A Kotlin Multiplatform SDK for Firebase, with a focus on Firebase AI (Generative AI) capabilities.

Module	Description	API Coverage
firebase-app	Core Firebase App initialization
firebase-ai	Firebase AI (Generative AI with Gemini)
firebase-analytics	Firebase Analytics (no advertising-ID collection by default)
firebase-analytics-advertising	Opt-in advertising-ID (IDFA/AAID) collection for firebase-analytics	—
firebase-auth	Firebase Authentication
firebase-firestore	Cloud Firestore (real-time database)
firebase-common	Shared utilities and types	—

• Android
• iOS (arm64, simulatorArm64)

Add to your gradle/libs.versions.toml:

[versions]
firebase-kotlin-sdk = "0.11.0"

[libraries]
firebase-app = { module = "dev.ynagai.firebase:firebase-app", version.ref = "firebase-kotlin-sdk" }
firebase-ai = { module = "dev.ynagai.firebase:firebase-ai", version.ref = "firebase-kotlin-sdk" }
firebase-analytics = { module = "dev.ynagai.firebase:firebase-analytics", version.ref = "firebase-kotlin-sdk" }
firebase-auth = { module = "dev.ynagai.firebase:firebase-auth", version.ref = "firebase-kotlin-sdk" }
firebase-firestore = { module = "dev.ynagai.firebase:firebase-firestore", version.ref = "firebase-kotlin-sdk" }
# Opt-in: only add if you need advertising-ID (IDFA/AAID) collection.
firebase-analytics-advertising = { module = "dev.ynagai.firebase:firebase-analytics-advertising", version.ref = "firebase-kotlin-sdk" }

Add to your module's build.gradle.kts:

kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation(libs.firebase.app)
            implementation(libs.firebase.ai)
            implementation(libs.firebase.auth)
            implementation(libs.firebase.firestore)
            // Firebase Analytics: see "Firebase Analytics & Advertising ID" below
            // (advertising-ID collection is opt-in via firebase-analytics-advertising).
        }
    }
}

See each module's README for detailed usage and examples:

• Firebase AI — Generative AI with Gemini (text generation, streaming, chat, content DSL)
• Firebase Auth — Authentication (email/password, social providers, phone, MFA)
• Firebase Firestore — Cloud Firestore (CRUD, queries, real-time listeners, transactions)

firebase-analytics does not collect the advertising ID by default — no IDFA on iOS and no AAID on Android. For most apps this is the right default: analytics keeps working, and this Firebase Analytics configuration stays off the advertising-ID surface, so it needs no App Tracking Transparency prompt on its own. (Other SDKs or app code that use the IDFA / AdSupport APIs may still require App Tracking Transparency.)

commonMain.dependencies {
    implementation(libs.firebase.analytics)
}

Only if you need advertising attribution (Google Ads, remarketing audiences, etc.), additionally depend on firebase-analytics-advertising. It has no API — linking it is enough to enable advertising-ID collection on both platforms. If you add it, update your App Store privacy and Play Data safety declarations accordingly.

commonMain.dependencies {
    implementation(libs.firebase.analytics)
    implementation(libs.firebase.analytics.advertising) // opt-in: enables IDFA / AAID
}

Android note: the advertising ID is not collected by default, but the Play Services measurement libraries still merge the com.google.android.gms.permission.AD_ID manifest permission (matching Firebase's own default). If you want a fully clean manifest, add the following to your app manifest — but be aware it also removes AD_ID for any other SDK that legitimately needs it:

<uses-permission android:name="com.google.android.gms.permission.AD_ID"
    tools:node="remove" />

Add your google-services.json to your app module and apply the Google Services plugin:

// build.gradle.kts (project)
plugins {
    id("com.google.gms.google-services") version "4.4.2" apply false
}

// build.gradle.kts (app)
plugins {
    id("com.google.gms.google-services")
}

Add your GoogleService-Info.plist to your Xcode project and initialize Firebase in your app delegate:

import FirebaseCore

@main
class AppDelegate: UIResponder, UIApplicationDelegate {
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        FirebaseApp.configure()
        return true
    }
}

Copyright 2025 Yuki Nagai

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.