Facebook Tag for Google Tag Manager Server Side

Using Facebook Conversions API, you can send events to Facebook Event Manager. That is the perfect alternative to Facebook SDK because Conversions API speeds up page loading and helps track users more accurately.

We created a Facebook tag for the GTM Server-Side container that uses Facebook Conversions API to track events.

The principal feature in writing this tag was easily integrating it into your current GTM Server setup. It can use GA4 server client for retrieving event data.

The data flow looks like this:

1. The user opens the page.

2. gtag.js tracks ‘page_view’ event and sends it to GTM Server Side.

3. GA4 Client on GTM Server Side receives the request and creates the EventData object.

4. Facebook Tag receives the EventData object, maps it onto the Facebook Conversions API event object, and then sends it to Facebook.

How to setup Facebook event tracking using Facebook GTM Server tag:Copy link to this section

1. Download Facebook tag template from GitHub repository

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2. Import Facebook server tag template into Google Tag Manager Server Side container. Click on Templates -> Tag Templates -> New. Then on the right upper corner, click on dots, and choose import.

3. Create a trigger that will fire on GA4 client. 

• For GA4, choose Client Name = “GA4”.

4. Now we need to obtain Facebook API Access Token. There is official documentation on how to get it.

5. Finally, we can create a Facebook tag. Click on Tags->New->Tag configuration and choose Facebook tag.

6. You need to set the required tag configuration parameters (Pixel ID, API Access Token). We recommend creating Custom Variables for storing Pixel ID, API Access Token.

7. That’s it. Now you can start sending test events.

How to test Google Tag Manager Facebook tag with "Test Your Events" featureCopy link to this section

Facebook provides the ability to test Browser and Server events. That is very useful if you set up Facebook pixel using GTM Server for the first time and wish to check that all data tracked correctly.

1. At first, you need to obtain test_event_code. For this, you need to log into your Facebook manager, choose the data source that you liked to test, and open the tab “Test events”. There you will find the test event code. It can look like this: TEST32229

2. Fill the Test ID field, in your Facebook tag, with the test event code that you get from the previous step.

3. Go to preview mode or publish changes to your Server Side container. If done right, you will see test events on the Facebook Test Event page.

Event Name mappingCopy link to this section

By default, the tag tries to map GA standard events to Facebook standard events. If it cannot match it, the raw event name that came from the GA client will be used. For example, if you send an event name like this: gtag(‘event’, ‘UserLikedProduct’), you will get the event “UserLikedProduct” in the Facebook event manager.

Below you will find the scheme of mapping GA events to Facebook events that we use in this tag by default:

Google Analytics EE to Facebook eventsCopy link to this section

To make migration of your web Facebook GTM tag to server-side container simpler, we tried to map all data that GA client receives to the Facebook event without any setup from your side. It also supports GA Enhanced Eccomerce events mapping, and of course, the tag can override all event parameters that will be sent to Facebook. 

For example, if the tag detects that the event type is “Purchase”, we will determine the product list, their currency, and value. 

In the sections below, we describe how exactly data mapped in every parameter group.

Default mapping and overriding Server Event DataCopy link to this section

There are only a few parameters that are in the category of Server Event Data. See this documentation for more details on what data parameters exist.

Parameters that are set by default:

Default mapping and overriding User DataCopy link to this section

With the “User Data” tag option, you can override or add any user data that will be sent to Facebook. See this Facebook documentation for more details on what user data parameters you can add to the call. If the documentation calls for the parameter to be hashed, you must hash it with SHA256 or the hit will not be sent to Facebook.

Default mapping and overriding Custom DataCopy link to this section

You also can override any other parameters or add your own using the “Custom Data” section in the tag setup. Check out this documentation for more details on what data parameters you can add to the call. 

If the EE parameter ‘items’ exists, tag set content_type to ‘product’. GA product parameters item_name, item_category map onto Facebook content_name, content_category accordingly.

Tag also tries to determine other product parameters, including the following:

If the event type is “Purchase” but the currency can’t be mapped, ‘USD’ is used as the default value. That’s because Facebook doesn’t accept “Purchase” events without the currency parameters.