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Usage guide

Setup, environment variables, and Python/JavaScript/Go usage examples.

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HumeAITTS

Hume AI TTS provider: expressive, emotion-aware speech synthesis via Hume’s Octave model. Uses Hume AI’s /v0/tts (Octave) endpoint, which supports both predefined library voices and user-designed or cloned voices. Voices can be specified by name (Hume AI library or custom) or by UUID. The API outputs audio at a fixed 48 kHz sample rate; the sample_rate argument controls the advertised rate, not the wire format.

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Constructor

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api_key
str | None
Hume AI API key. Falls back to the HUMEAI_API_KEY environment variable when None.
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voice
str
default:"Serene Assistant"
Voice name or UUID. Can be a name from Hume’s built-in voice library (e.g. "Serene Assistant", "Male English Actor"), the name of a custom saved voice, or a UUID string (e.g. "9e068547-5ba4-4c8e-8e03-69282a008f04"). Browse available voices at app.hume.ai/voices or via the GET /v0/tts/voices/list endpoint. Defaults to "Serene Assistant".
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speed
float
default:"1.0"
Speaking speed multiplier on a non-linear scale from 0.5 (much slower) to 2.0 (much faster), where 1.0 is normal pace. Changes are not strictly proportional to the multiplier value. Defaults to 1.0.
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sample_rate
int
default:"24000"
Advertised output sample rate in Hz. Note: Hume AI’s API always returns audio at 48 kHz regardless of this value. Defaults to 24000.

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aclose

Release any resources held by the provider.

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emit

Emit an event, invoking all registered handlers with the given arguments. Handlers are called in registration order. Coroutine handlers are scheduled on the running event loop. If the emitter is closed, the call is a no-op.
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event
T
required
The event to emit.

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interrupt

Interrupt and cancel the current synthesis for the active session, if any.

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off

Remove a previously registered handler for an event. If the handler is not registered for the event, the call is a no-op.
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event
T
required
The event the handler was registered for.
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callback
Callable[..., Any]
required
The handler to remove.

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on

Register a handler for an event. Can be used directly by passing a callback, or as a decorator when callback is omitted.
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event
T
required
The event to listen for.
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callback
Callable[..., Any] | None
The handler to invoke when the event is emitted. If None, a decorator is returned that registers the decorated function.
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returns
Callable[..., Any]
The registered callback when callback is provided, otherwise a decorator that registers and returns the function it wraps.

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on_first_audio_byte

Register the callback invoked when the first audio byte is produced.
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callback
'Callable[[int, int], Awaitable[None] | None]'
required
A callable, optionally async, invoked with synthesis timing information when the first audio byte is emitted.

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synthesize

Synthesize the given text into speech. Implementations should convert the text to audio. The default behavior forwards the text to the active session for playback when one is present.
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text
Any
required
The text to synthesize; coerced to a string if needed.