ElevenLabs

ElevenLabs is a text-to-speech plugin. It synthesizes the LLM’s reply into the agent’s voice, streaming low-latency audio over a WebSocket. It occupies the pipeline’s tts slot.

Setup

Set your ElevenLabs API key in the worker environment. Generate a key from the ElevenLabs dashboard:

export ELEVENLABS_API_KEY=<key>

Usage

Import the plugin and pass it to the pipeline’s tts slot.

from zrt.plugins import ElevenLabsTTS

tts = ElevenLabsTTS(
    model="eleven_turbo_v2",
    voice="21m00Tcm4TlvDq8ikWAM",
)

# Pipeline(tts=tts, ...)

The Python SDK defaults to model eleven_turbo_v2 and voice 21m00Tcm4TlvDq8ikWAM (the “Rachel” voice). Pass model and voice explicitly for consistent results across SDKs.

Voice settings

Fine-tune the voice with the stability, similarity_boost, style, and use_speaker_boost constructor parameters (Python). Each field is also exposed directly in the JavaScript and Go SDKs (stability, similarityBoost/SimilarityBoost, etc.).

Python

from zrt.plugins import ElevenLabsTTS

tts = ElevenLabsTTS(
    stability=0.5,
    similarity_boost=0.75,
    style=0.0,
    use_speaker_boost=True,
)

Parameters

Constructor parameters for the Python SDK (ElevenLabsTTS). The JavaScript and Go SDKs expose equivalent options where supported, in their idiomatic form (camelCase / TTSOptions struct).

Parameter	Type	Default	Description
`api_key`	`str`	`None`	ElevenLabs API key. Falls back to the `ELEVENLABS_API_KEY` environment variable when unset.
`voice`	`str`	`"21m00Tcm4TlvDq8ikWAM"`	Voice ID (the “Rachel” voice).
`model`	`str`	`"eleven_turbo_v2"`	ElevenLabs synthesis model (`eleven_v3`, `eleven_multilingual_v2`, `eleven_flash_v2_5`, `eleven_flash_v2`).
`sample_rate`	`int`	`24000`	Output sample rate in Hz.
`stability`	`float`	`0.5`	Voice consistency, 0.0-1.0 (higher is steadier).
`similarity_boost`	`float`	`0.75`	Adherence to the original voice, 0.0-1.0.
`style`	`float`	`0.0`	Style exaggeration, 0.0-1.0 (0 disables, adds latency).
`use_speaker_boost`	`bool`	`True`	Boost similarity to the speaker.
`apply_text_normalization`	`str`	`None`	Text normalization mode: `"auto"`, `"on"`, or `"off"`.
`enable_word_timestamps`	`bool`	`False`	Return per-word timing metadata.
`speed`	`float`	`None`	Speaking-rate multiplier (~0.7-1.2). Provider default when unset.
`language`	`str`	`None`	ISO-639-1 language hint for supported models.
`enable_ssml_parsing`	`bool`	`None`	Interpret SSML tags in the input text.
`stream`	`bool`	`True`	Stream audio as it is synthesized.

Import paths

SDK	Import	Constructor
Python	`from zrt.plugins import ElevenLabsTTS`	`ElevenLabsTTS(...)`
JavaScript	`from '@zrt/js-sdk/plugins/elevenlabs'`	`ElevenLabsTTS({ ... })`
Go	`.../zrt-golang-sdk/plugins/elevenlabs`	`elevenlabs.NewTTS(elevenlabs.TTSOptions{...})`

The synthesized audio is streamed back to the caller as the final stage of the pipeline.

Plugins

Inference Gateway

Speech-to-text

LLM

Text-to-speech

Realtime models

Avatars

Turn detection

Voice activity detection

Noise cancellation

Setup

Usage

Voice settings

Parameters

Import paths

​Setup

​Usage

​Voice settings

​Parameters

​Import paths

Setup

Usage

Voice settings

Parameters

Import paths