React Native SDK data collection

This page describes what the React Native SDK collects, what is outside its collection scope, and how to control the scope. All events are written with source: "react-native".

Event types

Event	Trigger	Description
view	Recorded automatically by the navigation tracking package, or `DdRum.startView` / `stopView`	One screen visit; records the time spent, the number of actions / resources / errors inside it, and the performance metrics during the view
action	`trackInteractions` collects `onPress` taps automatically, or `DdRum.addAction`	User interaction (tap / scroll / swipe / custom); can carry frustration signals
resource	`trackResources` intercepts JS `XMLHttpRequest` / `fetch`, or `DdRum.startResource` / `stopResource`	One network request; records URL, method, status code, and duration
error	Automatic (unhandled JS exception / native crash) or `DdRum.addError`	Errors and crashes, with type, message, and stack trace
long task	Native main thread enabled by default (`nativeLongTaskThresholdMs`); JS thread requires `longTaskThresholdMs`	Thread blocking beyond the threshold

Automatically collected context

Every event carries the following context (collected by the native layer):

Application: service, version, env, and application.id
Device: device model, OS and version, screen size
Session: session.id, sampled by sessionSamplingRate
Connectivity: network type (when available)
User: usr.id / usr.name / usr.email set through DdSdkReactNative.setUser
Global attributes: custom fields set through DdSdkReactNative.setAttributes

Network request collection boundary

Resource collection has a single entry point: the XMLHttpRequest proxy in the JavaScript layer (fetch in React Native is implemented on top of it).

Request origin	Collected	Recorded type
`fetch` / `XMLHttpRequest` / axios and similar in application code	Yes	`xhr`
Binary content such as images downloaded with `fetch`	Yes	`xhr` (not distinguished by Content-Type)
Resources loaded by the native networking stack, such as `<Image source={{ uri }}>`	No	—
Requests issued by native modules / third-party native SDKs themselves	No	—

As a result, the resource data of a React Native application contains API requests only, with no images, fonts, scripts, or other static resources. The console does not show static-resource panels for React Native applications. This is by design, following the collection boundary, and does not mean data is missing.

Performance data

The console shows a Performance page for React Native applications. Native vitals are collected by the wrapped Android / iOS SDKs, and the JS-thread frame rate is collected additionally by the React Native SDK:

Metric	Android	iOS	Description
App launch time	Not yet	Cold / warm launch	Android does not report launch time yet; the corresponding console card shows “No data”
Refresh rate	Supported	Supported	Rendering frame rate of the native UI thread
JS-thread frame rate	Supported	Supported	React Native-specific; reflects whether application JS code is janky; shown on the console’s Performance page
CPU	Supported	Supported	CPU usage during the view
Memory	Supported	Supported	Memory usage during the view
Slow / frozen frames	Supported	Supported	Number of slow and frozen frames during the view
ANR	Supported	—	Application not responding; whether non-fatal ANRs are collected by default depends on the Android version and can be overridden with `trackNonFatalAnrs`
App Hang	—	Supported	Main-thread hang; requires `appHangThreshold`, disabled by default

The collection frequency of native vitals is controlled by vitalsUpdateFrequency, default VitalsUpdateFrequency.AVERAGE; set it to NEVER to disable.

Logs

DdLogs.debug / info / warn / error send log events, which are not RUM events. Currently only Android actually sends them; iOS is a no-op.

Manual instrumentation

Besides automatic collection, you can record events and attributes manually.

import { DdRum, DdSdkReactNative, ErrorSource, RumActionType } from '@flashcatcloud/mobile-react-native';

// Manage views manually
DdRum.startView('checkout', 'Checkout');
DdRum.stopView('checkout');

// Record an action manually
DdRum.addAction(RumActionType.TAP, 'pay_button');

// Record a network request manually
DdRum.startResource('req-1', 'GET', 'https://api.example.com/orders');
DdRum.stopResource('req-1', 200, 'xhr');

// Report an error manually
DdRum.addError('payment failed', ErrorSource.SOURCE, stack);

// Attach global attributes (written to all subsequent events)
DdSdkReactNative.setAttributes({ tenant: 'acme' });

// Add a custom timing to the current view
DdRum.addTiming('first_order_rendered');

Sampling and controls

Option	Default	Description
`sessionSamplingRate`	100	Session sampling rate (percent); sessions not sampled produce no RUM data
`resourceTracingSamplingRate`	20	Distributed tracing sampling rate on resources
`telemetrySampleRate`	20	SDK internal telemetry sampling rate
`trackInteractions` / `trackResources` / `trackErrors`	Constructor arguments, default false	Whether to collect actions / network requests / JS errors automatically
`nativeCrashReportEnabled`	false	Whether to collect native crashes
`trackFrustrations`	true	Whether to derive frustration signals from user actions
`trackBackgroundEvents`	false	Whether to collect events while no view is active
`vitalsUpdateFrequency`	`AVERAGE`	Collection frequency of native vitals; `NEVER` disables
`nativeLongTaskThresholdMs`	200	Native main-thread long task threshold; `0` / `false` disables
`longTaskThresholdMs`	0 (disabled)	JS-thread long task threshold
`trackNonFatalAnrs`	Platform default	Whether to collect non-fatal ANRs
`appHangThreshold`	undefined	iOS App Hang threshold in seconds; unset means disabled

Data scrubbing

Event mappers let you modify or drop data before it is reported, for scrubbing or noise filtering. See Advanced configuration.

config.errorEventMapper = (event) => {
  // Return null to drop the event, or return a modified event
  if (event.message.includes('token=')) {
    return null;
  }
  return event;
};

Reporting behavior

The SDK buffers events in the native layer and uploads them in batches according to uploadFrequency, batchSize, and batchProcessingLevel
When the network is unavailable, events are persisted locally and retried once connectivity returns
The default intake endpoint is https://browser.flashcat.cloud/api/v2/rum; on-premises deployments can set the full RUM intake URL through customEndpoints.rum (it must include /api/v2/rum and keep the deployment’s path prefix)

Quick Start

Analytics

SDK Integration

Performance

Error Tracking

Explorer

Session Replay

Best Practices

Others

React Native SDK data collection

Event types

Automatically collected context

Network request collection boundary

Performance data

Logs

Manual instrumentation

Sampling and controls

Data scrubbing

Reporting behavior

​Event types

​Automatically collected context

​Network request collection boundary

​Performance data

​Logs

​Manual instrumentation

​Sampling and controls

​Data scrubbing

​Reporting behavior

Event types

Automatically collected context

Network request collection boundary

Performance data

Logs

Manual instrumentation

Sampling and controls

Data scrubbing

Reporting behavior