Kind>Static</Kind>
+      <ForceLoad>true</ForceLoad>
+      <Frameworks Condition="!$([System.String]::Copy('$(RuntimeIdentifier)').StartsWith('iossimulator'))">AVFoundation CoreMedia</Frameworks>
+    </NativeReference>
+    <AdditionalAppExtensions Include="$(VoiceCatBroadcastOutput)">
+      <Name>VoiceCatBroadcast</Name>
+      <BuildOutput>.</BuildOutput>
+      <CodesignEntitlements>$(VoiceCatBroadcastOutput)/VoiceCatBroadcast.xcent</CodesignEntitlements>
+    </AdditionalAppExtensions>
+    <BundleResource Include="../../../assets/sounds/*.wav" Link="Sounds/%(Filename)%(Extension)" />
+    <ImageAsset Include="Assets.xcassets/**" Link="Assets.xcassets/%(RecursiveDir)%(Filename)%(Extension)" />
+  </ItemGroup>
+  <Target Name="VoiceCatBuildBroadcastExtension" BeforeTargets="_ResolveAppExtensionReferences">
+    <Exec Command="&quot;$(MSBuildThisFileDirectory)build-broadcast-extension.sh&quot; &quot;$(Configuration)&quot; &quot;$(VoiceCatBroadcastSdk)&quot; &quot;$(VoiceCatBroadcastArch)&quot; &quot;$(VoiceCatBroadcastOutput)&quot;" />
+  </Target>
+  <Target Name="VoiceCatBuildIosCaptureBridge" BeforeTargets="PrepareForBuild">
+    <Exec Command="&quot;$(MSBuildThisFileDirectory)build-screen-capture-bridge.sh&quot; &quot;$(VoiceCatBroadcastSdk)&quot; &quot;$(VoiceCatBroadcastArch)&quot; &quot;$(VoiceCatIosCaptureOutput)&quot;" />
+  </Target>
+  <Target Name="VoiceCatPrepareIosNativeAssets">
+    <ItemGroup>
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'libvoicecat_media.dylib' or '%(Filename)%(Extension)' == 'voicecat_media.dll' or '%(Filename)%(Extension)' == 'libvoicecat_media.so'" />
+      <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" Condition="'%(Filename)%(Extension)' == 'NOTICE.txt' or '%(Filename)%(Extension)' == 'Opus.txt' or '%(Filename)%(Extension)' == 'RNNoise.txt'" />
+    </ItemGroup>
+  </Target>
+</Project>

clients/apple/VoiceCat.iOS/build-broadcast-extension.sh

@@ -0,0 +1,53 @@
+#!/bin/zsh
+set -euo pipefail
+
+configuration="${1:?configuration is required}"
+sdk="${2:?sdk is required}"
+architecture="${3:?architecture is required}"
+output="${4:?output directory is required}"
+script_dir="${0:A:h}"
+project="$script_dir/../../../native/apple/broadcast/VoiceCatBroadcast.xcodeproj"
+
+mkdir -p "$output"
+signing=()
+# Both keys must always be set. The extension manifest expands these placeholders, and an
+# empty CURRENT_PROJECT_VERSION drops CFBundleVersion, which installd rejects. The defaults
+# match ApplicationDisplayVersion/ApplicationVersion in VoiceCat.iOS.csproj so that the host
+# and extension versions agree when no release build number is supplied.
+versioning=(
+  MARKETING_VERSION="${VOICECAT_DISPLAY_VERSION:-0.0.1}"
+  CURRENT_PROJECT_VERSION="${VOICECAT_BUILD_NUMBER:-1}"
+)
+if [[ "$sdk" == "iphonesimulator" ]]; then
+  signing+=(CODE_SIGNING_ALLOWED=NO)
+elif [[ -n "${VOICECAT_BROADCAST_CODESIGN_KEY:-}" && -n "${VOICECAT_BROADCAST_CODESIGN_PROVISION:-}" ]]; then
+  signing+=(
+    DEVELOPMENT_TEAM="${VOICECAT_DEVELOPMENT_TEAM:?VOICECAT_DEVELOPMENT_TEAM is required for distribution signing}"
+    CODE_SIGN_STYLE=Manual
+    CODE_SIGN_IDENTITY="$VOICECAT_BROADCAST_CODESIGN_KEY"
+    PROVISIONING_PROFILE_SPECIFIER="$VOICECAT_BROADCAST_CODESIGN_PROVISION"
+  )
+elif [[ -n "${VOICECAT_DEVELOPMENT_TEAM:-}" ]]; then
+  signing+=(DEVELOPMENT_TEAM="$VOICECAT_DEVELOPMENT_TEAM" CODE_SIGN_STYLE=Automatic)
+  if [[ "${VOICECAT_ALLOW_PROVISIONING_UPDATES:-}" == "1" ]]; then
+    signing=(-allowProvisioningUpdates "${signing[@]}")
+  fi
+fi
+xcodebuild \
+  -project "$project" \
+  -scheme VoiceCatBroadcast \
+  -configuration "$configuration" \
+  -sdk "$sdk" \
+  -arch "$architecture" \
+  -derivedDataPath "$output/derived" \
+  CONFIGURATION_BUILD_DIR="$output" \
+  "${versioning[@]}" \
+  "${signing[@]}" \
+  build
+
+xcent=$(find "$output/derived" -name 'VoiceCatBroadcast.appex.xcent' -print -quit)
+if [[ -f "$xcent" ]]; then
+  cp "$xcent" "$output/VoiceCatBroadcast.xcent"
+else
+  cp "$script_dir/../../../native/apple/broadcast/VoiceCatBroadcast.entitlements" "$output/VoiceCatBroadcast.xcent"
+fi

clients/apple/VoiceCat.iOS/build-screen-capture-bridge.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -eu
+
+sdk="$1"
+arch="$2"
+output="$3"
+root="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
+mkdir -p "$output"
+sdk_path="$(xcrun --sdk "$sdk" --show-sdk-path)"
+target="arm64-apple-ios18.0"
+[ "$sdk" = "iphonesimulator" ] && target="arm64-apple-ios18.0-simulator"
+source="$root/native/ios_screen_capture.m"
+flags="-fobjc-arc -fmodules -fmodules-cache-path=$output/module-cache -Wno-unguarded-availability-new"
+if [ "$sdk" = "iphonesimulator" ]; then source="$root/native/ios_screen_capture_stub.c"; flags=""; fi
+# shellcheck disable=SC2086
+xcrun --sdk "$sdk" clang -target "$target" -isysroot "$sdk_path" $flags -Werror -c "$source" -o "$output/ios_screen_capture.o"
+xcrun --sdk "$sdk" ar rcs "$output/libvoicecat_ios_capture.a" "$output/ios_screen_capture.o"

clients/apple/VoiceCat.iOS/native/ios_screen_capture.m

@@ -0,0 +1,124 @@
+#import <AVFoundation/AVFoundation.h>
+#import <CoreMedia/CoreMedia.h>
+#import <Foundation/Foundation.h>
+#import <ScreenCaptureKit/ScreenCaptureKit.h>
+#import <fcntl.h>
+#import <stdatomic.h>
+#import <sys/mman.h>
+#import <sys/stat.h>
+#import <unistd.h>
+
+enum { VCRingHeader = 64, VCRingCapacity = 96000 };
+
+@interface VCScreenCaptureBridge : NSObject <SCContentSharingPickerObserver, SCStreamOutput, SCStreamDelegate>
+@property(nonatomic) SCStream *stream;
+@property(nonatomic) AVAudioConverter *converter;
+@property(nonatomic) AVAudioFormat *inputFormat;
+@property(nonatomic) AVAudioFormat *outputFormat;
+@property(nonatomic) NSString *ringPath;
+@property(nonatomic) int ringFd;
+@property(nonatomic) void *ringMap;
+@end
+
+@implementation VCScreenCaptureBridge
+
+static SCContentSharingPicker *VCSharedPicker(void) {
+    Class pickerClass = NSClassFromString(@"SCContentSharingPicker");
+    return pickerClass ? [pickerClass performSelector:@selector(sharedPicker)] : nil;
+}
+
+- (instancetype)init {
+    if ((self = [super init])) {
+        _ringFd = -1;
+        _outputFormat = [[AVAudioFormat alloc] initWithCommonFormat:AVAudioPCMFormatInt16 sampleRate:48000 channels:2 interleaved:YES];
+    }
+    return self;
+}
+
+- (void)openRing {
+    if (_ringMap || !_ringPath) return;
+    [[NSFileManager defaultManager] createDirectoryAtPath:[_ringPath stringByDeletingLastPathComponent] withIntermediateDirectories:YES attributes:nil error:nil];
+    _ringFd = open(_ringPath.fileSystemRepresentation, O_RDWR | O_CREAT, 0644);
+    size_t size = VCRingHeader + VCRingCapacity * sizeof(int16_t);
+    if (_ringFd < 0 || ftruncate(_ringFd, (off_t)size) != 0) return;
+    _ringMap = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, _ringFd, 0);
+    if (_ringMap == MAP_FAILED) _ringMap = NULL;
+    if (_ringMap && *(uint32_t *)_ringMap != 0x56434252) {
+        memset(_ringMap, 0, VCRingHeader); *(uint32_t *)((uint8_t *)_ringMap + 4) = 1; atomic_thread_fence(memory_order_seq_cst); *(uint32_t *)_ringMap = 0x56434252;
+    }
+}
+
+- (void)setRingActive:(BOOL)active {
+    [self openRing]; if (!_ringMap) return;
+    if (active) { *(uint32_t *)((uint8_t *)_ringMap + 8) = 2; *(uint32_t *)((uint8_t *)_ringMap + 12) = 48000; }
+    atomic_thread_fence(memory_order_seq_cst); *(uint32_t *)((uint8_t *)_ringMap + 16) = active ? 1 : 0;
+}
+
+- (void)push:(const int16_t *)samples count:(NSUInteger)count {
+    if (!_ringMap || count == 0 || count > VCRingCapacity) return;
+    uint8_t *base = _ringMap; uint64_t write = *(uint64_t *)(base + 24); atomic_thread_fence(memory_order_seq_cst); uint64_t read = *(uint64_t *)(base + 32);
+    if (VCRingCapacity - (write - read) < count) return;
+    int16_t *data = (int16_t *)(base + VCRingHeader); NSUInteger index = write % VCRingCapacity;
+    NSUInteger first = MIN(count, VCRingCapacity - index); memcpy(data + index, samples, first * sizeof(int16_t));
+    if (first < count) memcpy(data, samples + first, (count - first) * sizeof(int16_t));
+    atomic_thread_fence(memory_order_seq_cst); *(uint64_t *)(base + 24) = write + count;
+}
+
+- (void)present:(NSString *)path API_AVAILABLE(ios(27.0)) {
+    self.ringPath = path; [self openRing]; SCContentSharingPicker *picker = VCSharedPicker();
+    Class configurationClass = NSClassFromString(@"SCContentSharingPickerConfiguration");
+    SCContentSharingPickerConfiguration *configuration = [configurationClass new];
+    if (!picker || !configuration) return;
+    configuration.showsMicrophoneControl = NO; configuration.showsCameraControl = NO; picker.defaultConfiguration = configuration;
+    [picker removeObserver:self]; [picker addObserver:self]; picker.active = YES; [picker presentPickerUsingContentStyle:SCShareableContentStyleDisplay];
+}
+
+- (void)stop {
+    [self.stream stopCaptureWithCompletionHandler:^(__unused NSError *error) {}]; self.stream = nil;
+    SCContentSharingPicker *picker = VCSharedPicker(); [picker removeObserver:self]; picker.active = NO; [self setRingActive:NO];
+}
+
+- (void)contentSharingPicker:(SCContentSharingPicker *)picker didUpdateWithFilter:(SCContentFilter *)filter forStream:(SCStream *)stream API_AVAILABLE(ios(27.0)) {
+    [self stop]; Class configurationClass = NSClassFromString(@"SCStreamConfiguration"); Class streamClass = NSClassFromString(@"SCStream");
+    SCStreamConfiguration *configuration = [configurationClass new]; if (!configuration || !streamClass) return; configuration.capturesAudio = YES;
+    configuration.excludesCurrentProcessAudio = YES; configuration.sampleRate = 48000; configuration.channelCount = 2;
+    configuration.width = 2; configuration.height = 2;
+    self.stream = [[streamClass alloc] initWithFilter:filter configuration:configuration delegate:self]; NSError *error = nil;
+    if (![self.stream addStreamOutput:self type:SCStreamOutputTypeAudio sampleHandlerQueue:dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0) error:&error]) { self.stream = nil; return; }
+    [self.stream startCaptureWithCompletionHandler:^(NSError *captureError) { [self setRingActive:captureError == nil]; }];
+}
+
+- (void)contentSharingPicker:(SCContentSharingPicker *)picker didCancelForStream:(SCStream *)stream API_AVAILABLE(ios(27.0)) { [self stop]; }
+- (void)contentSharingPickerStartDidFailWithError:(NSError *)error API_AVAILABLE(ios(27.0)) { [self stop]; }
+- (void)stream:(SCStream *)stream didStopWithError:(NSError *)error { [self stop]; }
+
+- (void)stream:(SCStream *)stream didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer ofType:(SCStreamOutputType)type {
+    if (type != SCStreamOutputTypeAudio || !CMSampleBufferDataIsReady(sampleBuffer)) return;
+    CMAudioFormatDescriptionRef description = CMSampleBufferGetFormatDescription(sampleBuffer); const AudioStreamBasicDescription *asbd = CMAudioFormatDescriptionGetStreamBasicDescription(description);
+    if (!asbd) return; AVAudioFormat *format = [[AVAudioFormat alloc] initWithStreamDescription:asbd]; AVAudioFrameCount frames = (AVAudioFrameCount)CMSampleBufferGetNumSamples(sampleBuffer);
+    AVAudioPCMBuffer *input = [[AVAudioPCMBuffer alloc] initWithPCMFormat:format frameCapacity:frames]; input.frameLength = frames;
+    if (CMSampleBufferCopyPCMDataIntoAudioBufferList(sampleBuffer, 0, frames, input.mutableAudioBufferList) != noErr) return;
+    if (!self.converter || ![self.inputFormat isEqual:format]) { self.inputFormat = format; self.converter = [[AVAudioConverter alloc] initFromFormat:format toFormat:self.outputFormat]; }
+    AVAudioFrameCount capacity = (AVAudioFrameCount)ceil(frames * 48000.0 / format.sampleRate) + 64; AVAudioPCMBuffer *output = [[AVAudioPCMBuffer alloc] initWithPCMFormat:self.outputFormat frameCapacity:capacity];
+    __block BOOL supplied = NO; NSError *error = nil; AVAudioConverterOutputStatus status = [self.converter convertToBuffer:output error:&error withInputFromBlock:^AVAudioBuffer *(AVAudioPacketCount count, AVAudioConverterInputStatus *inputStatus) { if (supplied) { *inputStatus = AVAudioConverterInputStatus_NoDataNow; return nil; } supplied = YES; *inputStatus = AVAudioConverterInputStatus_HaveData; return input; }];
+    if (status == AVAudioConverterOutputStatus_Error || output.frameLength == 0 || !output.int16ChannelData) return;
+    [self push:output.int16ChannelData[0] count:output.frameLength * 2];
+}
+
+- (void)dealloc {
+    [self setRingActive:NO]; if (_ringMap) munmap(_ringMap, VCRingHeader + VCRingCapacity * sizeof(int16_t)); if (_ringFd >= 0) close(_ringFd);
+}
+@end
+
+static VCScreenCaptureBridge *bridge;
+
+int vc_ios_screen_capture_available(void) {
+    if (@available(iOS 27.0, *)) return VCSharedPicker().available ? 1 : 0;
+    return 0;
+}
+
+void vc_ios_screen_capture_present(const char *ring_path) {
+    if (@available(iOS 27.0, *)) { if (!bridge) bridge = [VCScreenCaptureBridge new]; [bridge present:[NSString stringWithUTF8String:ring_path]]; }
+}
+
+void vc_ios_screen_capture_stop(void) { [bridge stop]; }

clients/apple/VoiceCat.iOS/native/ios_screen_capture_stub.c

@@ -0,0 +1,3 @@
+int vc_ios_screen_capture_available(void) { return 0; }
+void vc_ios_screen_capture_present(const char *ring_path) { (void)ring_path; }
+void vc_ios_screen_capture_stop(void) {}

clients/apple/VoiceCat.iOS/packages.ios.lock.json

@@ -0,0 +1,59 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0-ios27.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.12, )",
+        "resolved": "10.0.12",
+        "contentHash": "xi+BDjFpW+Sb+MHFHaH6Y/gV9I8BluFwRXc1QyCdoZbIK26eNiBeFuMTe/FMwc33G1wdHCyDg7CVTmb8OdQrMQ=="
+      },
+      "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-ios27.0/ios-arm64": {},
+    "net10.0-ios27.0/iossimulator-arm64": {}
+  }
+}

clients/apple/VoiceCat.iOS/packages.lock.json

@@ -0,0 +1,58 @@
+{
+  "version": 1,
+  "dependencies": {
+    "net10.0-ios27.0": {
+      "Microsoft.NET.ILLink.Tasks": {
+        "type": "Direct",
+        "requested": "[10.0.12, )",
+        "resolved": "10.0.12",
+        "contentHash": "xi+BDjFpW+Sb+MHFHaH6Y/gV9I8BluFwRXc1QyCdoZbIK26eNiBeFuMTe/FMwc33G1wdHCyDg7CVTmb8OdQrMQ=="
+      },
+      "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-ios27.0/iossimulator-arm64": {}
+  }
+}

clients/apple/build-ios-device.sh

@@ -0,0 +1,53 @@
+#!/bin/sh
+set -eu
+
+root="$(CDPATH= cd -- "$(dirname -- "$0")/../.." && pwd)"
+configuration="${CONFIGURATION:-Debug}"
+output="$root/dist/ios-managed-device"
+dotnet_host="${VOICECAT_DOTNET:-/usr/local/share/dotnet/dotnet}"
+
+while [ "$#" -gt 0 ]; do
+    case "$1" in
+        --configuration) configuration="$2"; shift 2 ;;
+        --output) output="$2"; shift 2 ;;
+        -h|--help)
+            echo "usage: $0 [--configuration Debug|Release] [--output DIR]"
+            echo "optional env: VOICECAT_DOTNET, VOICECAT_BUILD_NUMBER, VOICECAT_DISPLAY_VERSION, VOICECAT_CODESIGN_KEY, VOICECAT_CODESIGN_PROVISION"
+            echo "distribution extension env: VOICECAT_DEVELOPMENT_TEAM, VOICECAT_BROADCAST_CODESIGN_KEY, VOICECAT_BROADCAST_CODESIGN_PROVISION"
+            exit 0 ;;
+        *) echo "unknown argument: $1" >&2; exit 2 ;;
+    esac
+done
+
+project="$root/clients/apple/VoiceCat.iOS/VoiceCat.iOS.csproj"
+"$root/scripts/build-native-ios.sh"
+"$dotnet_host" restore "$project" --locked-mode -p:VoiceCatIosStatic=true
+device_lock="obj/packages.device.lock.json"
+"$dotnet_host" restore "$project" -r ios-arm64 --no-dependencies \
+    -p:RestorePackagesWithLockFile=true -p:RestoreLockedMode=false -p:NuGetLockFilePath="$device_lock"
+
+set -- build "$project" -c "$configuration" -r ios-arm64 --no-restore -m:1 \
+    -p:NuGetLockFilePath="$device_lock"
+if [ -n "${VOICECAT_CODESIGN_KEY:-}" ]; then set -- "$@" -p:CodesignKey="$VOICECAT_CODESIGN_KEY"; fi
+if [ -n "${VOICECAT_CODESIGN_PROVISION:-}" ]; then set -- "$@" -p:CodesignProvision="$VOICECAT_CODESIGN_PROVISION"; fi
+if [ -n "${VOICECAT_BUILD_NUMBER:-}" ]; then set -- "$@" -p:ApplicationVersion="$VOICECAT_BUILD_NUMBER"; fi
+"$dotnet_host" "$@"
+
+app="$root/clients/apple/VoiceCat.iOS/bin/$configuration/net10.0-ios27.0/ios-arm64/VoiceCat.iOS.app"
+[ -d "$app" ] || { echo "device app was not produced at $app" >&2; exit 1; }
+/usr/bin/strings "$app/VoiceCat.Codec.dll" | /usr/bin/grep -q GetMainProgramHandle || {
+    echo "device codec does not contain the iOS static-library resolver" >&2
+    exit 1
+}
+/usr/bin/nm -gU "$app/VoiceCat.iOS" | /usr/bin/grep -q _vcm_decoder_create || {
+    echo "device executable does not export the statically linked media codec" >&2
+    exit 1
+}
+/usr/bin/nm -gU "$app/VoiceCat.iOS" | /usr/bin/grep -q _vcm_rnnoise_create || {
+    echo "device executable does not export the statically linked RNNoise processor" >&2
+    exit 1
+}
+mkdir -p "$output"
+/usr/bin/ditto "$app" "$output/VoiceCat.iOS.app"
+/usr/bin/codesign --verify --deep --strict "$output/VoiceCat.iOS.app"
+echo "$output/VoiceCat.iOS.app"

clients/apple/deploy-ios-device.sh

@@ -0,0 +1,35 @@
+#!/bin/sh
+set -eu
+
+root="$(CDPATH= cd -- "$(dirname -- "$0")/../.." && pwd)"
+device="${VOICECAT_IOS_DEVICE:-}"
+configuration="${CONFIGURATION:-Debug}"
+build=true
+console=false
+
+while [ "$#" -gt 0 ]; do
+    case "$1" in
+        --device) device="$2"; shift 2 ;;
+        --configuration) configuration="$2"; shift 2 ;;
+        --no-build) build=false; shift ;;
+        --console) console=true; shift ;;
+        --list) xcrun devicectl list devices; exit 0 ;;
+        -h|--help)
+            echo "usage: $0 --device NAME-OR-UDID [--configuration Debug|Release] [--no-build] [--console]"
+            echo "use --list to show devices, or set VOICECAT_IOS_DEVICE"
+            exit 0 ;;
+        *) echo "unknown argument: $1" >&2; exit 2 ;;
+    esac
+done
+
+[ -n "$device" ] || { echo "pass --device NAME-OR-UDID or set VOICECAT_IOS_DEVICE" >&2; exit 2; }
+app="$root/dist/ios-managed-device/VoiceCat.iOS.app"
+if $build; then "$root/clients/apple/build-ios-device.sh" --configuration "$configuration"; fi
+[ -d "$app" ] || { echo "managed device app not found at $app; run build-ios-device.sh first" >&2; exit 1; }
+
+xcrun devicectl device install app --device "$device" "$app"
+if $console; then
+    xcrun devicectl device process launch --device "$device" --terminate-existing --console me.iamtalon.voicecat
+else
+    xcrun devicectl device process launch --device "$device" --terminate-existing me.iamtalon.voicecat
+fi

clients/apple/publish-macos.sh

@@ -0,0 +1,112 @@
+#!/bin/zsh
+set -euo pipefail
+
+script_dir=${0:A:h}
+project="$script_dir/VoiceCat.Mac/VoiceCat.Mac.csproj"
+configuration=Release
+dry_run=0
+dotnet_host=${VOICECAT_DOTNET:-}
+
+if [[ -z "$dotnet_host" ]]; then
+  if [[ -x /usr/local/share/dotnet/dotnet ]]; then
+    dotnet_host=/usr/local/share/dotnet/dotnet
+  else
+    dotnet_host=$(command -v dotnet)
+  fi
+fi
+
+if [[ ${1:-} == "--dry-run" ]]; then
+  dry_run=1
+fi
+
+publish_properties=(-p:ArchiveOnBuild=false)
+if (( dry_run )); then
+  # Hardened-runtime library validation requires the executable and every bundled dylib to
+  # have the same real Team ID. Ad-hoc signatures have no Team ID, so a hardened ad-hoc app
+  # passes codesign verification but is rejected by dyld at launch. Keep local validation
+  # ad-hoc and reserve the hardened runtime for the Developer ID distribution path below.
+  publish_properties+=(-p:UseHardenedRuntime=false)
+fi
+
+"$dotnet_host" publish "$project" -c "$configuration" --no-restore "${publish_properties[@]}"
+built_app="$script_dir/VoiceCat.Mac/bin/Release/net10.0-macos27.0/osx-arm64/VoiceCat.app"
+if [[ ! -d "$built_app" ]]; then
+  print -u2 "VoiceCat.app was not produced at $built_app"
+  exit 1
+fi
+
+# Signing mutates every nested runtime binary. Work on a disposable distribution copy so a
+# validation run can never poison MSBuild's incremental output or its signing caches.
+distribution="$script_dir/VoiceCat.Mac/bin/Release/distribution"
+app="$distribution/VoiceCat.app"
+if [[ -e "$app" ]]; then
+  rm -rf "$app"
+fi
+mkdir -p "$distribution"
+ditto "$built_app" "$app"
+
+entitlements="$script_dir/VoiceCat.Mac/VoiceCat.Mac.entitlements"
+
+sign_nested_code() {
+  local identity=$1
+  local timestamp_option=${2:-}
+  local runtime_option=${3:-}
+  local nested
+  local sign_options=(--force)
+
+  [[ -n "$timestamp_option" ]] && sign_options+=("$timestamp_option")
+  [[ -n "$runtime_option" ]] && sign_options+=("$runtime_option")
+
+  # Do not use codesign --deep for signing. It is intended as an emergency repair operation
+  # and can apply the app's entitlements to nested code. Sign each bundled Mach-O library first,
+  # then sign the outer app once with its own entitlements.
+  while IFS= read -r -d '' nested; do
+    codesign "${sign_options[@]}" --sign "$identity" "$nested"
+  done < <(find "$app/Contents" -type f \( -name '*.dylib' -o -name '*.so' \) -print0)
+}
+
+install_verified_primary_bundle() {
+  # dotnet publish must create the workload bundle before it can be normalized. Replace that
+  # misleading intermediate with the verified result so both documented output paths work.
+  rm -rf "$built_app"
+  ditto "$app" "$built_app"
+}
+
+if (( dry_run )); then
+  sign_nested_code -
+  codesign --force --entitlements "$entitlements" --sign - "$app"
+  codesign --verify --deep --strict "$app"
+  spctl --assess --type execute "$app" 2>/dev/null || true
+  install_verified_primary_bundle
+  print "Validated ad-hoc build: $app"
+  exit 0
+fi
+
+identity=${VOICECAT_CODESIGN_IDENTITY:-}
+if [[ -z "$identity" ]]; then
+  print -u2 "Set VOICECAT_CODESIGN_IDENTITY to a Developer ID Application identity."
+  exit 2
+fi
+
+sign_nested_code "$identity" --timestamp --options=runtime
+codesign --force --timestamp --options runtime \
+  --entitlements "$entitlements" \
+  --sign "$identity" "$app"
+codesign --verify --deep --strict --verbose=2 "$app"
+install_verified_primary_bundle
+
+archive="$distribution/VoiceCat-macOS-arm64.zip"
+ditto -c -k --keepParent "$app" "$archive"
+
+if [[ -n ${APPLE_ID:-} && -n ${APPLE_TEAM_ID:-} && -n ${APPLE_APP_PASSWORD:-} ]]; then
+  xcrun notarytool submit "$archive" --wait \
+    --apple-id "$APPLE_ID" --team-id "$APPLE_TEAM_ID" --password "$APPLE_APP_PASSWORD"
+  xcrun stapler staple "$app"
+  xcrun stapler validate "$app"
+  spctl --assess --type execute --verbose=2 "$app"
+  ditto -c -k --keepParent "$app" "$archive"
+  print "Signed, notarized, and stapled: $archive"
+else
+  print "Signed archive produced without notarization: $archive"
+  print "Set APPLE_ID, APPLE_TEAM_ID, and APPLE_APP_PASSWORD to submit it."
+fi

clients/windows/README.md

@@ -1,18 +1,23 @@
-# Windows client — placeholder
+# Windows client
 
-Built in **M4** (see [`docs/roadmap.md`](../../docs/roadmap.md)). C# / .NET 8+, consuming
+The .NET 10 WinForms client uses `VoiceCat.Core` and `VoiceCat.Audio`. Its only native runtime
-`libvoicecat` through the C ABI ([`core/include/voicecat.h`](../../core/include/voicecat.h)).
+component is `voicecat_media.dll`, the narrow Opus/RNNoise shim.
 
-Planned shape (see [`docs/architecture.md`](../../docs/architecture.md) §4 and
+```powershell
-[`docs/tech-stack.md`](../../docs/tech-stack.md) §2):
+./scripts/build-native.ps1
+dotnet restore clients/windows/VoiceCat.slnx --locked-mode
+dotnet build clients/windows/VoiceCat.slnx -c Release --no-restore
+./clients/windows/publish-client.ps1
+```
 
-- A .NET solution with a P/Invoke interop layer over the C ABI using **`LibraryImport`**
+Publishing produces `artifacts/client/win-x64`. Runtime-specific restore graphs are generated
-  (source-generated, .NET 7+). Build `libvoicecat` as a **shared library**
+under each project's ignored `obj` directory; they are intentionally not committed because they
-  (`-DVOICECAT_BUILD_SHARED=ON`) so the DLL sits beside the app.
+include SDK-injected packages that change with servicing updates. The noninteractive form and
-- The `on_event` callback marshaled as a function pointer (`[UnmanagedCallersOnly]`) to avoid
+WASAPI device gate is:
-  delegate-lifetime issues; keep the interface "chunky" to minimize managed↔native crossings.
-- UI in **WinUI 3** (most native) or **Avalonia** (if a single C# desktop UI is wanted later).
-- Audio (capture/playback, WASAPI loopback for `SCREEN_AUDIO`) is handled inside the core; the
-  C# layer only drives device selection, meters, and the VAD/PTT + per-user NR controls.
 
-Nothing here yet — the core must reach M2 (working voice) before the GUI is worth building.
+```powershell
+./artifacts/client/win-x64/VoiceCat.App.exe --smoke-test --audio
+```
+
+Manual release validation includes keyboard operation, NVDA navigation, curated announcements,
+and a sustained real call.

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

@@ -0,0 +1,275 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace VoiceCat.App.Audio;
+
+// ── Scope types (mirror macOS ScreenAudioScope / ScreenAudioSelection) ────────
+
+public abstract record AppAudioScope;
+// ExcludeSelf=true captures the whole system render mix minus VoiceCat's own process tree
+// (kills the self-echo loop). Routed through the external-feed mixer as a single EXCLUDE
+// capture; ExcludeSelf=false keeps the core's whole-device loopback path.
+public sealed record EntireDesktop(bool ExcludeSelf = false) : AppAudioScope;
+public sealed record OnlyApps(IReadOnlyList<int> Pids, IReadOnlyList<string> Names) : AppAudioScope;
+public sealed record AllExceptApps(IReadOnlyList<int> Pids, IReadOnlyList<string> Names) : AppAudioScope;
+
+// IsPlaying = a process in this app's executable group currently has an *active* audio
+// session on some render endpoint. Purely informational for the picker — capture works
+// on any PID regardless (process-loopback yields silence until the app plays).
+public sealed record AudioAppInfo(int Pid, string DisplayName, bool IsPlaying);
+
+// ── Enumerator ─────────────────────────────────────────────────────────────────
+
+public static class AudioSessionEnumerator
+{
+    // Returns every app in the user's interactive session — windowed or not — so any of
+    // them can be picked for capture even before it starts producing audio. Process
+    // loopback (see ProcessLoopbackCapture) targets a PID and its child tree, so a silent
+    // selection simply starts working the moment that app plays.
+    //
+    // Apps are deduped by executable (multiple PIDs of the same program collapse to one
+    // row whose PID is the process-tree root). Session-0 services and VoiceCat itself are
+    // excluded. Apps currently producing audio are flagged IsPlaying and sorted first.
+    public static IReadOnlyList<AudioAppInfo> GetAudioApps()
+    {
+        int selfPid    = Environment.ProcessId;
+        int sessionId  = SafeCurrentSessionId();
+        var playingPids = GetActiveAudioPids();
+
+        // Group by executable name; keep the best representative PID per group.
+        var groups = new Dictionary<string, AppGroup>(StringComparer.OrdinalIgnoreCase);
+
+        foreach (var proc in Process.GetProcesses())
+        {
+            try
+            {
+                if (proc.Id == selfPid) continue;
+                if (proc.SessionId != sessionId) continue;   // drop session-0 services
+                string name = proc.ProcessName;
+                if (string.IsNullOrEmpty(name)) continue;
+
+                bool hasWindow = proc.MainWindowHandle != IntPtr.Zero;
+                bool playing   = playingPids.Contains(proc.Id);
+                string title   = hasWindow ? SafeWindowTitle(proc) : "";
+                string display = title.Length > 0 ? $"{name} — {title}" : name;
+
+                if (groups.TryGetValue(name, out var g))
+                {
+                    g.AnyPlaying |= playing;
+                    // Prefer a windowed PID (the process-tree root) as the capture target;
+                    // among non-windowed, prefer a currently-playing PID.
+                    bool better = (hasWindow && !g.HasWindow)
+                               || (!g.HasWindow && !hasWindow && playing && !g.RepPlaying);
+                    if (better)
+                    {
+                        g.Pid        = proc.Id;
+                        g.Display    = display;
+                        g.HasWindow  = hasWindow;
+                        g.RepPlaying = playing;
+                    }
+                }
+                else
+                {
+                    groups[name] = new AppGroup
+                    {
+                        Pid        = proc.Id,
+                        Display    = display,
+                        HasWindow  = hasWindow,
+                        RepPlaying = playing,
+                        AnyPlaying = playing,
+                    };
+                }
+            }
+            catch { /* protected/exited process — skip */ }
+            finally { proc.Dispose(); }
+        }
+
+        return groups.Values
+            .Select(g => new AudioAppInfo(g.Pid, g.Display, g.AnyPlaying))
+            .OrderByDescending(a => a.IsPlaying)
+            .ThenBy(a => a.DisplayName, StringComparer.OrdinalIgnoreCase)
+            .ToList();
+    }
+
+    private sealed class AppGroup
+    {
+        public int    Pid;
+        public string Display    = "";
+        public bool   HasWindow;
+        public bool   RepPlaying; // representative PID is playing
+        public bool   AnyPlaying; // any PID in the group is playing
+    }
+
+    private static int SafeCurrentSessionId()
+    {
+        try { using var me = Process.GetCurrentProcess(); return me.SessionId; }
+        catch { return 1; } // typical interactive session fallback
+    }
+
+    private static string SafeWindowTitle(Process proc)
+    {
+        try { return proc.MainWindowTitle; }
+        catch { return ""; }
+    }
+
+    // ── WASAPI: PIDs with an active render session (any endpoint) ─────────────
+    // Scans ALL active render endpoints, not just the default — an app routed to a
+    // secondary device still counts as "playing now".
+
+    private static HashSet<int> GetActiveAudioPids()
+    {
+        var pids = new HashSet<int>();
+        IMMDeviceEnumerator? enumerator = null;
+        IMMDeviceCollection? devices    = null;
+
+        try
+        {
+            enumerator = (IMMDeviceEnumerator)Activator.CreateInstance(
+                Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
+
+            if (enumerator.EnumAudioEndpoints(0 /*eRender*/, 0x1 /*DEVICE_STATE_ACTIVE*/,
+                    out devices) < 0 || devices == null)
+                return pids;
+
+            devices.GetCount(out int devCount);
+            for (int d = 0; d < devCount; d++)
+                CollectActivePids(devices, d, pids);
+        }
+        catch { /* no audio device or WASAPI unavailable — ignore */ }
+        finally
+        {
+            if (devices    != null) Marshal.ReleaseComObject(devices);
+            if (enumerator != null) Marshal.ReleaseComObject(enumerator);
+        }
+
+        return pids;
+    }
+
+    private static void CollectActivePids(IMMDeviceCollection devices, int index, HashSet<int> pids)
+    {
+        IMMDevice? device                = null;
+        IAudioSessionManager2? manager    = null;
+        IAudioSessionEnumerator? sessions = null;
+
+        try
+        {
+            if (devices.Item(index, out device) < 0 || device == null) return;
+
+            var mgr2Iid = new Guid("77AA99A0-1BD6-484F-8BC7-2C654C9A9B6F");
+            if (device.Activate(ref mgr2Iid, 0x17 /*CLSCTX_ALL*/, IntPtr.Zero, out object mgr) < 0)
+                return;
+            manager = (IAudioSessionManager2)mgr;
+
+            if (manager.GetSessionEnumerator(out sessions) < 0 || sessions == null) return;
+            sessions.GetCount(out int count);
+
+            for (int i = 0; i < count; i++)
+            {
+                IAudioSessionControl? ctrl = null;
+                try
+                {
+                    if (sessions.GetSession(i, out ctrl) < 0 || ctrl == null) continue;
+                    ctrl.GetState(out int state);
+                    if (state != 1 /*AudioSessionStateActive*/) continue;
+
+                    var ctrl2 = (IAudioSessionControl2)ctrl;
+                    ctrl2.GetProcessId(out uint pid);
+                    if (pid != 0) pids.Add((int)pid);
+                }
+                catch { /* stale session */ }
+                finally { if (ctrl != null) Marshal.ReleaseComObject(ctrl); }
+            }
+        }
+        catch { /* device went away */ }
+        finally
+        {
+            if (sessions != null) Marshal.ReleaseComObject(sessions);
+            if (manager  != null) Marshal.ReleaseComObject(manager);
+            if (device   != null) Marshal.ReleaseComObject(device);
+        }
+    }
+
+    // ── COM interface declarations ─────────────────────────────────────────────
+
+    [ComImport, Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDeviceEnumerator
+    {
+        [PreserveSig] int EnumAudioEndpoints(int dataFlow, int stateMask, out IMMDeviceCollection devices);
+        [PreserveSig] int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice endpoint);
+        [PreserveSig] int GetDevice([MarshalAs(UnmanagedType.LPWStr)] string id, out IMMDevice device);
+        [PreserveSig] int RegisterEndpointNotificationCallback(IntPtr client);
+        [PreserveSig] int UnregisterEndpointNotificationCallback(IntPtr client);
+    }
+
+    [ComImport, Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDeviceCollection
+    {
+        [PreserveSig] int GetCount(out int count);
+        [PreserveSig] int Item(int index, out IMMDevice device);
+    }
+
+    [ComImport, Guid("D666063F-1587-4E43-81F1-B948E807363F"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDevice
+    {
+        [PreserveSig] int Activate(ref Guid iid, int clsCtx, IntPtr activationParams,
+            [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
+        [PreserveSig] int OpenPropertyStore(int stgmAccess, out IntPtr propStore);
+        [PreserveSig] int GetId([MarshalAs(UnmanagedType.LPWStr)] out string id);
+        [PreserveSig] int GetState(out int state);
+    }
+
+    [ComImport, Guid("77AA99A0-1BD6-484F-8BC7-2C654C9A9B6F"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioSessionManager2
+    {
+        [PreserveSig] int GetAudioSessionControl(ref Guid audioSessionGuid, int streamFlags,
+            out IAudioSessionControl session);
+        [PreserveSig] int GetSimpleAudioVolume(ref Guid audioSessionGuid, int streamFlags,
+            out IntPtr audioVolume);
+        [PreserveSig] int GetSessionEnumerator(out IAudioSessionEnumerator sessionEnum);
+        [PreserveSig] int RegisterSessionNotification(IntPtr notification);
+        [PreserveSig] int UnregisterSessionNotification(IntPtr notification);
+        [PreserveSig] int RegisterDuckNotification([MarshalAs(UnmanagedType.LPWStr)] string sessionID,
+            IntPtr notification);
+        [PreserveSig] int UnregisterDuckNotification(IntPtr notification);
+    }
+
+    [ComImport, Guid("E2F5BB11-0570-40CA-ACDD-3AA01277DEE8"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioSessionEnumerator
+    {
+        [PreserveSig] int GetCount(out int sessionCount);
+        [PreserveSig] int GetSession(int sessionIndex, out IAudioSessionControl session);
+    }
+
+    [ComImport, Guid("F4B1A599-7266-4319-A8CA-E70ACB11E8CD"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioSessionControl
+    {
+        [PreserveSig] int GetState(out int state);
+        [PreserveSig] int GetDisplayName([MarshalAs(UnmanagedType.LPWStr)] out string name);
+        [PreserveSig] int SetDisplayName([MarshalAs(UnmanagedType.LPWStr)] string name,
+            ref Guid eventContext);
+        [PreserveSig] int GetIconPath([MarshalAs(UnmanagedType.LPWStr)] out string iconPath);
+        [PreserveSig] int SetIconPath([MarshalAs(UnmanagedType.LPWStr)] string iconPath,
+            ref Guid eventContext);
+        [PreserveSig] int GetGroupingParam(out Guid groupingParam);
+        [PreserveSig] int SetGroupingParam(ref Guid groupingParam, ref Guid eventContext);
+        [PreserveSig] int RegisterAudioSessionNotification(IntPtr notification);
+        [PreserveSig] int UnregisterAudioSessionNotification(IntPtr notification);
+    }
+
+    [ComImport, Guid("BFB7FF88-7239-4FC9-8FA2-07C950BE9C6D"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioSessionControl2 : IAudioSessionControl
+    {
+        [PreserveSig] int GetSessionIdentifier([MarshalAs(UnmanagedType.LPWStr)] out string id);
+        [PreserveSig] int GetSessionInstanceIdentifier([MarshalAs(UnmanagedType.LPWStr)] out string id);
+        [PreserveSig] int GetProcessId(out uint pid);
+        [PreserveSig] int IsSystemSoundsSession();
+        [PreserveSig] int SetDuckingPreference(bool optOut);
+    }
+}

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

@@ -0,0 +1,450 @@
+using System.Runtime.InteropServices;
+
+// Captures a second hardware input for AUX_DEVICE and feeds it through vc_stream_feed_pcm.
+// Endpoint identifiers are WASAPI-specific and cannot be exchanged with the core's miniaudio ids.
+namespace VoiceCat.App.Audio;
+
+/// <summary>An audio input (capture) endpoint for the aux-stream device picker. <see cref="Id"/>
+/// is a WASAPI endpoint id (round-trip only; never construct by hand) — pass null to capture the
+/// system default. <see cref="ToString"/> returns the friendly name for ComboBox display.</summary>
+public sealed record InputDeviceInfo(string Id, string Name, bool IsDefault)
+{
+    public override string ToString() => Name;
+}
+
+/// <summary>Enumerates WASAPI capture endpoints. Separate from the core's vc_list_devices because
+/// 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(bool input = true)
+    {
+        var result = new List<InputDeviceInfo>();
+        InputDeviceCapture.IMMDeviceEnumerator? enumerator = null;
+        IntPtr collectionPtr = IntPtr.Zero;
+        string? defaultId = null;
+
+        try
+        {
+            enumerator = (InputDeviceCapture.IMMDeviceEnumerator)Activator.CreateInstance(
+                Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
+
+            // Resolve the default capture endpoint id so the picker can flag it.
+            if (enumerator.GetDefaultAudioEndpoint(input ? 1 : 0, 0 /*eConsole*/,
+                    out var defDev) == 0 && defDev != null)
+            {
+                try { if (defDev.GetId(out string id) == 0) defaultId = id; }
+                finally { Marshal.ReleaseComObject(defDev); }
+            }
+
+            // DEVICE_STATE_ACTIVE = 0x1 — only currently-usable endpoints.
+            if (enumerator.EnumAudioEndpoints(input ? 1 : 0, 0x1, out collectionPtr) != 0
+                || collectionPtr == IntPtr.Zero)
+                return result;
+
+            var collection = (InputDeviceCapture.IMMDeviceCollection)
+                Marshal.GetObjectForIUnknown(collectionPtr);
+            collection.GetCount(out int count);
+
+            for (int i = 0; i < count; i++)
+            {
+                if (collection.Item(i, out var dev) != 0 || dev == null) continue;
+                try
+                {
+                    if (dev.GetId(out string id) != 0) continue;
+                    string name = ReadFriendlyName(dev) ?? "Unknown input device";
+                    result.Add(new InputDeviceInfo(id, name, id == defaultId));
+                }
+                finally { Marshal.ReleaseComObject(dev); }
+            }
+        }
+        catch { /* no audio subsystem / WASAPI unavailable — return what we have */ }
+        finally
+        {
+            if (collectionPtr != IntPtr.Zero) Marshal.Release(collectionPtr);
+            if (enumerator != null) Marshal.ReleaseComObject(enumerator);
+        }
+
+        return result.OrderBy(d => d.Name, StringComparer.OrdinalIgnoreCase).ToList();
+    }
+
+    private static string? ReadFriendlyName(InputDeviceCapture.IMMDevice dev)
+    {
+        if (dev.OpenPropertyStore(0 /*STGM_READ*/, out IntPtr storePtr) != 0
+            || storePtr == IntPtr.Zero)
+            return null;
+        try
+        {
+            var store = (InputDeviceCapture.IPropertyStore)Marshal.GetObjectForIUnknown(storePtr);
+            // PKEY_Device_FriendlyName = {a45c254e-df1c-4efd-8020-67d146a850e0}, pid 14.
+            var key = new InputDeviceCapture.PropertyKey
+            {
+                fmtid = new Guid("a45c254e-df1c-4efd-8020-67d146a850e0"),
+                pid = 14,
+            };
+            if (store.GetValue(ref key, out var pv) != 0) return null;
+            try
+            {
+                // VT_LPWSTR = 31.
+                return pv.vt == 31 ? Marshal.PtrToStringUni(pv.pointerValue) : null;
+            }
+            finally { InputDeviceCapture.PropVariantClear(ref pv); }
+        }
+        finally { Marshal.Release(storePtr); }
+    }
+}
+
+/// <summary>Captures a single hardware input device in WASAPI shared mode and raises a 20 ms
+/// (960 samples/channel @ 48 kHz, interleaved s16) frame event. The caller feeds these to the
+/// core's external-feed stream. Threading mirrors ProcessLoopbackCapture: all WASAPI work runs on
+/// a dedicated background (MTA) thread; the event fires on that thread.</summary>
+public sealed class InputDeviceCapture : IDisposable
+{
+    /// <summary>Fired on the capture thread every 20 ms: (interleaved s16 PCM, samplesPerChannel
+    /// = 960, channels).</summary>
+    public event Action<short[], int /*samplesPerChannel*/, int /*channels*/>? PcmFrameReady;
+
+    private const int SampleRate   = 48000;
+    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;
+
+    private AutoResetEvent? _bufferEvent;
+    private Thread?         _captureThread;
+    private volatile bool   _running;
+    private int             _channels;
+
+    // Accumulator: assembles driver-callback-sized fragments into FrameSamples chunks.
+    private short[] _accumBuf = [];
+    private int     _accumCount;
+
+    // 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, 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>
+    public bool Start()
+    {
+        if (_running) return false;
+        _running       = true;
+        _captureThread = new Thread(CaptureThreadProc)
+        {
+            IsBackground = true,
+            Name         = "AuxInputCapture",
+        };
+        _captureThread.Start();
+
+        bool ok = _initDone.Wait(5000) && _initOk;
+        if (!ok) _running = false;
+        return ok;
+    }
+
+    public void Stop()
+    {
+        _running = false;
+        _bufferEvent?.Set();
+        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();
+        _bufferEvent?.Dispose();
+        _initDone.Dispose();
+    }
+
+    // ── Capture thread (MTA) ──────────────────────────────────────────────────
+
+    private void CaptureThreadProc()
+    {
+        try
+        {
+            _initOk = ActivateAndStart();
+            _initDone.Set();
+            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()
+    {
+        if (!ActivateClient()) return false;
+
+        _bufferEvent = new AutoResetEvent(false);
+        if (_audioClient!.SetEventHandle(_bufferEvent.SafeWaitHandle.DangerousGetHandle()) < 0)
+            return false;
+
+        return _audioClient.Start() >= 0;
+    }
+
+    private bool ActivateClient()
+    {
+        IMMDeviceEnumerator? enumerator = null;
+        IMMDevice? device = null;
+        try
+        {
+            enumerator = (IMMDeviceEnumerator)Activator.CreateInstance(
+                Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
+
+            int hr = _deviceId is null
+                ? enumerator.GetDefaultAudioEndpoint(_loopback ? 0 : 1, 0 /*eConsole*/, out device)
+                : enumerator.GetDevice(_deviceId, out device);
+            if (hr != 0 || device == null) return false;
+
+            var iidAudioClient = new Guid("1CB9AD4C-DBFA-4c32-B178-C2F568A703B2");
+            if (device.Activate(ref iidAudioClient, 0x17 /*CLSCTX_ALL*/, IntPtr.Zero,
+                    out object acObj) != 0 || acObj is not IAudioClient ac)
+                return false;
+            _audioClient = ac;
+
+            return InitializeStream();
+        }
+        catch { return false; }
+        finally
+        {
+            if (device     != null) Marshal.ReleaseComObject(device);
+            if (enumerator != null) Marshal.ReleaseComObject(enumerator);
+        }
+    }
+
+    private bool InitializeStream()
+    {
+        // Try s16 stereo first; fall back to s16 mono. AUTOCONVERTPCM lets the audio engine
+        // resample/convert the device's native format to our requested 48 kHz s16; EVENTCALLBACK
+        // drives the buffer-ready event. Shared mode (0), no LOOPBACK (this is a capture device).
+        //   AUDCLNT_STREAMFLAGS_EVENTCALLBACK    = 0x00040000
+        //   AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM   = 0x80000000
+        //   AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY = 0x08000000
+        uint streamFlags = 0x00040000u | 0x80000000u | 0x08000000u | (_loopback ? 0x00020000u : 0u);
+
+        foreach (int ch in new[] { 2, 1 })
+        {
+            var fmt = new WaveFormatEx
+            {
+                wFormatTag      = 1,           // WAVE_FORMAT_PCM
+                nChannels       = (ushort)ch,
+                nSamplesPerSec  = SampleRate,
+                wBitsPerSample  = 16,
+                nBlockAlign     = (ushort)(ch * 2),
+                nAvgBytesPerSec = (uint)(SampleRate * ch * 2),
+                cbSize          = 0,
+            };
+
+            IntPtr pFmt = Marshal.AllocHGlobal(Marshal.SizeOf<WaveFormatEx>());
+            try
+            {
+                Marshal.StructureToPtr(fmt, pFmt, false);
+                int hr = _audioClient!.Initialize(0 /*AUDCLNT_SHAREMODE_SHARED*/, streamFlags,
+                    2_000_000 /*200 ms hns*/, 0, pFmt, IntPtr.Zero);
+                if (hr >= 0)
+                {
+                    _channels   = ch;
+                    _accumBuf   = new short[FrameSamples * ch];
+                    _accumCount = 0;
+
+                    var iidCapture = new Guid("C8ADBD64-E71E-48a0-A4DE-185C395CD317");
+                    if (_audioClient.GetService(ref iidCapture, out object ccObj) != 0
+                        || ccObj is not IAudioCaptureClient cc)
+                        return false;
+                    _captureClient = cc;
+                    return true;
+                }
+                if (ch == 1) return false;
+            }
+            finally { Marshal.FreeHGlobal(pFmt); }
+        }
+        return false;
+    }
+
+    // ── Capture loop ─────────────────────────────────────────────────────────
+
+    private void CaptureLoop()
+    {
+        while (_running)
+        {
+            _bufferEvent!.WaitOne(100);
+            if (!_running) break;
+
+            while (_running)
+            {
+                if (_captureClient!.GetNextPacketSize(out uint packetSize) < 0 || packetSize == 0)
+                    break;
+
+                if (_captureClient.GetBuffer(out IntPtr dataPtr, out uint framesAvailable,
+                        out uint flags, out _, out _) < 0)
+                    break;
+
+                bool silent = (flags & 2) != 0; // AUDCLNT_BUFFERFLAGS_SILENT
+                if (framesAvailable > 0)
+                {
+                    if (silent) AccumulateSilence((int)framesAvailable);
+                    else        AccumulatePcm(dataPtr, (int)framesAvailable);
+                }
+
+                _captureClient.ReleaseBuffer(framesAvailable);
+            }
+        }
+    }
+
+    private unsafe void AccumulatePcm(IntPtr data, int frames)
+    {
+        var src   = (short*)data.ToPointer();
+        int total = frames * _channels;
+        int idx   = 0;
+        while (idx < total)
+        {
+            int space = _accumBuf.Length - _accumCount;
+            int copy  = Math.Min(total - idx, space);
+            fixed (short* dst = _accumBuf)
+                Buffer.MemoryCopy(src + idx, dst + _accumCount, copy * 2L, copy * 2L);
+            _accumCount += copy;
+            idx         += copy;
+            if (_accumCount == _accumBuf.Length)
+                FlushFrame();
+        }
+    }
+
+    private void AccumulateSilence(int frames)
+    {
+        int total = frames * _channels;
+        int idx   = 0;
+        while (idx < total)
+        {
+            int space = _accumBuf.Length - _accumCount;
+            int fill  = Math.Min(total - idx, space);
+            Array.Clear(_accumBuf, _accumCount, fill);
+            _accumCount += fill;
+            idx         += fill;
+            if (_accumCount == _accumBuf.Length)
+                FlushFrame();
+        }
+    }
+
+    private void FlushFrame()
+    {
+        PcmFrameReady?.Invoke(_accumBuf, FrameSamples, _channels); // Borrowed until callback returns.
+        _accumCount = 0;
+    }
+
+    // ── COM declarations ───────────────────────────────────────────────────────
+    //
+    // Declared internal here so InputDeviceEnumerator can share them. These are standard MMDevice
+    // / WASAPI interfaces; a normal capture endpoint honours QueryInterface, so RCW marshalling is
+    // safe (unlike ProcessLoopbackCapture's process-loopback objects, which need raw vtable calls).
+
+    [ComImport, Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDeviceEnumerator
+    {
+        [PreserveSig] int EnumAudioEndpoints(int dataFlow, int stateMask, out IntPtr devices);
+        [PreserveSig] int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice endpoint);
+        [PreserveSig] int GetDevice([MarshalAs(UnmanagedType.LPWStr)] string id, out IMMDevice device);
+        [PreserveSig] int RegisterEndpointNotificationCallback(IntPtr client);
+        [PreserveSig] int UnregisterEndpointNotificationCallback(IntPtr client);
+    }
+
+    [ComImport, Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDeviceCollection
+    {
+        [PreserveSig] int GetCount(out int count);
+        [PreserveSig] int Item(int index, out IMMDevice device);
+    }
+
+    [ComImport, Guid("D666063F-1587-4E43-81F1-B948E807363F"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IMMDevice
+    {
+        [PreserveSig] int Activate(ref Guid iid, int clsCtx, IntPtr activationParams,
+            [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
+        [PreserveSig] int OpenPropertyStore(int stgmAccess, out IntPtr propStore);
+        [PreserveSig] int GetId([MarshalAs(UnmanagedType.LPWStr)] out string id);
+        [PreserveSig] int GetState(out int state);
+    }
+
+    [ComImport, Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IPropertyStore
+    {
+        [PreserveSig] int GetCount(out int count);
+        [PreserveSig] int GetAt(int index, out PropertyKey key);
+        [PreserveSig] int GetValue(ref PropertyKey key, out PropVariant value);
+        [PreserveSig] int SetValue(ref PropertyKey key, ref PropVariant value);
+        [PreserveSig] int Commit();
+    }
+
+    [ComImport, Guid("1CB9AD4C-DBFA-4C32-B178-C2F568A703B2"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioClient
+    {
+        [PreserveSig] int Initialize(int shareMode, uint streamFlags, long hnsBufferDuration,
+            long hnsPeriodicity, IntPtr pFormat, IntPtr audioSessionGuid);
+        [PreserveSig] int GetBufferSize(out uint numBufferFrames);
+        [PreserveSig] int GetStreamLatency(out long latency);
+        [PreserveSig] int GetCurrentPadding(out uint numPaddingFrames);
+        [PreserveSig] int IsFormatSupported(int shareMode, IntPtr pFormat, out IntPtr closestMatch);
+        [PreserveSig] int GetMixFormat(out IntPtr deviceFormat);
+        [PreserveSig] int GetDevicePeriod(out long defaultDevicePeriod, out long minimumDevicePeriod);
+        [PreserveSig] int Start();
+        [PreserveSig] int Stop();
+        [PreserveSig] int Reset();
+        [PreserveSig] int SetEventHandle(IntPtr eventHandle);
+        [PreserveSig] int GetService(ref Guid riid,
+            [MarshalAs(UnmanagedType.IUnknown)] out object ppv);
+    }
+
+    [ComImport, Guid("C8ADBD64-E71E-48A0-A4DE-185C395CD317"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal interface IAudioCaptureClient
+    {
+        [PreserveSig] int GetBuffer(out IntPtr data, out uint numFramesToRead, out uint flags,
+            out ulong devicePosition, out ulong qpcPosition);
+        [PreserveSig] int ReleaseBuffer(uint numFramesRead);
+        [PreserveSig] int GetNextPacketSize(out uint numFramesInNextPacket);
+    }
+
+    [StructLayout(LayoutKind.Sequential, Pack = 2)]
+    private struct WaveFormatEx
+    {
+        public ushort wFormatTag;
+        public ushort nChannels;
+        public uint   nSamplesPerSec;
+        public uint   nAvgBytesPerSec;
+        public ushort nBlockAlign;
+        public ushort wBitsPerSample;
+        public ushort cbSize;
+    }
+
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct PropertyKey
+    {
+        public Guid fmtid;
+        public int  pid;
+    }
+
+    // Minimal PROPVARIANT: we only ever read VT_LPWSTR (friendly name). x64 layout — the value
+    // union starts at offset 8 after vt(2)+reserved(6).
+    [StructLayout(LayoutKind.Explicit)]
+    internal struct PropVariant
+    {
+        [FieldOffset(0)] public ushort vt;
+        [FieldOffset(8)] public IntPtr pointerValue;
+    }
+
+    [DllImport("ole32.dll")]
+    internal static extern int PropVariantClear(ref PropVariant pvar);
+}

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

@@ -0,0 +1,85 @@
+using VoiceCat.Audio;
+using VoiceCat.Windows;
+
+namespace VoiceCat.App.Audio;
+
+// Capture threads own their ring producers; the mix thread alone consumes them.
+public sealed class ProcessAudioMixer : IDisposable
+{
+    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;
+        this.client = client; this.streamId = streamId;
+        var specs = ResolveCaptures(scope);
+        inputs = specs.Select(_ => new Input()).ToArray();
+        try
+        {
+            for (int i = 0; i < specs.Count; i++)
+            {
+                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.");
+            }
+            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;
+        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();
+    private void MixLoop()
+    {
+        var frame = new short[1920]; var mix = new short[1920]; var sums = new int[1920];
+        long deadline = System.Diagnostics.Stopwatch.GetTimestamp();
+        while (running)
+        {
+            sums.AsSpan().Clear();
+            foreach (Input input in inputs)
+            {
+                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();
+        }
+    }
+    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)],
+        EntireDesktop { ExcludeSelf: true } => [(Environment.ProcessId, ProcessLoopbackCapture.Mode.Exclude)],
+        _ => [],
+    };
+}

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

@@ -0,0 +1,438 @@
+using System.Runtime.InteropServices;
+
+// Process loopback requires MTA activation; blocking activation from the WinForms STA
+// deadlocks COM completion. The returned interfaces also reject RCW QueryInterface, so audio
+// calls use explicitly owned raw pointers and vtable dispatch.
+namespace VoiceCat.App.Audio;
+
+public sealed class ProcessLoopbackCapture : IDisposable
+{
+    public enum Mode { Include, Exclude }
+
+    // Fired on the capture thread every 20 ms (960 samples/channel @ 48 kHz, interleaved s16).
+    public event Action<short[], int /*samplesPerChannel*/, int /*channels*/>? PcmFrameReady;
+
+    private const int SampleRate   = 48000;
+    private const int FrameSamples = 960;  // 20 ms
+    private const string LoopbackDevicePath = "VAD\\Process_Loopback";
+
+    private readonly int  _pid;
+    private readonly Mode _mode;
+
+    // Raw COM pointers — managed via explicit AddRef/Release, no RCW wrapping.
+    private IntPtr _audioClientPtr;   // IAudioClient*
+    private IntPtr _captureClientPtr; // IAudioCaptureClient*
+
+    private AutoResetEvent? _bufferEvent;
+    private Thread?         _captureThread;
+    private volatile bool   _running;
+    private int             _channels;
+
+    // Accumulator: assembles driver-callback-sized fragments into FrameSamples chunks.
+    private short[] _accumBuf = [];
+    private int     _accumCount;
+
+    // Init-done signal: Set() by the capture thread after ActivateClient() completes.
+    private readonly ManualResetEventSlim _initDone = new(false);
+    private bool _initOk;
+
+    public ProcessLoopbackCapture(int pid, Mode mode)
+    {
+        _pid  = pid;
+        _mode = mode;
+    }
+
+    /// <summary>Starts capture. Blocks until WASAPI activation completes (typically &lt;100 ms).
+    /// Returns false if the process cannot be captured.</summary>
+    public bool Start()
+    {
+        if (_running) return false;
+        _running       = true;
+        _captureThread = new Thread(CaptureThreadProc)
+        {
+            IsBackground = true,
+            Name         = $"ProcLoopback:{_pid}",
+        };
+        _captureThread.Start();
+
+        bool ok = _initDone.Wait(5000) && _initOk;
+        if (!ok) _running = false;
+        return ok;
+    }
+
+    public void Stop()
+    {
+        _running = false;
+        _bufferEvent?.Set();
+        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();
+        _bufferEvent?.Dispose();
+        _initDone.Dispose();
+    }
+
+    // ── Capture thread (MTA) ──────────────────────────────────────────────────
+
+    private void CaptureThreadProc()
+    {
+        try
+        {
+            _initOk = ActivateAndStart();
+            _initDone.Set();
+            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()
+    {
+        if (!ActivateClient()) return false;
+
+        _bufferEvent = new AutoResetEvent(false);
+        if (AC_SetEventHandle(_audioClientPtr, _bufferEvent.SafeWaitHandle.DangerousGetHandle()) < 0)
+            return false;
+
+        return AC_Start(_audioClientPtr) >= 0;
+    }
+
+    // ── Activation ───────────────────────────────────────────────────────────
+
+    private unsafe bool ActivateClient()
+    {
+        var activationParams = new AudioClientActivationParams
+        {
+            ActivationType      = 1,   // AUDCLNT_ACTIVATIONTYPE_PROCESS_LOOPBACK
+            TargetProcessId     = (uint)_pid,
+            ProcessLoopbackMode = _mode == Mode.Include ? 0u : 1u,
+        };
+
+        var handler = new ActivationCompletionHandler();
+        var audioClientIid = new Guid("1CB9AD4C-DBFA-4c32-B178-C2F568A703B2");
+
+        IntPtr opPtr;
+        {
+            AudioClientActivationParams* pParams = &activationParams;
+            // PROPVARIANT (VT_BLOB) x64: vt(2)+res(6)+cbSize(4)+pad(4)+pBlobData(8) = 24 B.
+            var pv = stackalloc byte[24];
+            *(ushort*)(pv + 0)  = 65;
+            *(uint*)  (pv + 8)  = (uint)sizeof(AudioClientActivationParams);
+            *(nint*)  (pv + 16) = (nint)pParams;
+
+            int hr = ActivateAudioInterfaceAsync(
+                LoopbackDevicePath, ref audioClientIid,
+                (IntPtr)pv, handler, out opPtr);
+            if (hr < 0) return false;
+        }
+
+        if (!handler.CompletionEvent.Wait(3000))
+        {
+            ComRelease(ref opPtr);
+            return false;
+        }
+
+        // Call GetActivateResult via vtable (slot 3) — avoids QI on the async-op object.
+        if (!Vtable_GetActivateResult(handler.OperationPtr, out int activateHr, out IntPtr activatedPtr))
+        {
+            handler.ReleaseOp();
+            ComRelease(ref opPtr);
+            return false;
+        }
+        handler.ReleaseOp();
+        ComRelease(ref opPtr);
+
+        if (activateHr < 0 || activatedPtr == IntPtr.Zero) return false;
+
+        // Store the raw IAudioClient* — do NOT create an RCW; use vtable dispatch instead.
+        _audioClientPtr = activatedPtr;
+        // activatedPtr already has ref count from GetActivateResult; don't double-release.
+
+        return InitializeStream();
+    }
+
+    // IActivateAudioInterfaceAsyncOperation vtable slot 3: GetActivateResult(HRESULT*, IUnknown**)
+    private static unsafe bool Vtable_GetActivateResult(IntPtr op,
+        out int activateHr, out IntPtr activatedPtr)
+    {
+        activateHr   = unchecked((int)0x80004005);
+        activatedPtr = IntPtr.Zero;
+        if (op == IntPtr.Zero) return false;
+        void** vtable = *(void***)op.ToPointer();
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, int*, IntPtr*, int>)vtable[3];
+        fixed (int*    pHr  = &activateHr)
+        fixed (IntPtr* pPtr = &activatedPtr)
+            return fn(op, pHr, pPtr) >= 0;
+    }
+
+    private unsafe bool InitializeStream()
+    {
+        // Try s16 stereo first; fall back to s16 mono.
+        foreach (int ch in new[] { 2, 1 })
+        {
+            var fmt = new WaveFormatEx
+            {
+                wFormatTag      = 1,           // WAVE_FORMAT_PCM
+                nChannels       = (ushort)ch,
+                nSamplesPerSec  = SampleRate,
+                wBitsPerSample  = 16,
+                nBlockAlign     = (ushort)(ch * 2),
+                nAvgBytesPerSec = (uint)(SampleRate * ch * 2),
+                cbSize          = 0,
+            };
+
+            // Process-loopback requires LOOPBACK (deliver rendered audio) + EVENTCALLBACK +
+            // AUTOCONVERTPCM (resample the app's native format to our requested s16/48k). Without
+            // LOOPBACK every buffer comes back AUDCLNT_BUFFERFLAGS_SILENT; without AUTOCONVERTPCM
+            // the requested format is rejected. Matches the MS ApplicationLoopback sample.
+            //   AUDCLNT_SHAREMODE_SHARED      = 0
+            //   AUDCLNT_STREAMFLAGS_LOOPBACK  = 0x00020000
+            //   AUDCLNT_STREAMFLAGS_EVENTCALLBACK = 0x00040000
+            //   AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM = 0x80000000
+            const uint streamFlags = 0x00020000u | 0x00040000u | 0x80000000u;
+            int hr = AC_Initialize(_audioClientPtr, 0, streamFlags,
+                                   2_000_000 /*200ms hns*/, 0, &fmt, null);
+            if (hr >= 0)
+            {
+                _channels   = ch;
+                _accumBuf   = new short[FrameSamples * ch];
+                _accumCount = 0;
+                break;
+            }
+            if (ch == 1) return false;
+        }
+
+        var captureIid = new Guid("C8ADBD64-E71E-48a0-A4DE-185C395CD317");
+        int getHr = AC_GetService(_audioClientPtr, ref captureIid, out _captureClientPtr);
+        return getHr >= 0 && _captureClientPtr != IntPtr.Zero;
+    }
+
+    // ── Capture loop ─────────────────────────────────────────────────────────
+
+    private void CaptureLoop()
+    {
+        while (_running)
+        {
+            _bufferEvent!.WaitOne(100);
+            if (!_running) break;
+
+            while (_running)
+            {
+                int hr = CC_GetNextPacketSize(_captureClientPtr, out uint packetSize);
+                if (hr < 0 || packetSize == 0) break;
+
+                hr = CC_GetBuffer(_captureClientPtr, out IntPtr dataPtr, out uint framesAvailable,
+                    out uint flags);
+                if (hr < 0) break;
+
+                bool silent = (flags & 2) != 0; // AUDCLNT_BUFFERFLAGS_SILENT
+                if (framesAvailable > 0)
+                {
+                    if (silent) AccumulateSilence((int)framesAvailable);
+                    else        AccumulatePcm(dataPtr, (int)framesAvailable);
+                }
+
+                CC_ReleaseBuffer(_captureClientPtr, framesAvailable);
+            }
+        }
+    }
+
+    private unsafe void AccumulatePcm(IntPtr data, int frames)
+    {
+        var src   = (short*)data.ToPointer();
+        int total = frames * _channels;
+        int idx   = 0;
+        while (idx < total)
+        {
+            int space = _accumBuf.Length - _accumCount;
+            int copy  = Math.Min(total - idx, space);
+            fixed (short* dst = _accumBuf)
+                Buffer.MemoryCopy(src + idx, dst + _accumCount, copy * 2L, copy * 2L);
+            _accumCount += copy;
+            idx         += copy;
+            if (_accumCount == _accumBuf.Length)
+                FlushFrame();
+        }
+    }
+
+    private void AccumulateSilence(int frames)
+    {
+        int total = frames * _channels;
+        int idx   = 0;
+        while (idx < total)
+        {
+            int space = _accumBuf.Length - _accumCount;
+            int fill  = Math.Min(total - idx, space);
+            Array.Clear(_accumBuf, _accumCount, fill);
+            _accumCount += fill;
+            idx         += fill;
+            if (_accumCount == _accumBuf.Length)
+                FlushFrame();
+        }
+    }
+
+    private void FlushFrame()
+    {
+        // 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;
+    }
+
+    // ── IAudioClient vtable helpers (raw dispatch, no RCW / no QI) ───────────
+    //
+    // Vtable layout (IUnknown base: 0=QI 1=AddRef 2=Release; then IAudioClient methods):
+    //   3=Initialize  4=GetBufferSize  5=GetStreamLatency  6=GetCurrentPadding
+    //   7=IsFormatSupported  8=GetMixFormat  9=GetDevicePeriod
+    //   10=Start  11=Stop  12=Reset  13=SetEventHandle  14=GetService
+
+    private static unsafe int AC_Initialize(IntPtr ac, int shareMode, uint streamFlags,
+        long hnsBufferDuration, long hnsPeriodicity, WaveFormatEx* pFormat, Guid* pSession)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, int, uint, long, long, WaveFormatEx*, Guid*, int>)
+            (*(void***)ac)[3];
+        return fn(ac, shareMode, streamFlags, hnsBufferDuration, hnsPeriodicity, pFormat, pSession);
+    }
+
+    private static unsafe int AC_Start(IntPtr ac)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, int>)(*(void***)ac)[10];
+        return fn(ac);
+    }
+
+    private static unsafe int AC_Stop(IntPtr ac)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, int>)(*(void***)ac)[11];
+        return fn(ac);
+    }
+
+    private static unsafe int AC_SetEventHandle(IntPtr ac, IntPtr eventHandle)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, IntPtr, int>)(*(void***)ac)[13];
+        return fn(ac, eventHandle);
+    }
+
+    private static unsafe int AC_GetService(IntPtr ac, ref Guid riid, out IntPtr ppv)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, Guid*, IntPtr*, int>)(*(void***)ac)[14];
+        fixed (Guid* pIid = &riid)
+        fixed (IntPtr* pPpv = &ppv)
+            return fn(ac, pIid, pPpv);
+    }
+
+    // ── IAudioCaptureClient vtable helpers ────────────────────────────────────
+    //
+    // Vtable (IUnknown: 0-2; then): 3=GetBuffer  4=ReleaseBuffer  5=GetNextPacketSize
+
+    private static unsafe int CC_GetBuffer(IntPtr cc, out IntPtr ppData,
+        out uint pNumFrames, out uint pdwFlags)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, IntPtr*, uint*, uint*, ulong*, ulong*, int>)
+            (*(void***)cc)[3];
+        ulong devPos = 0, qpcPos = 0;
+        fixed (IntPtr* p0 = &ppData)
+        fixed (uint*   p1 = &pNumFrames)
+        fixed (uint*   p2 = &pdwFlags)
+            return fn(cc, p0, p1, p2, &devPos, &qpcPos);
+    }
+
+    private static unsafe int CC_ReleaseBuffer(IntPtr cc, uint numFrames)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, uint, int>)(*(void***)cc)[4];
+        return fn(cc, numFrames);
+    }
+
+    private static unsafe int CC_GetNextPacketSize(IntPtr cc, out uint pNumFrames)
+    {
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, uint*, int>)(*(void***)cc)[5];
+        fixed (uint* p = &pNumFrames)
+            return fn(cc, p);
+    }
+
+    // ── COM utilities ─────────────────────────────────────────────────────────
+
+    private static unsafe void ComRelease(ref IntPtr ptr)
+    {
+        if (ptr == IntPtr.Zero) return;
+        var fn = (delegate* unmanaged[Stdcall]<IntPtr, uint>)(*(void***)ptr)[2]; // IUnknown::Release
+        fn(ptr);
+        ptr = IntPtr.Zero;
+    }
+
+    // ── P/Invoke & structs ────────────────────────────────────────────────────
+
+    [DllImport("Mmdevapi.dll", CharSet = CharSet.Unicode)]
+    private static extern int ActivateAudioInterfaceAsync(
+        string deviceInterfacePath,
+        ref Guid riid,
+        IntPtr activationParams,
+        [MarshalAs(UnmanagedType.Interface)] IActivateAudioInterfaceCompletionHandler completionHandler,
+        out IntPtr activationOperation);
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct AudioClientActivationParams
+    {
+        public int  ActivationType;       // AUDCLNT_ACTIVATIONTYPE_PROCESS_LOOPBACK = 1
+        public uint TargetProcessId;
+        public uint ProcessLoopbackMode;  // INCLUDE=0, EXCLUDE=1
+    }
+
+    [StructLayout(LayoutKind.Sequential, Pack = 2)]
+    private struct WaveFormatEx
+    {
+        public ushort wFormatTag;
+        public ushort nChannels;
+        public uint   nSamplesPerSec;
+        public uint   nAvgBytesPerSec;
+        public ushort nBlockAlign;
+        public ushort wBitsPerSample;
+        public ushort cbSize;
+    }
+
+    // ── Completion handler CCW ────────────────────────────────────────────────
+    //
+    // Only this object still uses .NET COM interop (as a CCW). The activateOperation
+    // parameter is IntPtr to avoid QI on the incoming async-op pointer.
+
+    [ComVisible(true), ClassInterface(ClassInterfaceType.None)]
+    private sealed class ActivationCompletionHandler : IActivateAudioInterfaceCompletionHandler
+    {
+        public readonly ManualResetEventSlim CompletionEvent = new(false);
+        public IntPtr OperationPtr { get; private set; }
+
+        public void ActivateCompleted(IntPtr activateOperation)
+        {
+            OperationPtr = activateOperation;
+            if (OperationPtr != IntPtr.Zero) Marshal.AddRef(OperationPtr);
+            CompletionEvent.Set();
+        }
+
+        public void ReleaseOp()
+        {
+            if (OperationPtr == IntPtr.Zero) return;
+            Marshal.Release(OperationPtr);
+            OperationPtr = IntPtr.Zero;
+        }
+    }
+
+    [ComImport, Guid("41D949AB-9862-444A-80F6-C261334DA5EB"),
+     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    private interface IActivateAudioInterfaceCompletionHandler
+    {
+        void ActivateCompleted(IntPtr activateOperation);
+    }
+}

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

@@ -0,0 +1,111 @@
+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 AdaptivePcmBuffer pcm = new(2);
+        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 int BufferMilliseconds { get => pcm.BufferMilliseconds; set => pcm.BufferMilliseconds = value; }
+        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();
+                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));
+                    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/AccountsDialog.cs

@@ -0,0 +1,200 @@
+using VoiceCat.Windows;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Admin account management: list, create, reset password, and delete server accounts.
+/// </summary>
+public sealed class AccountsDialog : Form
+{
+    private readonly VoiceCatClient _client;
+    private readonly ListView _lvAccounts;
+    private readonly Button _btnRefresh;
+    private readonly Button _btnAdd;
+    private readonly Button _btnResetPassword;
+    private readonly Button _btnDelete;
+
+    public AccountsDialog(VoiceCatClient client)
+    {
+        _client = client;
+
+        Text = "Server accounts";
+        FormBorderStyle = FormBorderStyle.Sizable;
+        StartPosition = FormStartPosition.CenterParent;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(560, 360);
+        MinimumSize = new Size(420, 260);
+
+        _lvAccounts = new ListView
+        {
+            View = View.Details,
+            FullRowSelect = true,
+            GridLines = true,
+            Dock = DockStyle.Fill,
+            TabIndex = 0,
+        };
+        _lvAccounts.Columns.Add("Username", 160);
+        _lvAccounts.Columns.Add("Admin", 50);
+        _lvAccounts.Columns.Add("Created", 130);
+        _lvAccounts.Columns.Add("Last login", 130);
+        _lvAccounts.SelectedIndexChanged += (_, _) => UpdateButtons();
+
+        var pnlButtons = new Panel
+        {
+            Dock = DockStyle.Bottom,
+            Height = 44,
+        };
+
+        _btnRefresh = new Button
+        {
+            Text = "&Refresh",
+            Location = new Point(12, 9),
+            Size = new Size(75, 27),
+            TabIndex = 1,
+        };
+        _btnRefresh.Click += (_, _) => RefreshList();
+
+        _btnAdd = new Button
+        {
+            Text = "&Add...",
+            Location = new Point(100, 9),
+            Size = new Size(75, 27),
+            TabIndex = 2,
+        };
+        _btnAdd.Click += (_, _) => AddAccount();
+
+        _btnResetPassword = new Button
+        {
+            Text = "&Reset password...",
+            Location = new Point(188, 9),
+            Size = new Size(120, 27),
+            TabIndex = 3,
+            Enabled = false,
+        };
+        _btnResetPassword.Click += (_, _) => ResetPassword();
+
+        _btnDelete = new Button
+        {
+            Text = "&Delete",
+            Location = new Point(320, 9),
+            Size = new Size(75, 27),
+            TabIndex = 4,
+            Enabled = false,
+        };
+        _btnDelete.Click += (_, _) => DeleteAccount();
+
+        pnlButtons.Controls.AddRange([_btnRefresh, _btnAdd, _btnResetPassword, _btnDelete]);
+
+        Controls.Add(_lvAccounts);
+        Controls.Add(pnlButtons);
+
+        Load += (_, _) => RefreshList();
+    }
+
+    private void UpdateButtons()
+    {
+        bool selected = _lvAccounts.SelectedItems.Count > 0;
+        _btnResetPassword.Enabled = selected;
+        _btnDelete.Enabled = selected;
+    }
+
+    private void RefreshList()
+    {
+        _client.RequestAccountList();
+        // The event will come back asynchronously; poll briefly for the list.
+        var deadline = DateTime.UtcNow.AddSeconds(2);
+        List<AccountInfo>? accounts = null;
+        while (DateTime.UtcNow < deadline)
+        {
+            _client.PumpEvents();
+            accounts = _client.ListAccounts();
+            if (accounts.Count > 0) break;
+            Thread.Sleep(30);
+        }
+        accounts ??= _client.ListAccounts();
+
+        _lvAccounts.BeginUpdate();
+        _lvAccounts.Items.Clear();
+        foreach (var a in accounts.OrderBy(a => a.Username))
+        {
+            var item = new ListViewItem(a.Username);
+            item.SubItems.Add(a.IsAdmin ? "Yes" : "No");
+            item.SubItems.Add(FormatDate(a.CreatedAtUnixMs));
+            item.SubItems.Add(FormatDate(a.LastLoginUnixMs));
+            _lvAccounts.Items.Add(item);
+        }
+        _lvAccounts.EndUpdate();
+        UpdateButtons();
+    }
+
+    private static string FormatDate(ulong ms)
+    {
+        if (ms == 0) return "—";
+        try
+        {
+            return DateTimeOffset.FromUnixTimeMilliseconds((long)ms).LocalDateTime.ToString("g");
+        }
+        catch
+        {
+            return "—";
+        }
+    }
+
+    private void AddAccount()
+    {
+        using var userDlg = new InputDialog("Add account", "&Username:");
+        if (userDlg.ShowDialog(this) != DialogResult.OK || string.IsNullOrWhiteSpace(userDlg.TextValue))
+            return;
+
+        using var pwDlg = new PasswordPromptDialog($"Password for {userDlg.TextValue}:");
+        if (pwDlg.ShowDialog(this) != DialogResult.OK || string.IsNullOrEmpty(pwDlg.Password))
+            return;
+
+        var r = _client.CreateAccount(userDlg.TextValue, pwDlg.Password);
+        if (r != VcResult.Ok)
+        {
+            MessageBox.Show(this, $"Create account failed: {r}", "VoiceCat",
+                MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            return;
+        }
+        RefreshList();
+    }
+
+    private void ResetPassword()
+    {
+        if (_lvAccounts.SelectedItems.Count == 0) return;
+        string username = _lvAccounts.SelectedItems[0].Text;
+
+        using var dlg = new PasswordPromptDialog($"New password for {username}:");
+        if (dlg.ShowDialog(this) != DialogResult.OK || string.IsNullOrEmpty(dlg.Password))
+            return;
+
+        var r = _client.ResetPassword(username, dlg.Password);
+        if (r != VcResult.Ok)
+        {
+            MessageBox.Show(this, $"Reset password failed: {r}", "VoiceCat",
+                MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            return;
+        }
+        RefreshList();
+    }
+
+    private void DeleteAccount()
+    {
+        if (_lvAccounts.SelectedItems.Count == 0) return;
+        string username = _lvAccounts.SelectedItems[0].Text;
+
+        var confirm = MessageBox.Show(this, $"Delete account '{username}'?",
+            "VoiceCat", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
+        if (confirm != DialogResult.Yes) return;
+
+        var r = _client.DeleteAccount(username);
+        if (r != VcResult.Ok)
+        {
+            MessageBox.Show(this, $"Delete account failed: {r}", "VoiceCat",
+                MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            return;
+        }
+        RefreshList();
+    }
+}

clients/windows/VoiceCat.App/Forms/AddServerDialog.Designer.cs

@@ -0,0 +1,187 @@
+namespace VoiceCat.App.Forms;
+
+partial class AddServerDialog
+{
+    private System.ComponentModel.IContainer components = null!;
+    private Label lblDisplayName = null!;
+    private TextBox txtDisplayName = null!;
+    private Label lblHost = null!;
+    private TextBox txtHost = null!;
+    private Label lblPort = null!;
+    private NumericUpDown numPort = null!;
+    private GroupBox grpAuth = null!;
+    private RadioButton radioGuest = null!;
+    private RadioButton radioPassword = null!;
+    private Label lblNickname = null!;
+    private TextBox txtNickname = null!;
+    private Label lblUsername = null!;
+    private TextBox txtUsername = null!;
+    private Label lblPassword = null!;
+    private TextBox txtPassword = null!;
+    private CheckBox chkRememberPassword = null!;
+    private Button btnOk = null!;
+    private Button btnCancel = null!;
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing) components?.Dispose();
+        base.Dispose(disposing);
+    }
+
+    private void InitializeComponent()
+    {
+        components = new System.ComponentModel.Container();
+        lblDisplayName = new Label();
+        txtDisplayName = new TextBox();
+        lblHost = new Label();
+        txtHost = new TextBox();
+        lblPort = new Label();
+        numPort = new NumericUpDown();
+        grpAuth = new GroupBox();
+        radioGuest = new RadioButton();
+        radioPassword = new RadioButton();
+        lblNickname = new Label();
+        txtNickname = new TextBox();
+        lblUsername = new Label();
+        txtUsername = new TextBox();
+        lblPassword = new Label();
+        txtPassword = new TextBox();
+        chkRememberPassword = new CheckBox();
+        btnOk = new Button();
+        btnCancel = new Button();
+
+        int y = 12;
+        const int rowH = 30;
+
+        lblDisplayName.Text = "&Display name:";
+        lblDisplayName.AutoSize = true;
+        lblDisplayName.Location = new Point(12, y + 3);
+        lblDisplayName.TabIndex = 0;
+        txtDisplayName.AccessibleName = "Display name";
+        txtDisplayName.Location = new Point(140, y);
+        txtDisplayName.Size = new Size(280, 23);
+        txtDisplayName.TabIndex = 1;
+        y += rowH;
+
+        lblHost.Text = "&Host:";
+        lblHost.AutoSize = true;
+        lblHost.Location = new Point(12, y + 3);
+        lblHost.TabIndex = 2;
+        txtHost.AccessibleName = "Host";
+        txtHost.Location = new Point(140, y);
+        txtHost.Size = new Size(200, 23);
+        txtHost.TabIndex = 3;
+        txtHost.PlaceholderText = "127.0.0.1";
+        y += rowH;
+
+        lblPort.Text = "&Port:";
+        lblPort.AutoSize = true;
+        lblPort.Location = new Point(12, y + 3);
+        lblPort.TabIndex = 4;
+        numPort.AccessibleName = "Port";
+        numPort.Location = new Point(140, y);
+        numPort.Size = new Size(100, 23);
+        numPort.Minimum = 1;
+        numPort.Maximum = 65535;
+        numPort.Value = 8384;
+        numPort.TabIndex = 5;
+        y += rowH;
+
+        grpAuth.Text = "Authentication";
+        grpAuth.Location = new Point(12, y);
+        grpAuth.Size = new Size(408, 140);
+        grpAuth.TabIndex = 6;
+
+        radioGuest.Text = "Connect as &guest";
+        radioGuest.AutoSize = true;
+        radioGuest.Location = new Point(12, 24);
+        radioGuest.Checked = true;
+        radioGuest.TabIndex = 0;
+
+        lblNickname.Text = "&Nickname:";
+        lblNickname.AutoSize = true;
+        lblNickname.Location = new Point(30, 50);
+        lblNickname.TabIndex = 1;
+        txtNickname.AccessibleName = "Guest nickname";
+        txtNickname.Location = new Point(140, 47);
+        txtNickname.Size = new Size(240, 23);
+        txtNickname.TabIndex = 2;
+
+        radioPassword.Text = "Use a &saved account";
+        radioPassword.AutoSize = true;
+        radioPassword.Location = new Point(12, 76);
+        radioPassword.TabIndex = 3;
+
+        lblUsername.Text = "&Username:";
+        lblUsername.AutoSize = true;
+        lblUsername.Location = new Point(30, 102);
+        lblUsername.TabIndex = 4;
+        txtUsername.AccessibleName = "Username";
+        txtUsername.Location = new Point(140, 99);
+        txtUsername.Size = new Size(240, 23);
+        txtUsername.TabIndex = 5;
+
+        lblPassword.Text = "Pass&word:";
+        lblPassword.AutoSize = true;
+        lblPassword.Location = new Point(30, 132);
+        lblPassword.TabIndex = 6;
+        txtPassword.AccessibleName = "Password";
+        txtPassword.Location = new Point(140, 129);
+        txtPassword.Size = new Size(240, 23);
+        txtPassword.UseSystemPasswordChar = true;
+        txtPassword.TabIndex = 7;
+
+        grpAuth.Controls.Add(radioGuest);
+        grpAuth.Controls.Add(lblNickname);
+        grpAuth.Controls.Add(txtNickname);
+        grpAuth.Controls.Add(radioPassword);
+        grpAuth.Controls.Add(lblUsername);
+        grpAuth.Controls.Add(txtUsername);
+        grpAuth.Controls.Add(lblPassword);
+        grpAuth.Controls.Add(txtPassword);
+        y += 148;
+
+        chkRememberPassword.Text = "&Remember my password on this computer";
+        chkRememberPassword.AutoSize = true;
+        chkRememberPassword.AccessibleDescription =
+            "Stores the password protected by Windows Data Protection (DPAPI), decryptable " +
+            "only by your Windows account on this machine. Leave unchecked to be prompted " +
+            "for the password every time.";
+        chkRememberPassword.Location = new Point(12, y);
+        chkRememberPassword.TabIndex = 7;
+        y += rowH;
+
+        btnOk.Text = "&OK";
+        btnOk.DialogResult = DialogResult.OK;
+        btnOk.Location = new Point(264, y);
+        btnOk.Size = new Size(75, 27);
+        btnOk.TabIndex = 8;
+
+        btnCancel.Text = "&Cancel";
+        btnCancel.DialogResult = DialogResult.Cancel;
+        btnCancel.Location = new Point(345, y);
+        btnCancel.Size = new Size(75, 27);
+        btnCancel.TabIndex = 9;
+        y += rowH + 12;
+
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(432, y);
+        Controls.Add(lblDisplayName);
+        Controls.Add(txtDisplayName);
+        Controls.Add(lblHost);
+        Controls.Add(txtHost);
+        Controls.Add(lblPort);
+        Controls.Add(numPort);
+        Controls.Add(grpAuth);
+        Controls.Add(chkRememberPassword);
+        Controls.Add(btnOk);
+        Controls.Add(btnCancel);
+        AcceptButton = btnOk;
+        CancelButton = btnCancel;
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterParent;
+        Text = "Add server";
+    }
+}

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

@@ -0,0 +1,80 @@
+using VoiceCat.App.Models;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>Add or edit a saved server entry. DialogResult.OK -> read Result.</summary>
+public partial class AddServerDialog : Form
+{
+    private readonly SavedServer _editing;
+    private bool _passwordChanged;
+
+    public SavedServer? Result { get; private set; }
+
+    public AddServerDialog(SavedServer? existing = null)
+    {
+        InitializeComponent();
+        _editing = existing ?? new SavedServer();
+
+        txtDisplayName.Text = _editing.DisplayName;
+        txtHost.Text = _editing.Host;
+        numPort.Value = _editing.Port == 0 ? 8384 : _editing.Port;
+        txtNickname.Text = _editing.LastNickname;
+        radioGuest.Checked = _editing.AuthMode == AuthMode.Guest;
+        radioPassword.Checked = _editing.AuthMode == AuthMode.Password;
+        txtUsername.Text = _editing.SavedUsername ?? "";
+        chkRememberPassword.Checked = _editing.ProtectedPasswordBase64 is not null;
+        if (_editing.ProtectedPasswordBase64 is not null)
+            txtPassword.Text = "********"; // placeholder — never decrypt-and-show; re-typing replaces it
+
+        UpdateAuthFieldsEnabled();
+        radioGuest.CheckedChanged += (_, _) => UpdateAuthFieldsEnabled();
+        radioPassword.CheckedChanged += (_, _) => UpdateAuthFieldsEnabled();
+        txtPassword.TextChanged += (_, _) => _passwordChanged = true;
+
+        btnOk.Click += BtnOk_Click;
+    }
+
+    private void UpdateAuthFieldsEnabled()
+    {
+        bool password = radioPassword.Checked;
+        txtNickname.Enabled = !password;
+        txtUsername.Enabled = password;
+        txtPassword.Enabled = password;
+        chkRememberPassword.Enabled = password;
+    }
+
+    private void BtnOk_Click(object? sender, EventArgs e)
+    {
+        if (string.IsNullOrWhiteSpace(txtHost.Text))
+        {
+            MessageBox.Show(this, "Host is required.", "VoiceCat", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            DialogResult = DialogResult.None;
+            return;
+        }
+
+        _editing.DisplayName = txtDisplayName.Text.Trim();
+        _editing.Host = txtHost.Text.Trim();
+        _editing.Port = (ushort)numPort.Value;
+        _editing.AuthMode = radioPassword.Checked ? AuthMode.Password : AuthMode.Guest;
+
+        if (_editing.AuthMode == AuthMode.Guest)
+        {
+            _editing.LastNickname = txtNickname.Text.Trim();
+            _editing.SavedUsername = null;
+            _editing.ProtectedPasswordBase64 = null;
+        }
+        else
+        {
+            _editing.SavedUsername = txtUsername.Text.Trim();
+            if (chkRememberPassword.Checked && _passwordChanged && txtPassword.Text.Length > 0)
+                _editing.ProtectedPasswordBase64 = PasswordProtector.Protect(txtPassword.Text);
+            else if (!chkRememberPassword.Checked)
+                _editing.ProtectedPasswordBase64 = null;
+            // else: remember-password still checked and password box untouched (still shows
+            // the placeholder) — keep whatever was already protected/stored.
+        }
+
+        Result = _editing;
+        DialogResult = DialogResult.OK;
+    }
+}

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

@@ -0,0 +1,263 @@
+using VoiceCat.App.Audio;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Modal dialog for selecting which apps' audio to share.
+/// Returns the chosen <see cref="AppAudioScope"/> via <see cref="ChosenScope"/>,
+/// or <see cref="DialogResult.Cancel"/> if the user dismissed without sharing.
+/// </summary>
+public sealed class AppAudioPickerDialog : Form
+{
+    private readonly RadioButton  _rdoAll;
+    private readonly RadioButton  _rdoOnly;
+    private readonly RadioButton  _rdoExcept;
+    private readonly CheckBox     _chkExcludeSelf;
+    private readonly TextBox      _txtFilter;
+    private readonly ListView     _appList;
+    private readonly Label        _lblApps;
+
+    // Snapshot taken when the dialog opens (refresh on open, not on every check change).
+    private IReadOnlyList<AudioAppInfo> _apps = [];
+
+    // Checked apps survive filtering (a filtered-out row keeps its check here).
+    // pid → clean display name (used for the shared scope's Names).
+    private readonly Dictionary<int, string> _checked = new();
+
+    public AppAudioScope? ChosenScope { get; private set; }
+
+    public AppAudioPickerDialog()
+    {
+        // ── Radio buttons ───────────────────────────────────────────────────
+        _rdoAll = new RadioButton
+        {
+            Text      = "&Entire desktop",
+            Checked   = true,
+            Location  = new Point(12, 12),
+            Size      = new Size(360, 20),
+            TabIndex  = 0,
+        };
+        _rdoOnly = new RadioButton
+        {
+            Text     = "&Only selected apps",
+            Location = new Point(12, 36),
+            Size     = new Size(360, 20),
+            TabIndex = 1,
+        };
+        _rdoExcept = new RadioButton
+        {
+            Text     = "All apps e&xcept selected",
+            Location = new Point(12, 60),
+            Size     = new Size(360, 20),
+            TabIndex = 2,
+        };
+
+        _rdoAll.CheckedChanged    += OnModeChanged;
+        _rdoOnly.CheckedChanged   += OnModeChanged;
+        _rdoExcept.CheckedChanged += OnModeChanged;
+
+        // ── Self-exclude (echo prevention) ───────────────────────────────────
+        // Captures the whole desktop minus VoiceCat's own playback, so the channel
+        // doesn't echo back the voices you're already hearing. Only applies to the
+        // entire-desktop mode (the per-app modes already exclude this app's tree).
+        _chkExcludeSelf = new CheckBox
+        {
+            Text     = "E&xclude VoiceCat's own audio (prevents echo)",
+            Checked  = true,
+            Location = new Point(28, 84),
+            Size     = new Size(344, 20),
+            TabIndex = 3,
+        };
+
+        // ── App list ────────────────────────────────────────────────────────
+        _lblApps = new Label
+        {
+            Text     = "Apps (▶ = currently playing):",
+            AutoSize = true,
+            Location = new Point(12, 112),
+            Visible  = false,
+            TabIndex = 4,
+        };
+
+        _txtFilter = new TextBox
+        {
+            Location        = new Point(12, 132),
+            Size            = new Size(360, 23),
+            PlaceholderText = "Filter apps…",
+            Visible         = false,
+            TabIndex        = 5,
+        };
+        _txtFilter.TextChanged += (_, _) => PopulateList();
+
+        _appList = new ListView
+        {
+            Location      = new Point(12, 160),
+            Size          = new Size(360, 150),
+            CheckBoxes    = true,
+            View          = View.List,
+            Visible       = false,
+            TabIndex      = 6,
+            FullRowSelect = true,
+        };
+        // Exclude mode supports only one target process tree (WASAPI EXCLUDE takes a single
+        // PID), so enforce a single check while "All apps except selected" is active.
+        _appList.ItemCheck += OnAppItemCheck;
+
+        // ── Buttons ─────────────────────────────────────────────────────────
+        var btnShare = new Button
+        {
+            Text         = "&Share",
+            DialogResult = DialogResult.OK,
+            Location     = new Point(216, 320),
+            Size         = new Size(75, 27),
+            TabIndex     = 7,
+        };
+        var btnCancel = new Button
+        {
+            Text         = "&Cancel",
+            DialogResult = DialogResult.Cancel,
+            Location     = new Point(297, 320),
+            Size         = new Size(75, 27),
+            TabIndex     = 8,
+        };
+        btnShare.Click += OnShareClick;
+
+        AcceptButton  = btnShare;
+        CancelButton  = btnCancel;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize    = new Size(384, 360);
+        Controls.AddRange([_rdoAll, _rdoOnly, _rdoExcept, _chkExcludeSelf, _lblApps, _txtFilter,
+                           _appList, btnShare, btnCancel]);
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox     = false;
+        MinimizeBox     = false;
+        StartPosition   = FormStartPosition.CenterParent;
+        Text            = "Share App Audio";
+    }
+
+    protected override void OnLoad(EventArgs e)
+    {
+        base.OnLoad(e);
+        RefreshAppList();
+    }
+
+    private void RefreshAppList()
+    {
+        _apps = AudioSessionEnumerator.GetAudioApps();
+        PopulateList();
+    }
+
+    // Rebuild the visible rows from _apps + the current filter text, restoring check
+    // state from _checked so a selection persists while the user filters.
+    private void PopulateList()
+    {
+        string filter = _txtFilter.Text.Trim();
+
+        _suppressItemCheck = true;
+        _appList.BeginUpdate();
+        _appList.Items.Clear();
+        foreach (var app in _apps)
+        {
+            if (filter.Length > 0 &&
+                app.DisplayName.IndexOf(filter, StringComparison.OrdinalIgnoreCase) < 0)
+                continue;
+
+            string marker = app.IsPlaying ? "▶ " : "";
+            _appList.Items.Add(new ListViewItem($"{marker}{app.DisplayName}  (PID {app.Pid})")
+            {
+                Tag     = app,
+                Checked = _checked.ContainsKey(app.Pid),
+            });
+        }
+        _appList.EndUpdate();
+        _suppressItemCheck = false;
+    }
+
+    private void OnModeChanged(object? sender, EventArgs e)
+    {
+        bool showList = _rdoOnly.Checked || _rdoExcept.Checked;
+        _lblApps.Visible   = showList;
+        _txtFilter.Visible = showList;
+        _appList.Visible   = showList;
+        _lblApps.Text = _rdoExcept.Checked
+            ? "App to exclude (everything else is shared):"
+            : "Apps (▶ = currently playing):";
+
+        // Self-exclude only applies to entire-desktop; the per-app modes already exclude
+        // this app's own tree (Include) or spend the single EXCLUDE slot on the chosen app.
+        _chkExcludeSelf.Enabled = _rdoAll.Checked;
+
+        // Switching into exclude mode: collapse any multi-selection down to a single item.
+        if (_rdoExcept.Checked)
+            TrimCheckedToOne();
+
+        if (showList && _appList.Items.Count == 0)
+            RefreshAppList();
+        else
+            PopulateList(); // re-render markers/labels and restore check state
+    }
+
+    // In exclude mode the list behaves like radio buttons: checking one item clears the rest.
+    private bool _suppressItemCheck;
+
+    private void OnAppItemCheck(object? sender, ItemCheckEventArgs e)
+    {
+        if (_suppressItemCheck) return;
+        if (_appList.Items[e.Index].Tag is not AudioAppInfo app) return;
+
+        if (e.NewValue == CheckState.Checked)
+        {
+            if (_rdoExcept.Checked)
+            {
+                // Radio behavior: clear every other visible check and the persisted set.
+                _suppressItemCheck = true;
+                foreach (ListViewItem item in _appList.Items)
+                    if (item.Index != e.Index && item.Checked) item.Checked = false;
+                _suppressItemCheck = false;
+                _checked.Clear();
+            }
+            _checked[app.Pid] = app.DisplayName;
+        }
+        else
+        {
+            _checked.Remove(app.Pid);
+        }
+    }
+
+    // Reduce the persisted selection to a single (first) entry — used when entering
+    // exclude mode, whose single EXCLUDE slot can only target one process tree.
+    private void TrimCheckedToOne()
+    {
+        if (_checked.Count <= 1) return;
+        var first = _checked.First();
+        _checked.Clear();
+        _checked[first.Key] = first.Value;
+    }
+
+    private void OnShareClick(object? sender, EventArgs e)
+    {
+        if (_rdoAll.Checked)
+        {
+            ChosenScope = new EntireDesktop(_chkExcludeSelf.Checked);
+            return;
+        }
+
+        if (_checked.Count == 0)
+        {
+            MessageBox.Show(
+                "Select at least one app, or choose 'Entire desktop'.",
+                "No apps selected",
+                MessageBoxButtons.OK,
+                MessageBoxIcon.Warning);
+            DialogResult = DialogResult.None; // prevent close
+            return;
+        }
+
+        var pids  = _checked.Keys.ToList();
+        var names = _checked.Values.ToList();
+
+        ChosenScope = _rdoOnly.Checked
+            ? new OnlyApps(pids, names)
+            : new AllExceptApps(pids, names);
+    }
+}

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

@@ -0,0 +1,595 @@
+using System.ComponentModel;
+using VoiceCat.App.Audio;
+using VoiceCat.App.Models;
+using VoiceCat.Windows;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Edits audio input settings: device selection, transmission mode (VAD/PTT/always-on),
+/// VAD sensitivity, mic gain, and PTT key. Changes are applied live to the client for
+/// immediate feedback; Cancel reverts them.
+/// </summary>
+public sealed class AudioSettingsForm : Form
+{
+    private readonly VoiceCatClient _client;
+    private readonly VoiceSettings _settings;
+    private readonly uint _micStreamId;
+
+    // Aux-stream live-apply callbacks, supplied by MainForm (which owns the aux capture). Null
+    // when not connected — the controls still edit settings, just without live effect.
+    private readonly Action<bool>?    _applyAuxEnabled;
+    private readonly Action<string?>? _applyAuxDevice;
+    private readonly Action<float>?   _applyAuxGain;
+
+    // Snapshot of original values so Cancel can restore them
+    private readonly string? _origDeviceId;
+    private readonly VcInputMode _origMode;
+    private readonly int _origVadSlider;
+    private readonly int _origMicGain;
+    private readonly bool _origMicNoiseReduction;
+    private readonly bool _origStereoMic;
+    private readonly Keys _origPttKey;
+    private readonly bool _origSystemWidePtt;
+    private readonly bool _origAuxEnabled;
+    private readonly string? _origAuxDeviceId;
+    private readonly int _origAuxGain;
+    private readonly int _origAudioBufferMilliseconds;
+
+    private readonly ComboBox _cboDevice;
+    private readonly Button _btnRefresh;
+    private readonly RadioButton _radioVad;
+    private readonly RadioButton _radioPtt;
+    private readonly RadioButton _radioAlwaysOn;
+    private readonly Label _lblPttKey;
+    private readonly Button _btnChangePtt;
+    private readonly CheckBox _chkSystemWidePtt;
+    private readonly Label _lblSensitivity;
+    private readonly TrackBar _trkVad;
+    private readonly TrackBar _trkGain;
+    private readonly CheckBox _chkNoiseReduction;
+    private readonly CheckBox _chkStereoMic;
+    private readonly CheckBox _chkAux;
+    private readonly Label _lblAuxDevice;
+    private readonly ComboBox _cboAuxDevice;
+    private readonly Button _btnAuxRefresh;
+    private readonly Label _lblAuxGain;
+    private readonly TrackBar _trkAuxGain;
+    private readonly ComboBox _cboBuffer;
+
+    private Keys _pttKey;
+
+    public AudioSettingsForm(VoiceCatClient client, VoiceSettings settings, uint micStreamId,
+        Action<bool>? applyAuxEnabled = null, Action<string?>? applyAuxDevice = null,
+        Action<float>? applyAuxGain = null)
+    {
+        _client = client;
+        _settings = settings;
+        _micStreamId = micStreamId;
+        _applyAuxEnabled = applyAuxEnabled;
+        _applyAuxDevice = applyAuxDevice;
+        _applyAuxGain = applyAuxGain;
+        _pttKey = (Keys)settings.PttKey;
+
+        _origDeviceId = settings.InputDeviceId;
+        _origMode = (VcInputMode)settings.InputMode;
+        _origVadSlider = settings.VadThresholdSlider;
+        _origMicGain = settings.MicGain;
+        _origMicNoiseReduction = settings.MicNoiseReduction;
+        _origStereoMic = settings.StereoMic;
+        _origPttKey = _pttKey;
+        _origSystemWidePtt = settings.SystemWidePtt;
+        _origAuxEnabled = settings.AuxEnabled;
+        _origAuxDeviceId = settings.AuxDeviceId;
+        _origAuxGain = settings.AuxGain;
+        _origAudioBufferMilliseconds = settings.AudioBufferMilliseconds;
+
+        Text = "Audio settings";
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterParent;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(420, 690);
+
+        // ── Device row ────────────────────────────────────────────────────────
+        var lblDevice = new Label
+        {
+            Text = "Input &device:",
+            Location = new Point(12, 16),
+            AutoSize = true,
+        };
+
+        _cboDevice = new ComboBox
+        {
+            Location = new Point(12, 36),
+            Width = 300,
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            DisplayMember = "Name",
+            ValueMember = "Id",
+            AccessibleName = "Input device",
+            AccessibleDescription = "Select which microphone or audio input device to use.",
+        };
+        _cboDevice.SelectedIndexChanged += CboDevice_SelectedIndexChanged;
+
+        _btnRefresh = new Button
+        {
+            Text = "&Refresh",
+            Location = new Point(320, 34),
+            Size = new Size(80, 26),
+        };
+        _btnRefresh.Click += (_, _) => LoadDevices();
+
+        // ── Transmission mode ─────────────────────────────────────────────────
+        var lblMode = new Label
+        {
+            Text = "Transmission mode:",
+            Location = new Point(12, 76),
+            AutoSize = true,
+        };
+
+        _radioVad = new RadioButton
+        {
+            Text = "&Voice activation",
+            Location = new Point(20, 96),
+            AutoSize = true,
+        };
+        _radioVad.CheckedChanged += RadioMode_CheckedChanged;
+
+        _lblSensitivity = new Label
+        {
+            Text = "Sensitivity:",
+            Location = new Point(36, 122),
+            AutoSize = true,
+        };
+        _trkVad = new TrackBar
+        {
+            Location = new Point(36, 140),
+            Size = new Size(200, 45),
+            Minimum = 1,
+            Maximum = 100,
+            TickFrequency = 10,
+            SmallChange = 1,
+            LargeChange = 10,
+            Value = Math.Clamp(settings.VadThresholdSlider, 1, 100),
+        };
+        _trkVad.AccessibleName = "VAD sensitivity";
+        _trkVad.AccessibleDescription =
+            "Voice detection sensitivity. Higher = more sensitive. Range 1–100.";
+        _trkVad.Scroll += TrkVad_Scroll;
+
+        _radioPtt = new RadioButton
+        {
+            Text = "&Push to talk",
+            Location = new Point(20, 192),
+            AutoSize = true,
+        };
+        _radioPtt.CheckedChanged += RadioMode_CheckedChanged;
+
+        _lblPttKey = new Label
+        {
+            Location = new Point(140, 194),
+            AutoSize = true,
+        };
+
+        _btnChangePtt = new Button
+        {
+            Text = "Change key...",
+            Location = new Point(200, 189),
+            Size = new Size(105, 26),
+        };
+        _btnChangePtt.Click += BtnChangePtt_Click;
+
+        // Indented PTT sub-option: observe the key system-wide (Raw Input) so it works while
+        // another app is focused. Visible only in PTT mode (RadioMode_CheckedChanged).
+        _chkSystemWidePtt = new CheckBox
+        {
+            Text = "Wor&ks in the background (system-wide)",
+            Location = new Point(36, 218),
+            AutoSize = true,
+            Checked = settings.SystemWidePtt,
+            AccessibleName = "System-wide push-to-talk",
+            AccessibleDescription =
+                "Let push-to-talk work while another application is focused. Uses the Windows Raw " +
+                "Input API, not a keyboard hook.",
+        };
+        _chkSystemWidePtt.CheckedChanged += ChkSystemWidePtt_CheckedChanged;
+
+        _radioAlwaysOn = new RadioButton
+        {
+            Text = "A&lways on",
+            Location = new Point(20, 252),
+            AutoSize = true,
+        };
+        _radioAlwaysOn.CheckedChanged += RadioMode_CheckedChanged;
+
+        // ── Mic gain ──────────────────────────────────────────────────────────
+        var lblGain = new Label
+        {
+            Text = "Microphone &volume:",
+            Location = new Point(12, 296),
+            AutoSize = true,
+        };
+        _trkGain = new TrackBar
+        {
+            Location = new Point(12, 316),
+            Size = new Size(200, 45),
+            Minimum = 0,
+            Maximum = 400,
+            TickFrequency = 25,
+            SmallChange = 5,
+            LargeChange = 25,
+            Value = Math.Clamp(settings.MicGain, 0, 400),
+        };
+        _trkGain.AccessibleName = "Microphone volume";
+        _trkGain.AccessibleDescription =
+            "Boost a quiet microphone. 100 is unity gain; range 0–400 percent.";
+        _trkGain.Scroll += TrkGain_Scroll;
+
+        // ── Mic noise reduction ───────────────────────────────────────────────
+        // Send-side RNNoise denoise of the mic stream. MIC-only (the core's NR runs before
+        // the input gain and VAD/PTT gate; aux/screen are excluded). One pass for all listeners.
+        _chkNoiseReduction = new CheckBox
+        {
+            Text = "Noise &reduction (RNNoise)",
+            Location = new Point(12, 368),
+            AutoSize = true,
+            Checked = settings.MicNoiseReduction,
+            AccessibleName = "Microphone noise reduction",
+            AccessibleDescription =
+                "RNNoise denoising of your microphone. Cleans your signal for everyone listening.",
+        };
+        _chkNoiseReduction.CheckedChanged += ChkNoiseReduction_CheckedChanged;
+
+        // ── Stereo microphone ─────────────────────────────────────────────────
+        // Opens the mic capture device in stereo (interleaved L/R) instead of mono. Real stereo
+        // only reaches the wire on a stereo channel; the core folds a stereo mic to mono on a mono
+        // channel. Toggling while connected restarts the capture device (vc_audio_restart) so the
+        // new channel count takes effect immediately.
+        _chkStereoMic = new CheckBox
+        {
+            Text = "&Stereo microphone",
+            Location = new Point(12, 392),
+            AutoSize = true,
+            Checked = settings.StereoMic,
+            AccessibleName = "Stereo microphone",
+            AccessibleDescription =
+                "Capture your microphone in stereo. Only transmitted in stereo on a stereo channel.",
+        };
+        _chkStereoMic.CheckedChanged += ChkStereoMic_CheckedChanged;
+
+        // ── Aux input stream ──────────────────────────────────────────────────
+        // A second outgoing stream from another hardware input device (e.g. line-in / aux),
+        // captured client-side and fed to the core. Device + volume only — aux is always-on
+        // (the core never gates AUX_DEVICE on VAD/PTT).
+        _chkAux = new CheckBox
+        {
+            Text = "&Aux stream (second input device)",
+            Location = new Point(12, 432),
+            AutoSize = true,
+            Checked = settings.AuxEnabled,
+            AccessibleName = "Enable aux input stream",
+            AccessibleDescription =
+                "Transmit a second hardware input device alongside your microphone.",
+        };
+        _chkAux.CheckedChanged += ChkAux_CheckedChanged;
+
+        _lblAuxDevice = new Label
+        {
+            Text = "Aux d&evice:",
+            Location = new Point(12, 462),
+            AutoSize = true,
+        };
+        _cboAuxDevice = new ComboBox
+        {
+            Location = new Point(12, 482),
+            Width = 300,
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            DisplayMember = "Name",
+            ValueMember = "Id",
+            AccessibleName = "Aux input device",
+            AccessibleDescription = "Select the second audio input device to transmit.",
+        };
+        _cboAuxDevice.SelectedIndexChanged += CboAuxDevice_SelectedIndexChanged;
+
+        _btnAuxRefresh = new Button
+        {
+            Text = "Re&fresh",
+            Location = new Point(320, 480),
+            Size = new Size(80, 26),
+        };
+        _btnAuxRefresh.Click += (_, _) => LoadAuxDevices();
+
+        _lblAuxGain = new Label
+        {
+            Text = "Aux vo&lume:",
+            Location = new Point(12, 518),
+            AutoSize = true,
+        };
+        _trkAuxGain = new TrackBar
+        {
+            Location = new Point(12, 538),
+            Size = new Size(200, 45),
+            Minimum = 0,
+            Maximum = 400,
+            TickFrequency = 25,
+            SmallChange = 5,
+            LargeChange = 25,
+            Value = Math.Clamp(settings.AuxGain, 0, 400),
+        };
+        _trkAuxGain.AccessibleName = "Aux volume";
+        _trkAuxGain.AccessibleDescription =
+            "Volume of the aux input stream. 100 is unity gain; range 0–400 percent.";
+        _trkAuxGain.Scroll += TrkAuxGain_Scroll;
+
+        var lblBuffer = new Label { Text = "Audio &buffering:", Location = new Point(12, 590), AutoSize = true };
+        _cboBuffer = new ComboBox
+        {
+            Location = new Point(130, 586), Width = 190, DropDownStyle = ComboBoxStyle.DropDownList,
+            AccessibleName = "Audio buffering",
+            AccessibleDescription = "Local capture and playback buffering. Lower values reduce latency; higher values tolerate more scheduling jitter."
+        };
+        _cboBuffer.Items.AddRange(["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"]);
+        _cboBuffer.SelectedIndex = settings.AudioBufferMilliseconds switch { 20 => 0, 60 => 2, _ => 1 };
+        _cboBuffer.SelectedIndexChanged += (_, _) =>
+        {
+            _settings.AudioBufferMilliseconds = _cboBuffer.SelectedIndex switch { 0 => 20, 2 => 60, _ => 40 };
+            _client.SetAudioBufferMilliseconds(_settings.AudioBufferMilliseconds);
+        };
+
+        // ── OK / Cancel ───────────────────────────────────────────────────────
+        var btnOk = new Button
+        {
+            Text = "&OK",
+            DialogResult = DialogResult.OK,
+            Location = new Point(228, 642),
+            Size = new Size(80, 27),
+        };
+        var btnCancel = new Button
+        {
+            Text = "&Cancel",
+            DialogResult = DialogResult.Cancel,
+            Location = new Point(316, 642),
+            Size = new Size(80, 27),
+        };
+
+        AcceptButton = btnOk;
+        CancelButton = btnCancel;
+
+        btnOk.Click += (_, _) =>
+        {
+            _settings.Save();
+        };
+        FormClosing += AudioSettingsForm_FormClosing;
+
+        Controls.AddRange([
+            lblDevice, _cboDevice, _btnRefresh,
+            lblMode, _radioVad, _lblSensitivity, _trkVad,
+            _radioPtt, _lblPttKey, _btnChangePtt, _chkSystemWidePtt, _radioAlwaysOn,
+            lblGain, _trkGain, _chkNoiseReduction, _chkStereoMic,
+            _chkAux, _lblAuxDevice, _cboAuxDevice, _btnAuxRefresh, _lblAuxGain, _trkAuxGain,
+            lblBuffer, _cboBuffer,
+            btnOk, btnCancel,
+        ]);
+
+        // Apply saved mode (fires RadioMode_CheckedChanged which sets visibility)
+        switch ((VcInputMode)settings.InputMode)
+        {
+            case VcInputMode.PushToTalk: _radioPtt.Checked = true; break;
+            case VcInputMode.AlwaysOn:   _radioAlwaysOn.Checked = true; break;
+            default:                     _radioVad.Checked = true; break;
+        }
+
+        LoadDevices();
+        LoadAuxDevices();
+        UpdateAuxControlsEnabled();
+    }
+
+    private void LoadDevices()
+    {
+        string? currentId = (_cboDevice.SelectedItem as DeviceInfo)?.Id ?? _settings.InputDeviceId;
+
+        var devices = _client.ListDevices(VcDeviceKind.Input);
+        _cboDevice.SelectedIndexChanged -= CboDevice_SelectedIndexChanged;
+        _cboDevice.DataSource = new BindingList<DeviceInfo>(devices);
+        _cboDevice.SelectedIndexChanged += CboDevice_SelectedIndexChanged;
+
+        // Try to restore previous selection
+        int idx = -1;
+        if (currentId is not null)
+            idx = devices.FindIndex(d => d.Id == currentId);
+        if (idx < 0)
+            idx = devices.FindIndex(d => d.IsDefault);
+        _cboDevice.SelectedIndex = idx >= 0 ? idx : (devices.Count > 0 ? 0 : -1);
+    }
+
+    private void CboDevice_SelectedIndexChanged(object? sender, EventArgs e)
+    {
+        if (_cboDevice.SelectedItem is not DeviceInfo dev) return;
+        _settings.InputDeviceId = dev.IsDefault ? null : dev.Id;
+        if (_micStreamId != 0)
+            _client.SetInputDevice(_micStreamId, dev.IsDefault ? null : dev.Id);
+    }
+
+    // ── Aux input stream ──────────────────────────────────────────────────────
+
+    private void LoadAuxDevices()
+    {
+        string? currentId = (_cboAuxDevice.SelectedItem as InputDeviceInfo)?.Id
+                            ?? _settings.AuxDeviceId;
+
+        var devices = InputDeviceEnumerator.List().ToList();
+
+        // Set the data source AND restore the selection while unsubscribed so neither the initial
+        // populate nor a Refresh fires a spurious device-change (which would restart the capture).
+        _cboAuxDevice.SelectedIndexChanged -= CboAuxDevice_SelectedIndexChanged;
+        _cboAuxDevice.DataSource = new BindingList<InputDeviceInfo>(devices);
+
+        int idx = -1;
+        if (currentId is not null)
+            idx = devices.FindIndex(d => d.Id == currentId);
+        if (idx < 0)
+            idx = devices.FindIndex(d => d.IsDefault);
+        _cboAuxDevice.SelectedIndex = idx >= 0 ? idx : (devices.Count > 0 ? 0 : -1);
+        _cboAuxDevice.SelectedIndexChanged += CboAuxDevice_SelectedIndexChanged;
+
+        // Persist the resolved selection (null = default) so Join Voice opens the same device.
+        if (_cboAuxDevice.SelectedItem is InputDeviceInfo dev)
+            _settings.AuxDeviceId = dev.IsDefault ? null : dev.Id;
+    }
+
+    private void ChkAux_CheckedChanged(object? sender, EventArgs e)
+    {
+        _settings.AuxEnabled = _chkAux.Checked;
+        UpdateAuxControlsEnabled();
+        _applyAuxEnabled?.Invoke(_chkAux.Checked);
+    }
+
+    private void CboAuxDevice_SelectedIndexChanged(object? sender, EventArgs e)
+    {
+        if (_cboAuxDevice.SelectedItem is not InputDeviceInfo dev) return;
+        _settings.AuxDeviceId = dev.IsDefault ? null : dev.Id;
+        if (_chkAux.Checked)
+            _applyAuxDevice?.Invoke(dev.IsDefault ? null : dev.Id);
+    }
+
+    private void TrkAuxGain_Scroll(object? sender, EventArgs e)
+    {
+        _settings.AuxGain = _trkAuxGain.Value;
+        if (_chkAux.Checked)
+            _applyAuxGain?.Invoke(_trkAuxGain.Value / 100f);
+    }
+
+    private void UpdateAuxControlsEnabled()
+    {
+        bool on = _chkAux.Checked;
+        _lblAuxDevice.Enabled  = on;
+        _cboAuxDevice.Enabled  = on;
+        _btnAuxRefresh.Enabled = on;
+        _lblAuxGain.Enabled    = on;
+        _trkAuxGain.Enabled    = on;
+    }
+
+    private void RadioMode_CheckedChanged(object? sender, EventArgs e)
+    {
+        var mode = CurrentMode();
+        bool isVad = mode == VcInputMode.VoiceActivation;
+        bool isPtt = mode == VcInputMode.PushToTalk;
+
+        _lblSensitivity.Visible = isVad;
+        _trkVad.Visible = isVad;
+        _lblPttKey.Visible = isPtt;
+        _btnChangePtt.Visible = isPtt;
+        _chkSystemWidePtt.Visible = isPtt;
+        UpdatePttKeyLabel();
+
+        _settings.InputMode = (int)mode;
+        if (_micStreamId != 0)
+        {
+            _client.SetInputMode(mode);
+            if (isVad) _client.SetVadThreshold(VadThresholdFromSlider());
+            if (isPtt) _client.SetPushToTalk(false);
+        }
+    }
+
+    private void TrkVad_Scroll(object? sender, EventArgs e)
+    {
+        _settings.VadThresholdSlider = _trkVad.Value;
+        if (_micStreamId != 0 && CurrentMode() == VcInputMode.VoiceActivation)
+            _client.SetVadThreshold(VadThresholdFromSlider());
+    }
+
+    private void TrkGain_Scroll(object? sender, EventArgs e)
+    {
+        _settings.MicGain = _trkGain.Value;
+        if (_micStreamId != 0)
+            _client.SetInputGain(_trkGain.Value / 100f);
+    }
+
+    private void ChkNoiseReduction_CheckedChanged(object? sender, EventArgs e)
+    {
+        _settings.MicNoiseReduction = _chkNoiseReduction.Checked;
+        if (_micStreamId != 0)
+            _client.SetInputNoiseReduction(_chkNoiseReduction.Checked);
+    }
+
+    private void ChkStereoMic_CheckedChanged(object? sender, EventArgs e)
+    {
+        _settings.StereoMic = _chkStereoMic.Checked;
+        // Channel count only takes effect when the capture device (re)starts, so restart it live.
+        if (_micStreamId != 0)
+        {
+            _client.SetCaptureChannels(_micStreamId, _chkStereoMic.Checked ? 2u : 1u);
+            _client.AudioRestart();
+        }
+    }
+
+    private void ChkSystemWidePtt_CheckedChanged(object? sender, EventArgs e) =>
+        // No live effect here — MainForm reads SystemWidePtt after the dialog closes and
+        // registers/unregisters the Raw Input keyboard sink accordingly.
+        _settings.SystemWidePtt = _chkSystemWidePtt.Checked;
+
+    private void BtnChangePtt_Click(object? sender, EventArgs e)
+    {
+        using var dlg = new PttKeyCaptureDialog(_pttKey);
+        if (dlg.ShowDialog(this) == DialogResult.OK)
+        {
+            _pttKey = dlg.CapturedKey;
+            _settings.PttKey = (int)_pttKey;
+            UpdatePttKeyLabel();
+        }
+    }
+
+    private void AudioSettingsForm_FormClosing(object? sender, FormClosingEventArgs e)
+    {
+        if (DialogResult == DialogResult.OK) return;
+
+        // Cancel: restore originals to settings and live client
+        _settings.InputDeviceId = _origDeviceId;
+        _settings.InputMode = (int)_origMode;
+        _settings.VadThresholdSlider = _origVadSlider;
+        _settings.MicGain = _origMicGain;
+        _settings.MicNoiseReduction = _origMicNoiseReduction;
+        _settings.StereoMic = _origStereoMic;
+        _settings.PttKey = (int)_origPttKey;
+        _settings.SystemWidePtt = _origSystemWidePtt;
+        _settings.AudioBufferMilliseconds = _origAudioBufferMilliseconds;
+        _client.SetAudioBufferMilliseconds(_origAudioBufferMilliseconds);
+
+        if (_micStreamId != 0)
+        {
+            _client.SetInputDevice(_micStreamId, _origDeviceId);
+            _client.SetInputMode(_origMode);
+            if (_origMode == VcInputMode.VoiceActivation)
+                _client.SetVadThreshold(0.1f * (1f - (_origVadSlider - 1f) / 99f));
+            _client.SetInputGain(_origMicGain / 100f);
+            _client.SetInputNoiseReduction(_origMicNoiseReduction);
+            // Restore capture channel count; restart the device only if it actually changed.
+            if (_origStereoMic != _chkStereoMic.Checked)
+            {
+                _client.SetCaptureChannels(_micStreamId, _origStereoMic ? 2u : 1u);
+                _client.AudioRestart();
+            }
+        }
+
+        // Aux: restore originals to settings and re-apply live (order: device + gain first so a
+        // re-enable starts with the right configuration).
+        _settings.AuxEnabled  = _origAuxEnabled;
+        _settings.AuxDeviceId = _origAuxDeviceId;
+        _settings.AuxGain     = _origAuxGain;
+        _applyAuxDevice?.Invoke(_origAuxDeviceId);
+        _applyAuxGain?.Invoke(_origAuxGain / 100f);
+        _applyAuxEnabled?.Invoke(_origAuxEnabled);
+    }
+
+    private void UpdatePttKeyLabel() =>
+        _lblPttKey.Text = $"({_pttKey})";
+
+    private VcInputMode CurrentMode() =>
+        _radioPtt.Checked ? VcInputMode.PushToTalk :
+        _radioAlwaysOn.Checked ? VcInputMode.AlwaysOn :
+        VcInputMode.VoiceActivation;
+
+    private float VadThresholdFromSlider() =>
+        0.1f * (1f - (_trkVad.Value - 1f) / 99f);
+}

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

@@ -0,0 +1,94 @@
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Prompt for a ban reason and duration.
+/// </summary>
+public sealed class BanUserDialog : Form
+{
+    private readonly TextBox _txtReason;
+    private readonly ComboBox _cboDuration;
+
+    public string Reason => _txtReason.Text.Trim();
+    public ulong ExpiresUnixMs { get; private set; }
+
+    public BanUserDialog(string nickname)
+    {
+        Text = $"Ban {nickname}";
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterParent;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(384, 160);
+
+        var lblReason = new Label
+        {
+            Text = "&Reason:",
+            Location = new Point(12, 12),
+            AutoSize = true,
+        };
+        _txtReason = new TextBox
+        {
+            Location = new Point(12, 34),
+            Size = new Size(360, 23),
+            TabIndex = 1,
+        };
+
+        var lblDuration = new Label
+        {
+            Text = "&Duration:",
+            Location = new Point(12, 66),
+            AutoSize = true,
+        };
+        _cboDuration = new ComboBox
+        {
+            Location = new Point(12, 88),
+            Size = new Size(200, 23),
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            TabIndex = 2,
+        };
+        _cboDuration.Items.AddRange(new object[]
+        {
+            new DurationItem("1 hour", TimeSpan.FromHours(1)),
+            new DurationItem("1 day", TimeSpan.FromDays(1)),
+            new DurationItem("1 week", TimeSpan.FromDays(7)),
+            new DurationItem("Permanent", TimeSpan.Zero),
+        });
+        _cboDuration.SelectedIndex = 1;
+
+        var btnOk = new Button
+        {
+            Text = "&Ban",
+            DialogResult = DialogResult.OK,
+            Location = new Point(216, 126),
+            Size = new Size(75, 27),
+            TabIndex = 3,
+        };
+        var btnCancel = new Button
+        {
+            Text = "&Cancel",
+            DialogResult = DialogResult.Cancel,
+            Location = new Point(297, 126),
+            Size = new Size(75, 27),
+            TabIndex = 4,
+        };
+
+        AcceptButton = btnOk;
+        CancelButton = btnCancel;
+        Controls.AddRange([lblReason, _txtReason, lblDuration, _cboDuration, btnOk, btnCancel]);
+
+        btnOk.Click += (_, _) =>
+        {
+            var selected = _cboDuration.SelectedItem as DurationItem;
+            ExpiresUnixMs = selected?.Duration == TimeSpan.Zero
+                ? 0
+                : (ulong)DateTimeOffset.UtcNow.Add(selected!.Duration).ToUnixTimeMilliseconds();
+        };
+    }
+
+    private sealed class DurationItem(string label, TimeSpan duration)
+    {
+        public TimeSpan Duration { get; } = duration;
+        public override string ToString() => label;
+    }
+}

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

@@ -0,0 +1,435 @@
+using VoiceCat.Windows;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Create or edit a channel, including its full per-channel Opus audio config.
+/// Returns DialogResult.OK with Result set.
+/// </summary>
+public sealed class ChannelEditDialog : Form
+{
+    private readonly bool _isCreate;
+    private readonly uint _editingId;
+    private readonly List<ChannelInfo> _channels;
+
+    private TextBox _txtName = null!;
+    private TextBox _txtTopic = null!;
+    private ComboBox _cboParent = null!;
+    private NumericUpDown _numMaxUsers = null!;
+    private NumericUpDown _numSortOrder = null!;
+    private CheckBox _chkPassword = null!;
+    private TextBox _txtPassword = null!;
+
+    private ComboBox _cboMode = null!;
+    private NumericUpDown _numSampleRate = null!;
+    private NumericUpDown _numBitrate = null!;
+    private NumericUpDown _numFrameMs = null!;
+    private ComboBox _cboApplication = null!;
+    private CheckBox _chkFec = null!;
+    private CheckBox _chkAutomaticLoss = null!;
+    private ComboBox _cboLossSpeed = null!;
+    private NumericUpDown _numExpectedLoss = null!;
+    private CheckBox _chkDtx = null!;
+    private CheckBox _chkDred = null!;
+    private NumericUpDown _numComplexity = null!;
+
+    public ChannelEditInfo? Result { get; private set; }
+
+    private readonly bool _supportsAdaptivePacketLoss;
+
+    public ChannelEditDialog(IEnumerable<ChannelInfo> channels, ChannelEditInfo? existing = null, bool supportsAdaptivePacketLoss = true)
+    {
+        _isCreate = existing is null;
+        _editingId = existing?.Id ?? 0;
+        _channels = channels.Where(c => c.Id != _editingId).ToList();
+        _supportsAdaptivePacketLoss = supportsAdaptivePacketLoss;
+
+        Text = _isCreate ? "Create channel" : "Edit channel";
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterParent;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(520, 520);
+
+        var tabs = new TabControl
+        {
+            Dock = DockStyle.Fill,
+            TabIndex = 0,
+        };
+
+        var pageGeneral = new TabPage("General");
+        BuildGeneralPage(pageGeneral, existing);
+        var pageAudio = new TabPage("Audio config");
+        BuildAudioPage(pageAudio, existing?.Audio);
+
+        tabs.TabPages.Add(pageGeneral);
+        tabs.TabPages.Add(pageAudio);
+
+        var btnOk = new Button
+        {
+            Text = "&OK",
+            DialogResult = DialogResult.OK,
+            Location = new Point(350, 486),
+            Size = new Size(75, 27),
+            TabIndex = 100,
+        };
+        var btnCancel = new Button
+        {
+            Text = "&Cancel",
+            DialogResult = DialogResult.Cancel,
+            Location = new Point(431, 486),
+            Size = new Size(75, 27),
+            TabIndex = 101,
+        };
+
+        AcceptButton = btnOk;
+        CancelButton = btnCancel;
+
+        Controls.Add(tabs);
+        Controls.Add(btnOk);
+        Controls.Add(btnCancel);
+
+        btnOk.Click += BtnOk_Click;
+    }
+
+    private void BuildGeneralPage(TabPage page, ChannelEditInfo? existing)
+    {
+        int y = 16;
+        int labelWidth = 110;
+        int inputX = 128;
+
+        AddLabel(page, "&Name:", 12, y, labelWidth);
+        _txtName = new TextBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(360, 23),
+            Text = existing?.Name ?? "",
+            TabIndex = 1,
+        };
+        page.Controls.Add(_txtName);
+        y += 36;
+
+        AddLabel(page, "&Topic:", 12, y, labelWidth);
+        _txtTopic = new TextBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(360, 23),
+            Text = existing?.Topic ?? "",
+            TabIndex = 2,
+        };
+        page.Controls.Add(_txtTopic);
+        y += 36;
+
+        AddLabel(page, "&Parent channel:", 12, y, labelWidth);
+        _cboParent = new ComboBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(360, 23),
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            TabIndex = 3,
+        };
+        _cboParent.Items.Add(new ChannelItem("(root)", 0));
+        foreach (var ch in _channels.OrderBy(c => c.Name))
+            _cboParent.Items.Add(new ChannelItem(ch.Name, ch.Id));
+        SelectParent(existing?.ParentId ?? 0);
+        page.Controls.Add(_cboParent);
+        y += 36;
+
+        AddLabel(page, "&Max users:", 12, y, labelWidth);
+        _numMaxUsers = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 0,
+            Maximum = 10000,
+            Value = existing?.MaxUsers ?? 0,
+            TabIndex = 4,
+        };
+        page.Controls.Add(_numMaxUsers);
+        AddLabel(page, "(0 = unlimited)", inputX + 128, y, 100);
+        y += 36;
+
+        AddLabel(page, "&Sort order:", 12, y, labelWidth);
+        _numSortOrder = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = int.MinValue,
+            Maximum = int.MaxValue,
+            Value = existing?.SortOrder ?? 0,
+            TabIndex = 5,
+        };
+        page.Controls.Add(_numSortOrder);
+        y += 36;
+
+        _chkPassword = new CheckBox
+        {
+            Text = "&Password protected",
+            Location = new Point(inputX, y),
+            AutoSize = true,
+            Checked = existing?.PasswordProtected ?? false,
+            TabIndex = 6,
+        };
+        page.Controls.Add(_chkPassword);
+        y += 28;
+
+        _txtPassword = new TextBox
+        {
+            Location = new Point(inputX, y),
+            Size = new Size(360, 23),
+            UseSystemPasswordChar = true,
+            Enabled = _chkPassword.Checked,
+            Text = existing?.Password ?? "",
+            TabIndex = 7,
+        };
+        page.Controls.Add(_txtPassword);
+        _chkPassword.CheckedChanged += (_, _) => _txtPassword.Enabled = _chkPassword.Checked;
+    }
+
+    private void BuildAudioPage(TabPage page, AudioConfigInfo? audio)
+    {
+        audio ??= new AudioConfigInfo(0, false, 48000, 0, 20, 0, true, 0, false, 10, false);
+
+        int y = 16;
+        int labelWidth = 150;
+        int inputX = 168;
+
+        AddLabel(page, "Codec (0 = Opus):", 12, y, labelWidth);
+        var numCodec = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 0,
+            Maximum = 0,
+            Value = audio.Codec,
+            Enabled = false,
+        };
+        page.Controls.Add(numCodec);
+        y += 34;
+
+        AddLabel(page, "&Mode:", 12, y, labelWidth);
+        _cboMode = new ComboBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(160, 23),
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            TabIndex = 10,
+        };
+        _cboMode.Items.AddRange(["Mono", "Stereo"]);
+        _cboMode.SelectedIndex = audio.Stereo ? 1 : 0;
+        page.Controls.Add(_cboMode);
+        y += 34;
+
+        AddLabel(page, "Sample &rate (Hz):", 12, y, labelWidth);
+        _numSampleRate = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 8000,
+            Maximum = 96000,
+            Value = audio.SampleRate,
+            TabIndex = 11,
+        };
+        page.Controls.Add(_numSampleRate);
+        y += 34;
+
+        AddLabel(page, "&Bitrate (bps, 0 = default):", 12, y, labelWidth);
+        _numBitrate = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 0,
+            Maximum = 512000,
+            Increment = 1000,
+            Value = audio.BitrateBps,
+            TabIndex = 12,
+        };
+        page.Controls.Add(_numBitrate);
+        y += 34;
+
+        AddLabel(page, "Frame &ms:", 12, y, labelWidth);
+        _numFrameMs = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 5,
+            Maximum = 120,
+            Value = audio.FrameMs,
+            TabIndex = 13,
+        };
+        page.Controls.Add(_numFrameMs);
+        y += 34;
+
+        AddLabel(page, "&Application:", 12, y, labelWidth);
+        _cboApplication = new ComboBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(160, 23),
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            TabIndex = 14,
+        };
+        _cboApplication.Items.AddRange(["VoIP", "Audio", "Low delay"]);
+        _cboApplication.SelectedIndex = (int)Math.Min(2, audio.Application);
+        page.Controls.Add(_cboApplication);
+        y += 34;
+
+        _chkAutomaticLoss = new CheckBox
+        {
+            Text = "&Automatic packet loss",
+            Location = new Point(inputX, y),
+            AutoSize = true,
+            Checked = audio.PacketLossMode != VcPacketLossMode.Manual,
+            Enabled = _supportsAdaptivePacketLoss,
+            TabIndex = 15,
+        };
+        page.Controls.Add(_chkAutomaticLoss);
+        y += 30;
+
+        AddLabel(page, "Adaptation &speed:", 12, y, labelWidth);
+        _cboLossSpeed = new ComboBox
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(160, 23),
+            DropDownStyle = ComboBoxStyle.DropDownList,
+            TabIndex = 16,
+        };
+        _cboLossSpeed.Items.AddRange(["Fast", "Balanced", "Stable"]);
+        _cboLossSpeed.SelectedIndex = audio.PacketLossMode == VcPacketLossMode.Manual ? 1 : (int)audio.PacketLossMode - 1;
+        page.Controls.Add(_cboLossSpeed);
+        y += 34;
+
+        AddLabel(page, "Expected packet loss (%):", 12, y, labelWidth);
+        _numExpectedLoss = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 0,
+            Maximum = 100,
+            Value = audio.ExpectedPacketLoss,
+            TabIndex = 17,
+        };
+        page.Controls.Add(_numExpectedLoss);
+        void UpdateLossControls()
+        {
+            _numExpectedLoss.Enabled = !_chkAutomaticLoss.Checked;
+            _cboLossSpeed.Enabled = _supportsAdaptivePacketLoss && _chkAutomaticLoss.Checked;
+        }
+        _chkAutomaticLoss.CheckedChanged += (_, _) => UpdateLossControls();
+        UpdateLossControls();
+        y += 34;
+
+        AddLabel(page, "Com&plexity (0–10):", 12, y, labelWidth);
+        _numComplexity = new NumericUpDown
+        {
+            Location = new Point(inputX, y - 2),
+            Size = new Size(120, 23),
+            Minimum = 0,
+            Maximum = 10,
+            Value = audio.Complexity,
+            TabIndex = 18,
+        };
+        page.Controls.Add(_numComplexity);
+        y += 34;
+
+        _chkFec = new CheckBox
+        {
+            Text = "&FEC",
+            Location = new Point(inputX, y),
+            AutoSize = true,
+            Checked = audio.Fec,
+            TabIndex = 19,
+        };
+        page.Controls.Add(_chkFec);
+        y += 28;
+
+        _chkDtx = new CheckBox
+        {
+            Text = "&DTX",
+            Location = new Point(inputX, y),
+            AutoSize = true,
+            Checked = audio.Dtx,
+            TabIndex = 20,
+        };
+        page.Controls.Add(_chkDtx);
+        y += 28;
+
+        _chkDred = new CheckBox
+        {
+            Text = "D&RED (deep redundancy)",
+            Location = new Point(inputX, y),
+            AutoSize = true,
+            Checked = audio.Dred,
+            TabIndex = 21,
+        };
+        page.Controls.Add(_chkDred);
+    }
+
+    private static void AddLabel(Control parent, string text, int x, int y, int width)
+    {
+        parent.Controls.Add(new Label
+        {
+            Text = text,
+            Location = new Point(x, y),
+            Size = new Size(width, 17),
+            TextAlign = System.Drawing.ContentAlignment.MiddleLeft,
+        });
+    }
+
+    private void SelectParent(uint parentId)
+    {
+        for (int i = 0; i < _cboParent.Items.Count; i++)
+        {
+            if (_cboParent.Items[i] is ChannelItem item && item.Id == parentId)
+            {
+                _cboParent.SelectedIndex = i;
+                return;
+            }
+        }
+        _cboParent.SelectedIndex = 0;
+    }
+
+    private void BtnOk_Click(object? sender, EventArgs e)
+    {
+        string name = _txtName.Text.Trim();
+        if (string.IsNullOrEmpty(name))
+        {
+            MessageBox.Show(this, "Channel name is required.", "VoiceCat",
+                MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            DialogResult = DialogResult.None;
+            return;
+        }
+
+        uint parentId = (_cboParent.SelectedItem as ChannelItem)?.Id ?? 0;
+        var audio = new AudioConfigInfo(
+            Codec: 0,
+            Stereo: _cboMode.SelectedIndex == 1,
+            SampleRate: (uint)_numSampleRate.Value,
+            BitrateBps: (uint)_numBitrate.Value,
+            FrameMs: (uint)_numFrameMs.Value,
+            Application: (uint)_cboApplication.SelectedIndex,
+            Fec: _chkFec.Checked,
+            ExpectedPacketLoss: (uint)_numExpectedLoss.Value,
+            Dtx: _chkDtx.Checked,
+            Complexity: (uint)_numComplexity.Value,
+            Dred: _chkDred.Checked,
+            PacketLossMode: _chkAutomaticLoss.Checked ? (VcPacketLossMode)(_cboLossSpeed.SelectedIndex + 1) : VcPacketLossMode.Manual);
+
+        Result = new ChannelEditInfo(
+            Id: _editingId,
+            ParentId: parentId,
+            Name: name,
+            Topic: _txtTopic.Text.Trim(),
+            PasswordProtected: _chkPassword.Checked,
+            Password: _chkPassword.Checked ? _txtPassword.Text : null,
+            MaxUsers: (uint)_numMaxUsers.Value,
+            SortOrder: (int)_numSortOrder.Value,
+            Audio: audio);
+    }
+
+    private sealed class ChannelItem(string name, uint id)
+    {
+        public uint Id { get; } = id;
+        public override string ToString() => name;
+    }
+}

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

@@ -0,0 +1,83 @@
+namespace VoiceCat.App.Forms;
+
+partial class ConnectDialog
+{
+    private System.ComponentModel.IContainer components = null!;
+    private Label lblServers = null!;
+    private ListBox lstServers = null!;
+    private Button btnConnect = null!;
+    private Button btnAddNew = null!;
+    private Button btnEdit = null!;
+    private Button btnRemove = null!;
+    private Label lblStatus = null!;
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing) components?.Dispose();
+        base.Dispose(disposing);
+    }
+
+    private void InitializeComponent()
+    {
+        components = new System.ComponentModel.Container();
+        lblServers = new Label();
+        lstServers = new ListBox();
+        btnConnect = new Button();
+        btnAddNew = new Button();
+        btnEdit = new Button();
+        btnRemove = new Button();
+        lblStatus = new Label();
+
+        lblServers.Text = "&Saved servers:";
+        lblServers.AutoSize = true;
+        lblServers.Location = new Point(12, 12);
+        lblServers.TabIndex = 0;
+
+        lstServers.AccessibleName = "Saved servers";
+        lstServers.Location = new Point(12, 32);
+        lstServers.Size = new Size(360, 200);
+        lstServers.TabIndex = 1;
+        lstServers.SelectedIndexChanged += (_, _) => UpdateButtonsEnabled();
+
+        btnConnect.Text = "&Connect";
+        btnConnect.Location = new Point(384, 32);
+        btnConnect.Size = new Size(110, 27);
+        btnConnect.TabIndex = 2;
+
+        btnAddNew.Text = "&Add new...";
+        btnAddNew.Location = new Point(384, 65);
+        btnAddNew.Size = new Size(110, 27);
+        btnAddNew.TabIndex = 3;
+
+        btnEdit.Text = "&Edit...";
+        btnEdit.Location = new Point(384, 98);
+        btnEdit.Size = new Size(110, 27);
+        btnEdit.TabIndex = 4;
+
+        btnRemove.Text = "&Remove";
+        btnRemove.Location = new Point(384, 131);
+        btnRemove.Size = new Size(110, 27);
+        btnRemove.TabIndex = 5;
+
+        lblStatus.AccessibleName = "Connection status";
+        lblStatus.Location = new Point(12, 244);
+        lblStatus.Size = new Size(482, 23);
+        lblStatus.TabIndex = 6;
+
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(506, 280);
+        Controls.Add(lblServers);
+        Controls.Add(lstServers);
+        Controls.Add(btnConnect);
+        Controls.Add(btnAddNew);
+        Controls.Add(btnEdit);
+        Controls.Add(btnRemove);
+        Controls.Add(lblStatus);
+        AcceptButton = btnConnect;
+        MinimizeBox = false;
+        MaximizeBox = false;
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        StartPosition = FormStartPosition.CenterScreen;
+        Text = "VoiceCat — Connect to a server";
+    }
+}

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

@@ -0,0 +1,262 @@
+using VoiceCat.App.Models;
+using VoiceCat.Windows;
+
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// Saved-server list + connect flow. On success, ConnectedClient/SelfUserId/Nickname are set
+/// and DialogResult == OK; the caller (Program.cs) takes ownership of ConnectedClient (does
+/// NOT dispose it here — MainForm owns its lifetime from that point on).
+/// </summary>
+public partial class ConnectDialog : Form
+{
+    private readonly List<SavedServer> _servers;
+    private readonly System.Windows.Forms.Timer _pumpTimer = new() { Interval = 30 };
+
+    private VoiceCatClient? _client;
+    private bool _identityDialogShown;
+
+    public VoiceCatClient? ConnectedClient { get; private set; }
+    public uint SelfUserId { get; private set; }
+    public string Nickname { get; private set; } = "";
+    public string ServerName { get; private set; } = "";
+
+    public ConnectDialog()
+    {
+        InitializeComponent();
+        _servers = ServerListStore.Load();
+        RefreshServerList();
+
+        _pumpTimer.Tick += (_, _) =>
+        {
+            try { _client?.PumpEvents(); }
+            catch (Exception ex) { Console.Error.WriteLine($"[ConnectDialog] EXCEPTION in PumpEvents/event handler: {ex}"); }
+        };
+
+        btnAddNew.Click += BtnAddNew_Click;
+        btnEdit.Click += BtnEdit_Click;
+        btnRemove.Click += BtnRemove_Click;
+        btnConnect.Click += BtnConnect_Click;
+        lstServers.DoubleClick += BtnConnect_Click;
+    }
+
+    private void RefreshServerList()
+    {
+        object? previouslySelected = lstServers.SelectedItem;
+        lstServers.Items.Clear();
+        foreach (var s in _servers) lstServers.Items.Add(s);
+        if (previouslySelected is not null && _servers.Contains(previouslySelected))
+            lstServers.SelectedItem = previouslySelected;
+        else if (lstServers.Items.Count > 0)
+            lstServers.SelectedIndex = 0;
+        UpdateButtonsEnabled();
+    }
+
+    private void UpdateButtonsEnabled()
+    {
+        bool hasSelection = lstServers.SelectedItem is not null;
+        btnConnect.Enabled = hasSelection;
+        btnEdit.Enabled = hasSelection;
+        btnRemove.Enabled = hasSelection;
+    }
+
+    private void BtnAddNew_Click(object? sender, EventArgs e)
+    {
+        using var dlg = new AddServerDialog();
+        if (dlg.ShowDialog(this) != DialogResult.OK || dlg.Result is null) return;
+        _servers.Add(dlg.Result);
+        ServerListStore.Save(_servers);
+        RefreshServerList();
+        lstServers.SelectedItem = dlg.Result;
+    }
+
+    private void BtnEdit_Click(object? sender, EventArgs e)
+    {
+        if (lstServers.SelectedItem is not SavedServer existing) return;
+        using var dlg = new AddServerDialog(existing);
+        if (dlg.ShowDialog(this) != DialogResult.OK) return;
+        ServerListStore.Save(_servers);
+        RefreshServerList();
+    }
+
+    private void BtnRemove_Click(object? sender, EventArgs e)
+    {
+        if (lstServers.SelectedItem is not SavedServer existing) return;
+        var confirm = MessageBox.Show(this, $"Remove '{existing}' from the saved-server list?",
+            "VoiceCat", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
+        if (confirm != DialogResult.Yes) return;
+        _servers.Remove(existing);
+        ServerListStore.Save(_servers);
+        RefreshServerList();
+    }
+
+    private void BtnConnect_Click(object? sender, EventArgs e)
+    {
+        if (lstServers.SelectedItem is not SavedServer server)
+            return;
+        try
+        {
+            StartConnect(server);
+        }
+        catch (Exception ex)
+        {
+            Console.Error.WriteLine($"[ConnectDialog] EXCEPTION in StartConnect: {ex}");
+            lblStatus.Text = $"Internal error: {ex.Message}";
+            CleanupFailedAttempt();
+        }
+    }
+
+    private void StartConnect(SavedServer server)
+    {
+        SetBusy(true);
+        lblStatus.Text = "Connecting...";
+
+        ServerName = string.IsNullOrWhiteSpace(server.DisplayName)
+            ? $"{server.Host}:{server.Port}"
+            : server.DisplayName;
+
+        string tofuDir = Path.GetDirectoryName(ServerListStore.TofuStorePath)!;
+        Directory.CreateDirectory(tofuDir);
+
+        _client = new VoiceCatClient("VoiceCat-Windows", VoiceCatClient.VersionString,
+            VcLogLevel.Info, ServerListStore.TofuStorePath, new VoiceCat.App.Audio.WasapiAudioBackend());
+        _client.EventReceived += OnEvent;
+        _identityDialogShown = false;
+        _pumpTimer.Start();
+
+        var connectResult = _client.Connect(server.Host, server.Port);
+        if (connectResult != VcResult.Ok)
+        {
+            lblStatus.Text = $"Connect failed: {connectResult}";
+            CleanupFailedAttempt();
+            return;
+        }
+
+        if (server.AuthMode == AuthMode.Guest)
+        {
+            Nickname = string.IsNullOrWhiteSpace(server.LastNickname) ? Environment.UserName : server.LastNickname;
+            _client.AuthenticateGuest(Nickname);
+        }
+        else
+        {
+            string password;
+            if (server.ProtectedPasswordBase64 is not null)
+            {
+                password = PasswordProtector.Unprotect(server.ProtectedPasswordBase64);
+            }
+            else
+            {
+                using var pwDlg = new PasswordPromptDialog($"Password for {server.SavedUsername}@{server.Host}:");
+                if (pwDlg.ShowDialog(this) != DialogResult.OK)
+                {
+                    lblStatus.Text = "Cancelled.";
+                    CleanupFailedAttempt();
+                    return;
+                }
+                password = pwDlg.Password;
+            }
+            Nickname = server.SavedUsername ?? "";
+            _client.AuthenticateUser(server.SavedUsername ?? "", password);
+        }
+    }
+
+    private void OnEvent(VoiceCatEvent ev)
+    {
+        switch (ev.Type)
+        {
+            case VcEventType.ConnectionState:
+                lblStatus.Text = ev.ConnectionState switch
+                {
+                    VcConnectionState.Connecting => "Connecting...",
+                    VcConnectionState.TlsHandshake => "TLS handshake...",
+                    VcConnectionState.VerifyingIdentity => "Verifying server identity...",
+                    VcConnectionState.Authenticating => "Authenticating...",
+                    VcConnectionState.Connected => "Connected.",
+                    _ => lblStatus.Text,
+                };
+                break;
+
+            case VcEventType.ServerIdentity:
+                HandleServerIdentity((VcTofuStatus)ev.U32a, ev.Text ?? "");
+                break;
+
+            case VcEventType.AuthResult:
+                if (ev.Result == VcResult.Ok)
+                {
+                    SelfUserId = ev.UserId;
+                    ConnectedClient = _client;
+                    _pumpTimer.Stop();
+                    _client!.EventReceived -= OnEvent;
+                    DialogResult = DialogResult.OK;
+                    Close();
+                }
+                else
+                {
+                    lblStatus.Text = $"Authentication failed: {ev.Text}";
+                    CleanupFailedAttempt();
+                }
+                break;
+
+            case VcEventType.Disconnected:
+                if (ConnectedClient is null)
+                {
+                    lblStatus.Text = string.IsNullOrEmpty(ev.Text) ? "Disconnected." : $"Disconnected: {ev.Text}";
+                    CleanupFailedAttempt();
+                }
+                break;
+        }
+    }
+
+    private void HandleServerIdentity(VcTofuStatus status, string certFingerprintHex)
+    {
+        if (_identityDialogShown) return; // one decision per connect attempt
+        if (status == VcTofuStatus.Matched)
+        {
+            // Silent success path — no dialog. See ServerIdentityDialog's doc comment.
+            _client!.ConfirmServerIdentity(true);
+            return;
+        }
+
+        _identityDialogShown = true;
+        using var dlg = new ServerIdentityDialog(status, certFingerprintHex, _client!.GetServerIdentityDisplay());
+        bool accept = dlg.ShowDialog(this) == DialogResult.OK;
+        _client.ConfirmServerIdentity(accept);
+        if (!accept) lblStatus.Text = "Server identity rejected.";
+    }
+
+    private void CleanupFailedAttempt()
+    {
+        _pumpTimer.Stop();
+        if (_client is not null)
+        {
+            _client.EventReceived -= OnEvent;
+            _client.Dispose();
+            _client = null;
+        }
+        SetBusy(false);
+    }
+
+    private void SetBusy(bool busy)
+    {
+        lstServers.Enabled = !busy;
+        btnConnect.Enabled = !busy && lstServers.SelectedItem is not null;
+        btnAddNew.Enabled = !busy;
+        btnEdit.Enabled = !busy && lstServers.SelectedItem is not null;
+        btnRemove.Enabled = !busy && lstServers.SelectedItem is not null;
+    }
+
+    protected override void OnFormClosing(FormClosingEventArgs e)
+    {
+        if (DialogResult != DialogResult.OK)
+        {
+            _pumpTimer.Stop();
+            if (_client is not null)
+            {
+                _client.EventReceived -= OnEvent;
+                _client.Dispose();
+                _client = null;
+            }
+        }
+        base.OnFormClosing(e);
+    }
+}

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

@@ -0,0 +1,60 @@
+namespace VoiceCat.App.Forms;
+
+/// <summary>
+/// A small reusable modal that prompts for a single line of text (e.g., kick/ban reason).
+/// Returns DialogResult.OK with Text set, or DialogResult.Cancel.
+/// </summary>
+public sealed class InputDialog : Form
+{
+    private readonly TextBox _txtInput;
+
+    public string TextValue => _txtInput.Text.Trim();
+
+    public InputDialog(string caption, string label, string defaultText = "")
+    {
+        var lbl = new Label
+        {
+            Text = label,
+            AutoSize = true,
+            Location = new Point(12, 12),
+            TabIndex = 0,
+        };
+
+        _txtInput = new TextBox
+        {
+            Text = defaultText,
+            Location = new Point(12, 36),
+            Size = new Size(360, 23),
+            TabIndex = 1,
+        };
+
+        var btnOk = new Button
+        {
+            Text = "&OK",
+            DialogResult = DialogResult.OK,
+            Location = new Point(216, 72),
+            Size = new Size(75, 27),
+            TabIndex = 2,
+        };
+
+        var btnCancel = new Button
+        {
+            Text = "&Cancel",
+            DialogResult = DialogResult.Cancel,
+            Location = new Point(297, 72),
+            Size = new Size(75, 27),
+            TabIndex = 3,
+        };
+
+        AcceptButton = btnOk;
+        CancelButton = btnCancel;
+        AutoScaleMode = AutoScaleMode.Font;
+        ClientSize = new Size(384, 112);
+        Controls.AddRange([lbl, _txtInput, btnOk, btnCancel]);
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterParent;
+        Text = caption;
+    }
+}