Firebase Crashlytics - Android Setup Guide (Kotlin)

This guide describes the SDK setup and basic usage patterns for Firebase Crashlytics in an Android app using Kotlin DSL (build.gradle.kts) and Kotlin code.

Prerequisites

IMPORTANT: Before specifically working with Firebase Crashlytics, make sure to use the skill and reference firebase_basics/references/android_setup to ensure the following is done.

The Firebase CLI is available and authenticated.
An Android project exists and is registered with a Firebase Project.
The Android project has a Firebase config file (google-services.json) and the Google services Gradle plugin (google-services).

1. Add dependencies to Gradle build files

[!IMPORTANT] [AGENT] RESOLVING THE SDK & PLUGIN VERSIONS DETERMINISTICALLY Never guess or hardcode a memorized out-of-date SDK or plugin version. Before adding dependencies, you MUST query the latest available versions directly from the Google Maven Repository:

# Find the latest Firebase Android BoM version
curl -s https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-bom/maven-metadata.xml | grep -oE '<latest>[^<]+' | cut -d'>' -f2

# Find the latest Crashlytics Gradle plugin version
curl -s https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-crashlytics-gradle/maven-metadata.xml | grep -oE '<latest>[^<]+' | cut -d'>' -f2

# Find the latest firebase-crashlytics version
curl -s https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-crashlytics/maven-metadata.xml | grep -oE '<latest>[^<]+' | cut -d'>' -f2

# Find the latest firebase-crashlytics-ndk version
curl -s https://dl.google.com/dl/android/maven2/com/google/firebase/firebase-crashlytics-ndk/maven-metadata.xml | grep -oE '<latest>[^<]+' | cut -d'>' -f2

If the dependency is already declared, fetch the exact resolved version currently active in the workspace's build graph:

./gradlew -q :app:dependencyInsight --dependency firebase-crashlytics --configuration releaseRuntimeClasspath

These changes are made to the Android project's Gradle files.

Project-level `build.gradle.kts` (`<project>/build.gradle.kts`)

Add the latest version of the Crashlytics Gradle plugin to the plugins block:

plugins {
    // ... other plugins

    // [AGENT] Fetch the latest resolved version using the Gradle command above
    id("com.google.firebase.crashlytics") version "<latest_plugin_version>" apply false
}

Module (app-level) `build.gradle.kts` (`<project>/<app-module>/build.gradle.kts`)

Add the Crashlytics Gradle plugin to the plugins block:

plugins {
    // ... other plugins

    id("com.google.firebase.crashlytics")
}

Add the Firebase Crashlytics dependency to the dependencies block:

dependencies {
    // ... other dependencies

    // [AGENT] Fetch the latest resolved version using the Gradle command above
    implementation(platform("com.google.firebase:firebase-bom:<latest_bom_version>"))

    // Add the dependency for the Firebase Crashlytics library
    // When using the BoM, don't specify versions in Firebase library dependencies
    implementation("com.google.firebase:firebase-crashlytics")
}

2. Optional: Install the NDK SDK to capture native crashes

If the Android project uses native code (C/C++), or includes a library with native code, configure Crashlytics to report native crashes.

App-level build.gradle.kts (<project>/<app-module>/build.gradle.kts)

Add the firebase-crashlytics-ndk dependency:

dependencies {
    // ... other dependencies

    // [AGENT] Fetch the latest resolved version using the Gradle command above
    implementation(platform("com.google.firebase:firebase-bom:<latest_bom_version>"))

    // Add the dependency for the Firebase Crashlytics NDK library
    // When using the BoM, don't specify versions in Firebase library dependencies
    implementation("com.google.firebase:firebase-crashlytics-ndk")
}

Enable the nativeSymbolUpload flag in the buildTypes configuration. This will automatically upload symbol files for the native code, which are required to symbolicate native crash reports.

android {
    // ... other config
    buildTypes {
        getByName("release") {
            // ...
            firebaseCrashlytics {
                nativeSymbolUploadEnabled = true
            }
        }
    }
}

After these changes, Crashlytics will automatically report crashes in the app's native code.

3. Required: Force a test crash

To verify that Crashlytics is correctly set up in the Android project, force a test crash in the app.

Add code to the main activity (e.g., in onCreate) to trigger a crash a few seconds after app startup:

import android.os.Handler
import android.os.Looper

// ... in the Activity's onCreate method or similar startup logic
Handler(Looper.getMainLooper()).postDelayed({
    throw RuntimeException("Test Crash") // Force a crash after 3 seconds
}, 3000)

Run the app on a device or emulator. The app should crash after a short delay.
Restart the app. The Crashlytics SDK will send the crash report to Firebase on the next app launch.
After a few minutes, the crash should be available in Firebase.
- If the Firebase MCP server is installed, use the get_report tool to verify that a crash was received.
- As a fallback, tell the human user to go to the Crashlytics dashboard in the Firebase console to verify the new crash report. Provide the human user with a constructed Firebase console URL using the Firebase PROJECT_ID and the PACKAGE_NAME: https://console.firebase.google.com/u/0/project/PROJECT_ID/crashlytics/app/android:PACKAGE_NAME/issues
After verifying that Firebase has received the crash report -- either using the get_report tool or manually viewing it in the Firebase console -- remove the code that triggers the test crash.

Optional additional steps

Add custom debugging information

Customize reports to help better understand what's happening in the app and the circumstances around events reported to Crashlytics. See https://firebase.google.com/docs/crashlytics/android/customize-crash-reports.md.txt.

/firebase-crashlytics

referencesandroid_setup.md