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The official C# library for the Typecast API. Convert text to lifelike speech using AI-powered voices. Supports .NET Standard 2.0+, .NET 6+, Unity (via NuGetForUnity), and Blazor applications. Full async/await support with synchronous alternatives.

Package

Typecast C# SDK on NuGet

Source Code

Typecast C# SDK Source Code

Prerequisites

Installing .NET SDK

Using Homebrew (Recommended)
Using Official InstallerDownload from dotnet.microsoft.com/download and run the .pkg installer.

Installation

Latest registered version: 0.3.7 on NuGet. You can check with dotnet list package. Update with dotnet add package typecast-csharp to get the latest version.

Quick Start

Features

The Typecast C# SDK provides powerful features for text-to-speech conversion:
  • Multiple Voice Models: Support for ssfm-v30 (latest) and ssfm-v21 AI voice models
  • Multi-language Support: 37 languages including English, Korean, Spanish, Japanese, Chinese, and more
  • Emotion Control: Preset emotions (normal, happy, sad, angry, whisper, toneup, tonedown) or smart context-aware inference
  • Audio Customization: Control loudness (LUFS -70 to 0), pitch (-12 to +12 semitones), tempo (0.5x to 2.0x), and format (WAV/MP3)
  • Voice Discovery: V2 Voices API with filtering by model, gender, age, and use cases
  • Instant Voice Cloning: Upload a WAV/MP3 sample and create a custom voice ID
  • Timestamp TTS: Word- and character-level alignment data for subtitles, karaoke, and lip-sync
  • Unity Support: Compatible with Unity via NuGetForUnity
  • Blazor Support: Works with Blazor Server and WebAssembly
  • Async/Sync APIs: Full async/await support with synchronous alternatives
  • Streaming: Real-time chunked audio delivery for low-latency playback

Voice Recommendations

Use RecommendVoicesAsync when you know the desired style but not the exact voice_id.
Recommendation results contain only VoiceId, VoiceName, and Score. Use GetVoiceV2Async or GetVoicesV2Async when you need detailed metadata such as supported models, emotions, gender, age, or use cases.

Configuration

Set your API key via environment variable or constructor:
When requests go through your own proxy, set ApiHost to the proxy endpoint and omit ApiKey. The SDK will not send the X-API-KEY header for empty or missing keys. Requests to the default Typecast host still require an API key.
Proxy without API key

Advanced Usage

Emotion Control (ssfm-v30)

ssfm-v30 offers two emotion control modes: Preset and Smart.
Let the AI infer emotion from context:

Audio Customization

Control loudness, pitch, tempo, and output format:

Generate audio to a file

Use GenerateToFileAsync when you want the SDK to synthesize speech and write the audio bytes directly to a local file. The model defaults to SsfmV30, and .mp3 / .wav extensions infer the output format when Output.AudioFormat is not set. Browse available voice IDs on the Voices page.

Text pauses

Use text pause markup when you only need silent gaps inside one composed text segment. Put <|5s|>, <|1s|>, <|0.3s|>, or <|0.34413s|> directly in the text. The value is interpreted as seconds and must end with s. This keeps the pause expression visible in plain text without adding separate pause calls.

Multi-speaker composition

Use the composer chaining API when one output file needs different voices or per-segment options such as pitch, tempo, prompt, or seed. The composer generates each segment as WAV, trims leading/trailing silent PCM samples, and concatenates the result. If you need MP3, generate WAV first and convert it in your app or server pipeline.

Voice Discovery (V2 API)

List and filter available voices with enhanced metadata:

Multilingual Content

The SDK supports 37 languages with automatic language detection:

Unity Integration

Basic Unity Example

Blazor Integration

Blazor Server Example

Blazor Component

Streaming

Stream audio chunks in real-time for low-latency playback:
WAV streaming format: 32000 Hz, 16-bit, mono PCM. The first chunk includes a 44-byte WAV header (size = 0xFFFFFFFF); subsequent chunks are raw PCM only. For MP3: 320 kbps, 44100 Hz, each chunk is independently decodable.

Timestamp TTS

TextToSpeechWithTimestampsAsync() wraps POST /v1/text-to-speech/with-timestamps and returns the audio together with per-word and per-character alignment data — useful for karaoke highlights, subtitle generation, and lip-sync applications.

Basic Usage

Granularity

Set Granularity = Granularity.Word (default) or Granularity = Granularity.Char to control the alignment unit.

Subtitle Export

Japanese / Chinese: Word-level segmentation is not meaningful for languages without whitespace delimiters (jpn, zho). Use Granularity.Char for these languages to get character-level alignment.

Instant Voice Cloning

Clone a custom voice from a short audio sample, then pass the returned uc_ voice ID directly to TTS.
Voice cloning audio must be 25 MB or smaller, the audio duration must be 5-150 seconds, and the custom voice name must be 1-30 characters.

Supported Languages

The SDK supports 37 languages with automatic language detection:
If not specified, the language will be automatically detected from the input text.

Error Handling

The SDK provides specific exception types for handling API errors:

Synchronous API

For scenarios where async is not preferred, use synchronous methods:

Type Reference