deepgram-dotnet-voice-agent

# Using Deepgram Voice Agent (.NET SDK) Full-duplex voice agent sessions over a single WebSocket. **Use a different skill when:** - One-way transcription → `deepgram-dotnet-speech-to-text` or `deepgram-dotnet-conversational-stt`. - One-way synthesis → `deepgram-dotnet-text-to-speech`. - Admin APIs → `deepgram-dotnet-management-api`. ## Authentication ```bash dotnet add package Deepgram dotnet add package Deepgram.Microphone # only if you need local mic capture ``` ```csharp using Deepgram; Deepgram.Library.Initialize(); // Uses DEEPGRAM_API_KEY env var; pass apiKey: "..." to override var agentClient = ClientFactory.CreateAgentWebSocketClient(); ``` ## Quick start ```csharp using Deepgram.Models.Agent.v2.WebSocket; var agentClient = ClientFactory.CreateAgentWebSocketClient(); await agentClient.Subscribe(new EventHandler<ConversationTextResponse>((sender, e) => { Console.WriteLine(e); })); await agentClient.Subscribe(new EventHandler<AudioResponse>((sender, e) => { if (e.Stream != null) { // Raw linear16 PCM — see examples/agent/websocket/no_mic/Program.cs for WAV header. using var writer = new BinaryWriter(File.Open("output.raw", FileMode.Append)); writer.Write(e.Stream.ToArray()); } })); var settings = new SettingsSchema(); settings.Agent.Think.Provider.Type = "open_ai"; settings.Agent.Think.Provider.Model = "gpt-4o-mini"; settings.Agent.Greeting = "Hello! How can I help you today?"; settings.Agent.Listen.Provider.Type = "deepgram"; settings.Agent.Listen.Provider.Model = "nova-3"; settings.Agent.Speak.Provider.Type = "deepgram"; settings.Agent.Speak.Provider.Model = "aura-2-thalia-en"; settings.Audio.Input.Encoding = "linear16"; settings.Audio.Input.SampleRate = 24000; settings.Audio.Output.Encoding = "linear16"; settings.Audio.Output.SampleRate = 24000; bool connected = await agentClient.Connect(settings); if (!connected) { Console.Error.WriteLine("Agent WebSocket connection failed — check API key and network."); return; } await agentClient.SendInjectUserMessage("Say hello in one sentence."); // Cleanup when done Console.ReadKey(); await agentClient.Stop(); ``` ## Streaming microphone audio ```csharp var microphone = new Microphone( push_callback: (audioData, length) => { byte[] chunk = new byte[length]; Array.Copy(audioData, chunk, length); agentClient.SendBinary(chunk); }, rate: 24000, channels: 1, format: SampleFormat.Int16); microphone.Start(); // Cleanup Console.ReadKey(); microphone.Stop(); await agentClient.Stop(); ``` ## Key params and events Settings models: - `SettingsSchema` - `Audio`, `Input`, `Output` - `Agent`, `Listen`, `Think`, `Speak` - `Provider` (dynamic extra properties supported) Important events: - `ConversationTextResponse` - `AudioResponse` - `AgentStartedSpeakingResponse` - `AgentAudioDoneResponse` - `AgentThinkingResponse` - `UserStartedSpeakingResponse` - `FunctionCallRequestResponse` - `SettingsAppliedResponse` Send helpers: - `SendInjectUserMessage(string)` - `SendInjectUserMessage(InjectUserMessageSchema)` - `SendBinary(...)` - `SendBinaryImmediately(...)` - `SendKeepAlive()` ## References - In-repo: `Deepgram/Clients/Agent/v2/Websocket/Client.cs`, `Deepgram/Clients/Interfaces/v2/IAgentWebSocketClient.cs`, `Deepgram/Models/Agent/v2/WebSocket/*.cs`, `Deepgram.Microphone/Microphone.cs` - AsyncAPI (WSS): https://developers.deepgram.com/asyncapi.yaml - Product docs: https://developers.deepgram.com/docs/voice-agent, https://developers.deepgram.com/docs/voice-agent-message-flow ## Gotchas 1. **Use the actual event/model names in this repo.** `SettingsSchema`, `ConversationTextResponse`, etc. — not the Python names. 2. **`Provider` is dynamic.** Extra provider-specific properties are stored through `JsonExtensionData`; set them carefully. 3. **Function call support is partial.** `FunctionCallRequestResponse` is marked `TODO: this needs to be defined`, so inspect raw payload behavior before relying on typed fields. 4. **There is no convenience `SendFunctionCallResponse(...)` helper on the public interface.** If you need it, send serialized `FunctionCallResponseSchema` manually via the generic send path. 5. **Audio formats must match.** The examples align both input and output around `linear16` / `24000`. 6. **`Deepgram.Microphone` depends on PortAudio.** Local microphone examples need the helper project/package and a working PortAudio environment. ## Example files in this repo - `examples/agent/websocket/simple/Program.cs` - `examples/agent/websocket/no_mic/Program.cs` - `examples/agent/websocket/arbitrary_keys/Program.cs` Cross-language product knowledge (API reference, recipes, MCP setup): `npx skills add deepgram/skills`.