feat(android): Add standalone app start tracing by buenaflor · Pull Request #5342 · getsentry/sentry-java

buenaflor · 2026-04-28T14:51:10Z

📜 Description

Adds standalone Android app-start transaction support behind the opt-in enableStandaloneAppStartTracing option and the io.sentry.standalone-app-start-tracing.enable manifest key.

This PR also covers the non-activity startup path so cold starts triggered by broadcasts or foreground services can emit an App Start Cold/Warm transaction without waiting for an activity. The legacy flag-off behavior is preserved: activity app-start data remains nested under the ui.load transaction.

💡 Motivation and Context

Resolves: #5046

Standalone app-start traces make app-start performance visible independently from activity load transactions, and they let Android report app starts where no activity is launched. The implementation keeps the default behavior unchanged and adds tests for the new option, manifest metadata, transaction context trace reuse, app-start metrics, event processing, and activity lifecycle behavior.

💚 How did you test it?

./gradlew spotlessApply apiDump
Targeted unit coverage was added for the new option, manifest metadata, app-start metric resolution, event processing, lifecycle integration, and transaction context constructor behavior.
Manual end-to-end harness report from standalone_app_start_report.md:

End-to-end Sentry verification

#	What it tests	Locally emitted shape	Trace ID link
1a	Flag ON launcher cold start: standalone app-start plus sibling `ui.load`.	`app.start` + `activity.load` x2 + `process.load` + `application.load`; sibling `ui.load`	`d8e97ed6...`
1c	Flag OFF launcher cold start: legacy nested app-start span.	`ui.load` -> `app.start.cold` -> `process.load` + `activity.load` x2	`970768dc...`
2a	Broadcast cold start with Gradle-plugin timing simulation.	`app.start` + `process.load` + `application.load`; no `ui.load`	`a39fb47f...`
2b	Broadcast cold start using Android 15 `ApplicationStartInfo`.	`app.start` + `process.load`; no `application.load` or `ui.load`	`e100abb8...`
2c	Broadcast cold start using API 33 class-load fallback.	`app.start` + `process.load`; classified Cold	`5fb8e75d...`
2d	Foreground-service cold start through the non-activity path.	`app.start` + `process.load` + `application.load`; no `ui.load`	`f8ad7a62...`
2e	Broadcast then launcher: trace reuse without duplicate standalone.	Same trace: `app.start` + sibling `ui.load`; one standalone only	`04ffca08...`
2f	Flag OFF broadcast regression case.	No transaction emitted	--

📝 Checklist

I added GH Issue ID & Linear ID
I added tests to verify the changes.
No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
I updated the docs if needed.
I updated the wizard if needed.
Review from the native team if needed.
No breaking change or entry added to the changelog.
No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

Introduce experimental `enableStandaloneAppStartTracing` option that creates a separate app start transaction instead of attaching app start as a child span of the first activity transaction. This is the happy path only (foreground importance, activity launch, first frame drawn as end time). The standalone transaction shares the same trace ID as the activity transaction but is not bound to the scope. App start measurements and child spans (process init, content providers, application.onCreate) are attached to the standalone transaction instead of the activity transaction. Includes foreground importance check branching to prepare for the non-activity launch path (next PR). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

When the app starts without launching an activity (service, broadcast receiver, content provider), create a standalone app start transaction with the end time determined by priority: 1. onApplicationPostCreate (Gradle plugin bytecode instrumentation) 2. ApplicationStartInfo timestamps (API 35+) 3. firstIdle - main thread idle handler (pre-API 35 fallback) The non-activity app start transaction stores its trace ID so that if an activity is later launched, the activity transaction reuses the same trace ID to keep both in the same trace. Adds OnNoActivityStartedListener callback from AppStartMetrics to ActivityLifecycleIntegration, triggered by checkCreateTimeOnMain() when no activity was created after Application.onCreate(). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…entation When an app is launched via broadcast receiver, service, or content provider (no activity), detect this via Handler.post() and create a standalone app start transaction. Resolves app start end time with priority: Gradle plugin > ApplicationStartInfo (API 35+) > process init time. Also attaches child spans (process init, content providers, Application.onCreate) to standalone transactions. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Extract the "try appStartSpan, fall back to sdkInitTimeSpan" logic used for standalone (non-activity) app start transactions into a new AppStartMetrics.getAppStartTimeSpanDirect() helper, removing the duplicated inline fallback in ActivityLifecycleIntegration and the private helper in PerformanceAndroidEventProcessor. Also cache the API 35+ ApplicationStartInfo on registerLifecycleCallbacks so onAppStartSpansSent no longer re-queries ActivityManager, and simplify the non-activity detection path to always use the main-thread IdleHandler. Regenerates the sentry-android-core API to include method additions missed in prior commits on this branch (standalone-app-start options, trace id accessors, OnNoActivityStartedListener). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Wires up the TestBroadcastReceiver added earlier so the sample app can trigger a non-activity cold start via `adb shell am broadcast`. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…tart-tracing # Conflicts: # sentry-android-core/src/main/java/io/sentry/android/core/performance/AppStartMetrics.java

…icate emission Two pre-merge fixes for the standalone app-start tracing path introduced on this branch (issue #5046): - AppStartMetrics.checkCreateTimeOnMain() now defaults appStartType to COLD when UNKNOWN with no active activities. On API < 35 (where ApplicationStartInfo is unavailable) non-activity cold starts were stuck at UNKNOWN, which both misclassified the standalone transaction as App Start Warm and caused PerformanceAndroidEventProcessor.attachAppStartSpans to early-return (dropping process.load / application.load / contentprovider.load phase spans). - ActivityLifecycleIntegration.onActivityPreCreated() now skips emitting a second standalone App Start transaction when the non-activity path has already reported the process's app start (detected via the stashed appStartTraceId). Previously a broadcast followed by an activity launch produced two standalone transactions (a spurious App Start Warm in addition to the broadcast's App Start Cold), violating one-per-process semantics. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

buenaflor · 2026-04-28T15:02:06Z

+  /** Trace ID from a non-activity app start transaction, to be reused by a later activity. */
+  public @Nullable SentryId getAppStartTraceId() {
+    return appStartTraceId;
+  }
+
+  public void setAppStartTraceId(final @Nullable SentryId traceId) {
+    this.appStartTraceId = traceId;
+  }


later on this should generally be fixed to be trace connected by session and not only the app start + ui.load transactions

github-actions · 2026-04-28T15:05:04Z

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Generated by 🚫 dangerJS against 5387e76

sentry · 2026-04-28T15:07:46Z

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.40.0 (1)	release

⚙️ sentry-android Build Distribution Settings

github-actions · 2026-04-28T15:11:35Z

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	329.13 ms	392.38 ms	63.25 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`9770665`	315.64 ms	378.00 ms	62.36 ms
`cf708bd`	434.73 ms	502.96 ms	68.22 ms
`d501a7e`	348.06 ms	431.42 ms	83.36 ms
`72020f8`	312.32 ms	370.94 ms	58.62 ms
`b750b96`	421.25 ms	444.09 ms	22.84 ms
`319f256`	317.53 ms	370.83 ms	53.29 ms
`c8125f3`	397.65 ms	485.14 ms	87.49 ms
`55aaf9b`	310.45 ms	352.56 ms	42.12 ms
`b8bd880`	314.56 ms	336.50 ms	21.94 ms
`f064536`	349.86 ms	417.66 ms	67.80 ms

App size

Revision	Plain	With Sentry	Diff
`9770665`	0 B	0 B	0 B
`cf708bd`	1.58 MiB	2.11 MiB	539.71 KiB
`d501a7e`	0 B	0 B	0 B
`72020f8`	1.58 MiB	2.19 MiB	620.21 KiB
`b750b96`	1.58 MiB	2.10 MiB	533.20 KiB
`319f256`	1.58 MiB	2.19 MiB	619.79 KiB
`c8125f3`	1.58 MiB	2.10 MiB	532.32 KiB
`55aaf9b`	0 B	0 B	0 B
`b8bd880`	1.58 MiB	2.29 MiB	722.92 KiB
`f064536`	1.58 MiB	2.20 MiB	633.90 KiB

buenaflor and others added 10 commits April 2, 2026 14:43

chore(samples): Register TestBroadcastReceiver in manifest

5efab1d

Wires up the TestBroadcastReceiver added earlier so the sample app can trigger a non-activity cold start via `adb shell am broadcast`. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Merge remote-tracking branch 'origin/main' into feat/standalone-app-s…

f6c070d

…tart-tracing # Conflicts: # sentry-android-core/src/main/java/io/sentry/android/core/performance/AppStartMetrics.java

fix(android): refine standalone app start tracing

50a2f41

chore: Update generated files

26a83cc

style(core): Apply spotless formatting

a60d966

buenaflor mentioned this pull request Apr 28, 2026

feat: Send standalone app start transactions #5046

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changelog

09bac52

buenaflor commented Apr 28, 2026

View reviewed changes

Merge branch 'main' into feat/standalone-app-start-tracing

5387e76

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feat(android): Add standalone app start tracing#5342

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buenaflor commented Apr 28, 2026 •

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Baseline results on branch: main

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buenaflor commented Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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📜 Description

💡 Motivation and Context

💚 How did you test it?

End-to-end Sentry verification

📝 Checklist

🔮 Next steps

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buenaflor Apr 28, 2026

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github-actions Bot commented Apr 28, 2026

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sentry Bot commented Apr 28, 2026

📲 Install Builds

Android

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github-actions Bot commented Apr 28, 2026

Performance metrics 🚀

Baseline results on branch: main

Startup times

App size

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Development

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buenaflor commented Apr 28, 2026 •

edited

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