feat(extend-app-start): App start extension API

[buenaflor]

PR Stack (Extend App Start)

• feat(extend-app-start): App start extension API #5604
• feat(extend-app-start): [1/4] Add IAppStartExtender bridge #5605
• feat(extend-app-start): [2/4] Extract AppStartExtension component #5606
• feat(extend-app-start): [3/4] Eagerly create the extended app start transaction #5608
• feat(extend-app-start): [4/4] Add public Sentry app start extension API and update example app #5628

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Tested scenarios:

1 · Non-headless — extended after first frame (finish called ~5s in) → OK, app_start_cold = 6511 ms
https://sentry-sdks.sentry.io/explore/traces/trace/cb4ce5b65c42445da7d87d80fd49896a/

2 · Non-headless — finish never called → DEADLINE_EXCEEDED, measurement suppressed
https://sentry-sdks.sentry.io/explore/traces/trace/87bb5f4916f04837b5b4b6a31b021d0a/

3 · Headless — extended (finish called) → OK, app_start_cold = 6342 ms
https://sentry-sdks.sentry.io/explore/traces/trace/0563146982d44e05ac67000cc0089f6e/

4 · Headless — finish never called → DEADLINE_EXCEEDED, measurement suppressed
https://sentry-sdks.sentry.io/explore/traces/trace/6aa847bb646c4810b2991ad6b1c2687d/

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Collection PR for the Extend App Start stack. Squash-merge this into main once all stack PRs are merged.

Implements the app start extension API — Sentry.extendAppStart() / Sentry.finishAppStart() / Sentry.getExtendedAppStartSpan() — which lets apps extend the app start measurement to cover extra launch-time work.

Closes #5553 #3581

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

Generated by 🚫 dangerJS against 409b60a

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📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.47.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[romtsn]

pre-approving

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Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	340.74 ms	397.94 ms	57.20 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
d364ace	382.77 ms	443.21 ms	60.44 ms
4c04bb8	333.16 ms	408.16 ms	75.00 ms
bb0ff41	344.70 ms	413.82 ms	69.12 ms
91bb874	314.47 ms	440.00 ms	125.53 ms
bdbe1f4	380.66 ms	464.44 ms	83.78 ms
8687935	294.00 ms	304.02 ms	10.02 ms
eb95ded	317.51 ms	369.08 ms	51.57 ms
b936425	302.69 ms	372.86 ms	70.17 ms
d15471f	342.08 ms	415.44 ms	73.35 ms
5b66efd	308.67 ms	363.85 ms	55.18 ms

App size

Revision	Plain	With Sentry	Diff
d364ace	1.58 MiB	2.11 MiB	539.75 KiB
4c04bb8	0 B	0 B	0 B
bb0ff41	0 B	0 B	0 B
91bb874	1.58 MiB	2.13 MiB	559.07 KiB
bdbe1f4	1.58 MiB	2.11 MiB	538.88 KiB
8687935	1.58 MiB	2.19 MiB	619.17 KiB
eb95ded	0 B	0 B	0 B
b936425	0 B	0 B	0 B
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
5b66efd	1.58 MiB	2.13 MiB	559.07 KiB

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[Copilot]

Pull request overview

Adds a public “extend app start” API to the Sentry Java/Android SDK and wires it through Android app-start tracing so customers can keep the standalone app.start transaction open beyond the first frame and attach their own child spans.

Changes:

• Introduces Sentry.extendAppStart(), Sentry.finishExtendedAppStart(), and Sentry.getExtendedAppStartSpan() and the internal bridging contract (IAppStartExtender).
• Implements the Android-side extension lifecycle (AppStartExtension) and integrates it with standalone app start tracing + app start vital calculation/suppression behavior.
• Updates tests, sample app usage, API dumps, and changelog to reflect the new feature.

Reviewed changes

Copilot reviewed 20 out of 20 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
sentry/src/test/java/io/sentry/SentryTest.kt	Adds delegation/no-op tests for the new Sentry.*AppStart* facade.
sentry/src/test/java/io/sentry/SentryOptionsTest.kt	Verifies SentryOptions.appStartExtender default + setter behavior.
sentry/src/test/java/io/sentry/NoOpAppStartExtenderTest.kt	Adds unit tests for the no-op extender behavior.
sentry/src/main/java/io/sentry/SentryOptions.java	Adds internal appStartExtender option (defaulting to a no-op).
sentry/src/main/java/io/sentry/Sentry.java	Adds the public static app start extension methods.
sentry/src/main/java/io/sentry/NoOpAppStartExtender.java	Implements the default no-op bridge implementation.
sentry/src/main/java/io/sentry/IAppStartExtender.java	Adds the internal app start extension bridge interface.
sentry/api/sentry.api	Updates sentry module API surface dump for the new types/methods.
sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/MyApplication.java	Demonstrates extending app start and attaching child spans in the Android sample.
sentry-android-core/src/test/java/io/sentry/android/core/PerformanceAndroidEventProcessorTest.kt	Adds tests for extended-end app start measurement and deadline suppression behavior.
sentry-android-core/src/test/java/io/sentry/android/core/performance/AppStartMetricsTest.kt	Adds tests for the “can extend” gate and extension lifecycle reset behavior.
sentry-android-core/src/test/java/io/sentry/android/core/AppStartExtensionTest.kt	Adds focused tests for AppStartExtension state/finish/deadline semantics.
sentry-android-core/src/test/java/io/sentry/android/core/ActivityLifecycleIntegrationTest.kt	Adds end-to-end tests around eager standalone app.start creation, continuation into ui.load, and lifecycle edge cases.
sentry-android-core/src/main/java/io/sentry/android/core/PerformanceAndroidEventProcessor.java	Uses extended end time (when present) to compute/suppress app start measurements while still attaching spans.
sentry-android-core/src/main/java/io/sentry/android/core/performance/AppStartMetrics.java	Adds AppStartExtension, exposes canExtendAppStart(), and resets extension state appropriately.
sentry-android-core/src/main/java/io/sentry/android/core/AppStartExtension.java	Implements the Android app start extension lifecycle and internal contract.
sentry-android-core/src/main/java/io/sentry/android/core/AndroidOptionsInitializer.java	Wires the Android extender into SentryOptions during initialization.
sentry-android-core/src/main/java/io/sentry/android/core/ActivityLifecycleIntegration.java	Registers the extend listener (standalone-only) and implements eager standalone app.start + extended child span creation/continuation.
sentry-android-core/api/sentry-android-core.api	Updates android-core module API dump for new internal API surface.
CHANGELOG.md	Documents the new app start extension API and includes a usage snippet.

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