> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.onesignal.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Expo SDK setup
> Integrate the OneSignal Expo SDK into your iOS and Android apps using Expo SDK 53+ and EAS Build for push notifications and in-app messages.
export const SdkReleasesIframe = ({sdkFilter = undefined, viewMode = undefined, height, ...frameProps}) => {
const baseUrl = 'https://onesignal.github.io/sdk-releases';
const buildUrl = (theme, sdkFilter, viewMode) => {
const url = new URL(baseUrl);
const params = new URLSearchParams();
if (theme) {
params.set('theme', theme);
}
if (sdkFilter) {
params.set('sdk', sdkFilter);
}
if (viewMode) {
params.set('viewMode', viewMode);
}
if (params.toString()) {
url.search = params.toString();
}
return url.toString();
};
const detectTheme = () => {
if (document.documentElement.classList.contains('dark')) {
return 'dark';
}
return 'light';
};
const [theme, setTheme] = useState('light');
const [iframeSrc, setIframeSrc] = useState(() => {
const initialTheme = detectTheme();
return buildUrl(initialTheme, sdkFilter, viewMode);
});
useEffect(() => {
const currentTheme = detectTheme();
setTheme(currentTheme);
setIframeSrc(buildUrl(currentTheme, sdkFilter, viewMode));
const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
const handleThemeChange = () => {
const newTheme = detectTheme();
setTheme(newTheme);
setIframeSrc(buildUrl(newTheme, sdkFilter, viewMode));
};
if (mediaQuery.addEventListener) {
mediaQuery.addEventListener('change', handleThemeChange);
} else {
mediaQuery.addListener(handleThemeChange);
}
window.addEventListener('storage', handleThemeChange);
const observer = new MutationObserver(handleThemeChange);
observer.observe(document.documentElement, {
attributes: true,
attributeFilter: ['class', 'data-theme']
});
return () => {
if (mediaQuery.removeEventListener) {
mediaQuery.removeEventListener('change', handleThemeChange);
} else {
mediaQuery.removeListener(handleThemeChange);
}
window.removeEventListener('storage', handleThemeChange);
observer.disconnect();
};
}, [sdkFilter, viewMode]);
const getIframeHeight = () => {
if (viewMode === 'table') {
return '450';
}
if (viewMode === 'mini') {
return '170';
}
return '800';
};
const iframeHeight = height || getIframeHeight();
return
;
};
**Using an AI coding assistant?** Use this prompt for AI-driven installation:
```
Integrate the OneSignal Expo SDK into this codebase.
Follow the instructions at:
https://raw.githubusercontent.com/OneSignal/sdk-ai-prompts/main/docs/react-native-expo/ai-prompt.md
```
**Expo Go limitation:** Push notifications do not work in Expo Go. You must create a [development build](https://docs.expo.dev/develop/development-builds/introduction/) to test OneSignal features.
## Requirements
* A managed Expo app. For bare React Native apps, see [React Native SDK setup](./react-native-sdk-setup).
* Expo [development build](https://docs.expo.dev/develop/development-builds/introduction/)
* Expo SDK 53+ (React Native 0.79+) with [New Architecture](https://reactnative.dev/docs/new-architecture-intro) enabled
* EAS CLI ([EAS Build documentation](https://docs.expo.dev/build/introduction/))
* Configured OneSignal app and platform
**iOS Requirements**
* macOS with Xcode 14+ (setup instructions use Xcode 16.2)
* Device with iOS 12+, iPadOS 12+, or Xcode simulator running iOS 16.2+
* CocoaPods 1.16.2+
**Android Requirements**
* Android 7.0+ device or emulator with Google Play Store (Services) installed
### Configure your OneSignal app and platform
Configure your OneSignal app with the platforms you support — Apple (APNs), Google (FCM), Huawei (HMS), and/or Amazon (ADM).
If your organization already has a OneSignal account, [ask to be invited](/docs/en/manage-team-members) to the Organization. Otherwise, [sign up for a free account](https://onesignal.com) to get started.
Create a new app by clicking **New App/Website**, or add a platform to an existing app in **Settings > Push & In-App**. Select the platform(s) you want to configure and click **Next: Configure Your Platform**.
Enter the credentials for your platform:
* **Android**: [Set up Firebase credentials](/docs/en/android-firebase-credentials)
* **iOS**: [p8 token (recommended)](/docs/en/ios-p8-token-based-connection-to-apns) or [p12 certificate](/docs/en/ios-p12-generate-certificates)
* **Amazon**: [Generate API key](/docs/en/generate-an-amazon-api-key)
* **Huawei**: [Authorize OneSignal](/docs/en/authorize-onesignal-to-send-huawei-push)
Click **Save & Continue** after entering your credentials.
Your **App ID** is displayed on the final screen. Copy and save it — you need it when initializing the SDK. Select your SDK platform, then follow the setup guide.
***
## SDK setup
### 1. Add SDK
Install the OneSignal Expo plugin using the Expo CLI.
```shell npm theme={null}
npx expo install onesignal-expo-plugin
```
Add the `react-native-onesignal` package to your project.
```shell npm theme={null}
npm install --save react-native-onesignal
```
```shell Yarn theme={null}
yarn add react-native-onesignal
```
### 2. Configure the plugin
Open your `app.json` (or `app.config.js` / `app.config.ts`). You must include the following settings.
**Required settings**
Your app's bundle identifier. Must match the p8 or p12 authentication configured in your OneSignal app.
Must include the `UIBackgroundModes` key set to `["remote-notification"]`.
iOS entitlements required for push notifications.
* Set `aps-environment` to `"development"` for testing and `"production"` for TestFlight and App Store builds.
Make sure to add the plugin `[onesignal-expo-plugin]` to the front of the plugins array. It should be the first plugin in the array. Doing so will prevent the `OneSignal/OneSignal.h file not found` error.
| Prop | Required | Description |
| :----------------------: | :--------: | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `mode` | ✅ | Configures the [APNs environment](https://developer.apple.com/documentation/bundleresources/entitlements/aps-environment) entitlement. Use `"development"` or `"production"` — `"development"` for testing and `"production"` for TestFlight and App Store builds. |
| `devTeam` | Deprecated | **Deprecated.** Prefer [`ios.appleTeamId`](https://docs.expo.dev/versions/latest/config/app/#appleteamid) in your Expo config. The plugin falls back to `devTeam` if `appleTeamId` is not set. |
| `iPhoneDeploymentTarget` | ❌ | `IPHONEOS_DEPLOYMENT_TARGET` used when adding the iOS [Notification Service Extension](./service-extensions). Should match the minimum iOS version in your Podfile (e.g., `"15.0"`). |
| `smallIcons` | ❌ | Array of local paths to Android [small notification icons](./notification-icons#small-notification-icons) (white, transparent, 96×96px). Images are auto-scaled into the correct resource folders. Example: `["./assets/ic_stat_onesignal_default.png"]` |
| `largeIcons` | ❌ | Array of local paths to Android [large notification icons](./notification-icons#large-notification-icons) (white, transparent, 256×256px). Example: `["./assets/ic_onesignal_large_icon_default.png"]` |
| `smallIconAccentColor` | ❌ | Hex color for the Android notification icon accent (e.g., `"#FF0000"`). |
| `iosNSEFilePath` | ❌ | Local path to a custom Notification Service Extension in Objective-C. Example: `"./assets/NotificationService.m"` |
| `appGroupName` | ❌ | Custom iOS [App Group](./ios-sdk-setup#step-3-create-an-app-group) name. Defaults to `"group.{ios.bundleIdentifier}.onesignal"` if omitted (e.g., `"group.com.example.myapp.onesignal2"`). |
| `nseBundleIdentifier` | ❌ | Suffix for the NSE bundle ID. The full identifier is `{ios.bundleIdentifier}.{nseBundleIdentifier}`. Defaults to `OneSignalNotificationServiceExtension` if omitted. |
| `disableNSE` | ❌ | If `true`, the iOS NSE is not added. The NSE is required for badges, confirmed receipt, media attachments, and action buttons — only disable if you need basic push only. |
| `disableLocation` | ❌ | If `true`, the native OneSignal location module is excluded from iOS and Android builds. Use this only if your app does not call `OneSignal.Location`. |
| `sounds` | ❌ | Array of local paths to custom notification sounds (`.wav` only, ≤30 seconds). Copied into the app bundle on iOS and `res/raw/` on Android. Example: `["./assets/notification_sound.wav"]`. See [Notification sounds](./notification-sounds). |
#### Optional: Disable the location module
If your app does not use `OneSignal.Location`, set `disableLocation` to `true` in the OneSignal Expo plugin props. This option requires `react-native-onesignal` 5.5.1 or later. The plugin configures native dependency resolution so `react-native-onesignal` excludes the location module. On iOS, the plugin writes the Podfile environment setting used during CocoaPods resolution. On Android, the plugin writes `onesignal.disableLocation=true` to the generated Gradle properties.
```ts app.config.ts theme={null}
plugins: [
withOneSignal({
mode: 'development',
disableLocation: true,
}),
],
```
```json app.json theme={null}
"plugins": [
[
"onesignal-expo-plugin",
{
"mode": "development",
"disableLocation": true
}
]
]
```
Starting in `onesignal-expo-plugin` 2.6.0, you can import `withOneSignal` for full TypeScript support and autocompletion on the plugin props.
```ts app.config.ts theme={null}
import { ConfigContext, ExpoConfig } from '@expo/config';
import withOneSignal from 'onesignal-expo-plugin/plugin';
export default ({ config }: ConfigContext): ExpoConfig => ({
...config,
ios: {
bundleIdentifier: 'com.yourcompany.yourapp',
infoPlist: {
UIBackgroundModes: ['remote-notification'],
},
entitlements: {
'aps-environment': 'development',
},
},
android: {
package: 'com.yourcompany.yourapp',
},
plugins: [
withOneSignal({
mode: 'development',
}),
],
});
```
```json app.json theme={null}
{
"expo": {
"ios": {
"bundleIdentifier": "com.yourcompany.yourapp",
"infoPlist": {
"UIBackgroundModes": ["remote-notification"]
},
"entitlements": {
"aps-environment": "development"
}
},
"android": {
"package": "com.yourcompany.yourapp"
},
"plugins": [
[
"onesignal-expo-plugin",
{
"mode": "development"
}
]
]
}
}
```
### 3. Initialize SDK
Depending on your Expo structure (Traditional App entry or Expo Router), initialize OneSignal following these options.
In your `App.tsx` or `App.js` file initialize OneSignal with the provided methods.
Replace `YOUR_APP_ID` with your OneSignal App ID found in your OneSignal dashboard **Settings > [Keys & IDs](./keys-and-ids)**.
If you don't have access to the OneSignal app, ask your [Team Members](./manage-team-members) to invite you.
```javascript App.tsx theme={null}
import React, { useEffect } from 'react';
// Include the OneSignal package
import { OneSignal, LogLevel } from 'react-native-onesignal';
export default function App() {
useEffect(() => {
// Enable verbose logging for debugging (remove in production)
OneSignal.Debug.setLogLevel(LogLevel.Verbose);
// Replace with your OneSignal App ID from Dashboard > Settings > Keys & IDs
OneSignal.initialize('YOUR_APP_ID');
// Prompt for push permission on first launch.
// In production, consider using an in-app message instead for better opt-in rates.
OneSignal.Notifications.requestPermission(false);
// Define listeners once so the same reference is used to add and remove them.
const clickListener = (event) => {
console.log('OneSignal: notification clicked:', event);
};
// In v5, foreground notifications display automatically.
// Call event.preventDefault() to suppress, then
// event.getNotification().display() to show after async work.
const foregroundListener = (event) => {
console.log('OneSignal: foreground will display:', event);
};
OneSignal.Notifications.addEventListener('click', clickListener);
OneSignal.Notifications.addEventListener('foregroundWillDisplay', foregroundListener);
// Clean up listeners when the component unmounts to prevent memory leaks.
// The same listener reference passed to addEventListener must be passed here.
return () => {
OneSignal.Notifications.removeEventListener('click', clickListener);
OneSignal.Notifications.removeEventListener('foregroundWillDisplay', foregroundListener);
};
}, []);
}
```
In your `app/_layout.tsx` or `app/_layout.js` file initialize OneSignal with the provided methods. The example below uses `App` as the function name — Expo Router accepts any default-exported component, so renaming it to `RootLayout` is optional but conventional.
Replace `YOUR_APP_ID` with your OneSignal App ID found in your OneSignal dashboard **Settings > [Keys & IDs](./keys-and-ids)**.
If you don't have access to the OneSignal app, ask your [Team Members](./manage-team-members) to invite you.
```javascript App.tsx theme={null}
import React, { useEffect } from 'react';
// Include the OneSignal package
import { OneSignal, LogLevel } from 'react-native-onesignal';
export default function App() {
useEffect(() => {
// Enable verbose logging for debugging (remove in production)
OneSignal.Debug.setLogLevel(LogLevel.Verbose);
// Replace with your OneSignal App ID from Dashboard > Settings > Keys & IDs
OneSignal.initialize('YOUR_APP_ID');
// Prompt for push permission on first launch.
// In production, consider using an in-app message instead for better opt-in rates.
OneSignal.Notifications.requestPermission(false);
// Define listeners once so the same reference is used to add and remove them.
const clickListener = (event) => {
console.log('OneSignal: notification clicked:', event);
};
// In v5, foreground notifications display automatically.
// Call event.preventDefault() to suppress, then
// event.getNotification().display() to show after async work.
const foregroundListener = (event) => {
console.log('OneSignal: foreground will display:', event);
};
OneSignal.Notifications.addEventListener('click', clickListener);
OneSignal.Notifications.addEventListener('foregroundWillDisplay', foregroundListener);
// Clean up listeners when the component unmounts to prevent memory leaks.
// The same listener reference passed to addEventListener must be passed here.
return () => {
OneSignal.Notifications.removeEventListener('click', clickListener);
OneSignal.Notifications.removeEventListener('foregroundWillDisplay', foregroundListener);
};
}, []);
}
```
**Reusable listeners with `useCallback`**
If your listener needs access to props or state, define it outside `useEffect` with `useCallback` so the same reference is used to add and remove the listener. Passing different function references to `addEventListener` and `removeEventListener` is a silent no-op — the listener will not be removed and can fire after the component unmounts.
```javascript theme={null}
import React, { useCallback, useEffect } from 'react';
import { OneSignal } from 'react-native-onesignal';
export default function App() {
const clickListener = useCallback((event) => {
console.log('OneSignal: notification clicked:', event);
// your deps may vary
}, []);
useEffect(() => {
OneSignal.Notifications.addEventListener('click', clickListener);
return () => {
OneSignal.Notifications.removeEventListener('click', clickListener);
};
}, [clickListener]);
}
```
Review our [OneSignal Expo Plugin GitHub repo](https://github.com/OneSignal/onesignal-expo-plugin) for additional configuration options, more complex setup instructions or open an issue. Our SDKs are open source and we welcome PRs!
***
## Android setup
Make sure your OneSignal app is configured for the Android platform using your [Firebase credentials](/docs/en/android-firebase-credentials).
Set up your [notification icons](/docs/en/notification-icons) to match your app’s branding. If this step is skipped, a default bell icon will display for your push notifications.
**Build for Android**
At this point, you should be able to build and run your app on a physical Android device or emulator without issues.
After confirming that your Android build works:
* Continue with the [iOS setup](#ios-setup), if applicable.
* Or jump ahead to [Testing the OneSignal SDK integration](#testing-the-onesignal-sdk-integration).
***
## iOS setup
Make sure your OneSignal app is configured for the iOS platform using either the [p8 Token (Recommended)](./ios-p8-token-based-connection-to-apns) or [p12 Certificate](./ios-p12-generate-certificates).
This should use the same credentials setup in your EAS configuration.
### Build for iOS
You should now be able to build and run your app on a real iOS device or iOS simulator (16.2+).
#### Common iOS build errors
You may see this error when building with Xcode 15+, due to a default configuration change affecting cross platform systems.
1. Open your `.xcworkspace` folder in Xcode and navigate to **your app target > Build Phases**.
2. You should have a phase called **"Embed Foundation Extensions"** or **"Embed App Extensions"**.
3. Drag and move this build phase to *above* **"Run Script"**.
4. Build and run your app. The error should be resolved.
RuntimeError - `PBXGroup` attempted to initialize an object with unknown ISA `PBXFileSystemSynchronizedRootGroup` from attributes: `{"isa"=>"...", "exceptions"=>["//", "..."], "explicitFileTypes"=>{}, "explicitFolders"=>[], "path"=>"OneSignalNotificationServiceExtension", "sourceTree"=>""}`
Fix:
1. Find the folder listed under "path" in the error
2. In Xcode project sidebar, right-click the folder
3. Select **Convert to Group**
After confirming that your iOS build works, continue with [Testing the OneSignal SDK integration](#testing-the-onesignal-sdk-integration).
***
## Testing the OneSignal SDK integration
This guide helps you verify that your OneSignal SDK integration is working correctly by testing push notifications, subscription registration, and in-app messaging.
If you are testing with an Android emulator, it should start with a cold boot.
1. Go to **Device Manager** in Android Studio.
2. Select your emulator device and click **Edit**.
3. Go to **Additional Settings** or **More**.
4. Set the **Boot option** to **Cold Boot**.
5. Save changes and restart the emulator.
### Check mobile subscriptions
The native push permission prompt should appear automatically if you added the `requestPermission` method during initialization.
Before accepting the prompt, check the OneSignal dashboard:
* Go to **Audience > Subscriptions**.
* You should see a new entry with the status "Never Subscribed".
The subscription's status should now show **Subscribed**.
You have successfully created a [mobile subscription](/docs/en/subscriptions).
Mobile subscriptions are created when users first open your app on a device or if they uninstall and reinstall your app on the same device.
### Set up test users
test users are helpful for testing a push notification before sending a message.
In the dashboard, next to the subscription, click the **Options (three dots)** button and select **Add to Test Users**.
Name the subscription so you can easily identify your device later in the **test users tab**.
Go to **Audience > Segments > New Segment**.
Name the segment `Test Users` (the name is important because it will be used later).
You have successfully created a segment of test users.
We can now test sending messages to this individual device and groups of test users.
### Send test push via API
In your OneSignal dashboard, go to **Settings > [Keys & IDs](/docs/en/keys-and-ids)**.
Replace `YOUR_APP_API_KEY` and `YOUR_APP_ID` in the code below with your actual keys. This code uses the `Test Users` segment we created earlier.
```curl theme={null}
curl -X \
POST --url 'https://api.onesignal.com/notifications' \
--header 'content-type: application/json; charset=utf-8' \
--header 'authorization: Key YOUR_APP_API_KEY' \
--data \
'{
"app_id": "YOUR_APP_ID",
"target_channel": "push",
"name": "Testing basic setup",
"headings": {
"en": "👋"
},
"contents": {
"en": "Hello world!"
},
"included_segments": [
"Test Users"
],
"ios_attachments": {
"onesignal_logo": "https://avatars.githubusercontent.com/u/11823027?s=200&v=4"
},
"big_picture": "https://avatars.githubusercontent.com/u/11823027?s=200&v=4"
}'
```
Run the code in your terminal.
If all setup steps were completed successfully, the test users should receive a notification with an image included:
Images will appear small in the collapsed notification view. Expand the notification to see the full image.
In your dashboard, go to **Delivery > Sent Messages**, then click the message to view stats.
You should see the **confirmed** stat, meaning the device received the push.
You have successfully sent a notification via our API to a segment.
* No image received? Your [Notification Service Extension](#ios-setup) might be missing.
* No confirmed receipt? Review the troubleshooting guide [here](/docs/en/confirmed-delivery#troubleshooting-confirmed-delivery).
* Having issues? Copy-paste the api request and a log from start to finish of app launch into a `.txt` file. Then share both with `support@onesignal.com`.
### Send an in-app message
[In-app messages](/docs/en/in-app-messages-setup) let you communicate with users while they are using your app.
This is because users must meet the in-app audience criteria *before* a new session starts. In OneSignal, a new session starts when the user opens your app after it has been in the background or closed for at least 30 seconds. For more details, see our guide on [how in-app messages are displayed](/docs/en/in-app-messages-setup#how-are-iams-displayed%3F).
* In your OneSignal dashboard, navigate to **Messages > In-App > New In-App**.
* Find and select the **Welcome** message.
* Set your Audience as the **Test Users** segment we used previously.
Under **Schedule > How often do you want to show this message?** select **Every time trigger conditions are satisfied**.
Click **Make Message Live** so it is available to your Test Users each time they open the app.
After the in-app message is live, open your app. You should see it display:
Not seeing the message?
* Start a new session
* You must close or background the app for at least 30 seconds before reopening. This ensures a new session is started.
* For more, see [how in-app messages are displayed](/docs/en/in-app-messages-setup#how-are-iams-displayed%3F).
* Still in the `Test Users` segment?
* If you reinstalled or switched devices, re-add the device to [Test Users](#set-up-test-users) and confirm it's part of the Test Users segment.
* Having issues?
* Follow [Getting a Debug Log](/docs/en/capturing-a-debug-log) while reproducing the steps above. This will generate additional logging that you can share with `support@onesignal.com` and we will help investigate what's going on.
You have successfully setup the OneSignal SDK and learned important concepts like:
* Gathering [Subscriptions](/docs/en/subscriptions), setting [Test Users](/docs/en/find-set-test-subscriptions), and creating [Segments](/docs/en/segmentation).
* Sending [Push](/docs/en/push) with images and [Confirmed receipt](/docs/en/confirmed-delivery) using Segments and our [Create message](/reference/create-message) API.
* Sending [In-app messages](/docs/en/in-app-messages-setup).
Continue with this guide to identify users in your app and setup additional features.
***
## User identification
Previously, we demonstrated how to create mobile [Subscriptions](/docs/en/subscriptions). Now we'll expand to identifying [Users](/docs/en/users) across all their subscriptions (including push, email, and SMS) using the OneSignal SDK. We'll cover External IDs, tags, multi-channel subscriptions, privacy, and event tracking to help you unify and engage users across platforms.
### Assign External ID
Use an External ID to identify users consistently across devices, email addresses, and phone numbers using your backend's user identifier. This ensures your messaging stays unified across channels and 3rd party systems (especially important for [Integrations](/docs/en/integrations)).
Set the External ID with our SDK's [`login` method](/docs/en/mobile-sdk-reference#login-external-id) each time they are identified by your app.
OneSignal generates unique read-only IDs for subscriptions (Subscription ID) and users (OneSignal ID).
As users download your app on different devices, subscribe to your website, and/or provide you email addresses and phone numbers outside of your app, new subscriptions will be created.
Setting the External ID via our SDK is highly recommended to identify users across all their subscriptions, regardless of how they are created.
### Add Tags
[Tags](/docs/en/add-user-data-tags) are key-value pairs of string data you can use to store user properties (like `username`, `role`, or preferences) and events (like `purchase_date`, `game_level`, or user interactions). Tags power advanced [Message Personalization](/docs/en/message-personalization) and [Segmentation](/docs/en/segmentation) allowing for more advanced use cases.
Set tags with our SDK [`addTag` and `addTags` methods](/docs/en/mobile-sdk-reference#data-tags) as events occur in your app.
In this example, the user reached level 6 identifiable by the tag called `current_level` set to a value of `6`.
We can create a segment of users that have a level of between 5 and 10, and use that to send targeted and personalized messages:
### Add email and/or SMS subscriptions
Earlier we saw how our SDK creates mobile subscriptions to send push and in-app messages. You can also reach users through emails and SMS channels by creating the corresponding subscriptions.
* Use the [`addEmail` method](/docs/en/mobile-sdk-reference#addemail-%2C-removeemail) to create email subscriptions.
* Use the [`addSms` method](/docs/en/mobile-sdk-reference#addsms-%2C-removesms) to create SMS subscriptions.
If the email address and/or phone number already exist in the OneSignal app, the SDK will add it to the existing user, it will not create duplicates.
You can view unified users via **Audience > Users** in the dashboard or with the [View user API](/reference/view-user).
Best practices for multi-channel communication
* Obtain explicit consent before adding email or SMS subscriptions.
* Explain the benefits of each communication channel to users.
* Provide channel preferences so users can select which channels they prefer.
***
### Privacy & user consent
To control when OneSignal collects user data, use the SDK's consent gating methods:
* [`setConsentRequired(true)`](/docs/en/mobile-sdk-reference#setconsentrequired): Prevents data collection until consent is given.
* [`setConsentGiven(true)`](/docs/en/mobile-sdk-reference#setconsentgiven): Enables data collection once consent is granted.
See our Privacy & security docs for more on:
* [Data collected by the SDK](/docs/en/data-collected-by-the-onesignal-sdk)
* [Handling personal data](/docs/en/handling-personal-data)
***
## Prompt for push permissions
Instead of calling `requestPermission()` immediately on app open, take a more strategic approach. Use an in-app message to explain the value of push notifications before requesting permission.
For best practices and implementation details, see our [Prompt for push permissions](/docs/en/prompt-for-push-permissions) guide.
***
## Listen to push, user, and in-app events
Use SDK listeners to react to user actions and state changes.
The SDK provides several event listeners for you to hook into. See our [SDK reference guide](/docs/en/mobile-sdk-reference) for more details.
### Push notification events
* [`addClickListener()`](/docs/en/mobile-sdk-reference#addclicklistener-push): Detect when a notification is tapped. Helpful for [Deep Linking](/docs/en/deep-linking).
* [`addForegroundLifecycleListener()`](/docs/en/mobile-sdk-reference#addforegroundlifecyclelistener-push): Control how notifications behave in foreground.
For full customization, see [Mobile Service Extensions](/docs/en/service-extensions).
### User state changes
* [`addObserver()` for user state](/docs/en/mobile-sdk-reference#addobserver-user-state): Detect when the External ID is set.
* [`addPermissionObserver()`](/docs/en/mobile-sdk-reference#addpermissionobserver-push): Track the user's specific interaction with the native push permission prompt.
* [`addObserver()` for push subscription](/docs/en/mobile-sdk-reference#addobserver-push-subscription-changes): Track when the push subscription status changes.
### In-app message events
* [`addClickListener()`](/docs/en/mobile-sdk-reference#addclicklistener-in-app): Handle in-app click actions. Ideal for deep linking or tracking events.
* [`addLifecycleListener()`](/docs/en/mobile-sdk-reference#addclicklistener-in-app): Track full lifecycle of in-app messages (shown, clicked, dismissed, etc.).
***
## Advanced setup & capabilities
Explore more capabilities to enhance your integration:
* [🔁 Migrating to OneSignal from another service](/docs/en/migrating-to-onesignal)
* [🌍 Location tracking](/docs/en/mobile-sdk-reference#location)
* [🔗 Deep Linking](/docs/en/deep-linking)
* [🔌 Integrations](/docs/en/integrations)
* [🧩 Mobile Service Extensions](/docs/en/service-extensions)
* [🛎️ Action buttons](/docs/en/action-buttons)
* [🌐 Multi-language messaging](/docs/en/multi-language-messaging)
* [🛡️ Identity Verification](/docs/en/identity-verification)
* [📊 Custom Outcomes](/docs/en/custom-outcomes)
* [📲 Live Activities](/docs/en/live-activities)
### Mobile SDK setup & reference
Make sure you've enabled all key features by reviewing the [Mobile push setup](/docs/en/mobile-push-setup) guide.
For full details on available methods and configuration options, visit the [Mobile SDK reference](/docs/en/mobile-sdk-reference).
Congratulations! You've successfully completed the Mobile SDK setup guide.
***
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## Privacy and user consent
If your app requires user consent before collecting data (e.g., for GDPR compliance), you can delay OneSignal's data collection until consent is granted. Call `setConsentRequired` **before** `initialize`.
```javascript theme={null}
// Call BEFORE OneSignal.initialize()
OneSignal.setConsentRequired(true);
OneSignal.initialize('YOUR_APP_ID');
// Later, after the user grants consent (e.g., via a consent dialog)
OneSignal.setConsentGiven(true);
```
When consent is required but not yet given, the SDK initializes but does not send any data to OneSignal. Call `setConsentGiven(true)` once the user opts in. See [Handling Personal Data](./handling-personal-data) for more details.
***
## Troubleshooting
| Error / Symptom | Platform | Fix |
| ----------------------------------------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `OneSignal/OneSignal.h file not found` | iOS | Move `onesignal-expo-plugin` to the **first** position in the `plugins` array in `app.json` |
| `Unable to find onesignal-expo-plugin` | Both | Run `npx expo install onesignal-expo-plugin` and verify it appears in `package.json` |
| Push notifications don't work in Expo Go | Both | Push requires a [development build](https://docs.expo.dev/develop/development-builds/introduction/) — Expo Go does not support native modules like OneSignal |
| No push notifications on iOS | iOS | Verify APNs credentials in OneSignal and that `aps-environment` in `app.json` matches your build type (`development` or `production`) |
| No push notifications on Android | Android | Verify FCM credentials in OneSignal and that the device has Google Play Services |
| `Bundle identifier mismatch` | iOS | Ensure `ios.bundleIdentifier` in `app.json` matches your Apple Developer account and OneSignal APNs configuration |
| `eas build` fails with OneSignal errors | Both | Validate `app.json` plugin configuration — check required fields and plugin ordering |
| `Cycle Inside... building could produce unreliable results` | iOS | See the [iOS build errors section](#common-ios-build-errors) above |
| `PBXGroup` / `PBXFileSystemSynchronizedRootGroup` error | iOS | Right-click the folder in Xcode project sidebar and select **Convert to Group** — see [iOS build errors section](#common-ios-build-errors) |
| Can't diagnose the issue | Both | Add `OneSignal.Debug.setLogLevel(LogLevel.Verbose)` before `initialize` and check device logs |
Need help?
Chat with our Support team or email `support@onesignal.com`
Please include:
* Details of the issue you're experiencing and steps to reproduce if available
* Your OneSignal App ID
* The External ID or Subscription ID if applicable
* The URL to the message you tested in the OneSignal Dashboard if applicable
* Any relevant [logs or error messages](/docs/en/capturing-a-debug-log)
We're happy to help!