kugelaudio

KugelAudio Python SDK

Official Python SDK for the KugelAudio Text-to-Speech API.

Installation

pip install kugelaudio

Or with uv:

uv add kugelaudio

Quick Start

from kugelaudio import KugelAudio

# Initialize the client - just needs an API key!
client = KugelAudio(api_key="your_api_key")

# Generate speech
audio = client.tts.generate(
    text="Hello, world!",
    model_id="kugel-1-turbo",
)

# Save to file
audio.save("output.wav")

Client Configuration

from kugelaudio import KugelAudio

# Simple setup - single URL handles everything
client = KugelAudio(api_key="your_api_key")

# Or with custom options
client = KugelAudio(
    api_key="your_api_key",           # Required: Your API key
    api_url="https://api.kugelaudio.com",  # Optional: API base URL (default)
    timeout=60.0,                      # Optional: Request timeout in seconds
)

Region Selection

By default, KugelAudio uses the canonical geo-routed API endpoint. You can select the direct EU endpoint when you need to pin traffic to Europe.

Region hint	Endpoint
default	api.kugelaudio.com (geo-routed)
eu	api.eu.kugelaudio.com

Option 1 — API key prefix (simplest, works with env vars):

client = KugelAudio(api_key="eu-ka_your_api_key")       # → EU
client = KugelAudio(api_key="ka_your_api_key")          # → canonical geo-routed API

Option 2 — region parameter:

client = KugelAudio(api_key="ka_your_api_key", region="eu")

The prefix is always stripped before authentication. Priority: api_url > region > key prefix > default.

Single URL Architecture

The SDK uses a single URL for both REST API and WebSocket streaming. The TTS server provides both REST endpoints (/v1/models, /v1/voices) and WebSocket (/ws/tts) - no proxy needed, minimal latency.

Local Development

For local development, point directly to your TTS server:

client = KugelAudio(
    api_key="your_api_key",
    api_url="http://localhost:8000",   # TTS server handles everything
)

Or if you have separate backend and TTS servers:

client = KugelAudio(
    api_key="your_api_key",
    api_url="http://localhost:8001",   # Backend for REST API
    tts_url="http://localhost:8000",   # TTS server for WebSocket streaming
)

Available Models

Model ID	Name	Description
kugel-1-turbo	Kugel 1 Turbo	Fast, low-latency model for real-time applications
kugel-1	Kugel 1	Premium quality model for pre-recorded content

List Available Models

models = client.models.list()

for model in models:
    print(f"{model.id}: {model.name}")
    print(f"  Description: {model.description}")
    print(f"  Max Input: {model.max_input_length} characters")
    print(f"  Sample Rate: {model.sample_rate} Hz")

Voices

List Available Voices

# List all available voices (paginated)
result = client.voices.list()

for voice in result.voices:
    print(f"{voice.id}: {voice.name}")
    print(f"  Category: {voice.category}")
    print(f"  Languages: {', '.join(voice.supported_languages)}")
print(f"Showing {len(result.voices)} of {result.total} voices")

# Filter by language
result = client.voices.list(language="de")

# Get only public voices
result = client.voices.list(include_public=True)

# Paginate through results
page1 = client.voices.list(limit=10, offset=0)
page2 = client.voices.list(limit=10, offset=10)

Get a Specific Voice

voice = client.voices.get(voice_id=123)
print(f"Voice: {voice.name}")
print(f"Sample text: {voice.sample_text}")

Text-to-Speech Generation

Basic Generation (Non-Streaming)

Generate complete audio and receive it all at once:

audio = client.tts.generate(
    text="Hello, this is a test of the KugelAudio text-to-speech system.",
    model_id="kugel-1-turbo",  # 'kugel-1-turbo' (fast) or 'kugel-1' (quality)
    voice_id=123,              # Optional: specific voice ID
    cfg_scale=2.0,             # Guidance scale (1.0-5.0)
    max_new_tokens=2048,       # Maximum tokens to generate
    sample_rate=24000,         # Output sample rate
    normalize=True,            # Enable text normalization (see below)
    language="en",             # Language for normalization
)

# Audio properties
print(f"Duration: {audio.duration_seconds:.2f}s")
print(f"Samples: {audio.samples}")
print(f"Sample rate: {audio.sample_rate} Hz")
print(f"Generation time: {audio.generation_ms:.0f}ms")
print(f"RTF: {audio.rtf:.2f}")  # Real-time factor

# Save to WAV file
audio.save("output.wav")

# Get raw PCM bytes
pcm_data = audio.audio

# Get WAV bytes (with header)
wav_bytes = audio.to_wav_bytes()

Streaming Audio Output

Receive audio chunks as they are generated for lower latency:

# Synchronous streaming
for item in client.tts.stream(
    text="Hello, this is streaming audio.",
    model_id="kugel-1-turbo",
):
    if hasattr(item, 'audio'):  # AudioChunk
        # Process audio chunk immediately
        print(f"Chunk {item.index}: {len(item.audio)} bytes, {item.samples} samples")
        # play_audio(item.audio)
    elif isinstance(item, dict) and item.get('final'):
        # Final stats
        print(f"Total duration: {item.get('dur_ms', 0):.0f}ms")
        print(f"Generation time: {item.get('gen_ms', 0):.0f}ms")

Async Streaming

For async applications:

import asyncio

async def generate_speech():
    async for item in client.tts.stream_async(
        text="Async streaming example.",
        model_id="kugel-1-turbo",
    ):
        if hasattr(item, 'audio'):
            # Process chunk
            pass

asyncio.run(generate_speech())

Async Generation

import asyncio

async def main():
    audio = await client.tts.generate_async(
        text="Async generation example.",
        model_id="kugel-1-turbo",
    )
    audio.save("async_output.wav")

asyncio.run(main())

Text Normalization

Text normalization converts numbers, dates, times, and other non-verbal text into spoken words. For example:

• "I have 3 apples" → "I have three apples"
• "The meeting is at 2:30 PM" → "The meeting is at two thirty PM"
• "€50.99" → "fifty euros and ninety-nine cents"

Usage

# With explicit language (recommended - fastest)
audio = client.tts.generate(
    text="I bought 3 items for €50.99 on 01/15/2024.",
    normalize=True,
    language="en",  # Specify language for best performance
)

# With auto-detection (adds ~150ms latency)
audio = client.tts.generate(
    text="Ich habe 3 Artikel für 50,99€ gekauft.",
    normalize=True,
    # language not specified - will auto-detect
)

Supported Languages

Code	Language	Code	Language
de	German	nl	Dutch
en	English	pl	Polish
fr	French	sv	Swedish
es	Spanish	da	Danish
it	Italian	no	Norwegian
pt	Portuguese	fi	Finnish
cs	Czech	hu	Hungarian
ro	Romanian	el	Greek
uk	Ukrainian	bg	Bulgarian
tr	Turkish	vi	Vietnamese
ar	Arabic	hi	Hindi
zh	Chinese	ja	Japanese
ko	Korean

Performance Warning

⚠️ Latency Warning: Using normalize=True without specifying language adds approximately 150ms latency for language auto-detection. For best performance in latency-sensitive applications, always specify the language parameter.

LLM Integration: Streaming Text Input

For real-time TTS when streaming text from an LLM (GPT-4, Claude, etc.), use a StreamingSession. Forward LLM tokens directly to session.send() without flush=True — the server accumulates them and starts generation at natural sentence boundaries. Flush exactly once at the end of the assistant turn.

⚠️ Do not call session.send(text, flush=True) between sentences or words. Each explicit flush is a separate TTS request that pays the full model time-to-first-audio (TTFA) again and produces an audible gap. See Streaming best practices for the full rationale and ElevenLabs migration notes.

Async Streaming Session

import asyncio

async def speak_turn(llm_token_stream):
    async with client.tts.streaming_session(
        voice_id=123,
        model_id="kugel-1-turbo",
        language="en",
    ) as session:
        # Forward every LLM token directly. No flush=True per token —
        # the server's text buffer chunks at sentence boundaries.
        async for token in llm_token_stream:
            async for chunk in session.send(token):
                play_audio(chunk.audio)

        # Single flush at turn end emits any trailing text.
        async for chunk in session.flush():
            play_audio(chunk.audio)

asyncio.run(speak_turn(my_llm_stream()))

Synchronous Streaming Session

with client.tts.streaming_session_sync(
    voice_id=123,
    model_id="kugel-1-turbo",
    language="en",
) as session:
    for token in llm_token_stream:
        for chunk in session.send(token):  # no flush per token
            play_audio(chunk.audio)

    for chunk in session.flush():  # single flush at turn end
        play_audio(chunk.audio)

Error Handling

from kugelaudio import KugelAudio
from kugelaudio.exceptions import (
    KugelAudioError,
    AuthenticationError,
    RateLimitError,
    InsufficientCreditsError,
    ValidationError,
    NotFoundError,
)

try:
    audio = client.tts.generate(text="Hello!")
except AuthenticationError:
    print("Invalid API key")
except RateLimitError:
    print("Rate limit exceeded, please wait")
except InsufficientCreditsError:
    print("Not enough credits, please top up")
except ValidationError as e:
    print(f"Invalid request: {e}")
except NotFoundError as e:
    print(f"Resource not found (e.g. unknown voice_id): {e}")
except KugelAudioError as e:
    print(f"API error: {e}")

Data Models

AudioChunk

Represents a single audio chunk from streaming:

class AudioChunk:
    audio: bytes          # Raw PCM16 audio data
    encoding: str         # 'pcm_s16le'
    index: int           # Chunk index (0-based)
    sample_rate: int     # Sample rate (24000)
    samples: int         # Number of samples in chunk
    
    @property
    def duration_seconds(self) -> float:
        """Duration of this chunk in seconds."""

AudioResponse

Complete audio response from generation:

class AudioResponse:
    audio: bytes              # Complete PCM16 audio
    sample_rate: int          # Sample rate (24000)
    samples: int              # Total samples
    duration_ms: float        # Duration in milliseconds
    generation_ms: float      # Generation time in milliseconds
    rtf: float               # Real-time factor
    
    @property
    def duration_seconds(self) -> float:
        """Duration in seconds."""
    
    def save(self, path: str) -> None:
        """Save as WAV file."""
    
    def to_wav_bytes(self) -> bytes:
        """Get WAV file as bytes."""

Model

TTS model information:

class Model:
    id: str                   # 'kugel-1-turbo' or 'kugel-1'
    name: str                 # Human-readable name
    description: str          # Model description
    max_input_length: int     # Maximum input characters
    sample_rate: int          # Output sample rate

Voice

Voice information:

class Voice:
    id: int                          # Voice ID
    name: str                        # Voice name
    description: Optional[str]       # Description
    category: Optional[VoiceCategory]  # 'premade', 'cloned', 'generated'
    sex: Optional[VoiceSex]          # 'male', 'female', 'neutral'
    age: Optional[VoiceAge]          # 'young', 'middle_aged', 'old'
    supported_languages: List[str]   # ['en', 'de', ...]
    sample_text: Optional[str]       # Sample text for preview
    avatar_url: Optional[str]        # Avatar image URL
    sample_url: Optional[str]        # Sample audio URL
    is_public: bool                  # Whether voice is public
    verified: bool                   # Whether voice is verified

Complete Example

from kugelaudio import KugelAudio

# Initialize client
client = KugelAudio(api_key="your_api_key")

# List available models
print("Available Models:")
for model in client.models.list():
    print(f"  - {model.id}: {model.name}")

# List available voices
print("\nAvailable Voices:")
for voice in client.voices.list(limit=5).voices:
    print(f"  - {voice.id}: {voice.name}")

# Generate audio
print("\nGenerating audio...")
audio = client.tts.generate(
    text="Welcome to KugelAudio. This is an example of high-quality text-to-speech synthesis.",
    model_id="kugel-1-turbo",
)

print(f"Generated {audio.duration_seconds:.2f}s of audio in {audio.generation_ms:.0f}ms")
print(f"Real-time factor: {audio.rtf:.2f}x")

# Save to file
audio.save("example.wav")
print("Saved to example.wav")

# Close client
client.close()

License

MIT