Permissions
When you are creating an app that requires access to potentially sensitive information on a user's device, such as their location or contacts, you need to ask for the user's permission first. For example, to access the user's media library, you will need to use
MediaLibrary.requestPermissionsAsync().
In Expo Go, there isn't much you need to think about to interact with permissions beyond requesting permissions before using certain APIs. This changes when you want to deploy your app to an app store. Please read the
permissions on iOS and
permissions on Android sections carefully before deploying your app to stores. If you don't configure or explain the permissions properly
it may result in your app getting rejected or pulled from the stores. Read more about deploying to the stores in the
App Store Deployment Guide.
To request permissions on iOS, you have to describe why the permissions are requested and
install the library that can request this permission. In the managed workflow, you can do that by customizing the
ios.infoPlist property in your
app.json file.
To request permissions on iOS, you have to describe why the permissions are requested and install the library that requests and uses the permission. When using the bare workflow, you have to edit the project Info.plist.
On Android, permissions are little bit simpler than iOS. In the managed workflow, permissions are controlled via the
android.permissions property in your
app.json file. In the bare workflow, they have to be defined in your
AndroidManifest.xml.
Some Expo and React Native modules include permissions by default. If you use expo-location, for example, both the ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION are implied and added to your app's permissions automatically.
To limit the permissions your managed workflow app requires, set the
android.permissions property in your
app.json file to list only the permissions you need, and Expo will also include the minimum permissions it requires to run. See the
Permission types below to learn about which Android permissions are added. You can find a full list of all available permissions in the
Android Manifest.permissions reference.
- See the
android.permissions documentation to learn about which permissions are always included. - Apps using dangerous or signature permissions without valid reasons may be rejected by Google. Make sure you follow the Android permissions best practices when submitting your app.
- By default, the permissions implied by the modules you installed are added to the
AndroidManifest.xml at build time. To exclude permissions, you have to define the android.permissions manifest property.
In the bare workflow, permissions are controlled in your project AndroidManifest.xml.
Some Expo and React Native modules include permissions by default. If you use
expo-location, for example, both the
ACCESS_COARSE_LOCATION and
ACCESS_FINE_LOCATION are implied and added to your app's permissions automatically. To limit the permissions your managed workflow app requires, add them them to a
list of explicitly excluded permissions.
Apps using dangerous or signature permissions without valid reasons
may be rejected by Google. Make sure you follow the
Android permissions best practices when submitting your app.
When adding Expo and other React Native modules to your project, certain Android permissions might be implied automatically. The modules should only add relevant permissions required to use the module, however, sometimes you may want to remove some of these permissions.
Since the android.permissions manifest property doesn't work in the bare workflow- when you want to exclude specific permissions from the build, you have to "blacklist" them in your AndroidManifest.xml. You can do that with the tools:node="remove" attribute on the <use-permission> tag.
<manifest xmlns:tools="http://schemas.android.com/tools">
<uses-permission tools:node="remove" android:name="android.permission.ACCESS_FINE_LOCATION" />
</manifest>
Note: you have to define the xmlns:tools attribute on <manifest> before you can use the tools:node attribute on permissions.
On web permissions like the
Camera and
Location can only be requested from a
secure context, e.g. using
https:// or
http://localhost. This limitation is similar to Android's manifest permissions and iOS's infoPlist usage messages and enforced to increase privacy.
Often you want to be able to test what happens when a user rejects a permission, to ensure that it has the desired behavior. An operating-system level restriction on both iOS and Android prohibits an app from asking for the same permission more than once (you can imagine how this could be annoying for the user to be repeatedly prompted for permissions). So in order to test different flows involving permissions in development, you may need to uninstall and reinstall the Expo Go app. In the simulator this is as easy as deleting the app, and expo-cli will automatically install it again next time you launch the project.