Conversions API for Server-Side Google Tag Manager (GTM)

• Prerequisites, including how to create a server container
• How to configure the container to support your implementation of the GA4 Web Tag
• How to send data from your website to your GCP server
• How to share that data with Meta using the Conversions API
• Frequently asked questions

1. Get familiar with the Conversions API integration and the best practices for setup
2. Get familiar with Server-Side Tagging⁠ and Custom Tag Template⁠.

• Web container: If this is your first time using GTM, start with installing a web container to your account. Learn more here⁠.
• Server Container: You will need to create a server container in your GTM portal to set up a tagging server URL. Learn more about this step⁠.

• Click on Create Container
• Name your container and select “Server” as the target platform
• Click Create

1. On your web container, create the following artifacts:
   • GA4 Configuration to configure your tagging server URL.
   • GA4 Event to configure event schema to be delivered to the server.
2. On your server container, create the following artifacts:
   • GA4 Client, a listener for the event that fires the event to Meta.
   • Meta Conversions API Tag, a server-side tag that converts the standard event model from GA4 Client to Conversions API event schema and sends it to graph.facebook.com.

• If you select Send to server container, set your Server Container URL as the tagging server URL.
• If you do not select Send to server container, under Fields to Set, click Add Row and set:
  • Field name: transport_url
  • Field value: your tagging server URL

• Set the first_party_collection flag to true. You must do this to be able to pass the user_data parameters to the Server-Side GTM. Under Fields to Set, click Add Row and set:
  • Field name: first_party_collection
  • Field value: true

• Navigate to the variables section, and create a new User-Defined Variable for both the Meta Browser ID and Meta Click ID. Use the variable type 1st-Party Cookie.
  • For the Meta Browser ID, set the Cookie Name to _fbp
  • For the Meta Click ID, set the Cookie Name to _fbc
• Save these variables.
• In your GA4 Configuration tag, under Fields to Set, click Add Row and set:
  • Field name: x-fb-ck-fbp
  • Field value: your Meta Browser ID variable
• Add an additional row for the Click ID:
• Field name: x-fb-ck-fbc
• Field value: your Meta Click ID variable

• Configure your web container to send your website data to the created tagging server to add the Google Analytics. Learn more⁠ about how to configure the Google Analytics: GA4 Configuration Tag⁠.
• Add the Google Analytics: GA4 Event Tag to your Workspace from the Template Gallery:
  • Set up an Event Name for the tag. You can set this as a static value or configure it to read from a variable. For certain standard events, we’ll map Google Analytics standard events to Meta equivalents. For these events, you can use either the Google Analytics event name or the Meta event name. For all other standard events, use the Meta event name. For Custom Events, use the name of the Custom Event Learn more. Learn more⁠.

• In the Event Parameters section:
• If you are using the Meta Pixel, add the Event ID parameter. Use event_id as the parameter name, and the variable created for the event ID as the parameter value. Refer to the Deduplication section for guidance on creating the Event ID variable, and modifying the Meta Pixel.
• Map each of the parameters you want to configure. The variable name will be read from the event using a common event schema. For example, to set up email as an event parameter, you have to define it as Parameter Name: user_data.email_address and set up the Value as the variable name that reads the email_address (defined earlier in Section 1).
• For a full list, see the Custom Data Parameters section below.

1. In the Server-side debugger, choose the relevant event you want to check in the left hand menu.
2. Confirm your tag is showing under the Tags Fired section. If so, you’ll see either Conversions API Tag - Succeeded or Conversions API Tag - Failed.
   • Tag Not Fired: Review your Conversions API Tag trigger and relevant GA4 event trigger on the web container. Confirm the GA4 Event has fired in the web debugger.
   • Tag Fired: Succeeded: Click the tag and check the Test Event Code is correct. Update the test event code if required and restart preview mode.
   • Tag Fired: Failed: Open the Request tab, and click the Outgoing request sent to https://graph.facebook.com. Review the Response Body at the bottom of the request details to see what the error was, and update your integration as appropriate. Remember to restart preview mode after making any changes.

• Use the same trigger for your Meta Pixel Custom HTML Tag and GA4 Event Tag. For example, you could define a trigger condition based on the order confirmation page URL.
• Use the same event_id in both tags:
  1. Set a unique ID from Client: Set a custom parameter (x-fb-event_id) from the gtag event. Generate a unique ID (per event) on the website using a Javascript method (or using Google Tag Manager custom Javascript variable) and set the value in the event as:

  gtag('event', 'purchase', {
  'x-fb-event_id': generateEventId(),
  ...:...
  
  });
  
  You can create a variable that points to the custom Javascript shown above. Whenever the var is referred, the below Javascript is loaded in line:

  function() {
  var gtmData = window.google_tag_manager[{{Container ID}}].dataLayer.get('gtm');
  return gtmData.start + '.' + gtmData.uniqueEventId;
  }
  
  2. Create and populate a Data Layer Variable: You can create your own variable on the web container to read the value from event_id. You can do this by creating a new Data Layer Variable, for example, FBEventIdVar, with the Data Layer Variable Name as eventModel.event_id.
  3. Once the variable is set, you have the variable to plug into the web event in your custom HTML tag, and the server event as an additional GA4 Event Parameter.
  4. On the web, you can set up your Meta Tag on Google Tag Manager web containers to read event_id from a variable.

  fbq('track', Purchase, {..}, {eventID: FBEventIDVar });
  
  Configure the GA4 Event to send an extra parameter, named event_id, set to the FBEventIdVar variable.

gtag('event', 'purchase',
 {
   'event_id': generateEventId(),
   'transaction_id': 't_12345',
   'currency': 'USD',
   'value': 1.23,
   user_data: {
     email_address: '<HASHED_DATA>',
     phone_number: '<HASHED_DATA>',
     address: {
       first_name: '<HASHED_DATA>',
       last_name: '<HASHED_DATA>',
       city: '<HASHED DATA>',
       region: '<HASHED_DATA>',
       postal_code: '<HASHED_DATA>',
       country: '<HASHED_DATA>'
     },
   },
   items: [
     {
       item_id: '1',
       item_name: 'foo',
       quantity: 5,
       price: 123.45,
       item_category: 'bar',
       item_brand: 'baz'
     }
   ],
 });

• Conversions API
• Deduplication for Meta Pixel and Conversions API Events⁠