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

# Azure

> Python API reference for the azure text-to-speech plugin.

<Card title="Usage guide" icon="book" href="/plugins/tts/azure" horizontal>
  Setup, environment variables, and Python/JavaScript/Go usage examples.
</Card>

## AzureTTS

Azure Cognitive Services Neural Text-to-Speech provider.

Synthesizes speech using Azure Neural TTS voices, supporting hundreds
of voices across 60+ languages at up to 48 kHz.  Standard Neural voices
are available at 24 kHz and 48 kHz; streaming output is returned as
PCM audio.

### Constructor

```python theme={null}
AzureTTS(*, speech_key: 'Optional[str]' = None, speech_region: 'Optional[str]' = None, voice: 'str' = 'en-US-JennyNeural', sample_rate: 'int' = 24000, **kwargs: 'Any') -> 'None'
```

<ParamField path="speech_key" type="Optional[str]">
  Azure Speech resource subscription key.  Falls back to the `AZURE_SPEECH_KEY` environment variable when omitted.
</ParamField>

<ParamField path="speech_region" type="Optional[str]">
  Azure region identifier for the Speech resource (e.g. `"eastus"`, `"westeurope"`, `"southeastasia"`). Falls back to the `AZURE_REGION` environment variable, then `"eastus"` as a hard default.  Must match the region where your Azure Speech resource was created. Keys are region-scoped.
</ParamField>

<ParamField path="voice" type="str" default="en-US-JennyNeural">
  Azure Neural TTS voice name in `"&lt;locale>-&lt;Name>Neural"` format. Defaults to `"en-US-JennyNeural"` (female, US English). Common options include `"en-US-AriaNeural"`, `"en-US-GuyNeural"`, `"en-GB-SoniaNeural"`, `"fr-FR-DeniseNeural"`, `"de-DE-KatjaNeural"`, `"ja-JP-NanamiNeural"`.  See the Azure language-support docs for the full voice catalog.
</ParamField>

<ParamField path="sample_rate" type="int" default="24000">
  PCM output sample rate in Hz.  Azure Neural TTS natively supports `24000` (standard) and `48000` (high-fidelity).  Defaults to `24000`.
</ParamField>

### aclose

```python theme={null}
def aclose(self) -> 'None'
```

Release any resources held by the provider.

### emit

```python theme={null}
def emit(self, event: 'T', *args: 'Any') -> 'None'
```

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.

<ParamField path="event" type="T" required>
  The event to emit.
</ParamField>

### interrupt

```python theme={null}
def interrupt(self) -> 'None'
```

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

### off

```python theme={null}
def off(self, event: 'T', callback: 'Callable[..., Any]') -> 'None'
```

Remove a previously registered handler for an event.

If the handler is not registered for the event, the call is a no-op.

<ParamField path="event" type="T" required>
  The event the handler was registered for.
</ParamField>

<ParamField path="callback" type="Callable[..., Any]" required>
  The handler to remove.
</ParamField>

### on

```python theme={null}
def on(self, event: 'T', callback: 'Callable[..., Any] | None' = None) -> 'Callable[..., Any]'
```

Register a handler for an event.

Can be used directly by passing a callback, or as a decorator when
`callback` is omitted.

<ParamField path="event" type="T" required>
  The event to listen for.
</ParamField>

<ParamField path="callback" type="Callable[..., Any] | None">
  The handler to invoke when the event is emitted. If `None`, a decorator is returned that registers the decorated function.
</ParamField>

<ResponseField name="returns" type="Callable[..., Any]">
  The registered callback when `callback` is provided, otherwise a decorator that registers and returns the function it wraps.
</ResponseField>

### on\_first\_audio\_byte

```python theme={null}
def on_first_audio_byte(self, callback: "'Callable[[int, int], Awaitable[None] | None]'") -> 'None'
```

Register the callback invoked when the first audio byte is produced.

<ParamField path="callback" type="'Callable[[int, int], Awaitable[None] | None]'" required>
  A callable, optionally async, invoked with synthesis timing information when the first audio byte is emitted.
</ParamField>

### synthesize

```python theme={null}
def synthesize(self, text: 'Any', **kwargs: 'Any') -> 'None'
```

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.

<ParamField path="text" type="Any" required>
  The text to synthesize; coerced to a string if needed.
</ParamField>