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April 2026
APISDKStreaming
Streaming TTS & Subscription API

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New Endpoint: POST /v1/text-to-speech/stream

Added a low-latency streaming endpoint that delivers audio chunks as they are generated, enabling real-time playback without waiting for full synthesis.
POST /v1/text-to-speech/stream
Key Differences from /v1/text-to-speech:
FeatureStandardStreaming
ResponseComplete audio fileChunked audio stream
LatencyWait for full synthesisFirst chunk in ~200ms
volume / target_lufsSupportedNot supported
Output settingsOutputOutputStream (pitch, tempo, format only)
Request Schema:
{
  "voice_id": "tc_xxxxx",
  "text": "Thanks for reaching out. Your reservation has been confirmed for Friday at 7 PM.",
  "model": "ssfm-v30",
  "language": "eng",
  "output": {
    "audio_pitch": 0,
    "audio_tempo": 1.0,
    "audio_format": "wav"
  }
}
Response: Chunked binary stream (audio/wav or audio/mpeg).

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New Endpoint: GET /v1/users/me/subscription

Retrieve the authenticated user’s plan tier, credit usage, and concurrency limits.
GET /v1/users/me/subscription
Response Schema:
{
  "plan": "lite",
  "credits": {
    "plan_credits": 200000,
    "used_credits": 157300
  },
  "limits": {
    "concurrency_limit": 5
  }
}

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SDK Updates

All 9 official SDKs have been updated with streaming and subscription support:
SDKVersionStreaming Method
Python0.2.0text_to_speech_stream() (sync + async)
JavaScript0.3.0textToSpeechStream() → ReadableStream
Gov0.2.0TextToSpeechStream() → io.ReadCloser
Rust0.2.0text_to_speech_stream() → Stream<Bytes>
Swiftv0.2.0textToSpeechStream() → AsyncThrowingStream
C#0.2.0TextToSpeechStreamAsync() → Stream
Java1.1.0textToSpeechStream() → InputStream
Kotlin1.1.0textToSpeechStream() → InputStream
C1.1.0typecast_text_to_speech_stream() (callback)
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January 2026
ModelAPIVoices
ssfm-v30 Model & v2 API

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New Model: ssfm-v30

Added support for the new ssfm-v30 model with improved speech quality and expanded capabilities.New Features:
  • Smart Emotion - Context-aware emotion inference using SmartPrompt
  • 7 Emotion Presets - Added whisper, toneup, tonedown presets
  • Universal Emotion Support - All emotions available across all voices
  • 37 Languages - Added 10 new languages
New Languages: Bengali, Cantonese, Hindi, Hungarian, Min Nan, Norwegian, Punjabi, Thai, Turkish, VietnameseRequest Schema Changes:
// ssfm-v30 with SmartPrompt (context-aware emotion)
{
  "model": "ssfm-v30",
  "prompt": {
    "emotion_type": "smart",
    "previous_text": "I feel like I'm walking on air and I just want to scream with joy!",
    "next_text": "I am literally bursting with happiness and I never want this feeling to end!"
  }
}

// ssfm-v30 with PresetPrompt (manual emotion selection)
{
  "model": "ssfm-v30",
  "prompt": {
    "emotion_type": "preset",
    "emotion_preset": "happy",
    "emotion_intensity": 1.0
  }
}

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New Endpoint: GET /v2/voices

Added enhanced voice listing endpoint with model-grouped emotions and additional metadata.
GET /v2/voices
Query Parameters:
ParameterTypeDescription
modelstringFilter by model (ssfm-v21, ssfm-v30)
genderstringFilter by gender (male, female)
agestringFilter by age group (child, teenager, young_adult, middle_age, elder)
use_casesstringFilter by use case (Audiobook, Game, E-learning, etc.)
Response Schema:
[
  {
    "voice_id": "tc_xxxxx",
    "voice_name": "Voice Name",
    "models": [
      {
        "version": "ssfm-v30",
        "emotions": ["normal", "happy", "sad", "angry", "whisper", "toneup", "tonedown"]
      },
      {
        "version": "ssfm-v21",
        "emotions": ["normal", "happy", "sad"]
      }
    ],
    "gender": "female",
    "age": "young_adult",
    "use_cases": ["Audiobook", "E-learning"]
  }
]

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Deprecated: Voice Management Endpoints

The following endpoints have been deprecated and removed:
EndpointStatus
POST /v1/voicesRemoved
GET /v1/voices/{voice_id}Removed
Use GET /v2/voices for listing voices with enhanced metadata.
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April 2025
ModelAPI
Initial API Release

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Initial Release: ssfm-v21

Launched the Typecast Text-to-Speech API with the ssfm-v21 model.Endpoints:
MethodEndpointDescription
POST/v1/text-to-speechGenerate speech from text
GET/v1/voicesList available voices
Features:
  • Low latency speech synthesis
  • 4 Emotion presets: normal, happy, sad, angry
  • Emotion availability varies by voice
  • 27 languages supported
Supported Languages: English, Korean, Arabic, Bulgarian, Chinese, Croatian, Czech, Danish, Dutch, Finnish, French, German, Greek, Indonesian, Italian, Japanese, Malay, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Tagalog, Tamil, UkrainianRequest Schema:
{
  "voice_id": "tc_xxxxx",
  "text": "Everything is so incredibly perfect that I feel like I'm dreaming.",
  "model": "ssfm-v21",
  "language": "eng",
  "prompt": {
    "emotion_preset": "normal",
    "emotion_intensity": 1.0
  },
  "output": {
    "volume": 100,
    "audio_pitch": 0,
    "audio_tempo": 1.0,
    "audio_format": "wav"
  }
}