Expo Accessibility Service

An Expo module for managing Android accessibility service permissions and monitoring foreground app changes. This module provides a simple way to check if accessibility services are enabled, request permissions from users, and receive real-time events when users switch between apps.

• ✅ Check if accessibility service is enabled
• ✅ Request accessibility service permissions
• ✅ Monitor foreground app changes in real-time
• ✅ Event-based architecture with subscription management
• ✅ Support for multiple simultaneous listeners
• ✅ Cross-platform support (Android only)
• ✅ TypeScript support
• ✅ Expo SDK 53+ compatible

npm install expo-accessibility-service

Add the module to your app.json or app.config.js:

{
  "expo": {
    "plugins": ["expo-accessibility-service"]
  }
}

import * as AccessibilityService from 'expo-accessibility-service';
import { useEffect, useState } from 'react';
import { Button, Text, View } from 'react-native';

export default function App() {
  const [permissionStatus, setPermissionStatus] = useState('unknown');

  useEffect(() => {
    checkAccessibilityPermission();
  }, []);

  const checkAccessibilityPermission = async () => {
    try {
      const isEnabled = await AccessibilityService.isEnabled();
      setPermissionStatus(isEnabled ? 'enabled' : 'disabled');
    } catch (error) {
      console.error('Error checking accessibility permission:', error);
    }
  };

  const requestPermission = async () => {
    try {
      await AccessibilityService.askPermission();
      // Note: After returning from settings, you may want to recheck the status
      setTimeout(checkAccessibilityPermission, 1000);
    } catch (error) {
      console.error('Error requesting accessibility permission:', error);
    }
  };

  return (
    <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
      <Text>Accessibility Service Status: {permissionStatus}</Text>
      <Button title="Request Permission" onPress={requestPermission} />
    </View>
  );
}

import * as AccessibilityService from 'expo-accessibility-service';
import type { AccessibilityEvent } from 'expo-accessibility-service';
import { useEffect, useState, useRef } from 'react';
import { Button, Text, View, ScrollView } from 'react-native';

export default function App() {
  const [events, setEvents] = useState<AccessibilityEvent[]>([]);
  const subscriptionRef = useRef(null);

  useEffect(() => {
    // Start monitoring
    const subscription = AccessibilityService.addAccessibilityEventListener(
      (event: AccessibilityEvent) => {
        console.log('App changed:', event.packageName);
        setEvents((prev) => [event, ...prev].slice(0, 10)); // Keep last 10 events
      }
    );

    subscriptionRef.current = subscription;

    // Cleanup on unmount
    return () => {
      subscription.remove();
    };
  }, []);

  return (
    <ScrollView>
      <Text>Recent App Changes:</Text>
      {events.map((event, index) => (
        <View key={`${event.timestamp}-${index}`}>
          <Text>App: {event.packageName}</Text>
          <Text>Class: {event.className}</Text>
          <Text>Time: {new Date(event.timestamp).toLocaleTimeString()}</Text>
        </View>
      ))}
    </ScrollView>
  );
}

Checks if the accessibility service is currently enabled for your app.

Returns: A promise that resolves to true if the accessibility service is enabled, false otherwise.

Example:

const enabled = await AccessibilityService.isEnabled();
console.log("Accessibility service enabled:", enabled);

Opens the device's accessibility settings page where users can enable the accessibility service for your app.

Returns: A promise that resolves when the settings page is opened.

Example:

await AccessibilityService.askPermission();
// User will be taken to accessibility settings

Registers a listener for foreground app change events. The listener will be called whenever a new app comes to the foreground.

Parameters:

• listener: A callback function that receives AccessibilityEvent objects

Returns: An AccessibilityEventSubscription object with a remove() method to unsubscribe

Example:

const subscription = AccessibilityService.addAccessibilityEventListener(
  (event) => {
    console.log('App changed:', event.packageName);
    console.log('Activity:', event.className);
    console.log('Timestamp:', event.timestamp);
  }
);

// Later, to stop listening:
subscription.remove();

Important Notes:

• Supports multiple simultaneous listeners
• Events are delivered with sub-100ms latency
• The service continues running when the JS app is backgrounded
• Properly handles permission revocation
• Always call subscription.remove() when done to prevent memory leaks

Configure the accessibility service class name to check for. This allows using custom service class names instead of the default "MyAccessibilityService".

Parameters:

• className: The fully qualified class name (e.g., "com.example.MyCustomAccessibilityService")

Returns: A promise that resolves when the configuration is set

Example:

await AccessibilityService.setServiceClassName('com.myapp.CustomAccessibilityService');

Get a list of accessibility services detected in the app's manifest. This can help identify available services for configuration.

Returns: A promise that resolves to an array of service class names

Example:

const services = await AccessibilityService.getDetectedServices();
console.log('Available services:', services);

Event object emitted when a foreground app change is detected.

type AccessibilityEvent = {
  packageName: string;  // The package name of the app (e.g., "com.android.chrome")
  className: string;    // The activity/window class name
  timestamp: number;    // Unix timestamp in milliseconds
};

Subscription object returned by addAccessibilityEventListener().

type AccessibilityEventSubscription = {
  remove: () => void;  // Call this to unsubscribe from events
};

• ✅ Full support
• Checks for accessibility service status
• Opens accessibility settings for permission granting

• ❌ Not supported
• Methods will reject with "This method is not implemented on iOS" error
• iOS doesn't have the same accessibility service concept as Android
• Consider using iOS-specific accessibility APIs like VoiceOver detection instead

• ⚠️ Not applicable
• Web browsers don't have accessibility service permissions

This module is designed to work with Android's accessibility service framework. To use it effectively:

1. Service Implementation: You'll need to implement an AccessibilityService class in your Android app
2. Manifest Declaration: Declare the service in your AndroidManifest.xml
3. Service Configuration: Create an accessibility service configuration XML file

The module expects a service named {packageName}.MyAccessibilityService. Make sure your accessibility service follows this naming convention or modify the module accordingly.

• Node.js
• Expo CLI
• Android Studio (for Android development)
• Xcode (for iOS development)

npm run build

cd example
npx expo run:android

If you encounter build errors like "Could not resolve project :react-native-edge-to-edge" or similar dependency resolution failures, regenerate the Android native project:

cd example
npx expo prebuild --clean --platform android
npx expo run:android

Why this happens:

• The Android Gradle configuration may become out of sync with Expo's autolinking
• Dependencies introduced by Expo SDK updates may not be properly configured
• Running prebuild --clean regenerates all native Android files with the correct configuration

Note: The first build after running prebuild --clean may take longer as it compiles all native dependencies from scratch.

npm test

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

• Expo Modules API
• Android Accessibility Service