React Native logs installation

PostHog's React Native SDK has built-in support for capturing structured logs. Unlike other languages where you wire OpenTelemetry directly, the SDK handles the OTLP encoding, batching, persistence, and lifecycle for you. You just call posthog.captureLog(...) or posthog.logger.{trace,debug,info,warn,error,fatal}(...).

JavaScript layer only. Logs are captured from the JavaScript side of your app. Native logs from your iOS or Android code (e.g. os_log, Log.d) are not collected.

Minimum version: posthog-react-native@4.44.0 or later. Run npx expo install posthog-react-native (Expo) or your package manager's equivalent to update.

Install posthog-react-native

Required

If you haven't already, install and initialize posthog-react-native using the steps below. For full details, see the React Native SDK guide.

Our React Native enables 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.

To install, add the posthog-react-native package to your project as well as the required peer dependencies.

Expo apps

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

React Native apps

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

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. This utilizes the Context API to pass the PostHog client around, and enables autocapture.

To set up PostHogProvider, add it to your App.js or App.ts file:

App.js
// App.(js|ts)
import { usePostHog, PostHogProvider } from 'posthog-react-native'
...

export function MyApp() {
    return (
        <PostHogProvider apiKey="<ph_project_token>" options={{
            // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
            host: 'https://us.i.posthog.com', 
        }}>
            <MyComponent />
        </PostHogProvider>
    )
}

Then you can access PostHog using the usePostHog() hook:

React Native
const MyComponent = () => {
    const posthog = usePostHog()

    useEffect(() => {
        posthog.capture("event_name")
    }, [posthog])
}

Without the PosthogProvider

If you prefer not to use the provider, you can initialize PostHog in its own file and import the instance from there:

posthog.ts
import PostHog from 'posthog-react-native'

export const posthog = new PostHog('<ph_project_token>', {
  // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'  
  host: 'https://us.i.posthog.com' 
})

Then you can access PostHog by importing your instance:

React Native
import { posthog } from './posthog'

export function MyApp1() {
    useEffect(() => {
        posthog.capture('event_name')
    }, [])

    return <View>Your app code</View>
}

You can even use this instance with the PostHogProvider:

React Native
import { posthog } from './posthog'

export function MyApp() {
  return <PostHogProvider client={posthog}>{/* Your app code */}</PostHogProvider>
}

Configure logs in your PostHog options

Required

Add a logs block to your PostHog initialization. All fields are optional; defaults are tuned for mobile (cellular bandwidth, battery, OS lifecycle).

React Native
import PostHog from 'posthog-react-native'

const posthog = new PostHog('<ph_project_token>', {
  host: 'https://us.i.posthog.com',
  logs: {
    serviceName: 'my-app',          // OTLP service.name – shown in the Logs UI
    environment: 'production',      // OTLP deployment.environment
    serviceVersion: '1.2.3',        // OTLP service.version
  },
})

Capture logs

Required

Use posthog.logger for the per-level convenience API, or posthog.captureLog for full control over level, attributes, and trace context.

React Native
// Per-level convenience methods
posthog.logger.info('checkout completed', { order_id: 'ord_789', amount_cents: 4999 })
posthog.logger.warn('payment retry', { attempt: 2 })
posthog.logger.error('payment failed', { code: 'E001' })

// Lower-level API for custom severity / trace context
posthog.captureLog({
  body: 'checkout failed',
  level: 'error',
  attributes: { order_id: 'ord_789', step: 'auth' },
  trace_id: '4bf92f3577b34da6a3ce929d0e0e4736',  // optional W3C trace context
  span_id: '00f067aa0ba902b7',
})

Records are buffered, batched, persisted to disk, and flushed automatically – every 10 seconds, on AppState change (foreground ↔ background), on buffer fill, or on posthog.shutdown(). For an immediate drain, call await posthog.flushLogs().

Each record is automatically tagged with the user's distinct ID, session ID, current screen, app foreground/background state, and active feature flags at the moment of capture.

4
Test your setup
Recommended
1. Capture a test log from your app:
  React Native
  posthog.logger.info('hello from RN') await posthog.flushLogs()
2. Open the PostHog Logs UI.
3. Filter by service.name = 'my-app' (or whatever value you set above).
You should see your record arrive within a few seconds.
View your logs in PostHog

Tune buffering, rate cap, and filtering

Optional

The logs config has knobs for high-volume apps:

React Native
const posthog = new PostHog('<ph_project_token>', {
  logs: {
    serviceName: 'my-app',
    flushIntervalMs: 5000,                       // default 10000ms
    maxBufferSize: 200,                          // default 100
    rateCap: { maxLogs: 5000, windowMs: 60000 }, // default 500/10s
    beforeSend: (record) =>
      record.body.includes('secret') ? null : record, // redact or drop
  },
})

Full configuration reference:

Field	Default	What it does
`serviceName`	`'unknown_service'`	OTLP `service.name` resource attribute
`serviceVersion`	undefined	OTLP `service.version` resource attribute
`environment`	undefined	OTLP `deployment.environment` resource attribute
`resourceAttributes`	`{}`	Extra OTLP resource attributes
`flushIntervalMs`	`10000`	Periodic flush interval in ms
`maxBufferSize`	`100`	Max records held in memory before eviction
`maxBatchRecordsPerPost`	`50`	Max records per outbound POST (halved on 413)
`rateCap.maxLogs`	`500`	Max records per `windowMs` window
`rateCap.windowMs`	`10000`	Rate-cap window length in ms
`beforeSend`	undefined	Pre-send filter (return `null` to drop)

Defaults are tuned for cellular-aware mobile apps (~50 logs/sec ceiling, ~16KB max queue file). Raise rateCap.maxLogs and maxBufferSize for high-volume scenarios.

Filtering with beforeSend

Optional

The beforeSend hook runs synchronously before the rate cap, so dropped records don't consume the per-interval budget. Use it for redaction, sampling, or filtering by level:

React Native
const posthog = new PostHog('<ph_project_token>', {
  host: 'https://us.i.posthog.com',
  logs: {
    serviceName: 'my-app',
    beforeSend: (record) => {
      // Drop debug logs in production
      if (record.level === 'debug') return null

      // Redact secrets in the body
      return {
        ...record,
        body: record.body.replace(/api_key=\S+/g, 'api_key=[REDACTED]'),
      }
    },
  },
})

You can also pass an array of functions to form a chain (evaluated left-to-right). A null return from any link short-circuits and drops the record. A throwing filter is caught and skipped – the chain continues with the previous return value, so a buggy filter degrades to a no-op rather than crashing your app.

Next steps

Checkpoint

What you can do with your logs

Action	Description
Why you need logs	What logs show you that nothing else does
Search logs	Use the search interface to find specific log entries
Filter by level	Filter by `INFO`, `WARN`, `ERROR`, etc.
Link session replay	Connect logs to users and session replays by passing `posthogDistinctId` and `sessionId`
Logging best practices	Learn what to log, how to structure logs, and patterns that make logs useful in production

Troubleshoot common issues

React Native logs installation

Install posthog-react-native

Expo apps

React Native apps

React Native Web and macOS

Configuration

With the PosthogProvider

Without the PosthogProvider

Configure logs in your PostHog options

Capture logs

Test your setup

Tune buffering, rate cap, and filtering

Filtering with beforeSend

Next steps

Community questions

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