Uninstall Tracking

Uninstall tracking helps you understand user behavior and optimize campaigns:

Purpose: Tracks app uninstalls to assess user engagement and campaign performance.
Mechanism: Uses Firebase Analytics to set a user property (ct_objectId) linked to Trackier's unique identifier, and captures the app_remove event.
Workflow:
1. Set ct_objectId with TrackierSDK.getTrackierId() in your app.
2. Configure app_remove as a conversion event in Firebase.
3. Use a Firebase Cloud Function to send uninstall data to Trackier MMP.
Use Case: Measure uninstall rates for a campaign to refine targeting.

Implementation

1. Add Dependencies

dependencies {
    implementation platform('com.google.firebase:firebase-bom:33.1.0')
    implementation 'com.google.firebase:firebase-analytics'
}

2. Set User Property

Java
Kotlin

private FirebaseAnalytics mFirebaseAnalytics;

// Initialize Firebase Analytics
FirebaseAnalytics mFirebaseAnalytics = FirebaseAnalytics.getInstance(this);

// Set the user property with Trackier ID
mFirebaseAnalytics.setUserProperty("ct_objectId", Objects.requireNonNull(TrackierSDK.getTrackierId()));

private lateinit var firebaseAnalytics: FirebaseAnalytics

// Initialize Firebase Analytics
firebaseAnalytics = FirebaseAnalytics.getInstance(this)

// Set the user property with Trackier ID
firebaseAnalytics.setUserProperty("ct_objectId", TrackierSDK.getTrackierId() ?: "unknown")

3. Setup Cloud Functions

Prerequisites

Node.js 20.x or 22.x (use nvm for easy version management)
Firebase CLI (npm install -g firebase-tools)
Firebase project on Blaze plan (required for analytics triggers)
Google account with access to Firebase Console
App with Firebase Analytics SDK integrated
Trackier account (for uninstall event tracking)

Set Up Node.js and Firebase CLI

# Install Node Version Manager (nvm) if not already installed
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

# Install and use Node.js 22 (recommended)
nvm install 22
nvm use 22

# Install Firebase CLI globally
npm install -g firebase-tools

# Login to Firebase
firebase login

Create or Select Your Firebase Project

If you already have a Firebase project for your app:

Go to Firebase Console
Select your project

If you need to create a new Firebase project:

In the Firebase Console, click Add project and follow the steps
Link Google Analytics when prompted
Register your Android app and download google-services.json for your app

Initialize Firebase Functions in Your Project Directory

# Create a new directory for your project (if needed)
mkdir YourProjectName
cd YourProjectName

# Initialize Firebase in this directory
firebase init functions

Choose:
- Use an existing project (if you already have one) or create a new one
- Language: JavaScript
- ESLint: Yes (recommended)
- Install dependencies: Yes

Prepare Your Functions Directory

Your folder structure should look like this:

YourProjectName/
  functions/
    index.js
    package.json
    .eslintrc.js
    ...

If you already have a functions directory, use it.

Add the Uninstall Tracking Function Code

Replace the contents of functions/index.js with:

const functions = require("firebase-functions");
const admin = require("firebase-admin");
const axios = require("axios");

// Set your SDK key here (or use environment variables for security)
const SDK_KEY = "YOUR_SDK_KEY_HERE";

admin.initializeApp();

// Defensive: Only export analytics trigger if available
if (!functions.analytics) {
  // This will prevent deployment errors in unsupported environments
  console.warn("Analytics triggers are not available in this environment.");
  exports.sendAndroidUninstallToTrackierApptrove = () => {};
} else {
  exports.sendAndroidUninstallToTrackierApptrove = functions.analytics
      .event("app_remove")
      .onLog(async (event) => {
      // Defensive extraction of user properties
        const userProps =
        event.user && event.user.userProperties ?
          event.user.userProperties :
          {};
        const installId =
        userProps.ct_objectId && userProps.ct_objectId.value ?
          userProps.ct_objectId.value :
          "";
        const mode =
        userProps.ct_mode && userProps.ct_mode.value ?
          userProps.ct_mode.value :
          "production";
        const cuid =
        userProps.ct_uid && userProps.ct_uid.value ?
          userProps.ct_uid.value :
          "";
        const cmail =
        userProps.ct_mail && userProps.ct_mail.value ?
          userProps.ct_mail.value :
          "";

        if (!installId) {
          functions.logger.warn(
              "No ct_objectId found in event",
              {userProps},
          );
          return null;
        }

        const url = "https://events.trackier.io/v1/uninstall";
        const data = {
          installId,
          sdkKey: SDK_KEY,
          mode,
          cuid,
          cmail,
          meta: event,
        };

        try {
          const response = await axios.post(
              url,
              data,
              {
                headers: {"Content-Type": "application/json"},
                timeout: 10000,
              },
          );
          functions.logger.log(
              "Tracked uninstall",
              {
                installId,
                status: response.status,
                data: response.data,
              },
          );
        } catch (error) {
          functions.logger.error(
              "Uninstall tracking failed",
              {
                installId,
                status: error.response ? error.response.status : "N/A",
                data: error.response ? error.response.data : error.message,
              },
          );
        }
        return null;
      });
}

Set Up Dependencies In package.json

{
  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "scripts": {
    "lint:fix": "eslint . --fix",
    "lint": "eslint .",
    "serve": "firebase emulators:start --only functions",
    "shell": "firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "engines": {
    "node": "20"
  },
  "main": "index.js",
  "dependencies": {
    "axios": "^1.10.0",
    "firebase-admin": "^11.0.0",
    "firebase-functions": "^3.23.0"
  },
  "devDependencies": {
    "eslint": "^8.15.0",
    "eslint-config-google": "^0.14.0"
  },
  "private": true
}

ESLint Configuration

Create a .eslintrc.js file in your functions directory:

// .eslintrc.js
module.exports = {
  parserOptions: {
    ecmaVersion: 2020, // or at least 2015
    sourceType: 'module', // if you're using ES modules (import/export)
  },
  env: {
    es6: true,
    node: true, // if you're in a Node.js environment
  },
};

Deploy Your Function And Fix link Error

# In the functions directory
cd functions

# Install dependencies
npm install

# (Optional) Run linter and auto-fix issues
npm run lint:fix

firebase deploy --only functions

If you see errors about CPU/Gen 2 or function already existing as 2nd Gen:

firebase functions:delete sendAndroidUninstallToTrackierApptrove --force

// After delete your function redeploy the function

firebase deploy --only functions

Ignore warnings about outdated firebase-functions if you need analytics triggers.

Verify and Debug

A. See Data in Firebase Console

Go to Firebase Console
Select your project
Navigate to Analytics > Dashboard and look for the app_remove event

B. Use Analytics DebugView

In the Firebase Console, go to Analytics > DebugView

Enable DebugView on your device:

adb shell setprop debug.firebase.analytics.app <your.app.package>
# Example:
adb shell setprop debug.firebase.analytics.app com.example.myapp
# To turn off:
adb shell setprop debug.firebase.analytics.app .none.

Open your app and trigger uninstall or other events
Watch for real-time events in DebugView

C. Check Cloud Function Logs

In Firebase Console: Build > Functions > View logs
monitor the status of your cloud function here:
https://console.cloud.google.com/functions/list

Look for logs like Tracked uninstall or Uninstall tracking failed

D. Check Trackier Uninstall Log

Log in to your [Trackier dashboard]
Navigate to uninstall/event logs
Filter by installId or other user properties
Confirm the uninstall event was received

Troubleshooting & Tips

Analytics triggers not working?
- Make sure you are on Blaze plan and Analytics is linked
- Only deploy to production (not emulator)
- Use firebase-functions@3.x and firebase-admin@11.x
CPU/Gen 2 errors?
- Remove any "cpu" option from firebase.json or CLI flags
- Delete the function if it was previously deployed as Gen 2, then redeploy
Dependency conflicts?
- Downgrade firebase-admin to ^11.0.0 if needed
Linting errors?
- Use npm run lint:fix and break up long lines/fix indentation
Function not triggering?
- Ensure your app is setting the user property:
```
mFirebaseAnalytics.setUserProperty("ct_objectId", trackierId)
```
- Use Analytics DebugView to verify the event is sent
Still stuck?
- Check Firebase Functions Docs and Firebase Analytics Triggers

Implementation​

1. Add Dependencies​

2. Set User Property​

3. Setup Cloud Functions​

Prerequisites​

Set Up Node.js and Firebase CLI​

Create or Select Your Firebase Project​

If you already have a Firebase project for your app:​

If you need to create a new Firebase project:​

Initialize Firebase Functions in Your Project Directory​

Prepare Your Functions Directory​

Add the Uninstall Tracking Function Code​

Set Up Dependencies In package.json​

ESLint Configuration​

Deploy Your Function And Fix link Error​

Verify and Debug​

A. See Data in Firebase Console​

B. Use Analytics DebugView​

C. Check Cloud Function Logs​

D. Check Trackier Uninstall Log​

Troubleshooting & Tips​