Real User Monitoring

Last9 Real User Monitoring (RUM) captures real user experience data from web and mobile applications. Each SDK instruments sessions, views, network requests, unhandled errors, and resource metrics (plus ANRs on Android), then exports spans and logs to Last9 over OTLP/HTTP.

Supported platforms

What gets captured

All SDKs auto-instrument the same signals:

• Sessions — rolling session IDs with idle + max-duration expiry. Session ID is propagated on every span and log.
• Views / page loads — screen transitions tracked as spans. Auto-tracked via SPA route changes (web), activity lifecycle (Android), UIKit/SwiftUI hooks (iOS), React Navigation (React Native), or NavigatorObserver (Flutter). Manual startView(name) is available on every platform.
• Network — HTTP requests captured with URL, method, status, duration, request/response sizes. Traceparent header is injected so spans link to backend traces.
• Errors — unhandled JS exceptions, promise rejections, native crashes, and Flutter framework errors. ANR detection is Android-only. Manual captureError(e, context) is available on every platform.
• Core Web Vitals (web) — LCP, FCP, CLS, INP, TTFB.
• Resources (mobile) — periodic memory and CPU samples (configurable interval, default 30s).
• Custom events + attributes — addEvent, spanAttributes, and identify for user context.

Distribution

SDKs are distributed from Last9’s CDN:

Platform	Latest versioned	Artifact	Stable CDN root	Versioned CDN root
Web	2.8.0	UMD script	https://cdn.last9.io/rum-sdk/builds/stable/v2/	https://cdn.last9.io/rum-sdk/builds/2.8.0/
Android	1.5.1	AAR + POM	https://cdn.last9.io/rum-sdk/android/builds/stable/v1/	https://cdn.last9.io/rum-sdk/android/maven/io/last9/rum-android/1.5.1/
iOS	1.5.1	CocoaPods podspec + SPM (Git + CDN)	https://cdn.last9.io/rum-sdk/ios/builds/stable/v1/	https://cdn.last9.io/rum-sdk/ios/builds/1.5.1/
React Native	1.5.1	npm tarball	https://cdn.last9.io/rum-sdk/react-native/builds/stable/v1/	https://cdn.last9.io/rum-sdk/react-native/builds/1.5.1/
Flutter	1.5.1	tar.gz package	https://cdn.last9.io/rum-sdk/flutter/builds/stable/v1/	https://cdn.last9.io/rum-sdk/flutter/builds/1.5.1/

Stable channels are major-version pinned: Web stable/v2 currently serves 2.8.0; mobile stable/v1 currently serves 1.5.0. The latest versioned mobile release is 1.5.1. Pin versioned CDN URLs for 1.5.1 (iOS Swift Package Manager Git URL, lockfiles, checksums). Mobile staging builds use the -alpha suffix and explicit versioned URLs.

Latest versioned changes

• iOS 1.5.1 adds Swift Package Manager from a git URL (https://github.com/last9/last9-rum-ios.git) — pin an exact version tag or track stable/v1. Android, React Native, and Flutter 1.5.1 are version-parity releases with no functional changes.
• Mobile 1.5.0 adds autoViewTrackingEnabled (default true) and stops startView from leaving a duplicate native view alongside Activity/ViewController auto-tracking. setViewName renames the active view in place. Android also stops WebView re-injection from mis-tagging later screens as view.type=webview.
• Mobile 1.4.1 keeps the RUM session alive across Home / background (and system file pickers). Returning within 30 minutes resumes the same session.id. A force-quit or crash backfills Session End on the next cold start (session.end_reason=process_death).
• Mobile 1.4.0 adds scheduleDelayMs so batch export can flush in ~1s when debugLogs is on (default 5s in production).
• Web 2.8.0 and mobile 1.3.0 fold fully-numeric and UUID path segments in network span names (GET /workspaces/1 → GET /workspaces/?) so per-endpoint metrics aggregate. GraphQL span names are unchanged; the raw URL is kept on http.url / url.full.
• Web 2.7.1 stops emitting source map files from production ESM and UMD bundles.
• Mobile 1.2.1 fixes an iOS main-thread hang when calling instrument(webView:) on a WKWebView, and hardens React Native instrumentWebView so it accepts a WebView load event (event.nativeEvent.target), a numeric tag, a ref, or a component instance without throwing — recommended: onLoadStart={(e) => L9Rum.instrumentWebView(e.nativeEvent.target)}. Android and Flutter pick up the iOS fix via native pin bumps; no Dart or Android SDK changes.
• React Native 1.2.0 adds an Expo config plugin for Continuous Native Generation — add "@last9/rum-react-native" to app.json plugins and the CDN Maven repo and Last9RUM pod source are re-applied on every expo prebuild. Requires a development build (not Expo Go).
• React Native 1.1.10 fixes a New Architecture Android clean-build failure at :app:configureCMakeDebug when the codegen JNI directory does not exist yet under parallel Gradle execution.
• Mobile 1.1.9 makes getSessionId() reliable: it returns a real session id (never an empty string) and, on iOS, is available synchronously as soon as initialize() returns. On React Native and Flutter, initialize() now resolves with a real session id on iOS instead of null or empty. 1.1.8 is a version-parity release with no functional changes.
• Mobile 1.1.7 removes the unused OpenTelemetry Android agent so the SDK no longer forces androidx.core 1.17.0 and AGP 8.9.1+ onto consumers — fixes :app:checkReleaseAarMetadata failures on older Android toolchains (Android, React Native, Flutter).
• React Native 1.1.6 migrates the bridge to a real TurboModule so await L9Rum.initialize() resolves on the New Architecture (bridgeless, default from RN 0.76+). Old Architecture (Paper) remains supported. Upgrade to 1.1.6 or later if init hangs on bridgeless.
• Web 2.7.0 adds automatic GraphQL network observability — descriptive span names, graphql.operation.* attributes, and detection of errors[] returned on HTTP 200 responses.
• Mobile 1.1.0 adds the same GraphQL observability across Android, iOS, React Native, and Flutter, including opt-in Layer 2 client integrations (Apollo Link on React Native; Dio and gql interceptors on Flutter).
• Mobile 0.9.0 adds an embedded per-flow lifecycle — shutdown() and isActive() — so RUM can be scoped to a single flow and safely re-initialized.
• Android 1.1.2 requires Kotlin 1.9.0+ / AGP 8.3.0+; Android 1.1.1 isolates telemetry attribute collection from the request path so a missing READ_PHONE_STATE permission can no longer fail a network request.
• Mobile 0.8.0 changes the ingestion Client-ID header to an SDK-generated per-install UUID instead of serviceName, preventing all devices for an app from sharing the same ingestion rate-limit bucket.

Next steps

Pick your platform:

• Web
• Android / Kotlin
• iOS / Swift
• React Native
• Flutter

Once data is flowing, explore it in Discover > Applications — performance, errors, sessions, and session correlation with backend traces. To turn RUM signals into alerts (HTTP error rates, p95 latency, crashes, ANRs), see Alerting on RUM Metrics.

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Troubleshooting

Please get in touch with us on Discord or Email if you have any questions.