> ## 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.
# Neuphonic
> JavaScript API reference for the neuphonic text-to-speech plugin.
## NeuphonicTTS
Neuphonic text-to-speech (TTS) provider.
### Constructor
```typescript theme={null}
new NeuphonicTTS(opts: NeuphonicTTSOptions)
```
Neuphonic API key used to authenticate requests.
Defaults to the `NEUPHONIC_API_KEY` environment variable when omitted.
Identifier of the Neuphonic voice to synthesize with.
Defaults to `null`, in which case the provider's default voice is used.
BCP-47 language code for synthesis (e.g. `"en"`).
No default is applied; when omitted the provider's default language is used.
Audio output sampling rate in Hz. Defaults to `22050`.
### close
```typescript theme={null}
close(): Promise
```
Release any resources held by the provider.
### closeEmitter
```typescript theme={null}
closeEmitter(): Promise
```
Close the emitter: drop all handlers and stop emitting. Waits up to 2 seconds
for in-flight async handlers to settle before returning.
### emit
```typescript theme={null}
emit(event: string, ...args: any[]): void
```
### getRuntimeConfig
```typescript theme={null}
getRuntimeConfig(): Record
```
### interrupt
```typescript theme={null}
interrupt(): Promise
```
Stop the current synthesis.
### listenerCount
```typescript theme={null}
listenerCount(event: string): number
```
### off
```typescript theme={null}
off(event: string, handler: EventHandler): void
```
### on
```typescript theme={null}
on(event: string, handler: EventHandler): EventHandler
```
### once
```typescript theme={null}
once(event: string, handler: EventHandler): EventHandler
```
### onFirstAudioByte
```typescript theme={null}
onFirstAudioByte(callback: FirstAudioByteCallback): void
```
Register a callback fired when the first synthesized audio byte is emitted.
### removeAllListeners
```typescript theme={null}
removeAllListeners(event?: string): void
```
### synthesize
```typescript theme={null}
synthesize(text: any, ..._extra: any[]): Promise
```
Synthesize and speak `text` on the active session.