Azure voice live .net

--- name: azure-ai-voicelive-dotnet description: Azure AI Voice LiveSDKs for .NET. Build real-time voice AI applications with bidirectional WebSocket communication. risk: unknown source: community date_added: '2026-02-27' --- # Azure.AI.VoiceLive (.NET) Real-time voice AI SDK for building bidirectional voice assistants with Azure AI. ## Installation ``bash dotnet add package Azure.AI.VoiceLive dotnet add package Azure.Identity dotnet add package NAudio # For audio capture/playback ` **Current Versions**: Stable v1.0.0, Preview v1.1.0-beta.1 ## Environment Variables `bash AZURE_VOICELIVE_ENDPOINT=https://<resource>.services.ai.azure.com/ AZURE_VOICELIVE_MODEL=gpt-4o-realtime-preview AZURE_VOICELIVE_VOICE=en-US-AvaNeural # Optional: API key if not using Entra ID AZURE_VOICELIVE_API_KEY=<your-api-key> ` ## Authentication ### Microsoft Entra ID (Recommended) `csharp using Azure.Identity; using Azure.AI.VoiceLive; Uri endpoint = new Uri("https://your-resource.cognitiveservices.azure.com"); DefaultAzureCredential credential = new DefaultAzureCredential(); VoiceLiveClient client = new VoiceLiveClient(endpoint, credential); ` **Required Role**: Cognitive Services User (assign in Azure Portal → Access control) ### API Key `csharp Uri endpoint = new Uri("https://your-resource.cognitiveservices.azure.com"); AzureKeyCredential credential = new AzureKeyCredential("your-api-key"); VoiceLiveClient client = new VoiceLiveClient(endpoint, credential); ` ## Client Hierarchy ` VoiceLiveClient └── VoiceLiveSession (WebSocket connection) ├── ConfigureSessionAsync() ├── GetUpdatesAsync() → SessionUpdate events ├── AddItemAsync() → UserMessageItem, FunctionCallOutputItem ├── SendAudioAsync() └── StartResponseAsync() ` ## Core Workflow ### 1. Start Session and Configure `csharp using Azure.Identity; using Azure.AI.VoiceLive; var endpoint = new Uri(Environment.GetEnvironmentVariable("AZURE_VOICELIVE_ENDPOINT")); var client = new VoiceLiveClient(endpoint, new DefaultAzureCredential()); var model = "gpt-4o-mini-realtime-preview"; // Start session using VoiceLiveSession session = await client.StartSessionAsync(model); // Configure session VoiceLiveSessionOptions sessionOptions = new() { Model = model, Instructions = "You are a helpful AI assistant. Respond naturally.", Voice = new AzureStandardVoice("en-US-AvaNeural"), TurnDetection = new AzureSemanticVadTurnDetection() { Threshold = 0.5f, PrefixPadding = TimeSpan.FromMilliseconds(300), SilenceDuration = TimeSpan.FromMilliseconds(500) }, InputAudioFormat = InputAudioFormat.Pcm16, OutputAudioFormat = OutputAudioFormat.Pcm16 }; // Set modalities (both text and audio for voice assistants) sessionOptions.Modalities.Clear(); sessionOptions.Modalities.Add(InteractionModality.Text); sessionOptions.Modalities.Add(InteractionModality.Audio); await session.ConfigureSessionAsync(sessionOptions); ` ### 2. Process Events `csharp await foreach (SessionUpdate serverEvent in session.GetUpdatesAsync()) { switch (serverEvent) { case SessionUpdateResponseAudioDelta audioDelta: byte[] audioData = audioDelta.Delta.ToArray(); // Play audio via NAudio or other audio library break; case SessionUpdateResponseTextDelta textDelta: Console.Write(textDelta.Delta); break; case SessionUpdateResponseFunctionCallArgumentsDone functionCall: // Handle function call (see Function Calling section) break; case SessionUpdateError error: Console.WriteLine($"Error: {error.Error.Message}"); break; case SessionUpdateResponseDone: Console.WriteLine("\n--- Response complete ---"); break; } } ` ### 3. Send User Message `csharp await session.AddItemAsync(new UserMessageItem("Hello, can you help me?")); await session.StartResponseAsync(); ` ### 4. Function Calling ``csharp // Define function var weatherFunction = new VoiceLiveFunctionDefinition("getcurrentwe