expo-constants

@amazon-devices/expo-constants provides system information that remains constant throughout the lifetime of your app's install.

• Installation
• Examples
• API reference
• Implementation details
• Supported versions
• Additional resources

Installation

1. Add the JavaScript library dependency in the package.json file.

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    dependencies: {
        ...
        "@amazon-devices/expo-constants": "~2.0.0",
        "expo": "~50.0.0",
        ...
    }
   

2. Reinstall dependencies using npm install command.

Examples

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import React from 'react';
import Constants from '@amazon-devices/expo-constants';
import {StyleSheet, Text, View} from 'react-native';

export const App = () => {
  return (
    <View style={styles.container}>
      <Text style={styles.text}>
        isHeadless: {String(Constants.isHeadless)}
      </Text>
      <Text style={styles.text}>
        statusBarHeight: {Constants.statusBarHeight}
      </Text>
      <Text style={styles.text}>
        systemFonts: {Constants.systemFonts.join(', ')}
      </Text>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'white',
    justifyContent: 'center',
    alignItems: 'center',
  },
  text: {
    fontSize: 30,
    color: 'black',
  },
});

API reference

Check out the dedicated documentation page for info about this library, API reference and more: Official Expo documentation for expo-constants.

Implementation details

Currently, all values are mocks. Don't depend on any of the constants inside this package.

Supported versions

Additional resources

For information on additional libraries, see Supported Third-Party Libraries and Services.

Last updated: Sep 30, 2025