> ## Documentation Index
> Fetch the complete documentation index at: https://typecast.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

> API changes and updates for Typecast Text-to-Speech API

<Update label="April 2026" tags={["API","SDK","Timestamps"]} description="Timestamp TTS & SDK v0.3/0.4 Release">
  ### New Endpoint: POST /v1/text-to-speech/with-timestamps

  Returns the synthesized audio together with word- and character-level alignment data in a single response — ideal for auto-subtitling, karaoke highlights, and lip-sync animations.

  ```text theme={null}
  POST /v1/text-to-speech/with-timestamps
  ```

  **Request Schema:**

  ```json theme={null}
  {
    "voice_id": "tc_60e5426de8b95f1d3000d7b5",
    "text": "Hello.",
    "model": "ssfm-v30"
  }
  ```

  **Response Schema (summary):**

  ```json theme={null}
  {
    "audio": "<base64>",
    "audio_format": "wav",
    "audio_duration": 0.52,
    "words": [
      { "text": "Hello.", "start": 0.0, "end": 0.52 }
    ],
    "characters": [
      { "text": "H", "start": 0.0, "end": 0.08 },
      { "text": "e", "start": 0.08, "end": 0.18 },
      { "text": "l", "start": 0.18, "end": 0.28 },
      { "text": "l", "start": 0.28, "end": 0.36 },
      { "text": "o", "start": 0.36, "end": 0.48 },
      { "text": ".", "start": 0.48, "end": 0.52 }
    ]
  }
  ```

  **`granularity` parameter:**

  `granularity` is optional. If omitted, the API returns both word- and character-level alignment in a single response.

  | Value  | Description                                                                 |
  | :----- | :-------------------------------------------------------------------------- |
  | `word` | Per-word alignment. Recommended for all languages with whitespace.          |
  | `char` | Per-character alignment. Required for Japanese (`jpn`) and Chinese (`zho`). |

  **Captioning rules:** Captions are split on sentence terminators (`. ? ! 。 ？ ！`) with a 7 s / 42-character hard cap per cue (BBC/Netflix subtitle guidelines).

  ### SDK Updates — Timestamp TTS added to all 11 SDKs

  | SDK        | Version | Method                                      |
  | :--------- | :------ | :------------------------------------------ |
  | Python     | 0.3.0   | `text_to_speech_with_timestamps()`          |
  | JavaScript | 0.4.0   | `textToSpeechWithTimestamps()`              |
  | Go         | v0.3.0  | `TextToSpeechWithTimestamps()`              |
  | Rust       | 0.3.0   | `text_to_speech_with_timestamps()`          |
  | Swift      | v0.3.0  | `textToSpeechWithTimestamps()`              |
  | C#         | 0.3.0   | `TextToSpeechWithTimestampsAsync()`         |
  | Java       | 1.2.0   | `textToSpeechWithTimestamps()`              |
  | Kotlin     | 1.2.0   | `textToSpeechWithTimestamps()`              |
  | C          | 1.2.0   | `typecast_text_to_speech_with_timestamps()` |
  | Zig        | v0.2.0  | `textToSpeechWithTimestamps()`              |
  | PHP        | v0.1.0  | `textToSpeechWithTimestamps()`              |

  All SDK response objects include `toSrt()` / `toVtt()` subtitle export helpers and a `saveAudio(path)` / `audio_bytes()` convenience method.
</Update>

<Update label="April 2026" tags={["API","SDK","Streaming"]} description="Streaming TTS & Subscription API">
  ### 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.

  ```text theme={null}
  POST /v1/text-to-speech/stream
  ```

  **Key Differences from `/v1/text-to-speech`:**

  | Feature         | Standard                | Streaming                                           |
  | :-------------- | :---------------------- | :-------------------------------------------------- |
  | Response        | Complete audio file     | Chunked audio stream                                |
  | Latency         | Wait for full synthesis | First chunk in \~200ms                              |
  | `volume`        | Supported               | Not supported                                       |
  | `target_lufs`   | Supported               | Supported                                           |
  | Output settings | `Output`                | `OutputStream` (pitch, tempo, format, target\_lufs) |

  **Request Schema:**

  ```json theme={null}
  {
    "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`).

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

  Retrieve the authenticated user's plan tier, credit usage, and concurrency limits.

  ```text theme={null}
  GET /v1/users/me/subscription
  ```

  **Response Schema:**

  ```json theme={null}
  {
    "plan": "lite",
    "credits": {
      "plan_credits": 200000,
      "used_credits": 157300
    },
    "limits": {
      "concurrency_limit": 5
    }
  }
  ```

  ### SDK Updates

  All 9 official SDKs have been updated with streaming and subscription support:

  | SDK        | Version | Streaming Method                               |
  | :--------- | :------ | :--------------------------------------------- |
  | Python     | 0.2.0   | `text_to_speech_stream()` (sync + async)       |
  | JavaScript | 0.3.0   | `textToSpeechStream()` → `ReadableStream`      |
  | Go         | v0.2.0  | `TextToSpeechStream()` → `io.ReadCloser`       |
  | Rust       | 0.2.0   | `text_to_speech_stream()` → `Stream<Bytes>`    |
  | Swift      | v0.2.0  | `textToSpeechStream()` → `AsyncThrowingStream` |
  | C#         | 0.2.0   | `TextToSpeechStreamAsync()` → `Stream`         |
  | Java       | 1.1.0   | `textToSpeechStream()` → `InputStream`         |
  | Kotlin     | 1.1.0   | `textToSpeechStream()` → `InputStream`         |
  | C          | 1.1.0   | `typecast_text_to_speech_stream()` (callback)  |
</Update>

<Update label="January 2026" tags={["Model","API","Voices"]} description="ssfm-v30 Model & v2 API">
  ### 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, Vietnamese

  **Request Schema Changes:**

  ```json theme={null}
  // 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
    }
  }
  ```

  ### New Endpoint: GET /v2/voices

  Added enhanced voice listing endpoint with model-grouped emotions and additional metadata.

  ```text theme={null}
  GET /v2/voices
  ```

  **Query Parameters:**

  | Parameter   | Type   | Description                                                                     |
  | :---------- | :----- | :------------------------------------------------------------------------------ |
  | `model`     | string | Filter by model (`ssfm-v21`, `ssfm-v30`)                                        |
  | `gender`    | string | Filter by gender (`male`, `female`)                                             |
  | `age`       | string | Filter by age group (`child`, `teenager`, `young_adult`, `middle_age`, `elder`) |
  | `use_cases` | string | Filter by use case (`Audiobook`, `Game`, `E-learning`, etc.)                    |

  **Response Schema:**

  ```json theme={null}
  [
    {
      "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"]
    }
  ]
  ```

  ### Deprecated: Voice Management Endpoints

  The following endpoints have been deprecated and removed:

  | Endpoint                    | Status  |
  | :-------------------------- | :------ |
  | `POST /v1/voices`           | Removed |
  | `GET /v1/voices/{voice_id}` | Removed |

  Use `GET /v2/voices` for listing voices with enhanced metadata.
</Update>

<Update label="July 2025" tags={["Model","API"]} description="Initial API Release">
  ### Initial Release: ssfm-v21

  Launched the Typecast Text-to-Speech API with the `ssfm-v21` model.

  **Endpoints:**

  | Method | Endpoint             | Description               |
  | :----- | :------------------- | :------------------------ |
  | POST   | `/v1/text-to-speech` | Generate speech from text |
  | GET    | `/v1/voices`         | List 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, Ukrainian

  **Request Schema:**

  ```json theme={null}
  {
    "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"
    }
  }
  ```
</Update>