ProviderEventAdapter

Defined in: src/core/ProviderEventAdapter.ts:70

Optional adapter that bridges provider callbacks to a typed EventEmitter.

Remarks

This is not used by the default pipeline. CompositeVoice wires providers directly via callbacks for minimal overhead. Use this adapter when you need provider-level event subscriptions outside of CompositeVoice, such as for testing, debugging, or building custom pipelines.

The adapter registers itself as the callback consumer on each provider via bridgeSTT() and bridgeTTS(), then re-emits each callback invocation as a typed event through the inherited EventEmitter interface.

Important: Calling bridgeSTT() or bridgeTTS() will replace any previously registered callback on the provider. Do not use this adapter on providers that are already wired into a CompositeVoice instance.

Examples

import { ProviderEventAdapter } from 'composite-voice';
import { DeepgramSTT, DeepgramTTS } from 'composite-voice';

const adapter = new ProviderEventAdapter();
const stt = new DeepgramSTT({ apiKey: '...' });
const tts = new DeepgramTTS({ apiKey: '...' });

adapter.bridgeSTT(stt);
adapter.bridgeTTS(tts);

// Subscribe to provider-level events
adapter.on('tts.audio', (event) => {
  console.log('Raw TTS chunk:', event.chunk.data.byteLength, 'bytes');
});

adapter.on('transcription.interim', (event) => {
  console.log('Interim:', event.text);
});

const adapter = new ProviderEventAdapter();
adapter.bridgeSTT(myCustomSTT);

const results: TranscriptionResult[] = [];
adapter.on('stt.transcription', (event) => {
  results.push(event.result);
});

await myCustomSTT.initialize();
// ... trigger transcription ...
expect(results).toHaveLength(1);

See

• EventEmitter for subscription methods (on, once, off)
• ARCHITECTURE.md for why this adapter exists and when to use it

Extends

• EventEmitter

Constructors

Constructor

new ProviderEventAdapter(maxListeners?): ProviderEventAdapter;

Defined in: src/core/events/EventEmitter.ts:77

Creates a new EventEmitter instance.

Parameters

Returns

ProviderEventAdapter

Inherited from

EventEmitter.constructor

Methods

bridgeSTT()

bridgeSTT(stt): void;

Defined in: src/core/ProviderEventAdapter.ts:83

Bridge an STT provider’s transcription callback to this event emitter.

Parameters

Returns

void

Remarks

Registers an onTranscription callback on the provider that re-emits each TranscriptionResult as an 'stt.transcription' event.

Warning: This replaces any previously registered transcription callback on the provider.

bridgeTTS()

bridgeTTS(tts): void;

Defined in: src/core/ProviderEventAdapter.ts:105

Bridge a TTS provider’s audio and metadata callbacks to this event emitter.

Parameters

Returns

void

Remarks

Registers onAudio and onMetadata callbacks on the provider that re-emit as 'tts.audio' and 'tts.metadata' events respectively.

Warning: This replaces any previously registered audio and metadata callbacks on the provider.

emit()

emit<T>(event): Promise<void>;

Defined in: src/core/events/EventEmitter.ts:206

Emit an event to all registered listeners

Type Parameters

Parameters

Returns

Promise<void>

Inherited from

EventEmitter.emit

emitSync()

emitSync<T>(event): void;

Defined in: src/core/events/EventEmitter.ts:228

Emit an event synchronously (doesn’t wait for async listeners)

Type Parameters

Parameters

Returns

void

Inherited from

EventEmitter.emitSync

eventNames()

eventNames(): (
  | "transcription.start"
  | "transcription.interim"
  | "transcription.final"
  | "transcription.speechFinal"
  | "transcription.preflight"
  | "transcription.error"
  | "llm.start"
  | "llm.chunk"
  | "llm.complete"
  | "llm.error"
  | "tts.start"
  | "tts.audio"
  | "tts.metadata"
  | "tts.complete"
  | "tts.error"
  | "agent.ready"
  | "agent.stateChange"
  | "agent.error"
  | "audio.capture.start"
  | "audio.capture.stop"
  | "audio.capture.error"
  | "audio.playback.start"
  | "audio.playback.end"
  | "audio.playback.error"
  | "queue.overflow"
  | "queue.stats"
  | "*")[];

Defined in: src/core/events/EventEmitter.ts:258

Get all event types that have listeners

Returns

( | "transcription.start" | "transcription.interim" | "transcription.final" | "transcription.speechFinal" | "transcription.preflight" | "transcription.error" | "llm.start" | "llm.chunk" | "llm.complete" | "llm.error" | "tts.start" | "tts.audio" | "tts.metadata" | "tts.complete" | "tts.error" | "agent.ready" | "agent.stateChange" | "agent.error" | "audio.capture.start" | "audio.capture.stop" | "audio.capture.error" | "audio.playback.start" | "audio.playback.end" | "audio.playback.error" | "queue.overflow" | "queue.stats" | "*")[]

Array of event types

Inherited from

EventEmitter.eventNames

getMaxListeners()

getMaxListeners(): number;

Defined in: src/core/events/EventEmitter.ts:274

Get the maximum number of listeners per event

Returns

number

Maximum number of listeners

Inherited from

EventEmitter.getMaxListeners

listenerCount()

listenerCount(event): number;

Defined in: src/core/events/EventEmitter.ts:249

Get the number of listeners for an event

Parameters

Returns

number

Number of listeners

Inherited from

EventEmitter.listenerCount

off()

off<T>(event, listener): void;

Defined in: src/core/events/EventEmitter.ts:177

Remove an event listener

Type Parameters

Parameters

Returns

void

Inherited from

EventEmitter.off

on()

on<T>(event, listener): () => void;

Defined in: src/core/events/EventEmitter.ts:110

Registers an event listener for the specified event type.

Type Parameters

Parameters

Returns

A function that, when called, removes this listener (equivalent to calling off()).

(): void;

Returns

void

Remarks

If the number of listeners for the given event exceeds the configured maximum (see setMaxListeners()), a warning is logged to the console to help detect memory leaks. The listener is stored in a Set, so adding the same function reference twice for the same event is a no-op.

Example

const unsubscribe = emitter.on('tts.complete', () => {
  console.log('TTS playback finished');
});

// Later, remove the listener
unsubscribe();

Inherited from

EventEmitter.on

once()

once<T>(event, listener): () => void;

Defined in: src/core/events/EventEmitter.ts:160

Registers a one-time event listener that automatically unsubscribes after its first invocation.

Type Parameters

Parameters

Returns

A function that, when called, removes this listener before it has a chance to fire.

(): void;

Returns

void

Remarks

Internally, this wraps the provided listener in a function that calls off() before invoking the original callback. The returned unsubscribe function can be called to cancel the listener before it fires.

Example

emitter.once('agent.ready', () => {
  console.log('This will only fire once');
});

Inherited from

EventEmitter.once

removeAllListeners()

removeAllListeners(event?): void;

Defined in: src/core/events/EventEmitter.ts:194

Remove all listeners for an event, or all listeners if no event specified

Parameters

Returns

void

Inherited from

EventEmitter.removeAllListeners

setMaxListeners()

setMaxListeners(n): void;

Defined in: src/core/events/EventEmitter.ts:266

Set the maximum number of listeners per event

Parameters

Returns

void

Inherited from

EventEmitter.setMaxListeners