crashlytics attribution per library

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title: "How do I attribute a crash to a specific cmp-* library?" reviewed_by: date: 2026-06 version: 3.5.x

How do I attribute a crash to a specific cmp-* library?

When FirebaseCrashlyticsAttributionHook is registered, every cmp-* library auto-tags its own initialization, navigation, and uncaught exceptions with a cmp_library custom key so you can filter Crashlytics issues per library without per-call boilerplate.

Quick start (minimal MWE)

import org.koin.core.context.startKoin
import com.mobilebytelabs.kmptoolkit.observe.koin.observeKoinModule
import com.mobilebytelabs.kmptoolkit.observe.koin.FirebaseCrashlyticsAttributionHook

startKoin {
    modules(
        observeKoinModule(
            hooks = listOf(FirebaseCrashlyticsAttributionHook()),
        ),
    )
}

In the Firebase console:

Crashlytics → Issues → Filter → Custom key: cmp_library == "cmp-share"

Caveats / per-platform notes

• Tag is set on the cmp-* notifyInit thread — if a crash happens during JVM startup before any cmp-* module initializes, the tag is absent.
• iOS: custom keys propagate to Crashlytics within 200ms (vs Android's synchronous setCustomKey).
• The cmp_library key reflects the LAST library to call notifyInit on the current thread; for genuine multi-library crashes, inspect the breadcrumbs trail rather than the tag alone.

Related

• Module: cmp-observe-koin
• Library observability surface: RULE-LIB-OBSERVABILITY-SURFACE-001
• See also: Register Firebase hooks at app startup