EventManager

The EventManager handles event subscriptions and dispatching within a TpaSession. It provides methods for subscribing to various event types from the AugmentOS platform.

You access the EventManager through the events property of a TpaSession instance:

const eventManager = tpaSession.events;

Event Handler Methods

onTranscription()

Registers a handler for real-time speech transcription events.

onTranscription(handler: (data: TranscriptionData) => void): () => void

Parameters:

• handler: Callback function that receives TranscriptionData objects

Returns: An unsubscribe function to remove the handler

Example:

const unsubscribe = tpaSession.events.onTranscription((data) => {
  console.log(`Transcription: ${data.text}, Final: ${data.isFinal}`);
  if (data.isFinal) {
    // Process the final transcription
  }
});

// Later, to stop receiving events:
unsubscribe();

onHeadPosition()

Registers a handler for head position change events.

onHeadPosition(handler: (data: HeadPosition) => void): () => void

Parameters:

• handler: Callback function that receives HeadPosition objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onHeadPosition((data) => {
  if (data.position === 'up') {
    console.log('User looked up');
  } else if (data.position === 'down') {
    console.log('User looked down');
  }
});

onButtonPress()

Registers a handler for hardware button press events on the glasses.

onButtonPress(handler: (data: ButtonPress) => void): () => void

Parameters:

• handler: Callback function that receives ButtonPress objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onButtonPress((data) => {
  console.log(`Button ${data.buttonId} was ${data.pressType} pressed`);
});

onPhoneNotifications()

Registers a handler for notifications received from the connected phone.

onPhoneNotifications(handler: (data: PhoneNotification) => void): () => void

Parameters:

• handler: Callback function that receives PhoneNotification objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onPhoneNotifications((data) => {
  console.log(`Notification from ${data.app}: ${data.title} - ${data.content}`);
});

onGlassesBattery()

Registers a handler for glasses battery update events.

onGlassesBattery(handler: (data: GlassesBatteryUpdate) => void): () => void

Parameters:

• handler: Callback function that receives GlassesBatteryUpdate objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onGlassesBattery((data) => {
  console.log(`Glasses battery: ${data.level}%, Charging: ${data.charging}`);
});

onPhoneBattery()

Registers a handler for phone battery update events.

onPhoneBattery(handler: (data: PhoneBatteryUpdate) => void): () => void

Parameters:

• handler: Callback function that receives PhoneBatteryUpdate objects

Returns: An unsubscribe function to remove the handler

onVoiceActivity()

Registers a handler for Voice Activity Detection (VAD) events.

onVoiceActivity(handler: (data: Vad) => void): () => void

Parameters:

• handler: Callback function that receives Vad objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onVoiceActivity((data) => {
  if (data.status === true || data.status === "true") {
    console.log('User is speaking');
  } else {
    console.log('User stopped speaking');
  }
});

onLocation()

Registers a handler for location update events.

onLocation(handler: (data: LocationUpdate) => void): () => void

Parameters:

• handler: Callback function that receives LocationUpdate objects

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onLocation((data) => {
  console.log(`Location updated: Lat ${data.lat}, Lng ${data.lng}`);
});

onCalendarEvent()

Registers a handler for calendar event notifications.

onCalendarEvent(handler: (data: CalendarEvent) => void): () => void

Parameters:

• handler: Callback function that receives CalendarEvent objects

Returns: An unsubscribe function to remove the handler

onAudioChunk()

Registers a handler for raw audio data chunks. Requires explicit subscription.

onAudioChunk(handler: (data: AudioChunk) => void): () => void

Parameters:

• handler: Callback function that receives AudioChunk objects

Returns: An unsubscribe function to remove the handler

Note: Audio chunks require an explicit subscription using tpaSession.subscribe([StreamType.AUDIO_CHUNK](/reference/enums#streamtype)).

System Event Handlers

onConnected()

Registers a handler for when the WebSocket connection is successfully established and authenticated.

onConnected(handler: (data: AppSettings | undefined) => void): () => void

Parameters:

• handler: Callback function that receives optional AppSettings upon connection

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onConnected((settings) => {
  console.log('Connected to AugmentOS Cloud');
  if (settings) {
    console.log('Initial settings received:', settings);
  }
});

onDisconnected()

Registers a handler for when the WebSocket connection is closed or lost.

onDisconnected(handler: (reason: string) => void): () => void

Parameters:

• handler: Callback function that receives a reason string

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onDisconnected((reason) => {
  console.log(`Disconnected from AugmentOS Cloud. Reason: ${reason}`);
});

onError()

Registers a handler for WebSocket or SDK-level errors.

onError(handler: (error: WebSocketError | Error) => void): () => void

Parameters:

• handler: Callback function that receives a WebSocketError or standard Error object

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onError((error) => {
  console.error('Error in TPA session:', error);
});

onSettingsUpdate()

Registers a handler for when the application settings are updated by the user via AugmentOS Cloud.

onSettingsUpdate(handler: (settings: AppSettings) => void): () => void

Parameters:

• handler: Callback function that receives the complete updated AppSettings array

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onSettingsUpdate((settings) => {
  console.log('Settings updated:', settings);
});

onSettingChange()

Registers a handler that triggers only when a specific setting's value changes.

onSettingChange<T>(
  key: string, 
  handler: (value: T, previousValue: T | undefined) => void
): () => void

Parameters:

• key: The key of the setting to monitor
• handler: Callback function that receives the new value and the previous value (or undefined initially)

Returns: An unsubscribe function to remove the handler

Example:

tpaSession.events.onSettingChange<boolean>('enableNotifications', (newValue, oldValue) => {
  console.log(`enableNotifications changed from ${oldValue} to ${newValue}`);
  if (newValue) {
    // Enable notification features
  } else {
    // Disable notification features
  }
});

Generic Event Handler

on()

Generic event handler for any StreamType. Use specific methods above where possible.

on<T extends StreamType>(
  type: T, 
  handler: (data: StreamDataTypes[T]) => void
): () => void

Parameters:

• type: The StreamType to listen for
• handler: Callback function that receives data of the appropriate type for the specified StreamType

Returns: An unsubscribe function to remove the handler

Example:

import { StreamType } from '@augmentos/sdk';

// Subscribe to a specific stream type
tpaSession.events.on(StreamType.LOCATION_UPDATE, (data) => {
  console.log(`Location update: ${data.lat}, ${data.lng}`);
});

// Using a language-specific stream
const transcriptionStream = createTranscriptionStream('en-US');
tpaSession.events.on(transcriptionStream, (data) => {
  console.log(`English transcription: ${data.text}`);
});