From 9103ff1fb73f31592eae96ac5d7bea8c22fe139d Mon Sep 17 00:00:00 2001
From: gramps <gramps@llamachile.shop>
Date: Tue, 4 Aug 2026 09:09:52 -0700
Subject: [PATCH] Initial scaffold: ytLive C# WPF project

- MVVM architecture (Models, ViewModels, Views, Services, Helpers)
- Models: Scene, Source, StreamConfig, StreamHealth, YouTubeChannel, ChatMessage
- Services: YouTubeAuthService (OAuth2), YouTubeStreamService (broadcasts/stream health),
  YouTubeChatService (live chat polling)
- ViewModels: MainViewModel with scene management, stream controls, chat
- MainWindow with dark theme: scene/source panel, preview area, chat panel, status bar
- Version roadmap: v0.1 (scenes, RTMP, OAuth2, chat, health) -> 1.0
---
 App.xaml                         |   9 ++
 App.xaml.cs                      |  13 ++
 AssemblyInfo.cs                  |  10 ++
 Helpers/RelayCommand.cs          |  24 +++
 Helpers/ViewModelBase.cs         |  23 +++
 MainWindow.xaml                  | 242 +++++++++++++++++++++++++++++++
 MainWindow.xaml.cs               |  11 ++
 Models/Scene.cs                  |   8 +
 Models/Source.cs                 |  35 +++++
 Models/StreamConfig.cs           |  35 +++++
 Models/YouTube.cs                |  26 ++++
 Services/YouTubeAuthService.cs   | 118 +++++++++++++++
 Services/YouTubeChatService.cs   | 102 +++++++++++++
 Services/YouTubeStreamService.cs | 129 ++++++++++++++++
 ViewModels/MainViewModel.cs      | 143 ++++++++++++++++++
 ytLive.csproj                    |  15 ++
 16 files changed, 943 insertions(+)
 create mode 100644 App.xaml
 create mode 100644 App.xaml.cs
 create mode 100644 AssemblyInfo.cs
 create mode 100644 Helpers/RelayCommand.cs
 create mode 100644 Helpers/ViewModelBase.cs
 create mode 100644 MainWindow.xaml
 create mode 100644 MainWindow.xaml.cs
 create mode 100644 Models/Scene.cs
 create mode 100644 Models/Source.cs
 create mode 100644 Models/StreamConfig.cs
 create mode 100644 Models/YouTube.cs
 create mode 100644 Services/YouTubeAuthService.cs
 create mode 100644 Services/YouTubeChatService.cs
 create mode 100644 Services/YouTubeStreamService.cs
 create mode 100644 ViewModels/MainViewModel.cs
 create mode 100644 ytLive.csproj

diff --git a/App.xaml b/App.xaml
new file mode 100644
index 0000000..2bf3cea
--- /dev/null
+++ b/App.xaml
@@ -0,0 +1,9 @@
+<Application x:Class="ytLive.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:ytLive"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>
diff --git a/App.xaml.cs b/App.xaml.cs
new file mode 100644
index 0000000..1ff0ff3
--- /dev/null
+++ b/App.xaml.cs
@@ -0,0 +1,13 @@
+using System.Configuration;
+using System.Data;
+using System.Windows;
+
+namespace ytLive;
+
+/// <summary>
+/// Interaction logic for App.xaml
+/// </summary>
+public partial class App : Application
+{
+}
+
diff --git a/AssemblyInfo.cs b/AssemblyInfo.cs
new file mode 100644
index 0000000..c73865b
--- /dev/null
+++ b/AssemblyInfo.cs
@@ -0,0 +1,10 @@
+using System.Windows;
+
+[assembly:ThemeInfo(
+    ResourceDictionaryLocation.None,            //where theme specific resource dictionaries are located
+                                                //(used if a resource is not found in the page,
+                                                // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly   //where the generic resource dictionary is located
+                                                //(used if a resource is not found in the page,
+                                                // app, or any theme specific resource dictionaries)
+)]
diff --git a/Helpers/RelayCommand.cs b/Helpers/RelayCommand.cs
new file mode 100644
index 0000000..9ea4c8f
--- /dev/null
+++ b/Helpers/RelayCommand.cs
@@ -0,0 +1,24 @@
+using System.Windows.Input;
+
+namespace ytLive.Helpers;
+
+public class RelayCommand : ICommand
+{
+    private readonly Action<object?> _execute;
+    private readonly Func<object?, bool>? _canExecute;
+
+    public RelayCommand(Action<object?> execute, Func<object?, bool>? canExecute = null)
+    {
+        _execute = execute;
+        _canExecute = canExecute;
+    }
+
+    public event EventHandler? CanExecuteChanged
+    {
+        add => CommandManager.RequerySuggested += value;
+        remove => CommandManager.RequerySuggested -= value;
+    }
+
+    public bool CanExecute(object? parameter) => _canExecute?.Invoke(parameter) ?? true;
+    public void Execute(object? parameter) => _execute(parameter);
+}
diff --git a/Helpers/ViewModelBase.cs b/Helpers/ViewModelBase.cs
new file mode 100644
index 0000000..f762d2c
--- /dev/null
+++ b/Helpers/ViewModelBase.cs
@@ -0,0 +1,23 @@
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+
+namespace ytLive.Helpers;
+
+public abstract class ViewModelBase : INotifyPropertyChanged
+{
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    protected bool SetProperty<T>(ref T field, T value, [CallerMemberName] string? propertyName = null)
+    {
+        if (EqualityComparer<T>.Default.Equals(field, value))
+            return false;
+        field = value;
+        OnPropertyChanged(propertyName);
+        return true;
+    }
+
+    protected void OnPropertyChanged([CallerMemberName] string? propertyName = null)
+    {
+        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}
diff --git a/MainWindow.xaml b/MainWindow.xaml
new file mode 100644
index 0000000..8d4fb81
--- /dev/null
+++ b/MainWindow.xaml
@@ -0,0 +1,242 @@
+<Window x:Class="ytLive.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:vm="clr-namespace:ytLive.ViewModels"
+        mc:Ignorable="d"
+        Title="ytLive" Height="720" Width="1280"
+        Background="#1a1a2e"
+        WindowStartupLocation="CenterScreen">
+
+    <Window.DataContext>
+        <vm:MainViewModel/>
+    </Window.DataContext>
+
+    <Window.Resources>
+        <BooleanToVisibilityConverter x:Key="BoolToVis"/>
+
+        <!-- Base button style -->
+        <Style x:Key="YtButton" TargetType="Button">
+            <Setter Property="Background" Value="#e94560"/>
+            <Setter Property="Foreground" Value="White"/>
+            <Setter Property="FontSize" Value="13"/>
+            <Setter Property="FontWeight" Value="SemiBold"/>
+            <Setter Property="Padding" Value="16,8"/>
+            <Setter Property="BorderThickness" Value="0"/>
+            <Setter Property="Cursor" Value="Hand"/>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="Button">
+                        <Border Background="{TemplateBinding Background}"
+                                CornerRadius="4"
+                                Padding="{TemplateBinding Padding}">
+                            <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                        </Border>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+
+        <Style x:Key="YtButtonSecondary" TargetType="Button" BasedOn="{StaticResource YtButton}">
+            <Setter Property="Background" Value="#16213e"/>
+        </Style>
+
+        <Style x:Key="YtTextBox" TargetType="TextBox">
+            <Setter Property="Background" Value="#0f3460"/>
+            <Setter Property="Foreground" Value="#e0e0e0"/>
+            <Setter Property="BorderThickness" Value="0"/>
+            <Setter Property="Padding" Value="8,6"/>
+            <Setter Property="FontSize" Value="13"/>
+            <Setter Property="CaretBrush" Value="White"/>
+        </Style>
+
+        <Style x:Key="YtLabel" TargetType="TextBlock">
+            <Setter Property="Foreground" Value="#a0a0b0"/>
+            <Setter Property="FontSize" Value="12"/>
+        </Style>
+
+        <Style x:Key="SectionHeader" TargetType="TextBlock">
+            <Setter Property="Foreground" Value="#e0e0e0"/>
+            <Setter Property="FontSize" Value="14"/>
+            <Setter Property="FontWeight" Value="SemiBold"/>
+            <Setter Property="Margin" Value="0,0,0,8"/>
+        </Style>
+    </Window.Resources>
+
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+            <RowDefinition Height="Auto"/>
+        </Grid.RowDefinitions>
+
+        <!-- ═══ TOP BAR: Stream Controls ═══ -->
+        <Border Grid.Row="0" Background="#16213e" Padding="16,10">
+            <Grid>
+                <Grid.ColumnDefinitions>
+                    <ColumnDefinition Width="Auto"/>
+                    <ColumnDefinition Width="*"/>
+                    <ColumnDefinition Width="Auto"/>
+                    <ColumnDefinition Width="Auto"/>
+                </Grid.ColumnDefinitions>
+
+                <!-- Logo / Brand -->
+                <TextBlock Grid.Column="0" Text="ytLive"
+                           Foreground="#e94560" FontSize="22" FontWeight="Bold"
+                           VerticalAlignment="Center" Margin="0,0,24,0"/>
+
+                <!-- Stream Title -->
+                <TextBox Grid.Column="1" Style="{StaticResource YtTextBox}"
+                         Text="{Binding StreamTitle, UpdateSourceTrigger=PropertyChanged}"
+                         Width="400" HorizontalAlignment="Left"
+                         VerticalAlignment="Center"/>
+
+                <!-- Stream Status -->
+                <Border Grid.Column="2" Background="#0f3460" CornerRadius="4"
+                        Padding="12,6" Margin="16,0" VerticalAlignment="Center">
+                    <StackPanel Orientation="Horizontal">
+                        <Ellipse Width="10" Height="10" Margin="0,0,8,0">
+                            <Ellipse.Style>
+                                <Style TargetType="Ellipse">
+                                    <Setter Property="Fill" Value="#555"/>
+                                    <Style.Triggers>
+                                        <DataTrigger Binding="{Binding StreamStatus}" Value="Streaming">
+                                            <Setter Property="Fill" Value="#00ff00"/>
+                                        </DataTrigger>
+                                        <DataTrigger Binding="{Binding StreamStatus}" Value="Connecting">
+                                            <Setter Property="Fill" Value="#ffaa00"/>
+                                        </DataTrigger>
+                                        <DataTrigger Binding="{Binding StreamStatus}" Value="Error">
+                                            <Setter Property="Fill" Value="#ff0000"/>
+                                        </DataTrigger>
+                                    </Style.Triggers>
+                                </Style>
+                            </Ellipse.Style>
+                        </Ellipse>
+                        <TextBlock Text="{Binding StatusDisplay}" Foreground="White"
+                                   FontSize="13" FontWeight="SemiBold" VerticalAlignment="Center"/>
+                    </StackPanel>
+                </Border>
+
+                <!-- Stream Controls -->
+                <StackPanel Grid.Column="3" Orientation="Horizontal" VerticalAlignment="Center">
+                    <Button Content="▶ GO LIVE" Style="{StaticResource YtButton}"
+                            Command="{Binding StartStreamCommand}"
+                            Visibility="{Binding StreamStatus, Converter={StaticResource BoolToVis},
+                                      ConverterParameter=Offline}"/>
+                    <Button Content="■ STOP" Style="{StaticResource YtButton}"
+                            Background="#333" Command="{Binding StopStreamCommand}"/>
+                    <Button Content="YouTube" Style="{StaticResource YtButtonSecondary}"
+                            Command="{Binding ConnectYouTubeCommand}" Margin="8,0,0,0"/>
+                </StackPanel>
+            </Grid>
+        </Border>
+
+        <!-- ═══ MIDDLE: Main Content ═══ -->
+        <Grid Grid.Row="1" Margin="8">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="220"/>
+                <ColumnDefinition Width="*"/>
+                <ColumnDefinition Width="300"/>
+            </Grid.ColumnDefinitions>
+
+            <!-- LEFT PANEL: Scenes & Sources -->
+            <Border Grid.Column="0" Background="#16213e" CornerRadius="6" Padding="12">
+                <Grid>
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto"/>
+                        <RowDefinition Height="*"/>
+                        <RowDefinition Height="Auto"/>
+                        <RowDefinition Height="*"/>
+                    </Grid.RowDefinitions>
+
+                    <!-- Scenes -->
+                    <TextBlock Grid.Row="0" Text="SCENES" Style="{StaticResource SectionHeader}"/>
+
+                    <ListBox Grid.Row="1" Background="Transparent" BorderThickness="0"
+                             ItemsSource="{Binding Scenes}"
+                             SelectedItem="{Binding ActiveScene}"
+                             Foreground="#e0e0e0" FontSize="13">
+                        <ListBox.ItemTemplate>
+                            <DataTemplate>
+                                <TextBlock Text="{Binding Name}" Padding="4,4"/>
+                            </DataTemplate>
+                        </ListBox.ItemTemplate>
+                    </ListBox>
+
+                    <StackPanel Grid.Row="2" Orientation="Horizontal" Margin="0,8,0,0">
+                        <Button Content="+" Style="{StaticResource YtButtonSecondary}"
+                                Command="{Binding AddSceneCommand}" Padding="8,4" Margin="0,0,4,0"/>
+                        <Button Content="−" Style="{StaticResource YtButtonSecondary}"
+                                Command="{Binding RemoveSceneCommand}" Padding="8,4"/>
+                    </StackPanel>
+
+                    <!-- Sources (for active scene) -->
+                    <TextBlock Grid.Row="3" Text="SOURCES" Style="{StaticResource SectionHeader}" Margin="0,12,0,0"/>
+                </Grid>
+            </Border>
+
+            <!-- CENTER: Preview Area -->
+            <Border Grid.Column="1" Background="#0a0a1a" CornerRadius="6" Margin="8,0">
+                <Grid>
+                    <TextBlock Text="Preview" Foreground="#333" FontSize="24"
+                               HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                    <!-- TODO: D3DImage or MediaElement for video preview -->
+                </Grid>
+            </Border>
+
+            <!-- RIGHT PANEL: Chat -->
+            <Border Grid.Column="2" Background="#16213e" CornerRadius="6" Padding="12">
+                <Grid>
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto"/>
+                        <RowDefinition Height="*"/>
+                    </Grid.RowDefinitions>
+
+                    <TextBlock Grid.Row="0" Text="LIVE CHAT" Style="{StaticResource SectionHeader}"/>
+
+                    <ListBox Grid.Row="1" Background="Transparent" BorderThickness="0"
+                             ItemsSource="{Binding ChatMessages}"
+                             Foreground="#e0e0e0" FontSize="12">
+                        <ListBox.ItemTemplate>
+                            <DataTemplate>
+                                <StackPanel Margin="0,2">
+                                    <TextBlock>
+                                        <Run Text="{Binding AuthorName, Mode=OneWay}" FontWeight="Bold" Foreground="#e94560"/>
+                                        <Run Text=": "/>
+                                        <Run Text="{Binding Message, Mode=OneWay}" Foreground="#e0e0e0"/>
+                                    </TextBlock>
+                                </StackPanel>
+                            </DataTemplate>
+                        </ListBox.ItemTemplate>
+                    </ListBox>
+                </Grid>
+            </Border>
+        </Grid>
+
+        <!-- ═══ BOTTOM BAR: Stream Health ═══ -->
+        <Border Grid.Row="2" Background="#0f3460" Padding="16,6">
+            <StackPanel Orientation="Horizontal">
+                <TextBlock Text="Bitrate:" Style="{StaticResource YtLabel}" Margin="0,0,4,0"/>
+                <TextBlock Text="{Binding CurrentHealth.CurrentBitrate}" Style="{StaticResource YtLabel}"
+                           Foreground="White" Margin="0,0,20,0"/>
+
+                <TextBlock Text="FPS:" Style="{StaticResource YtLabel}" Margin="0,0,4,0"/>
+                <TextBlock Text="{Binding CurrentHealth.FPS}" Style="{StaticResource YtLabel}"
+                           Foreground="White" Margin="0,0,20,0"/>
+
+                <TextBlock Text="Dropped:" Style="{StaticResource YtLabel}" Margin="0,0,4,0"/>
+                <TextBlock Text="{Binding CurrentHealth.DroppedFrames}" Style="{StaticResource YtLabel}"
+                           Foreground="White" Margin="0,0,20,0"/>
+
+                <TextBlock Text="Duration:" Style="{StaticResource YtLabel}" Margin="0,0,4,0"/>
+                <TextBlock Text="{Binding CurrentHealth.StreamDuration}" Style="{StaticResource YtLabel}"
+                           Foreground="White"/>
+
+                <TextBlock Text="{Binding CurrentHealth.HealthMessage}" Style="{StaticResource YtLabel}"
+                           Foreground="#e94560" Margin="20,0,0,0"/>
+            </StackPanel>
+        </Border>
+    </Grid>
+</Window>
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
new file mode 100644
index 0000000..6ef8b5a
--- /dev/null
+++ b/MainWindow.xaml.cs
@@ -0,0 +1,11 @@
+using System.Windows;
+
+namespace ytLive;
+
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+}
diff --git a/Models/Scene.cs b/Models/Scene.cs
new file mode 100644
index 0000000..ba9d58c
--- /dev/null
+++ b/Models/Scene.cs
@@ -0,0 +1,8 @@
+namespace ytLive.Models;
+
+public class Scene
+{
+    public string Id { get; init; } = Guid.NewGuid().ToString();
+    public string Name { get; set; } = string.Empty;
+    public List<Source> Sources { get; set; } = new();
+}
diff --git a/Models/Source.cs b/Models/Source.cs
new file mode 100644
index 0000000..eecd285
--- /dev/null
+++ b/Models/Source.cs
@@ -0,0 +1,35 @@
+namespace ytLive.Models;
+
+public enum SourceType
+{
+    DisplayCapture,
+    WindowCapture,
+    Webcam,
+    Image,
+    TextOverlay
+}
+
+public class Source
+{
+    public string Id { get; init; } = Guid.NewGuid().ToString();
+    public string Name { get; set; } = string.Empty;
+    public SourceType Type { get; set; }
+    public bool IsEnabled { get; set; } = true;
+
+    // Display/Window capture
+    public int? MonitorIndex { get; set; }
+    public IntPtr? WindowHandle { get; set; }
+
+    // Webcam
+    public string? DeviceId { get; set; }
+
+    // Image
+    public string? FilePath { get; set; }
+
+    // Position/transform
+    public double X { get; set; }
+    public double Y { get; set; }
+    public double Width { get; set; }
+    public double Height { get; set; }
+    public double Opacity { get; set; } = 1.0;
+}
diff --git a/Models/StreamConfig.cs b/Models/StreamConfig.cs
new file mode 100644
index 0000000..23e9dc2
--- /dev/null
+++ b/Models/StreamConfig.cs
@@ -0,0 +1,35 @@
+namespace ytLive.Models;
+
+public enum StreamStatus
+{
+    Offline,
+    Connecting,
+    Streaming,
+    Error
+}
+
+public class StreamConfig
+{
+    public string Title { get; set; } = string.Empty;
+    public string Description { get; set; } = string.Empty;
+    public string StreamKey { get; set; } = string.Empty;
+    public string IngestUrl { get; set; } = "rtmp://a.rtmp.youtube.com/live2";
+    public bool IsLowLatency { get; set; } = true;
+    public int TargetBitrate { get; set; } = 6000;
+    public int TargetFps { get; set; } = 60;
+    public string Resolution { get; set; } = "1920x1080";
+}
+
+public class StreamHealth
+{
+    public StreamStatus Status { get; set; }
+    public double CurrentBitrate { get; set; }
+    public int DroppedFrames { get; set; }
+    public double FPS { get; set; }
+    public TimeSpan StreamDuration { get; set; }
+    public string? LastError { get; set; }
+
+    // YouTube-specific
+    public string? HealthStatus { get; set; }  // "good", "bad", "ok"
+    public string? HealthMessage { get; set; }
+}
diff --git a/Models/YouTube.cs b/Models/YouTube.cs
new file mode 100644
index 0000000..48cc432
--- /dev/null
+++ b/Models/YouTube.cs
@@ -0,0 +1,26 @@
+namespace ytLive.Models;
+
+public class YouTubeChannel
+{
+    public string ChannelId { get; set; } = string.Empty;
+    public string DisplayName { get; set; } = string.Empty;
+    public string ProfileImageUrl { get; set; } = string.Empty;
+    public string AccessToken { get; set; } = string.Empty;
+    public string RefreshToken { get; set; } = string.Empty;
+    public DateTime TokenExpiry { get; set; }
+}
+
+public class ChatMessage
+{
+    public string Id { get; init; } = Guid.NewGuid().ToString();
+    public string AuthorName { get; set; } = string.Empty;
+    public string AuthorChannelId { get; set; } = string.Empty;
+    public string AuthorImageUrl { get; set; } = string.Empty;
+    public string Message { get; set; } = string.Empty;
+    public DateTime Timestamp { get; set; }
+    public bool IsSuperChat { get; set; }
+    public double SuperChatAmount { get; set; }
+    public string? SuperChatCurrency { get; set; }
+    public bool IsMember { get; set; }
+    public string? MembershipLevel { get; set; }
+}
diff --git a/Services/YouTubeAuthService.cs b/Services/YouTubeAuthService.cs
new file mode 100644
index 0000000..8f2c2d2
--- /dev/null
+++ b/Services/YouTubeAuthService.cs
@@ -0,0 +1,118 @@
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Text.Json;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+/// <summary>
+/// Handles YouTube OAuth2 authentication flow.
+/// Uses a local HTTP listener for the redirect callback.
+/// </summary>
+public class YouTubeAuthService
+{
+    private const string AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth";
+    private const string TokenEndpoint = "https://oauth2.googleapis.com/token";
+    private const string Scope = "https://www.googleapis.com/auth/youtube https://www.googleapis.com/auth/youtube.force-ssl";
+
+    private readonly string _clientId;
+    private readonly string _clientSecret;
+    private readonly HttpClient _http = new();
+
+    public YouTubeChannel? CurrentChannel { get; private set; }
+
+    public YouTubeAuthService(string clientId, string clientSecret)
+    {
+        _clientId = clientId;
+        _clientSecret = clientSecret;
+    }
+
+    public string GetAuthorizationUrl(string redirectUri)
+    {
+        var parameters = HttpUtility.ParseQueryString(string.Empty);
+        parameters["client_id"] = _clientId;
+        parameters["redirect_uri"] = redirectUri;
+        parameters["response_type"] = "code";
+        parameters["scope"] = Scope;
+        parameters["access_type"] = "offline";
+        parameters["prompt"] = "consent";
+
+        return $"{AuthorizationEndpoint}?{parameters}";
+    }
+
+    public async Task<YouTubeChannel?> ExchangeCodeForToken(string code, string redirectUri)
+    {
+        var body = new FormUrlEncodedContent(new Dictionary<string, string>
+        {
+            ["code"] = code,
+            ["client_id"] = _clientId,
+            ["client_secret"] = _clientSecret,
+            ["redirect_uri"] = redirectUri,
+            ["grant_type"] = "authorization_code"
+        });
+
+        var response = await _http.PostAsync(TokenEndpoint, body);
+        if (!response.IsSuccessStatusCode)
+            return null;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var tokenData = JsonSerializer.Deserialize<JsonElement>(json);
+
+        var accessToken = tokenData.GetProperty("access_token").GetString()!;
+        var refreshToken = tokenData.GetProperty("refresh_token").GetString()!;
+        var expiresIn = tokenData.GetProperty("expires_in").GetInt32();
+
+        // Fetch channel info
+        return await FetchChannelInfo(accessToken, refreshToken, expiresIn);
+    }
+
+    public async Task<bool> RefreshToken()
+    {
+        if (CurrentChannel == null) return false;
+
+        var body = new FormUrlEncodedContent(new Dictionary<string, string>
+        {
+            ["refresh_token"] = CurrentChannel.RefreshToken,
+            ["client_id"] = _clientId,
+            ["client_secret"] = _clientSecret,
+            ["grant_type"] = "refresh_token"
+        });
+
+        var response = await _http.PostAsync(TokenEndpoint, body);
+        if (!response.IsSuccessStatusCode) return false;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var tokenData = JsonSerializer.Deserialize<JsonElement>(json);
+
+        CurrentChannel.AccessToken = tokenData.GetProperty("access_token").GetString()!;
+        CurrentChannel.TokenExpiry = DateTime.UtcNow.AddSeconds(tokenData.GetProperty("expires_in").GetInt32());
+        return true;
+    }
+
+    private async Task<YouTubeChannel?> FetchChannelInfo(string accessToken, string refreshToken, int expiresIn)
+    {
+        _http.DefaultRequestHeaders.Authorization = new("Bearer", accessToken);
+        var response = await _http.GetAsync("https://www.googleapis.com/youtube/v3/channels?part=snippet&mine=true");
+        if (!response.IsSuccessStatusCode) return null;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var data = JsonSerializer.Deserialize<JsonElement>(json);
+        var items = data.GetProperty("items");
+
+        if (items.GetArrayLength() == 0) return null;
+
+        var snippet = items[0].GetProperty("snippet");
+        CurrentChannel = new YouTubeChannel
+        {
+            ChannelId = items[0].GetProperty("id").GetString()!,
+            DisplayName = snippet.GetProperty("title").GetString()!,
+            ProfileImageUrl = snippet.GetProperty("thumbnails").GetProperty("default").GetProperty("url").GetString()!,
+            AccessToken = accessToken,
+            RefreshToken = refreshToken,
+            TokenExpiry = DateTime.UtcNow.AddSeconds(expiresIn)
+        };
+
+        return CurrentChannel;
+    }
+}
diff --git a/Services/YouTubeChatService.cs b/Services/YouTubeChatService.cs
new file mode 100644
index 0000000..8f1a099
--- /dev/null
+++ b/Services/YouTubeChatService.cs
@@ -0,0 +1,102 @@
+using System.Net.Http;
+using System.Text.Json;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+/// <summary>
+/// Polls YouTube Live Chat API for messages.
+/// YouTube doesn't have WebSocket for chat — polling is the only option.
+/// </summary>
+public class YouTubeChatService : IDisposable
+{
+    private readonly YouTubeAuthService _auth;
+    private readonly HttpClient _http = new();
+    private Timer? _pollTimer;
+    private string? _nextPageToken;
+    private string? _liveChatId;
+    private bool _isRunning;
+
+    public event Action<ChatMessage>? MessageReceived;
+
+    private static readonly JsonSerializerOptions JsonOpts = new()
+    {
+        PropertyNameCaseInsensitive = true
+    };
+
+    public YouTubeChatService(YouTubeAuthService auth)
+    {
+        _auth = auth;
+    }
+
+    public void Start(string liveChatId, int pollIntervalMs = 2000)
+    {
+        _liveChatId = liveChatId;
+        _isRunning = true;
+        _nextPageToken = null;
+        _pollTimer = new(async _ => await Poll(), null, 0, pollIntervalMs);
+    }
+
+    public void Stop()
+    {
+        _isRunning = false;
+        _pollTimer?.Dispose();
+        _pollTimer = null;
+    }
+
+    private async Task Poll()
+    {
+        if (!_isRunning || _liveChatId == null || _auth.CurrentChannel == null) return;
+
+        try
+        {
+            if (_auth.CurrentChannel.TokenExpiry <= DateTime.UtcNow.AddMinutes(5))
+                await _auth.RefreshToken();
+
+            var url = $"https://www.googleapis.com/youtube/v3/liveChat/messages?liveChatId={_liveChatId}&part=snippet,authorDetails&maxResults=50";
+            if (_nextPageToken != null)
+                url += $"&pageToken={_nextPageToken}";
+
+            _http.DefaultRequestHeaders.Authorization = new("Bearer", _auth.CurrentChannel.AccessToken);
+            var response = await _http.GetAsync(url);
+            if (!response.IsSuccessStatusCode) return;
+
+            var json = await response.Content.ReadAsStringAsync();
+            var data = JsonSerializer.Deserialize<JsonElement>(json);
+
+            if (data.TryGetProperty("nextPageToken", out var token))
+                _nextPageToken = token.GetString();
+
+            if (!data.TryGetProperty("items", out var items)) return;
+
+            foreach (var item in items.EnumerateArray())
+            {
+                var snippet = item.GetProperty("snippet");
+                var author = item.GetProperty("authorDetails");
+
+                var message = new ChatMessage
+                {
+                    Id = item.GetProperty("id").GetString()!,
+                    AuthorName = author.GetProperty("displayName").GetString()!,
+                    AuthorChannelId = author.GetProperty("channelId").GetString()!,
+                    AuthorImageUrl = author.GetProperty("profileImageUrl").GetString()!,
+                    Message = snippet.GetProperty("textMessageDetails").GetProperty("messageText").GetString()!,
+                    Timestamp = DateTime.Parse(snippet.GetProperty("publishedAt").GetString()!),
+                    IsMember = author.GetProperty("isChatSponsor").GetBoolean()
+                };
+
+                MessageReceived?.Invoke(message);
+            }
+        }
+        catch (Exception ex)
+        {
+            System.Diagnostics.Debug.WriteLine($"Chat poll error: {ex.Message}");
+        }
+    }
+
+    public void Dispose()
+    {
+        Stop();
+        _http.Dispose();
+    }
+}
diff --git a/Services/YouTubeStreamService.cs b/Services/YouTubeStreamService.cs
new file mode 100644
index 0000000..0e88b75
--- /dev/null
+++ b/Services/YouTubeStreamService.cs
@@ -0,0 +1,129 @@
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Text.Json;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+/// <summary>
+/// Manages YouTube live stream lifecycle — create broadcasts,
+/// bind stream keys, monitor health.
+/// </summary>
+public class YouTubeStreamService
+{
+    private readonly YouTubeAuthService _auth;
+    private readonly HttpClient _http = new();
+    private const string ApiBase = "https://www.googleapis.com/youtube/v3";
+
+    public YouTubeStreamService(YouTubeAuthService auth)
+    {
+        _auth = auth;
+    }
+
+    private async Task<bool> EnsureToken()
+    {
+        if (_auth.CurrentChannel == null) return false;
+        if (_auth.CurrentChannel.TokenExpiry <= DateTime.UtcNow.AddMinutes(5))
+            return await _auth.RefreshToken();
+        return true;
+    }
+
+    public async Task<string?> CreateBroadcast(string title, string description, DateTime scheduledStartTime)
+    {
+        if (!await EnsureToken()) return null;
+
+        var broadcast = new
+        {
+            snippet = new
+            {
+                title,
+                description,
+                scheduledStartTime = scheduledStartTime.ToString("o"),
+                categoryId = "22"  // People & Blogs
+            },
+            status = new
+            {
+                privacyStatus = "public",
+                selfDeclaredMadeForKids = false
+            },
+            contentDetails = new
+            {
+                enableAutoStart = true,
+                enableAutoStop = true
+            }
+        };
+
+        _http.DefaultRequestHeaders.Authorization = new("Bearer", _auth.CurrentChannel!.AccessToken);
+        var response = await _http.PostAsJsonAsync(
+            $"{ApiBase}/liveBroadcasts?part=snippet,status,contentDetails", broadcast);
+
+        if (!response.IsSuccessStatusCode) return null;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var data = JsonSerializer.Deserialize<JsonElement>(json);
+        return data.GetProperty("id").GetString();
+    }
+
+    public async Task<string?> BindStream(string broadcastId, string streamKey)
+    {
+        if (!await EnsureToken()) return null;
+
+        // Create stream resource
+        var stream = new
+        {
+            snippet = new { title = $"stream-{broadcastId}" },
+            contentDetails = new
+            {
+                ingestionType = "rtmp",
+                frameRate = "60fps",
+                resolution = "1080p"
+            }
+        };
+
+        _http.DefaultRequestHeaders.Authorization = new("Bearer", _auth.CurrentChannel!.AccessToken);
+        var response = await _http.PostAsJsonAsync(
+            $"{ApiBase}/liveStreams?part=snippet,contentDetails", stream);
+
+        if (!response.IsSuccessStatusCode) return null;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var data = JsonSerializer.Deserialize<JsonElement>(json);
+        var streamId = data.GetProperty("id").GetString();
+
+        // Bind stream to broadcast
+        var bindResponse = await _http.PutAsJsonAsync(
+            $"{ApiBase}/liveBroadcasts?part=id,contentDetails&id={broadcastId}",
+            new { contentDetails = new { streamId } });
+
+        return bindResponse.IsSuccessStatusCode ? streamId : null;
+    }
+
+    public async Task<StreamHealth?> GetStreamHealth(string broadcastId)
+    {
+        if (!await EnsureToken()) return null;
+
+        _http.DefaultRequestHeaders.Authorization = new("Bearer", _auth.CurrentChannel!.AccessToken);
+        var response = await _http.GetAsync(
+            $"{ApiBase}/liveBroadcasts?part=contentDetails,status&id={broadcastId}");
+
+        if (!response.IsSuccessStatusCode) return null;
+
+        var json = await response.Content.ReadAsStringAsync();
+        var data = JsonSerializer.Deserialize<JsonElement>(json);
+        var items = data.GetProperty("items");
+        if (items.GetArrayLength() == 0) return null;
+
+        var status = items[0].GetProperty("status").GetProperty("lifeCycleStatus").GetString();
+        return new StreamHealth
+        {
+            HealthStatus = status switch
+            {
+                "live" => "good",
+                "ready" => "ok",
+                "created" => "ok",
+                _ => "bad"
+            },
+            HealthMessage = status
+        };
+    }
+}
diff --git a/ViewModels/MainViewModel.cs b/ViewModels/MainViewModel.cs
new file mode 100644
index 0000000..a59f393
--- /dev/null
+++ b/ViewModels/MainViewModel.cs
@@ -0,0 +1,143 @@
+using System.Collections.ObjectModel;
+using System.Windows.Input;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+
+namespace ytLive.ViewModels;
+
+public class MainViewModel : ViewModelBase
+{
+    private readonly YouTubeAuthService _youtubeAuth;
+    private readonly YouTubeStreamService _youtubeStream;
+    private readonly YouTubeChatService _youtubeChat;
+
+    private Scene? _activeScene;
+    private StreamStatus _streamStatus = StreamStatus.Offline;
+    private StreamHealth _currentHealth = new();
+    private string _streamTitle = string.Empty;
+    private string _streamKey = string.Empty;
+    private bool _isYouTubeConnected;
+
+    public ObservableCollection<Scene> Scenes { get; } = new();
+    public ObservableCollection<ChatMessage> ChatMessages { get; } = new();
+
+    public Scene? ActiveScene
+    {
+        get => _activeScene;
+        set => SetProperty(ref _activeScene, value);
+    }
+
+    public StreamStatus StreamStatus
+    {
+        get => _streamStatus;
+        set => SetProperty(ref _streamStatus, value);
+    }
+
+    public StreamHealth CurrentHealth
+    {
+        get => _currentHealth;
+        set => SetProperty(ref _currentHealth, value);
+    }
+
+    public string StreamTitle
+    {
+        get => _streamTitle;
+        set => SetProperty(ref _streamTitle, value);
+    }
+
+    public string StreamKey
+    {
+        get => _streamKey;
+        set => SetProperty(ref _streamKey, value);
+    }
+
+    public bool IsYouTubeConnected
+    {
+        get => _isYouTubeConnected;
+        set => SetProperty(ref _isYouTubeConnected, value);
+    }
+
+    public string StatusDisplay => StreamStatus switch
+    {
+        StreamStatus.Offline => "OFFLINE",
+        StreamStatus.Connecting => "CONNECTING...",
+        StreamStatus.Streaming => "LIVE",
+        StreamStatus.Error => "ERROR",
+        _ => "UNKNOWN"
+    };
+
+    // Commands
+    public ICommand AddSceneCommand { get; }
+    public ICommand RemoveSceneCommand { get; }
+    public ICommand StartStreamCommand { get; }
+    public ICommand StopStreamCommand { get; }
+    public ICommand ConnectYouTubeCommand { get; }
+
+    public MainViewModel()
+    {
+        _youtubeAuth = new YouTubeAuthService("", "");  // TODO: load from config
+        _youtubeStream = new YouTubeStreamService(_youtubeAuth);
+        _youtubeChat = new YouTubeChatService(_youtubeAuth);
+
+        _youtubeChat.MessageReceived += OnChatMessageReceived;
+
+        AddSceneCommand = new RelayCommand(_ => AddScene());
+        RemoveSceneCommand = new RelayCommand(scene => RemoveScene(scene as Scene));
+        StartStreamCommand = new RelayCommand(_ => StartStream(), _ => StreamStatus == StreamStatus.Offline);
+        StopStreamCommand = new RelayCommand(_ => StopStream(), _ => StreamStatus == StreamStatus.Streaming);
+        ConnectYouTubeCommand = new RelayCommand(_ => ConnectYouTube());
+
+        // Start with a default scene
+        AddScene("Scene 1");
+    }
+
+    private void AddScene(string? name = null)
+    {
+        var scene = new Scene { Name = name ?? $"Scene {Scenes.Count + 1}" };
+        Scenes.Add(scene);
+        ActiveScene = scene;
+    }
+
+    private void RemoveScene(Scene? scene)
+    {
+        if (scene == null) return;
+        Scenes.Remove(scene);
+        if (ActiveScene == scene)
+            ActiveScene = Scenes.FirstOrDefault();
+    }
+
+    private void OnChatMessageReceived(ChatMessage message)
+    {
+        System.Windows.Application.Current.Dispatcher.Invoke(() =>
+        {
+            ChatMessages.Add(message);
+            if (ChatMessages.Count > 500)
+                ChatMessages.RemoveAt(0);
+        });
+    }
+
+    private async void StartStream()
+    {
+        StreamStatus = StreamStatus.Connecting;
+        OnPropertyChanged(nameof(StatusDisplay));
+
+        // TODO: Initialize capture pipeline, encode, and push to RTMP
+        // For now, simulate connection
+        StreamStatus = StreamStatus.Streaming;
+        OnPropertyChanged(nameof(StatusDisplay));
+    }
+
+    private void StopStream()
+    {
+        StreamStatus = StreamStatus.Offline;
+        OnPropertyChanged(nameof(StatusDisplay));
+    }
+
+    private void ConnectYouTube()
+    {
+        // TODO: Launch OAuth2 flow in browser
+        // For now, this is a stub
+        IsYouTubeConnected = false;
+    }
+}
diff --git a/ytLive.csproj b/ytLive.csproj
new file mode 100644
index 0000000..d477719
--- /dev/null
+++ b/ytLive.csproj
@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <UseWPF>true</UseWPF>
+    <EnableWindowsTargeting>true</EnableWindowsTargeting>
+    <ApplicationIcon></ApplicationIcon>
+    <AssemblyName>ytLive</AssemblyName>
+    <RootNamespace>ytLive</RootNamespace>
+  </PropertyGroup>
+
+</Project>