Expo

Expo

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Configuration with app.json

app.json is your go-to place for configuring parts of your app that don't belong in code. It is located at the root of your project next to your package.json. It looks something like this:
{
  "expo": {
    "name": "My app",
    "slug": "my-app"
  }
}
Most configuration from app.json is accessible at runtime from your JavaScript code via Constants.manifest. Sensitive information such as secret keys are removed. See the "extra" key below for information about how to pass arbitrary configuration data to your app.
👉 Using ExpoKit? Jump to the ExpoKit usage section. Note that ExpoKit is deprecated and will no longer be supported after SDK 38.

App Config

For more customization you can use the JavaScript and TypeScript app.config.js, or app.config.ts. These configs have the following properties:
  • Comments, variables, and single quotes!
  • ES module support (import/export).
  • TypeScript support with nullish coalescing and optional chaining.
  • Updated whenever Metro bundler reloads.
  • Provide environment information to your app.
  • Does not support Promises.
For example, you can export an object as default to define your config:
// app.config.js

const myValue = 'My App';

export default {
  name: myValue,
  version: process.env.MY_CUSTOM_PROJECT_VERSION || '1.0.0',
  // All values in extra will be passed to your app.
  extra: {
    fact: 'kittens are cool',
  },
};
Extras can be accessed via expo-constants:
// App.js
import Constants from 'expo-constants';

Constants.manifest.extra.fact === 'kittens are cool';
You can access and modify incoming config values by exporting a function that returns an object. This is useful if your project also has an app.json. By default, Expo CLI will read the app.json first and send the normalized results to the app.config.js. This functionality is disabled when the --config is used to specify a custom config.
app.json
{
  "expo": {
    "name": "My App"
  }
}

// app.config.js

export default ({ config }) => {
  console.log(config.name); // prints 'My App'
  return {
    ...config,
  };
};

TypeScript Config

⚠️ This is experimental and subject to breaking changes.
You can use autocomplete and doc-blocks with a TypeScript config app.config.ts.
Install the unversioned typings for Expo config with yarn add -D @expo/config
// app.config.ts

// WARNING THIS ISN'T VERSIONED
import { ExpoConfig, ConfigContext } from '@expo/config';

export default ({ config }: ConfigContext): ExpoConfig => ({
  ...config,
  name: 'My App',
});

Rules

There are two different types of configs static (app.config.json, app.json) and dynamic (app.config.js, app.config.ts). Static configs can be automatically updated with CLI tools, whereas dynamic configs must be manually updated by the developer.
  1. First the static config will be read by checking first if app.config.json exists, then falling back on app.json. If no static config exists then default values will be inferred from the package.json and installed node modules.
  2. The dynamic config will read by first checking if app.config.ts or app.config.js exists. If both exist then the TypeScript config will be used.
  3. If the dynamic config returns a function, then the static config will be passed to the function with ({ config }) => ({}). This can be used to mutate the static config values.
  4. Whatever is returned from the dynamic config will be used as the final config. It cannot have any promises.
  5. All functions in the config will be evaluated and serialized before any tool in the Expo ecosystem uses it. This is because the config must be a json manifest when it's hosted.

Properties

The following is a list of properties that are available for you under the "expo" key in app.json or app.config.json. These properties can be passed to the top level object of app.config.js or app.config.ts.

"name"

The name of your app as it appears both within Expo and on your home screen as a standalone app.
Bare workflow: To change the name of your app, edit the "Display Name" field in Xcode and the app_name string in android/app/src/main/res/values/strings.xml.

"description"

A short description of what your app is and why it is great.

"slug"

The friendly url name for publishing. eg: my-app-name will refer to the expo.io/@project-owner/my-app-name project.

"backgroundColor"

The background color for your app, behind any of your React views. This is also known as the root view background color. This value should be a 6 character long hex color string, eg: '#000000'. Default is white — '#ffffff'.

"owner"

The primary user to use for publishing and creating builds. If not provided, defaults to the username of the current user.

"privacy"

If not provided, defaults to unlisted. unlisted hides the project from search results. hidden restricts access to the project page to only the owner and other users that have been granted access. Valid values: public, unlisted, hidden.

"sdkVersion"

The Expo sdkVersion to run the project on. This should line up with the version specified in your package.json.

"version"

Your app version. In addition to this field, you'll also use ios.buildNumber and android.versionCode- read more about how to version your app here. On iOS this corresponds to CFBundleShortVersionString, and on Android, this corresponds to versionName. The required format can be found here.
Bare workflow: To change your app version, edit the "Version" field in Xcode and the versionName string in android/app/build.gradle.

"platforms"

Platforms that your project explicitly supports. If not specified, it defaults to ["ios", "android"].

"githubUrl"

If you would like to share the source code of your app on Github, enter the URL for the repository here and it will be linked to from your Expo project page.

"orientation"

Lock your app to a specific orientation with portrait or landscape. Defaults to no lock. Valid values: 'default', 'portrait', 'landscape'

"primaryColor"

On Android, this will determine the color of your app in the multitasker. Currently this is not used on iOS, but it may be used for other purposes in the future.
6 character long hex color string, eg: "#000000"

"icon"

Local path or remote url to an image to use for your app's icon. We recommend that you use a 1024x1024 png file. This icon will appear on the home screen and within the Expo app.
ExpoKit: To change your app's icon, edit or replace the files in ios/<PROJECT-NAME>/Assets.xcassets/AppIcon.appiconset (we recommend using Xcode), and android/app/src/main/res/mipmap-<RESOLUTION>. Be sure to follow the guidelines for each platform (iOS, Android 7.1 and below, and Android 8+) and to provide your new icon in each existing size.

"appKey"

By default, Expo looks for the application registered with the AppRegistry as main. If you would like to change this, you can specify the name in this property.

"androidShowExponentNotificationInShellApp"

Adds a notification to your standalone app with refresh button and debug info.

"scheme"

Standalone Apps Only. URL scheme to link into your app. For example, if we set this to 'demo', then demo:// URLs would open your app when tapped. String beginning with a lowercase letter followed by any combination of lowercase letters, digits, "+", "." or "-"
ExpoKit: To change your app's scheme, replace all occurrences of the old scheme in Info.plist, AndroidManifest.xml, and android/app/src/main/java/host/exp/exponent/generated/AppConstants.java.

"entryPoint"

The relative path to your main JavaScript file.

"extra"

Any extra fields you want to pass to your experience. Values are accessible via Constants.manifest.extra (read more)

"rnCliPath"

"packagerOpts"

"ignoreNodeModulesValidation"

"nodeModulesPath"

"facebookAppId"

Used for all Facebook libraries. Set up your Facebook App ID at https://developers.facebook.com.
ExpoKit: To change this field, edit Info.plist and AndroidManifest.xml.

"facebookAutoInitEnabled"

Whether the Facebook SDK should be initialized automatically. The default in Expo (Client and in standalone apps) is false.
ExpoKit: To change this field, edit Info.plist and AndroidManifest.xml.

"facebookAutoLogAppEventsEnabled"

Whether the Facebook SDK log app events automatically. If you don't set this property, Facebook's default will be used. (Applicable only to standalone apps.)
Note that Facebook SDK must be initialized for app events to work. You may autoinitialize Facebook SDK by setting facebookAutoInitEnabled to true.
ExpoKit: To change this field, edit Info.plist and AndroidManifest.xml.

"facebookAdvertiserIDCollectionEnabled"

Whether the Facebook SDK should collect advertiser ID properties, like the Apple IDFA and Android Advertising ID, automatically. If you don't set this property, Facebook's default policy will be used. (Applicable only to standalone apps.)
ExpoKit: To change this field, edit Info.plist and AndroidManifest.xml.

"facebookDisplayName"

Used for native Facebook login.
ExpoKit: To change this field, edit Info.plist and AndroidManifest.xml.

"facebookScheme"

Used for Facebook native login. Starts with 'fb' and followed by a string of digits, like 'fb1234567890'. You can find your scheme at https://developers.facebook.com/docs/facebook-login/ios in the 'Configuring Your info.plist' section.
ExpoKit: To change this field, edit Info.plist.

"locales"

Provide overrides by locale for System Dialog prompts like Permissions alerts
ExpoKit: To add or change language and localization information in your iOS app, you need to use Xcode.

"assetBundlePatterns"

An array of file glob strings which point to assets that will be bundled within your standalone app binary. Read more in the Offline Support guide

"androidStatusBar"

Configuration for the status bar on Android. For more details please navigate to Configuring StatusBar.
{
  "androidStatusBar": {
    /*
      Configures the status-bar icons to have a light or dark color.
      Valid values: "light-content", "dark-content".
      Defaults to "dark-content".
    */
    "barStyle": "light-content" | "dark-content",

    /*
      Specifies the background color of the status bar.
      Six-character hex color string "#RRGGBB" (e.g. "#000000" for white) or eight-character hex color string "#RRGGBBAA" (e.g. "#00000088" for semi-transparent black).
      Defaults to "#00000000" (transparent) for "dark-content" bar style and "#00000088" (semi-transparent black) for "light-content" bar style.
    */
    "backgroundColor": STRING,

    /**
     * Instructs the system whether status bar should be visible or not.
     * Defaults to false.
     */
    "hidden": BOOLEAN,

    /**
     * Specifies whether status bar should be translucent (whether it should be treated as a block element that will take up space on the device's screen and limit space available for the rest of your app to be rendered, or be treated as an element with "position = absolute" that is rendered above your app's content).
     * Defaults to true (default iOS behavior - iOS status bar cannot be set translucent by the system).
     */
    "translucent": BOOLEAN
  }
}

"androidNavigationBar"

Configuration for the bottom navigation bar on Android.
{
  "androidNavigationBar": {
    /*
      Determines how and when the navigation bar is shown. For details, see https://developer.android.com/training/system-ui/immersive
      "leanback" results in the navigation bar being hidden until the first touch gesture is registered
      "immersive" results in the navigation bar being hidden until the user swipes up from the edge where the navigation bar is hidden
      "sticky-immersive" is identical to "immersive" except that the navigation bar will be semi-transparent and will be hidden again after a short period of time
      Valid values: "leanback", "immersive", "sticky-immersive"
    */
    "visible": STRING,
    /*
      Configure the navigation-bar icons to have a light or dark color. Supported on Android Oreo and newer.
      Valid values: "light-content", "dark-content".
    */
    "barStyle": STRING,

    /*
      Specifies the background color of the navigation bar.
      Six-character hex color string, e.g., "#000000"
    */
    "backgroundColor": STRING
  }
}

"splash"

Configuration for loading and splash screen for standalone apps.
{
  "splash": {
    /*
      Color to fill the loading screen background
      6 character long hex color string, eg: "#000000"
    */
    "backgroundColor": STRING,

    /*
      Determines how the "image" will be displayed in the splash loading screen.
      Valid values: "cover", "contain", or "native". Defaults to "contain".
    */
    "resizeMode": STRING,

    /*
      Local path or remote url to an image.
      Will fill the background of the loading/splash screen.
      Image size and aspect ratio are up to you. Must be a .png.
    */
    "image": STRING
  }
}
ExpoKit: To change your iOS app's splash screen, use Xcode to edit LaunchScreen.xib. For Android, edit or replace the files in android/app/src/main/res/drawable-<RESOLUTION>; to change the background color, edit android/app/src/main/res/values/colors.xml; and to change the resizeMode, set SHOW_LOADING_VIEW_IN_SHELL_APP in android/app/src/main/java/host/exp/exponent/generated/AppConstants.java (true for "contain", false for "cover").

"notification"

Configuration for remote (push) notifications.
{
  "notification": {
    /*
      Local path or remote url to an image to use as the icon for push notifications.
      96x96 png grayscale with transparency.
    */
    "icon": STRING,

    /*
      Tint color for the push notification image when it appears in the notification tray.
      6 character long hex color string eg: "#000000"
    */
    "color": STRING,

    /*
      Whether or not to display notifications when the app is in the foreground on iOS.
      `_displayInForeground` option in the individual push notification message overrides this option.
      Learn more: https://docs.expo.io/push-notifications/overview#3-handle-receiving-andor-selecting-the-notification
      Defaults to `false`.
    */
    "iosDisplayInForeground": BOOLEAN,

    /*
      Show each push notification individually "default" or collapse into one "collapse".
      Valid values: "default", "collapse"
    */
    "androidMode": STRING,

    /*
      If "androidMode" is set to "collapse", this title is used for the collapsed notification message.
      eg: "#{unread_notifications} new interactions"
    */
    "androidCollapsedTitle": STRING
  }
}
ExpoKit: To change the notification icon, edit or replace the shell_notification_icon.png files in android/app/src/main/res/mipmap-<RESOLUTION>. On iOS, notification icons are the same as the app icon. All other properties are set at runtime.

"hooks"

Configuration for scripts to run to hook into the publish process
{
  "hooks": {
    "postPublish": STRING
  }
}

"updates"

Configuration for how and when the app should request OTA JavaScript updates
{
  "updates": {
    /*
      If set to false, your standalone app will never download any code.
      And will only use code bundled locally on the device.
      In that case, all updates to your app must be submitted through Apple review.
      Defaults to true.

      Note that this will not work out of the box with ExpoKit projects.
    */
    "enabled": BOOLEAN,

    /*
      By default, Expo will check for updates every time the app is loaded.
      Set this to `'ON_ERROR_RECOVERY'` to disable automatic checking unless recovering from an error.

      Must be one of `ON_LOAD` or `ON_ERROR_RECOVERY`.
    */
    "checkAutomatically": STRING,

    /*
      How long (in ms) to allow for fetching OTA updates before falling back to a cached version of the app.

      Defaults to 30000 (30 sec). Must be between 0 and 300000 (5 minutes).
    */
    "fallbackToCacheTimeout": NUMBER
  }
}
ExpoKit: To change the value of enabled, edit the areRemoteUpdatesEnabled key in ios/<PROJECT-NAME>/Supporting/EXShell.plist and the ARE_REMOTE_UPDATES_ENABLED variable in android/app/src/main/java/host/exp/exponent/generated/AppConstants.java. All other properties are set at runtime.

"ios"

Configuration that is specific to the iOS platform.
{
  "ios": {
    /*
      The bundle identifier for your iOS standalone app.
      You make it up, but it needs to be unique on the App Store.

      stackoverflow.com/questions/11347470/what-does-bundle-identifier-mean-in-the-ios-project.

      iOS bundle identifier notation unique name for your app.
      For example, host.exp.exponent, where exp.host is our domain
      and Expo is our app.

      ExpoKit: use Xcode to set this.
    */
    "bundleIdentifier": STRING,

    /*
      Build number for your iOS standalone app. Corresponds to `CFBundleVersion`
      and must match Apple's specified format.
      developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html#//apple_ref/doc/uid/20001431-102364.

      Note- Application loader will pull the value for "Version Number" from `expo.version` and NOT from `expo.ios.buildNumber`

      ExpoKit: use Xcode to set this.
    */
    "buildNumber": STRING,

    /*
      The background color for your iOS app, behind any of your React views. Overrides the top-level `backgroundColor` key if it is present.
    */
    "backgroundColor": STRING,

    /*
      Local path or remote URL to an image to use for your app's
      icon on iOS. If specified, this overrides the top-level "icon" key.

      Use a 1024x1024 icon which follows Apple's interface guidelines for icons, including color profile and transparency.

      Expo will generate the other required sizes.
      This icon will appear on the home screen and within the Expo app.
    */
    "icon": STRING,

    /*
      URL to your app on the Apple App Store, if you have deployed it there.
      This is used to link to your store page from your Expo project page if your app is public.
    */
    "appStoreUrl": STRING,

    /*
      Whether your standalone iOS app supports tablet screen sizes.
      Defaults to `false`.

      ExpoKit: use Xcode to set this.
    */
    "supportsTablet": BOOLEAN,

    /*
      If true, indicates that your standalone iOS app does not support Slide Over
      and Split View on iPad.
      Defaults to `true` currently, but will change to `false` in a future SDK version.

      ExpoKit: use Xcode to set `UIRequiresFullScreen`.
    */
    "requireFullScreen": BOOLEAN,

    /*
      If true, indicates that your standalone iOS app does not support handsets.
      Your app will only support tablets.

      ExpoKit: use Xcode to set this.
    */
    "isTabletOnly": BOOLEAN,

    /*
      Dictionary of arbitrary configuration to add to your standalone app's native Info.plist. Applied prior to all other Expo-specific configuration.
      Must be customized if your app requests system permissions.

      No other validation is performed, so use this at your own risk of rejection from the App Store.
    */
    "infoPlist": OBJECT,

    /*
      An array that contains Associated Domains for the standalone app. See apple's docs for config: https://developer.apple.com/documentation/uikit/core_app/allowing_apps_and_websites_to_link_to_your_content/enabling_universal_links

      Entries must follow the format "applinks:<fully qualified domain>[:port number]". See Apple's docs for details -> https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_developer_associated-domains

      ExpoKit: use Xcode to set this.
    */
    "associatedDomains": ARRAY,

    /*
      Location of the GoogleService-Info.plist file for configuring Firebase.
    */
    "googleServicesFile": STRING,

    /*
      A boolean indicating if the app uses iCloud Storage for DocumentPicker.
      See DocumentPicker docs for details.

      ExpoKit: use Xcode to set this.
    */
    "usesIcloudStorage": BOOLEAN,

    /*
      A boolean indicating if the app uses Apple Sign In.
      See AppleAuthentication docs for details.

      ExpoKit: use Xcode to set this.
    */
    "usesAppleSignIn": BOOLEAN,

    /*
      A boolean value indicating if the app may access the notes stored in contacts.
      See Contacts docs for details.

      ExpoKit: use Xcode to set this.
    */
    "accessesContactNotes": BOOLEAN,

    /*
      Extra module configuration to be added to your app's native Info.plist.

      For ExpoKit apps, just add these to the Info.plist file directly.
    */
    "config": {
      /*
        Branch (https://branch.io/) key to hook up Branch linking services.
      */
      "branch": {
        /*
          Your Branch API key
        */
        "apiKey": STRING
      },

      /*
        Sets `ITSAppUsesNonExemptEncryption` in the standalone ipa's Info.plist to the given boolean value.
      */
      "usesNonExemptEncryption": BOOLEAN,

      /*
        Google Maps iOS SDK key for your standalone app.

        developers.google.com/maps/documentation/ios-sdk/start
      */
      "googleMapsApiKey": STRING,

      /*
        Google Mobile Ads App ID for your standalone app.

        https://developers.google.com/admob/ios/quick-start#update_your_infoplist
      */
      "googleMobileAdsAppId": STRING,

      /*
        A boolean indicating whether to initialize Google App Measurement and begin sending
        user-level event data to Google immediately when the app starts. The default in Expo
        (Client and in standalone apps) is `false`.

        Sets the opposite of the given value to the following key in Info.plist:
        https://developers.google.com/admob/ios/eu-consent#delay_app_measurement_optional
      */
      "googleMobileAdsAutoInit": BOOLEAN,

      /*
        Google Sign-In iOS SDK keys for your standalone app.

        developers.google.com/identity/sign-in/ios/start-integrating
      */
      "googleSignIn": {
        /*
          The reserved client ID URL scheme.
          Can be found in GoogleService-Info.plist.
        */
        "reservedClientId": STRING
      }
    },

    "splash": {
      /*
        Local path to a .xib interface builder document which will be used as the
        loading screen of the standalone iOS app.
        Note that this will only be used in the standalone app (i.e., after you
        build the app). It will not be used in the Expo client.
      */
      "xib": STRING,

      /*
        Color to fill the loading screen background 6 character long hex color string, eg: "#000000"
      */
      "backgroundColor": STRING,

      /*
        Determines how the "image" will be displayed in the splash loading screen.
        Must be one of "cover" or "contain", defaults to "contain".
        Valid values: "cover", "contain"
      */
      "resizeMode": STRING,

      /*
        Local path or remote url to an image to fill the background of the loading screen.
        Image size and aspect ratio are up to you.
        Must be a .png.
      */
      "image": STRING,

      /*
        Local path or remote url to an image to fill the background of the loading screen.
        Image size and aspect ratio are up to you.
        Must be a .png.
      */
      "tabletImage": STRING,

      /*
        Supported user interface styles. If left blank, "light" will be used. Use "automatic" if you would like to support either "light" or "dark" depending on iOS settings.
      */
      "userInterfaceStyle": "automatic" | "light" | "dark"
    }
  }
}

"android"

Configuration that is specific to the Android platform.
{
  "android": {
    /*
      The package name for your Android standalone app.
      You make it up, but it needs to be unique on the Play Store.

      stackoverflow.com/questions/6273892/android-package-name-convention

      Reverse DNS notation unique name for your app.
      For example, host.exp.exponent, where exp.host is our domain and Expo is our app.
      The name may only contain lowercase and uppercase letters (a-z, A-Z),
      numbers (0-9) and underscores (_). Each component of the name should start
      with a lowercase letter.

      ExpoKit: this is set in `android/app/build.gradle` as well as your
      AndroidManifest.xml file (multiple places).
    */
    "package": STRING,

    /*
      Version number required by Google Play.
      Increment by one for each release.
      Must be an integer.
      developer.android.com/studio/publish/versioning.html

      ExpoKit: this is set in `android/app/build.gradle`.
    */
    "versionCode": NUMBER,

    /*
      The background color for your Android app, behind any of your React views. Overrides the top-level `backgroundColor` key if it is present.
    */
    "backgroundColor": STRING,

    /*
      Local path or remote url to an image to use for your app's icon on Android.
      If specified, this overrides the top-level "icon" key.

      We recommend that you use a 1024x1024 png file.
      Transparency is recommended for the Google Play Store.
      This icon will appear on the home screen and within the Expo app.
    */
    "icon": STRING,

    /*
      Settings for an Adaptive Launcher Icon on Android.
      https://developer.android.com/guide/practices/ui_guidelines/icon_design_adaptive

      ExpoKit: icons are saved in `android/app/src/main/res/mipmap-<RESOLUTION>-v26`
      and the "backgroundColor" is set in `android/app/src/main/res/values/colors.xml`.
    */
    "adaptiveIcon": {
      /*
        Local path or remote url to an image to use for
        the foreground of your app's icon on Android.

        We recommend that you use a 1024x1024 png file,
        leaving at least the outer 1/6 transparent on each side.
        If specified, this overrides the top-level "icon" and the "android.icon" keys.
        This icon will appear on the home screen.
      */
      "foregroundImage": STRING,

      /*
        Color to use as the background for your app's Adaptive Icon on Android.
        Defaults to white (#FFFFFF).

        Has no effect if "foregroundImage" is not specified.
      */
      "backgroundColor": STRING,

      /*
        Local path or remote url to a background image for
        the background of your app's icon on Android.

        If specified, this overrides the "backgroundColor" key.
        Must have the same dimensions as "foregroundImage", and has no effect if
        "foregroundImage" is not specified.
      */
      "backgroundImage": STRING
    },

    /*
      URL to your app on the Google Play Store, if you have deployed it there.
      This is used to link to your store page from your Expo project page if your app is public.
    */
    "playStoreUrl": STRING,

    /*
      List of additional permissions the standalone app will request upon installation,
      along with the minimum necessary for an Expo app to function.

      To use ALL permissions supported by Expo, do not specify the "permissions" key.

      To use ONLY the following minimum necessary permissions and none of the extras supported
      by Expo, set "permissions" to []. The minimum necessary permissions do not require a
      Privacy Policy when uploading to Google Play Store and are:

      • receive data from Internet
      • view network connections
      • full network access
      • change your audio settings
      • draw over other apps
      • prevent device from sleeping

      To use the minimum necessary permissions ALONG with certain additional permissions,
      specify those extras in "permissions", e.g.

      ["CAMERA", "RECORD_AUDIO"]

      ExpoKit: to change the permissions your app requests, you'll need to edit
      AndroidManifest.xml manually. To prevent your app from requesting one of the
      permissions listed below, you'll need to explicitly add it to `AndroidManifest.xml`
      along with a `tools:node="remove"` tag.
    */
    "permissions": [
      "ACCESS_COARSE_LOCATION",
      "ACCESS_FINE_LOCATION",
      "CAMERA",
      "MANAGE_DOCUMENTS",
      "READ_CONTACTS",
      "READ_CALENDAR",
      "WRITE_CALENDAR",
      "READ_EXTERNAL_STORAGE",
      "READ_PHONE_STATE",
      "RECORD_AUDIO",
      "USE_FINGERPRINT",
      "VIBRATE",
      "WAKE_LOCK",
      "WRITE_EXTERNAL_STORAGE",
      "com.anddoes.launcher.permission.UPDATE_COUNT",
      "com.android.launcher.permission.INSTALL_SHORTCUT",
      "com.google.android.c2dm.permission.RECEIVE",
      "com.google.android.gms.permission.ACTIVITY_RECOGNITION",
      "com.google.android.providers.gsf.permission.READ_GSERVICES",
      "com.htc.launcher.permission.READ_SETTINGS",
      "com.htc.launcher.permission.UPDATE_SHORTCUT",
      "com.majeur.launcher.permission.UPDATE_BADGE",
      "com.sec.android.provider.badge.permission.READ",
      "com.sec.android.provider.badge.permission.WRITE",
      "com.sonyericsson.home.permission.BROADCAST_BADGE"
    ],

    /*
      Location of the google-services.json file for configuring Firebase. Including this
      key automatically enables FCM in your standalone app.

      For ExpoKit apps, add or edit the file directly at `android/app/google-services.json`.
      To enable FCM, edit the value of `FCM_ENABLED` in
      `android/app/src/main/java/host/exp/exponent/generated/AppConstants.java`.
    */
    "googleServicesFile": STRING,

    /*
      Extra module configuration to be added to your app's native AndroidManifest.xml.

      For ExpoKit apps, just add these to the AndroidManifest.xml file directly.
    */
    "config": {
      /*
        Branch (https://branch.io/) key to hook up Branch linking services.
      */
      "branch": {
        /*
          Your Branch API key
        */
        "apiKey": STRING
      },

      /*
        Google Maps Android SDK key for your standalone app.
        developers.google.com/maps/documentation/android-api/signup
      */
      "googleMaps": {
        /*
          Your Google Maps Android SDK API key
        */
        "apiKey": STRING
      },

      /*
        Google Mobile Ads App ID for your standalone app.

        https://developers.google.com/admob/android/quick-start#update_your_androidmanifestxml
      */
      "googleMobileAdsAppId": STRING,

      /*
        A boolean indicating whether to initialize Google App Measurement and begin sending
        user-level event data to Google immediately when the app starts. The default in Expo
        (Client and in standalone apps) is `false`.

        Sets the opposite of the given value to the following tag in AndroidManifest.xml:
        https://developers.google.com/admob/android/eu-consent#delay_app_measurement_optional
      */
      "googleMobileAdsAutoInit": BOOLEAN,

      /*
        Google Sign-In Android SDK keys for your standalone app.
        developers.google.com/identity/sign-in/android/start-integrating
      */
      "googleSignIn": {
        /*
          The Android API key.
          Can be found in the credentials section of the developer console
          or in "google-services.json"
        */
        "apiKey": STRING,

        /*
          The SHA-1 hash of the signing certificate used to build the apk without any separator `:`.
          Can be found in "google-services.json".
          developers.google.com/android/guides/client-auth
        */
        "certificateHash": STRING
      }
    },

    /*
      Configuration for loading and splash screen for standalone Android apps.
    */
    "splash": {
      /*
        Color to fill the loading screen background
        6 character long hex color string, eg: "#000000"
      */
      "backgroundColor": STRING,

      /*
        Determines how the "image" will be displayed in the splash loading screen.
        Must be one of "cover", "contain" or "native", defaults to "contain".
        Valid values: "cover", "contain", "native"
      */
      "resizeMode": STRING,

      /*
        Local path or remote url to an image to fill the background of the loading screen in 'cover' mode.
        Image size and aspect ratio are up to you.
        Pay extra attention to the size of each image.
        See here: https://docs.expo.io/guides/splash-screens.html#differences-between-environments-android
        Must be a .png
        For more information see https://developer.android.com/training/multiscreen/screendensities
      */
      "mdpi": STRING,   // natural sized image (baseline)
      "hdpi": STRING,   // scale 1.5x
      "xhdpi": STRING,  // scale 2x
      "xxhdpi": STRING, // scale 3x
      "xxxhdpi": STRING // scale 4x
    },

    /*
      Configuration for setting custom intent filters in Android manifest.
      The following example demonstrates how to set up deep links. When
      the user taps a link matching *.myapp.io, they will be shown a
      dialog asking whether the link should be handled by your app or by
      the web browser.

      The data attribute may either be an object or an array of objects.
      The object may have the following keys to specify attributes of URLs matched by the filter:

      - scheme (string): the scheme of the URL, e.g. "https"
      - host (string): the host, e.g. "myapp.io"
      - port (string): the port, e.g. "3000"
      - path (string): an exact path for URLs that should be matched by the filter, e.g. "/records"
      - pathPattern (string): a regex for paths that should be matched by the filter, e.g. ".*"
      - pathPrefix (string): a prefix for paths that should be matched by the filter, e.g. "/records/" will match "/records/123"
      - mimeType (string): a mime type for URLs that should be matched by the filter

      See Android's documentation for more details on intent filter matching:

      developer.android.com/guide/components/intents-filters

      You may also use an intent filter to set your app as the default handler
      for links (without showing the user a dialog with options). To do so, you
      must set "autoVerify": true on the filter object below, and then
      configure your server to serve a JSON file verifying that you own the
      domain. See Android's documentation for details:

      developer.android.com/training/app-links

      To add or edit intent filters in an ExpoKit project, edit AndroidManifest.xml directly.
    */
    "intentFilters": [
      {
        "action": "VIEW",
        "data": {
          "scheme": "https",
          "host": "*.myapp.io"
        },
        "category": [
          "BROWSABLE",
          "DEFAULT"
        ]
      }
    ]

    /*
      Determines how the software keyboard will impact the layout of your application. This maps
      to the "android:windowSoftInputMode" property. Defaults to "resize". Only supported in SDK 38 and higher.
      Valid values: "resize", "pan".
    */
    "softwareKeyboardLayoutMode": STRING,

    /*
      Allows your user's app data to be automatically backed up to their Google Drive. If this is set to false,
      no backup or restore of the application will ever be performed (this is useful if your app deals with sensitive information).
      Defaults to the Android default, which is true.
    */
    "allowBackup": BOOLEAN,
  }
}

"web"

Configuration that is specific to the web platform.
{
  "web": {

    /*
      Extra web-specific configuration options.
    */
    "config": {

      /*
        Firebase web configuration.
        Used by the expo-firebase packages on both web and native.
        See here: https://firebase.google.com/docs/reference/js/firebase.html#initializeapp
      */
      "firebase": {
        "apiKey": STRING,
        "authDomain": STRING,
        "databaseURL": STRING,
        "projectId": STRING,
        "storageBucket": STRING,
        "messagingSenderId": STRING,
        "appId": STRING,
        "measurementId": STRING
      }
    }
  }
}

"experiments"

Toggle features that aren't ready to be turned on by default for everyone.
{
  "experiments": {

    /*
      Use the unstable LogBox re-design available in React Native 0.62. This option is only available in SDK 38.
    */
    "redesignedLogBox": BOOLEAN
  }
}

ExpoKit

Note that ExpoKit is deprecated and will no longer be supported after SDK 38. We recommend using the bare workflow instead.
While some of the properties defined in app.json can be applied at runtime, others require modifying native build configuration files. For ExpoKit projects, we only apply these settings once, at the time the native projects are generated (i.e. when you run expo eject).
This means that for existing ExpoKit projects, changing certain properties in app.json will not have the desired effect. Instead, you must modify the corresponding native configuration files. In most cases, we've provided here a brief description of the files or settings that need to be changed, but you can also refer to the Apple and Android documentation for more information.