Supertone

MCP server for Supertone TTS API. Generate high-quality speech, browse the voice catalog, predict synthesis cost, and create cloned voices — directly from Claude Desktop, Cursor, or any MCP-compatible client.

supertone-inc/supertone-mcp MCP server

Features

Synthesis

• text_to_speech — Convert text (≤300 chars) to audio. Output as files, MCP resources, or both.
• predict_duration — Estimate audio length (and credit cost) without synthesizing.

Voice discovery (preset)

• search_voice — Filter the catalog by language, gender, age, use_case, style, model, name, or description.
• get_voice — Full detail for one voice.
• preview_voice — Sample audio URLs for a voice (filterable by language/style/model).
• get_credit_balance — Check remaining credits.

Custom voice cloning

• clone_voice — Create a cloned voice from a local WAV/MP3 (≤3MB).
• search_custom_voice — List/filter cloned voices.
• edit_custom_voice — Update name and/or description.
• delete_custom_voice — Permanently delete (irreversible).

Supports Korean, English, Japanese, and 20+ other languages. Speed (0.5x–2.0x), pitch shift (-24 to +24 semitones), and emotion styles.

Breaking change in v0.2: list_voices was removed and replaced by search_voice. To reproduce the old behavior, call search_voice with no arguments.

Installation

# Using uvx (recommended)
uvx supertone-mcp

# Using pip
pip install supertone-mcp

Configuration

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "supertone-tts": {
      "command": "uvx",
      "args": ["supertone-mcp"],
      "env": {
        "SUPERTONE_API_KEY": "your-api-key-here"
      }
    }
  }
}

Cursor

Add to your Cursor MCP settings (same JSON shape as above).

Environment Variables

Variable	Required	Default	Description
SUPERTONE_API_KEY	Yes	—	Your Supertone API key
SUPERTONE_MCP_VOICE_ID	No	preset voice (Aiden, multilingual)	Default voice_id for text_to_speech / predict_duration
SUPERTONE_OUTPUT_DIR	No	~/supertone-tts-output/	Directory where audio files are saved
SUPERTONE_MCP_OUTPUT_MODE	No	files	One of files, resources, both. Controls how text_to_speech returns audio (see below)
SUPERTONE_MCP_AUTOPLAY	No	true	Auto-play generated audio on macOS via afplay (enabled by default). Set false/0/no to disable

Output modes (text_to_speech)

Mode	Returns	Use when
files (default)	Plain text with the saved file path + metadata	You want the file on disk
resources	MCP AudioContent + TextContent (no file written)	The client renders audio inline (e.g., Claude.ai chat)
both	File on disk and AudioContent/TextContent	You want both — preview inline, keep the file

Usage Examples

Natural language phrasing — the MCP client routes these to the right tool automatically.

Synthesis

"Read this aloud: Hello, how are you today?" "한국어로 '안녕하세요' 천천히 읽어줘"

Estimate before synthesizing

"이 문단 합성하면 몇 초쯤 나와?" → calls predict_duration

Browse / pick a voice

"Find me a female Korean voice for narration" → calls search_voice(language="ko", gender="female", use_case="narration")

"그 중에 첫 번째 목소리 샘플 들어보자" → calls preview_voice(voice_id=...) and returns sample URLs

Check credits

"내 크레딧 얼마 남았어?" → calls get_credit_balance

Clone a voice from a local file

"이 파일로 클론 만들어줘: ~/recordings/sample.wav, 이름은 MyVoice" → calls clone_voice(name="MyVoice", audio_path="~/recordings/sample.wav")

Manage cloned voices

"내가 만든 커스텀 보이스 목록 보여줘" → search_custom_voice "MyVoice 이름을 NarratorA로 바꿔" → edit_custom_voice "MyVoice 삭제해" → delete_custom_voice (prompts for confirmation; irreversible)

Tool Parameters

text_to_speech

Parameter	Type	Required	Default	Description
text	string	Yes	—	Text to convert (≤300 chars; longer text is auto-chunked)
voice_id	string	No	env or preset	Voice identifier (browse via search_voice)
language	string	No	ko	Language code (ko, en, ja, …)
output_format	string	No	mp3	mp3 or wav
model	string	No	sona_speech_1	TTS model
speed	float	No	1.0	0.5–2.0
pitch_shift	int	No	0	-24 to +24 semitones
style	string	No	—	Emotion style (varies by voice)

predict_duration

Same parameter schema as text_to_speech (no auto-chunking — hard 300-char limit). Returns "Predicted duration: 2.34s (credit usage is proportional to duration).".

search_voice

All parameters optional. With no filters → full catalog. With any filter → first response line is Filters applied: ....

Parameter	Type	Description
language	string	e.g., ko, en, ja
gender	string	e.g., male, female
age	string	e.g., young_adult, child
use_case	string	e.g., narration, advertisement
style	string	e.g., neutral, happy
model	string	e.g., sona_speech_1
name	string	partial match
description	string	partial match

get_voice / preview_voice

Tool	Required	Optional
get_voice	voice_id	—
preview_voice	voice_id	language, style, model (filter samples)

clone_voice

Parameter	Type	Required	Description
name	string	Yes	Display name (non-empty)
audio_path	string	Yes	Local WAV or MP3 path (≤3MB). Supports ~ expansion
description	string	No	Optional note

Custom voice CRUD

Tool	Required	Optional
search_custom_voice	—	name, description (partial match)
edit_custom_voice	voice_id	name, description (at least one required)
delete_custom_voice	voice_id	— (IRREVERSIBLE)

Development

# Clone and install
git clone https://github.com/supertone-inc/supertone-mcp.git
cd supertone-mcp
uv sync

# Run tests
uv run pytest -q

# Run with coverage
uv run pytest --cov=src --cov-report=term-missing

License

MIT