React Native

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Which features are available in this library?
  • Event capture
  • Autocapture
  • User identification
  • Session recording
  • Feature flags
  • Group analytics

Purely built for React Native, this library allows you to integrate PostHog with your React Native project. For React Native projects built with Expo, there are no mobile native dependencies outside of supported Expo packages.

Installation

In your React Native or Expo project add the posthog-react-native package to your project as well as the required peer dependencies.

Expo apps

sh
npx expo install posthog-react-native expo-file-system expo-application expo-device expo-localization

React Native apps

sh
yarn add posthog-react-native @react-native-async-storage/async-storage react-native-device-info
# or
npm i -s posthog-react-native @react-native-async-storage/async-storage react-native-device-info

React Native Web and macOS

If you're using React Native Web or React Native macOS, do not use the expo-file-system package since the Web and macOS targets aren't supported, use the @react-native-async-storage/async-storage package instead.

Configuration

With the PosthogProvider

The recommended way to set up PostHog for React Native is to use the PostHogProvider which utilizes the Context API to pass the PostHog client around, enable autocapture, and ensure that the queue is flushed at the right time:

React Native
// App.(js|ts)
import { usePostHog, PostHogProvider } from 'posthog-react-native'
...
export function MyApp() {
return (
<PostHogProvider apiKey="<ph_project_api_key>" options={{
// usually 'https://app.posthog.com' or 'https://eu.posthog.com'
host: '<ph_instance_address>',
}}>
<MyComponent />
</PostHogProvider>
)
}
// Now you can simply access PostHog elsewhere in the app like so:
const MyComponent = () => {
const posthog = usePostHog()
useEffect(() => {
posthog.capture("mycomponent_loaded", { foo: "bar" })
}, [])
}

Without the PosthogProvider

React Native
// posthog.ts
import PostHog from 'posthog-react-native'
export const posthog = new PostHog('<ph_project_api_key>', {
// usually 'https://app.posthog.com' or 'https://eu.posthog.com'
host: '<ph_instance_address>'
})
// app.ts
import { posthog } from './posthog'
export function MyApp1() {
useEffect(async () => {
posthog.capture('myapp1_loaded')
}, [])
return <View>Your app code</View>
}
// You can even use this instance with the PostHogProvider
export function MyApp2() {
return <PostHogProvider client={posthog}>{/* Your app code */}</PostHogProvider>
}

Configuration options

You can further customize how PostHog works through its configuration on initialization.

TypeScript
export const posthog = new PostHog("<ph_project_api_key>", {
/** PostHog API host (usually 'https://app.posthog.com' by default or 'https://eu.posthog.com') */
host?: string,
/** The number of events to queue before sending to PostHog (flushing) */
flushAt?: number = 20,
/** The interval in milliseconds between periodic flushes */
flushInterval?: number = 10000,
/** If set to true the SDK is essentially disabled (useful for local environments where you don't want to track anything) */
disabled?: boolean,
/** If set to false the SDK will not track until the 'optIn' function is called. */
defaultOptIn?: boolean = true,
/** Whether to track that 'getFeatureFlag' was called (used by Experiments) */
sendFeatureFlagEvent?: boolean = true,
/** Whether to load feature flags when initialized or not */
preloadFeatureFlags?: boolean = true,
/** Option to bootstrap the library with given distinctId and feature flags */
bootstrap?: {
distinctId?: string
isIdentifiedId?: boolean
featureFlags?: Record<string, boolean | string>
featureFlagPayloads?: Record<string, JsonType>
},
/** How many times we will retry HTTP requests */
fetchRetryCount?: number = 3,
/** The delay between HTTP request retries */
fetchRetryDelay?: number = 3000,
/** Timeout in milliseconds for any calls. Defaults to 10 seconds. */
requestTimeout?: number = 10000,
/** For Session Analysis how long before we expire a session (defaults to 30 mins) */
sessionExpirationTimeSeconds?: number = 1800,
/** Whether to post events to PostHog in JSON or compressed format. Defaults to 'form' */
captureMode?: 'json' | 'form',
/** Allows you to provide the storage type. By default 'file'.
* 'file' will try to load the best available storage, the provided 'customStorage', 'customAsyncStorage' or in-memory storage.
*/
persistence?: 'memory' | 'file',
/** Allows you to provide your own implementation of the common information about your App or a function to modify the default App properties generated */
customAppProperties?:
| PostHogCustomAppProperties
| ((properties: PostHogCustomAppProperties) => PostHogCustomAppProperties),
/** Allows you to provide a custom asynchronous storage such as async-storage, expo-file-system or a synchronous storage such as mmkv.
* If not provided, PostHog will attempt to use the best available storage via optional peer dependencies (async-storage, expo-file-system).
* If 'persistence' is set to 'memory', this option will be ignored.
*/
customStorage?: PostHogCustomStorage,
/** Captures native app lifecycle events such as Application Installed, Application Updated, Application Opened, Application Became Active and Application Backgrounded.
* By default is false.
* If you're already using the 'captureLifecycleEvents' options with 'withReactNativeNavigation' or 'PostHogProvider, you should not set this to true, otherwise you may see duplicated events.
*/
captureNativeAppLifecycleEvents?: boolean = false
})

Usage

Capturing events

You can send custom events using capture:

React Native
posthog.capture('user_signed_up')

Tip: We recommend using a '[object][verb]' format for your event names, where '[object]' is the entity that the behavior relates to, and '[verb]' is the behavior itself. For example, project created, user signed up, or invite sent.

Setting event properties

Optionally, you can also include additional information in the event by setting the properties value:

React Native
posthog.capture('user_signed_up', {
login_type: "email",
is_free_trial: true
})

Autocapture

PostHog autocapture automatically tracks the following events for you:

  • Application Opened - when the app is opened from a closed state
  • Application Became Active - when the app comes to the foreground (e.g. from the app switcher)
  • Application Backgrounded - when the app is sent to the background by the user
  • Application Installed - when the app is installed.
  • Application Updated - when the app is updated.
  • $screen - when the user navigates (if using @react-navigation/native or react-native-navigation)
  • $autocapture - touch events when the user interacts with the screen

With autocapture, all touch events for children of PosthogProvider are tracked, capturing a snapshot of the view hierarchy at that point. This enables you to create insights in PostHog without having to add custom events.

PostHog will try to generate a sensible name for the touched element based on the React component displayName or name but you can force this to something reliable (and also clearly marked for PostHog tracking) using the ph-label prop.

React Native
<View ph-label="my-special-label"></View>

If there are elements you don't want to be captured, you can add the ph-no-capture property like so. If this property is found anywhere in the view hierarchy, the entire touch event is ignored.

React Native
<View ph-no-capture>Sensitive view here</View>

Tracking Screen views and touches with @react-navigation/native:

React Native
// App.(js|ts)
import { PostHogProvider } from 'posthog-react-native'
import { NavigationContainer } from '@react-navigation/native'
export function App() {
return (
<NavigationContainer>
<PostHogProvider apiKey="<ph_project_api_key>" autocapture>
{/* Rest of app */}
</PostHogProvider>
</NavigationContainer>
)
}

Tracking Screen views and touches with react-native-navigation:

React Native
import PostHog, { PostHogProvider } from 'posthog-react-native'
import { Navigation } from 'react-native-navigation';
export const posthog = new PostHog('<ph_project_api_key>');
// Simplify the wrapping of your Screens with a shared PostHogProvider
export const SharedPostHogProvider = (props: any) => {
return (
<PostHogProvider client={posthog} autocapture={{
captureLifecycleEvents: false, // Lifecycle events are handled differently for react-native-navigation
captureTouches: true,
}}>
{props.children}
</PostHogProvider>
);
};
export const MyScreen = () => {
return (
// Every screen needs to be wrapped with this provider if you want to capture touches or use the hook `usePostHog()`
<SharedPostHogProvider>
<View>
...
</View>
</SharedPostHogProvider>
);
};
Navigation.registerComponent('Screen', () => MyScreen);
Navigation.events().registerAppLaunchedListener(async () => {
posthog.initReactNativeNavigation({
navigation: {
// (Optional) Set the name based on the route. Defaults to the route name.
routeToName: (name, properties) => name,
// (Optional) Tracks all passProps as properties. Defaults to undefined
routeToProperties: (name, properties) => properties,
},
});
});

Autocapture configuration

You can tweak how autocapture works by passing custom options.

React Native
<PostHogProvider apiKey="<ph_project_api_key>" autocapture={{
captureTouches: true, // If you don't want to capture touch events set this to false
captureLifecycleEvents: true, // If you don't want to capture the Lifecycle Events (e.g. Application Opened) set this to false
captureScreens: true, // If you don't want to capture screen events set this to false
ignoreLabels: [], // Any labels here will be ignored from the stack in touch events
customLabelProp: "ph-label",
noCaptureProp: "ph-no-capture",
propsToCapture = ["testID"], // Limit which props are captured. By default, identifiers and text content are captured.
navigation: {
// By default only the Screen name is tracked but it is possible to track the
// params or modify the name by intercepting theautocapture like so
routeToName: (name, params) => {
if (params.id) return `${name}/${params.id}`
return name
},
routeToParams: (name, params) => {
if (name === "SensitiveScreen") return undefined
return params
},
}
}}>
...
</PostHogProvider>

Capturing screen views

With the PostHogProvider, screen tracking is automatically captured if the autocapture property is used. Currently only @react-navigation/native is supported by autocapture and it is important that the PostHogProvider is configured as a child of the NavigationContainer.

If you want to manually send a new screen capture event, use the screen function. This function requires a name. You may also pass in an optional properties object.

JavaScript
posthog.screen('dashboard', {
background: 'blue',
hero: 'superhog',
})

Identify

We highly recommend reading our section on Identifying users to better understand how to correctly use this method.

Using identify, you can associate events with specific users. This enables you to gain full insights as to how they're using your product across different sessions, devices, and platforms.

An identify call has the following arguments:

React Native
posthog.identify('distinctID',
{ // userProperties:
email: 'user@posthog.com',
name: 'My Name'
},
{ // userPropertiesSetOnce:
date_of_first_log_in: '2024-03-01'
}
)

You should call identify as soon as you're able to. Typically, this is every time your app loads for the first time as well as directly after your user logs in. This ensures that events sent during your user's sessions are correctly associated with them.

When you call identify, all previously tracked anonymous events will be linked to the user.

Setting user properties via an event

When capturing an event, you can pass a property called $set as an event property, and specify its value to be an object with properties to be set on the user that will be associated with the user who triggered the event.

$set

Example

JavaScript
posthog.capture('some_event', { $set: { userProperty: 'value' } })

Usage

When capturing an event, you can pass a property called $set as an event property, and specify its value to be an object with properties to be set on the user that will be associated with the user who triggered the event.

$set_once

Example

JavaScript
posthog.capture('some_event', { $set_once: { userProperty: 'value' } })

Usage

$set_once works just like $set, except that it will only set the property if the user doesn't already have that property set.

Super Properties

Super Properties are properties associated with events that are set once and then sent with every capture call, be it a $screen, an autocaptured touch, or anything else.

They are set using posthog.register, which takes a properties object as a parameter, and they persist across sessions.

For example, take a look at the following call:

JavaScript
posthog.register({
'icecream pref': 'vanilla',
team_id: 22,
})

The call above ensures that every event sent by the user will include "icecream pref": "vanilla" and "team_id": 22. This way, if you filtered events by property using icecream_pref = vanilla, it would display all events captured on that user after the posthog.register call, since they all include the specified Super Property.

However, please note that this does not store properties against the User, only against their events. To store properties against the User object, you should use posthog.identify. More information on this can be found on the Sending User Information section.

Removing stored Super Properties

Super Properties are persisted across sessions so you have to explicitly remove them if they are no longer relevant. In order to stop sending a Super Property with events, you can use posthog.unregister, like so:

JavaScript
posthog.unregister('icecream pref'),

This will remove the Super Property and subsequent events will not include it.

If you are doing this as part of a user logging out you can instead simply use posthog.reset which takes care of clearing all stored Super Properties and more.

Flush

You can set the number of events in the configuration that should queue before flushing. Setting this to 1 will send events immediately and will use more battery. This is set to 20 by default.

You can also configure the flush interval. By default we flush all events after 30 seconds, no matter how many events have gathered.

You can also manually flush the queue. If a flush is already in progress it returns a promise for the existing flush.

JavaScript
await posthog.flush()

Reset

To reset the user's ID and anonymous ID, call reset. Usually you would do this right after the user logs out.

JavaScript
posthog.reset()

Opt in/out

By default, PostHog has tracking enabled unless it is forcefully disabled by default using the option { defaultOptIn: false }.

You can give your users the option to opt in or out by calling the relevant methods. Once these have been called they are persisted and will be respected until optIn/Out is called again or the reset function is called.

To Opt in/out of tracking, use the following calls.

JavaScript
posthog.optIn() // opt in
posthog.optOut() // opt out

If you still wish capture these events but want to create a distinction between users and team in PostHog, you should look into Cohorts.

Feature Flags

PostHog's feature flags enable you to safely deploy and roll back new features.

There are two ways to implement feature flags in React Native:

  1. Using hooks.
  2. Loading the flag directly.

Method 1: Using hooks

Example 1: Boolean feature flags

React Native
import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
const booleanFlag = useFeatureFlag('key-for-your-boolean-flag')
if (showFlaggedFeature === undefined) {
// the response is undefined if the flags are being loaded
return null
}
return showFlaggedFeature ? <Text>Testing feature 😄</Text> : <Text>Not Testing feature 😢</Text>
}

Example 2: Multivariate feature flags

React Native
import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
const multiVariantFeature = useFeatureFlag('key-for-your-multivariate-flag')
if (multiVariantFeature === undefined) {
// the response is undefined if the flags are being loaded
return null
} else if (multiVariantFeature === 'variant-name') { // replace 'variant-name' with the name of your variant
// Do something
}
return <div/>
}

Method 2: Loading the flag directly

React Native
// Defaults to undefined if not loaded yet or if there was a problem loading
posthog.getFeatureFlag('key-for-your-boolean-flag')
// Multivariant feature flags are returned as a string
posthog.getFeatureFlag('key-for-your-multivariate-flag')

Reloading flags

PostHog loads feature flags when instantiated and refreshes whenever methods are called that affect the flag.

If you have the need to forcefully trigger the refresh however you can use reloadFeatureFlagsAsync():

React Native
posthog.reloadFeatureFlagsAsync().then((refreshedFlags) => console.log(refreshedFlags))

Request timeout

You can configure the feature_flag_request_timeout_ms parameter when initializing your PostHog client to set a flag request timeout. This helps prevent your code from being blocked in the case when PostHog's servers are too slow to respond. By default, this is set at 3 seconds.

JavaScript
posthog.init('<ph_project_api_key>', {
api_host: '<ph_instance_address>',
feature_flag_request_timeout_ms: 3000 // Time in milliseconds. Default is 3000 (3 seconds).
}
)

Bootstrapping Flags

Since there is a delay between initializing PostHog and fetching feature flags, feature flags are not always available immediately. This is detrimental if you want to do something like redirecting to a different page based on a feature flag.

To have your feature flags available immediately, you can initialize PostHog with precomputed values until PostHog has had a chance to fetch them. This is called bootstrapping.

For details on how to implement bootstrapping, see our bootstrapping guide.

Experiments (A/B tests)

Since experiments use feature flags, the code for running an experiment is very similar to the feature flags code:

React Native
// With the useFeatureFlag hook
import { useFeatureFlag } from 'posthog-react-native'
const MyComponent = () => {
const variant = useFeatureFlag('experiment-feature-flag-key')
if (variant === undefined) {
// the response is undefined if the flags are being loaded
return null
}
if (variant == 'variant-name') {
// do something
}
}

It's also possible to run experiments without using feature flags.

Group analytics

Group analytics allows you to associate the events for that person's session with a group (e.g. teams, organizations, etc.). Read the Group Analytics guide for more information.

Note: This is a paid feature and is not available on the open-source or free cloud plan. Learn more here.

  • Associate the events for this session with a group
JavaScript
posthog.group('company', 'company_id_in_your_db')
posthog.capture('upgraded_plan') // this event is associated with company ID `company_id_in_your_db`
  • Associate the events for this session with a group AND update the properties of that group
JavaScript
posthog.group('company', 'company_id_in_your_db', {
name: 'Awesome Inc.',
employees: 11,
})

The name is a special property which is used in the PostHog UI for the name of the Group. If you don't specify a name property, the group ID will be used instead.

Disabling for local development

You may want to disable PostHog when working locally or in a test environment. You can do this by setting the disable option to true when initializing PostHog. Helpfully this allows you to continue using usePostHog and safely calling it without anything actually happening.

React Native
// App.(js|ts)
import { usePostHog, PostHogProvider } from 'posthog-react-native'
...
export function MyApp() {
return (
<PostHogProvider apiKey="<ph_project_api_key>" options={{
// Disable PostHog in development (or whatever other logic you choose)
disabled: __DEV__,
}}>
<MyComponent />
</PostHogProvider>
)
}
const MyComponent = () => {
const posthog = usePostHog()
useEffect(() => {
// Safe to call even when disabled!
posthog.capture("mycomponent_loaded", { foo: "bar" })
}, [])
}

Upgrading from V1 or V2 to V3

V1 of this library utilised the underlying posthog-ios and posthog-android SDKs to do most of the work. Since the new version is written entirely in JS, using only Expo supported libraries, there are some changes to the way PostHog is configured as well as actually calling PostHog.

For iOS, the new React Native SDK will attempt to migrate the previously persisted data (such as distinctId and anonymousId) which should result in no unexpected changes to tracked data.

For Android, it is unfortunately not possible for persisted Android data to be loaded which means stored information such as the randomly generated anonymousId or the distinctId set by posthog.identify will not be present. For identified users, the simple workaround is to ensure that identify is called at least once when the app loads. For anonymous users there is unfortunately no straightforward workaround they will show up as new anonymous users in PostHog.

Events such as Application Installed and Application Updated that require previously persisted data were unable to be migrated, the side effect being that you may see much higher numbers for Application Installed events. This is due to the fact that there is no native way of detecting a real "install" and as such, we store a marker the first time the SDK loads and treat that as an install.

JSX
// DEPRECATED V1 Setup
import PostHog from 'posthog-react-native'
await PostHog.setup('<ph_project_api_key>', {
// usually 'https://app.posthog.com' or 'https://eu.posthog.com'
host: '<ph_instance_address>',
captureApplicationLifecycleEvents: false, // Replaced by 'PostHogProvider'
captureDeepLinks: false, // No longer supported
recordScreenViews: false, // Replaced by 'PostHogProvider' supporting @react-navigation/native
flushInterval: 30, // Stays the same
flushAt: 20, // Stays the same
android: {...}, // No longer needed
iOS: {...}, // No longer needed
})
PostHog.capture("foo")
// V2 Setup difference
import PostHog from 'posthog-react-native'
const posthog = await Posthog.initAsync('<ph_project_api_key>', {
// usually 'https://app.posthog.com' or 'https://eu.posthog.com'
host: '<ph_instance_address>',
// Add any other options here.
})
// Use created instance rather than the PostHog class
posthog.capture("foo")
// V3 Setup difference
import PostHog from 'posthog-react-native'
const posthog = new PostHog('<ph_project_api_key>', {
// usually 'https://app.posthog.com' or 'https://eu.posthog.com'
host: '<ph_instance_address>',
// Add any other options here.
})
// Use created instance rather than the PostHog class
posthog.capture("foo")

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