Shiny.Speech

Shiny.Speech

Cross-platform speech services for .NET MAUI and Blazor WebAssembly — speech-to-text, text-to-speech, audio capture, and audio playback with pluggable cloud providers.

Libraries

Getting Started

Native Platform Speech

Use the built-in OS speech engines — no cloud account needed. Works on MAUI (iOS, Android, Windows) and Blazor WebAssembly (via Web Speech API).

builder.Services.AddSpeechServices();
// Registers: ISpeechToTextService, ITextToSpeechService, IAudioSource, IAudioPlayer
// On Browser/WASM: auto-detected via OperatingSystem.IsBrowser()

Azure AI Speech (Cloud)

builder.Services.AddAzureSpeech("your-subscription-key", "your-region");

ElevenLabs TTS (Cloud)

builder.Services.AddElevenLabsTextToSpeech("your-api-key");

Usage

Text-to-Speech

public class MyService(ITextToSpeechService tts)
{
    public async Task SpeakAsync()
    {
        await tts.SpeakAsync("Hello world!", new TextToSpeechOptions
        {
            SpeechRate = 1.2f,
            Pitch = 1.0f,
            Volume = 0.8f
        });
    }
}

Speech-to-Text

public class MyService(ISpeechToTextService stt)
{
    public async Task ListenAsync(CancellationToken ct)
    {
        var access = await stt.RequestAccess();
        if (access != AccessState.Available)
            return;

        // Check if already listening
        if (stt.IsListening)
            return;

        // Simple: wait for silence
        var text = await stt.ListenUntilSilence(cancellationToken: ct);

        // Streaming: get partial results
        await foreach (var result in stt.ContinuousRecognize(cancellationToken: ct))
        {
            Console.WriteLine($"[{(result.IsFinal ? "FINAL" : "partial")}] {result.Text}");
            if (result.IsFinal)
                break;
        }
    }
}

Wake Word Listening

// "Hey Siri" style — listens continuously until wake phrase is detected,
// then captures everything spoken after it until silence
var command = await stt.ListenWithWakeWord("Hey Computer", cancellationToken: ct);
// User says: "Hey Computer, what's the weather" → returns "what's the weather"
// User says: "Hey Computer" [pause] "what's the weather" → returns "what's the weather"

Keyword Listening

// Listens until one of the specified keywords is detected
var answer = await stt.ListenForKeyword(["Yes", "No", "Maybe"], cancellationToken: ct);
// User says: "I think yes" → returns "Yes"

Custom Cloud Provider

Implement ISpeechToTextProvider and/or ITextToSpeechProvider from Shiny.Speech.Cloud:

public class MyCloudSttProvider : ISpeechToTextProvider
{
    public async IAsyncEnumerable<SpeechRecognitionResult> RecognizeAsync(
        Stream audioStream,
        SpeechRecognitionOptions? options = null,
        CancellationToken cancellationToken = default)
    {
        // Read PCM audio from audioStream (16kHz, 16-bit, mono)
        // Yield recognition results...
    }
}

// Register:
builder.Services.AddCloudSpeechToText<MyCloudSttProvider>();

Platform Requirements

Browser (Blazor WebAssembly)

No manifest changes needed — the browser prompts the user for microphone access automatically. Include the JS interop module in your index.html:

<script src="shiny-speech.js"></script>

Note: IAudioSource (raw PCM capture) is not supported in the browser. The Web Speech API handles audio internally. Audio playback (IAudioPlayer) accepts any browser-supported format via a base64 data URL.

iOS/macOS

Add to Info.plist:

<key>NSSpeechRecognitionUsageDescription</key>
<string>Speech recognition description</string>
<key>NSMicrophoneUsageDescription</key>
<string>Microphone description</string>

Android

Add to AndroidManifest.xml:

<uses-permission android:name="android.permission.RECORD_AUDIO" />