Server-side GTM for Apps: more control over your app data while preserving all performance benefits

Server-side GTM for Apps: more control over your app data while preserving all performance benefits
Introduction: sGTM for Apps, the server-side for applications
Use cases: what does sGTM for Apps do?
Why switch to sGTM for Apps?
Option 1: Firebase SDK only
Option 2: Firebase SDK + GTM iOS/Android
Option 3: Firebase SDK + sGTM for Apps (new)
Is sGTM for Apps right for you?
How do I implement sGTM for Apps?
1. Prepare the application for server-side data collection
2. Create and configure the server container
3. Visualize and debug
4. Deploy gradually
Useful sources and resources

💡

EdgeAngel is an independent French data marketing consultancy with particular expertise in tracking and data activation.👉🏼 Find out more about our mobile application tracking services. Don't hesitate to contact us if you have a specific need.

Introduction: sGTM for Apps, the server-side for applications

Officially available since October 2024, Server-side GTM for Apps (sGTM for Apps) enables mobile applications (iOS and Android) using the Firebase SDK to send their data directly to a server-side GTM container.

This breakthrough innovation takes application data collection a step further: until now, server-side tagging was reserved for websites. With sGTM for Apps, mobile applications can benefit from the same level of control, transparency and personalization of data transmitted to third-party platforms.

Use cases: what does sGTM for Apps do?

The integration of sGTM for Apps opens the way to advanced use cases before reserved for the Web. The main benefit lies in the ability to take back control of data before it is sent to Google Analytics, Google Ads or other platforms.

For example, it is possible to remove or anonymize sensitive information such as IP address, user-agent, or mobile device identifiers. This makes it possible to adapt data collection to internal (compliance, security) and regulatory (RGPD, CNIL, etc.) requirements.

It's also a powerful way of centralizing Web and App flows within a common architecture, facilitating maintenance, tracking consistency and cross-device analysis.

Finally, the use of sGTM enables the same event to be sent to several destinations in a controlled and unified way: multiple GA properties, Google Ads, BigQuery, third-party partners (MMP, Meta CAPI, etc.).

This diagram shows how a single event stream can be routed and transformed to different destinations from the server.

Why switch to sGTM for Apps?

There are three possible technical approaches to collecting data in a mobile app with Firebase tracking. Each has its advantages and limitations:

Option 1: Firebase SDK only

This is the default implementation. The Firebase SDK (GA4F: Google Analytics for Firebase) is embedded in the app and sends events to Google Analytics via Firebase. This is the fastest solution to set up, but also the least flexible: no enrichment or filtering is possible. You can't inspect or transform the data before it's sent.

Option 2: Firebase SDK + GTM iOS/Android

This configuration adds another level of abstraction to the app, thanks to a mobile GTM container. This makes it possible to modify the configuration of certain events or tags without having to re-release the app. However, this remains a client-side solution: no anonymization, no RGPD filtering, and always a direct send to Firebase/GA.

Option 3: Firebase SDK + sGTM for Apps (new)

Here, all processing logic passes through the server. The app sends Firebase events to the sGTM container, where they can be inspected, modified, deleted or redirected before being sent to the destination tools. This is the only solution offering total control over data, with a scalable, privacy-first approach.

Is sGTM for Apps right for you?

Implementing sGTM for Apps requires a certain amount of technical maturity, but it's becoming a must for any company that wants to take its responsible data collection strategy a step further.

Here are a few signs that this solution is right for you:

You're already using GTM Server-side for your website: pooling the infrastructure for your apps makes your system more coherent, maintainable and scalable.
Your mobile app is based on Firebase (Google Analytics for Firebase SDK: GA4F SDK): this is an essential technical prerequisite for robust tracking, now compatible with Flutter, React Native, Android and iOS.
You have privacy, RGPD or data silos issues: sGTM enables you to prevent certain data from being transmitted to third parties, or to filter it before sending.
You want to enrich the data collected with Firebase on your application, particularly with first-party data such as:

- User-provided data (email, phone, etc.) for better advertising matching

- Product margins or customer lifetime value to improve advertising performance (value based bidding)

You have the internal resources or a technical partner to maintain a GTM Server instance (GCP, Addingwell, etc.).

💡

So, shall we get started?

If you answer yes to these points, investing in such an architecture has every chance of being a strong point for your data collection.

How do I implement sGTM for Apps?

The complete implementation is based on three main steps, with several detailed sub-steps, which we describe below.

1. Prepare the application for server-side data collection

Install up-to-date Firebase SDK: download the latest version of the Google Analytics for Firebase (GA4F) SDK compatible with server-side routing.
Configure application files: in the AndroidManifest.xml (Android) or Info.plist (iOS) file, activate sGTM and, if necessary, GTM's Preview Mode (recommended).
Activate the option in Google Analytics: in your GA mobile data stream, check "Enable sending events to GTM Server". This will enable the Firebase SDK to link up with sGTM for Apps.

If required, particularly for tests or a progressive roll-out, you can choose the percentage of traffic to be routed (10%, 50%, 100%).

2. Create and configure the server container

Create a GTM Server-side container on your GCP instance or third-party partner (e.g. Addingwell).
Add a "GA (App)" client: this client will intercept calls from the Firebase SDK
Create server-side tags: you can then route data to GA, Google Ads, Search Ads 360, or any other partner (via HTTP tags, webhook, etc.).

3. Visualize and debug

Use GTM Server preview mode with the app: from GTM, select "Send requests from app", generate a QR code and scan it with your app to view events in real time.

4. Deploy gradually

Gradually activate routing via GA: start with a low percentage to test (e.g. 10%), then gradually increase to 100% once validated.
Check the behavior of all destinations (GA, Google Ads, Piano Analytics, Meta,...) in server container reports and logs.

Useful sources and resources

Would you like to find out more about app tracking or how to set up sGTM for Apps with our experts?

EdgeAngel can support you in auditing your data architecture, technical deployment, tag setup, and compliance with RGPD constraints for sGTM for Apps: our service offering on mobile app tracking 👉 https://edgeangel.co/en/app-tracking
And for all your data marketing needs and/or support on campaign strategy and management, contact us for a first discovery call!