Expo

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API Reference

app.json / app.config.js

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.
For more general information on app configuration, such as the differences between the various app configuration files, check out our introductory guide.
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ExpoKit Update: Note that ExpoKit is deprecated and will no longer be supported after SDK 38.

Properties

PropertyDescription
(string) - The name of your app as it appears both within Expo client 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
(string) - A short description of what your app is and why it is great.
(string) - The friendly URL name for publishing. For example, myAppName will refer to the expo.io/@project-owner/myAppName project.
(string) - The Expo account name of the team owner, only applicable if you are enrolled in Expo Developer Services. If not provided, defaults to the username of the current user.
(enum) - 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.
(string) - The Expo sdkVersion to run the project on. This should line up with the version specified in your package.json.
(string) - Note: Don't use this property unless you are sure what you're doing
The runtime version associated with this manifest for bare workflow projects. If provided, this must match the version set in Expo.plist or AndroidManifest.xml.
(string) - 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
(array) - Platforms that your project explicitly supports. If not specified, it defaults to ["ios", "android"].
(string) - 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.
(enum) - Locks your app to a specific orientation with portrait or landscape. Defaults to no lock. Valid values: default, portrait, landscape
(enum) - Configuration to force the app to always use the light or dark user-interface appearance, such as "dark mode", or make it automatically adapt to the system preferences. If not provided, defaults to light.
(string) - The background color for your app, behind any of your React views. This is also known as the root view background color.
6 character long hex color string, for example, '#000000'. Default is white: '#ffffff'
(string) - 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, for example, '#000000'
(string) - 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.
Bare Workflow
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.
(object) - Configuration for remote (push) notifications.
(string) - Local path or remote URL to an image to use as the icon for push notifications. 96x96 png grayscale with transparency.
ExpoKit
For Android, 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.
(string) - Tint color for the push notification image when it appears in the notification tray.
6 character long hex color string, for example, '#000000'
(boolean) - 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. Defaults to false.
(enum) - Show each push notification individually (default) or collapse into one (collapse).
(string) - If androidMode is set to collapse, this title is used for the collapsed notification message. For example, '#{unread_notifications} new interactions'.
(string) - 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.
(object) - Configuration for the status bar on Android. For more details please navigate to Configuring StatusBar.
(enum) - Configures the status bar icons to have a light or dark color. Valid values: light-content, dark-content. Defaults to dark-content
(string) - Specifies the background color of the status bar. Defaults to #00000000 (transparent) for dark-content bar style and #00000088 (semi-transparent black) for light-content bar style
6 character long hex color string '#RRGGBBAA', for example, '#000000' for black. Or 8 character long hex color string '#RRGGBBAA', for example, '#00000088' for semi-transparent black.
(boolean) - Instructs the system whether the status bar should be visible or not. Defaults to false
(boolean) - Specifies whether the 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, the iOS status bar cannot be set translucent by the system)
(object) - Configuration for the bottom navigation bar on Android.
(enum) - Determines how and when the navigation bar is shown. Learn more. Valid values: leanback, immersive, sticky-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
(enum) - Configure the navigation bar icons to have a light or dark color. Supported on Android Oreo and newer. Valid values: 'light-content', 'dark-content'
(string) - Specifies the background color of the navigation bar.
6 character long hex color string, for example, '#000000'
(boolean) - Adds a notification to your standalone app with refresh button and debug info.
(string) - 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.
Bare Workflow
To change your app's scheme, replace all occurrences of the old scheme in Info.plist and AndroidManifest.xml
(string) - The relative path to your main JavaScript file.
(object) - Any extra fields you want to pass to your experience. Values are accessible via Expo.Constants.manifest.extra (Learn more)
(string)
(object)
(boolean)
(string)
(object) - Configuration for how and when the app should request OTA JavaScript updates
(boolean) - 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: This will not work out of the box with ExpoKit projects)
ExpoKit
For iOS, edit the areRemoteUpdatesEnabled key in ios/<PROJECT-NAME>/Supporting/EXShell.plist. For Android, edit 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.
(enum) - 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
(number) - 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).
(object) - Provide overrides by locale for System Dialog prompts like Permissions Boxes
Bare Workflow
To add or change language and localization information in your iOS app, you need to use Xcode.
(object) - Configuration that is specific to the iOS platform.
(string) - The manifest for the Android version of your app will be written to this path during publish.
(string) - The bundle for the Android version of your app will be written to this path during publish.
(string) - The bundle identifier for your iOS standalone app. You make it up, but it needs to be unique on the App Store. See this StackOverflow question.
iOS bundle identifier notation unique name for your app. For example, host.exp.expo, where exp.host is our domain and expo is our app name.
Bare Workflow
Set this value in info.plist under CFBundleIdentifier
(string) - Build number for your iOS standalone app. Corresponds to CFBundleVersion and must match Apple's specified format. (Note: Transporter will pull the value for Version Number from expo.version and NOT from expo.ios.buildNumber.)
Bare Workflow
Set this value in info.plist under CFBundleIdentifier
(string) - The background color for your iOS app, behind any of your React views. Overrides the top-level backgroundColor key if it is present.
6 character long hex color string, for example, '#000000'
(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.
(string) - Merchant ID for use with Apple Pay in your standalone app.
(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.
(object) - Note: This property key is not included in the production manifest and will evaluate to undefined. It is used internally only in the build process, because it contains API keys that some may want to keep private.
(object) - Branch key to hook up Branch linking services.
(string) - Your Branch API key
(boolean) - Sets ITSAppUsesNonExemptEncryption in the standalone ipa's Info.plist to the given boolean value.
(string) - Google Maps iOS SDK key for your standalone app.
(string) - Google Mobile Ads App ID Google AdMob App ID.
(boolean) - 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.
(object) - Google Sign-In iOS SDK keys for your standalone app.
(string) - The reserved client ID URL scheme. Can be found in GoogeService-Info.plist.
(string) - Firebase Configuration File Location of the GoogleService-Info.plist file for configuring Firebase.
(boolean) - Whether your standalone iOS app supports tablet screen sizes. Defaults to false.
Bare Workflow
Set this value in info.plist under UISupportedInterfaceOrientations~ipad
(boolean) - If true, indicates that your standalone iOS app does not support handsets, and only supports tablets.
Bare Workflow
Set this value in info.plist under UISupportedInterfaceOrientations
(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.
Bare Workflow
Use Xcode to set UIRequiresFullScreen
(enum) - Configuration to force the app to always use the light or dark user-interface appearance, such as "dark mode", or make it automatically adapt to the system preferences. If not provided, defaults to light.
(object) - Dictionary of arbitrary configuration to add to your standalone app's native Info.plist. Applied prior to all other Expo-specific configuration. No other validation is performed, so use this at your own risk of rejection from the App Store.
(array) - An array that contains Associated Domains for the standalone app. See Apple's docs for config.
Entries must follow the format applinks:<fully qualified domain>[:port number]. See Apple's docs for details
Bare Workflow
Use Xcode to set this. See Apple's documentation for details.
(boolean) - A boolean indicating if the app uses iCloud Storage for DocumentPicker. See DocumentPicker docs for details.
Bare Workflow
Use Xcode to set this.
(boolean) - A boolean indicating if the app uses Apple Sign-In. See AppleAuthentication docs for details.
ExpoKit
Use Xcode to set this.
(boolean) - A Boolean value that indicates whether the app may access the notes stored in contacts. You must receive permission from Apple before you can submit your app for review with this capability.
ExpoKit
Use Xcode to set this.
(object) - Configuration for loading and splash screen for standalone iOS apps.
(string) - Local path to a XIB file as the loading screen. It overrides other loading screen options. Note: 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.
(string) - Color to fill the loading screen background
6 character long hex color string, for example, '#000000'
(enum) - Determines how the image will be displayed in the splash loading screen. Must be one of cover or contain, defaults to contain.
ExpoKit
For Android, change SHOW_LOADING_VIEW_IN_SHELL_APP in android/app/src/main/java/host/exp/exponent/generated/AppConstants.java (true for contain, false for cover)
(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.
(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.
(enum) - 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.
(object) - Configuration that is specific to the Android platform.
(boolean) - If set to true, APK will contain only unimodules that are explicitly added in package.json and their dependecies
(string) - The manifest for the Android version of your app will be written to this path during publish.
(string) - The bundle for the Android version of your app will be written to this path during publish.
(string) - The package name for your Android standalone app. You make it up, but it needs to be unique on the Play Store. See this StackOverflow question.
Reverse DNS notation unique name for your app. Valid Android Application ID. For example, com.example.App, where com.example is our domain and App is our app. The name may only contain lowercase and uppercase letters (a-z, A-Z), numbers (0-9) and underscores (_), separated by periods (.). Each component of the name should start with a lowercase letter.
Bare Workflow
This is set in android/app/build.gradle as applicationId as well as in your AndroidManifest.xml file (multiple places).
(integer) - Version number required by Google Play. Increment by one for each release. Must be an integer. Learn more
Bare Workflow
This is set in android/app/build.gradle as versionCode
(string) - The background color for your Android app, behind any of your React views. Overrides the top-level backgroundColor key if it is present.
6 character long hex color string, for example, '#000000'
Bare Workflow
This is set in android/app/src/main/AndroidManifest.xml under android:windowBackground
(enum) - Configuration to force the app to always use the light or dark user-interface appearance, such as "dark mode", or make it automatically adapt to the system preferences. If not provided, defaults to light.
(boolean) - A Boolean value that indicates whether the app should use the new notifications API.
(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.
(object) - Settings for an Adaptive Launcher Icon on Android. Learn more
ExpoKit
Icons are saved in android/app/src/main/res/mipmap-<RESOLUTION>-v26
(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 and the android.icon keys. Should follow the specified guidelines. This icon will appear on the home screen.
(string) - Local path or remote URL to a background image for your app's Adaptive 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. Should follow the specified guidelines.
(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.
6 character long hex color string, for example, '#000000'
(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.
(array) - List of permissions used by the standalone app.
To use ONLY the following minimum necessary permissions and none of the extras supported by Expo in a default managed app, 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 ALL permissions supported by Expo by default, do not specify the permissions key.
To use the minimum necessary permissions ALONG with certain additional permissions, specify those extras in permissions, e.g.
[ "CAMERA", "ACCESS_FINE_LOCATION" ].
You can specify the following permissions depending on what you need:
  • ACCESS_COARSE_LOCATION
  • ACCESS_FINE_LOCATION
  • CAMERA
  • MANAGE_DOCUMENTS
  • READ_CONTACTS
  • READ_EXTERNAL_STORAGE
  • READ_INTERNAL_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
(string) - Firebase Configuration File Location of the GoogleService-Info.plist file for configuring Firebase. Including this key automatically enables FCM in your standalone app.
(object) - Note: This property key is not included in the production manifest and will evaluate to undefined. It is used internally only in the build process, because it contains API keys that some may want to keep private.
(object) - Branch key to hook up Branch linking services.
(string) - Your Branch API key
(object) - Google Maps Android SDK configuration for your standalone app.
(string) - Your Google Maps Android SDK API key
(string) - Google Mobile Ads App ID Google AdMob App ID.
(boolean) - 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
(object) - Configuration for loading and splash screen for standalone Android apps.
(string) - Color to fill the loading screen background
6 character long hex color string, for example, '#000000'
(enum) - Determines how the image will be displayed in the splash loading screen. Must be one of cover, contain or native, defaults to contain.
(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. Learn more
Natural sized image (baseline)
(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. Learn more
Scale 1.5x
(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. Learn more
Scale 2x
(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. Learn more
Scale 3x
(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. Learn more
Scale 4x
(array) - Configuration for setting an array of custom intent filters in Android manifest. Learn more
Bare Workflow
This is set in AndroidManifest.xml directly. Learn more.
[{ "autoVerify": true, "action": "VIEW", "data": { "scheme": "https", "host": "*.expo.io" }, "category": ["BROWSABLE", "DEFAULT"] }]
(boolean) - 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 use true and then configure your server to serve a JSON file verifying that you own the domain. Learn more
(string)
(array || object)
(string)
(string)
(string)
(string)
(string)
(string)
(string)
(array || string)
(boolean) - 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.
(enum) - Determines how the software keyboard will impact the layout of your application. This maps to the android:windowSoftInputMode property. Defaults to resize. Valid values: resize, pan.
(object) - Configuration that is specific to the web platform.
(string) - Relative path of an image to use for your app's favicon.
(string) - Defines the title of the document, defaults to the outer level name
(string) - A short version of the app's name, 12 characters or fewer. Used in app launcher and new tab pages. Maps to short_name in the PWA manifest.json. Defaults to the name property.
Maximum 12 characters long
(string) - Specifies the primary language for the values in the name and short_name members. This value is a string containing a single language tag.
(string) - Defines the navigation scope of this website's context. This restricts what web pages can be viewed while the manifest is applied. If the user navigates outside the scope, it returns to a normal web page inside a browser tab/window. If the scope is a relative URL, the base URL will be the URL of the manifest.
(string) - Defines the color of the Android tool bar, and may be reflected in the app's preview in task switchers.
6 character long hex color string, for example, '#000000'
(string) - Provides a general description of what the pinned website does.
(enum) - Specifies the primary text direction for the name, short_name, and description members. Together with the lang member, it helps the correct display of right-to-left languages.
(enum) - Defines the developers’ preferred display mode for the website.
(string) - The URL that loads when a user launches the application (e.g., when added to home screen), typically the index. Note: This has to be a relative URL, relative to the manifest URL.
(enum) - Defines the default orientation for all the website's top level browsing contexts.
(string) - Defines the expected “background color” for the website. This value repeats what is already available in the site’s CSS, but can be used by browsers to draw the background color of a shortcut when the manifest is available before the stylesheet has loaded. This creates a smooth transition between launching the web application and loading the site's content.
6 character long hex color string, for example, '#000000'
(enum) - If content is set to default, the status bar appears normal. If set to black, the status bar has a black background. If set to black-translucent, the status bar is black and translucent. If set to default or black, the web content is displayed below the status bar. If set to black-translucent, the web content is displayed on the entire screen, partially obscured by the status bar.
(boolean) - Hints for the user agent to indicate to the user that the specified native applications (defined in expo.ios and expo.android) are recommended over the website.
(object) - Experimental features. These will break without deprecation notice.
(string) - Viewport meta tag for your index.html. By default this is optimized for mobile usage, disabling zooming, and resizing for iPhone X.
(string) - Message that is rendered when the browser using your page doesn't have JS enabled.
(object) - Configuration for PWA splash screens.
Bare Workflow
(string) - Color to fill the loading screen background
6 character long hex color string, for example, '#000000'
(enum) - Determines how the image will be displayed in the splash loading screen. Must be one of cover or contain, defaults to contain.
(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.
(object) - Firebase web configuration. Used by the expo-firebase packages on both web and native. Learn more
(object)
(string)
(string)
(string)
(string)
(string)
(string)
(string)
(string)
(string) - Used for all Facebook libraries. Set up your Facebook App ID at https://developers.facebook.com.
Bare Workflow
(boolean) - Whether the Facebook SDK should be initialized automatically. The default in Expo (Client and in standalone apps) is false.
(boolean) - 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: The Facebook SDK must be initialized for app events to work. You may autoinitialize Facebook SDK by setting facebookAutoInitEnabled to true
Bare Workflow
(boolean) - 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.)
Bare Workflow
(string) - Used for native Facebook login.
Bare Workflow
(string) - Used for Facebook native login. Starts with 'fb' and followed by a string of digits, like 'fb1234567890'. You can find your scheme herein the 'Configuring Your info.plist' section (only applicable to standalone apps and custom Expo clients).
Bare Workflow
(boolean) - Is app detached
(object) - Extra fields needed by detached apps
(object) - Configuration for loading and splash screen for standalone apps.
Bare Workflow
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> (Android Studio can generate the appropriate image files for you). 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 required size.
(string) - Color to fill the loading screen background
6 character long hex color string, for example, '#000000'
Bare Workflow
For Android, edit the colorPrimary item in android/app/src/main/res/values/colors.xml
(enum) - Determines how the image will be displayed in the splash loading screen. Must be one of cover or contain, defaults to contain.
(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.
(object) - Configuration for scripts to run to hook into the publish process
(array)
(array) - 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
(object) - Enable experimental features that may be unstable, unsupported, or removed without deprecation notices.
(boolean) - Use the unstable LogBox re-design available in React Native 0.62. This option is only available in SDK 38.