Postscript tag

The Postscript tag for the server Google Tag Manager container sends Subscriber and Event data to Postscript using their REST API. This tag supports several types of requests:

• Track Event: record custom events linked to a subscriber, such as purchases or form completions.
• Create Subscriber: add new subscribers and optionally include tags, keyword subscriptions, or custom attributes.
• Update Subscriber: modify existing subscriber details, including email, tags, or other custom fields.

Benefits of using the Postscript tag

• Seamless subscriber and event tracking: send subscriber updates and custom event data (like purchases or sign-ups) directly to Postscript’s REST API, ensuring all interactions are logged reliably without relying on browser-side scripts.
• Better personalization and segmentation: with support for tags, custom fields, and properties, you can enrich subscriber profiles and use that data for more precise targeting, segmentation, and tailored messaging in Postscript.
• Improved data accuracy and performance: server-side tracking bypasses ad blockers and browser limitations, reducing data loss.

Requirements for setting up the Postscript tag

Please ensure that you already have Google Tag Manager web and server containers, as well as a configured server container and custom domain in Stape. Please follow these guides if you don’t have any of those:

• How to create a web container in Google Tag Manager
• How to create a server container in Google Tag Manager
• How to create a server container in Stape
• How to add a custom domain in Stape

How to set up the Postscript tag

1. Configure sending data to the server GTM container. The two most popular options for sending data to sGTM are Google Analytics 4 and Data Tag/Data Client. Here is a step-by-step guide on sending data to sGTM.

2. Add the Postscript tag template in the server GTM container by importing it from GitHub:

• Download the tag template.
• In the server Google Tag Manager container, open the Templates menu → click New.

• Click Import → select the Postscript tag template you’ve downloaded → click Save.

3. Create the Postscript tag:

• Go to the Tags menu → click New.

• Click Tag Configuration → select Postscript.

4. Configure the Postscript tag:

• Type - select the type of requests to process (Track Event, Create Subscriber, Update Subscriber). 
• Event Name (only for the Track Event Type) - the name of the event that will show in the Postscript application. Postscript will automatically prefix your partner/shop name in front of the event (e.g., an event called "OrderPlaced" will show in the UI as [Your Partner/Shop Name] - OrderPlaced.
• Private API Key - you can find or create your Private API Key in Postscript Account API Settings.
• Use Optimistic Scenario - the tag will call gtmOnSuccess() without waiting for a response from the API. This will speed up sGTM response time, but your tag will always return the status fired successfully even if it is not.

• Create Subscriber Data (only available if you’ve selected the Create Subscriber type of requests) - allows you to enter the Keyword or Keyword ID that the subscriber should be added to, and where the subscriber originated from.
• User Properties - identifiers (such as subscriber_id, phone, or email) to associate the tag’s events with a specific Subscriber. You may send multiple identifiers in a single API request. When identifiers are provided, Postscript will attempt to match them to a Subscriber. If no Subscriber is found for the provided identifier(s), the event will still be recorded and available for use in Flows.
• Event Properties (only available if you’ve selected the Track Event type of requests) - optional properties to send with the event, like Occurred At and Event ID.
• Event Custom Properties (for the Track Event type of requests) or User Custom Properties (for the Create Subscriber and Update Subscriber type of requests) - additional metadata about the event or user that can be used in segmentation or filtering.
• Consent Settings - gives you an option to send data only if marketing consent is given. Should only be enabled when the web container is configured to send to the server container the consent status (e.g., via the Data Tag); otherwise, leave this option disabled to avoid tracking issues.
• Logs Settings - choose if you want to log requests to your account. This feature is handy when setting up server-side tagging since it allows seeing incoming and outgoing requests and network responses.
• BigQuery Logs Settings - allows you to configure BigQuery logging.
• Advanced Settings (Additional Tag Metadata) - specify additional tag metadata to be included in the event data when the tag is fired.

5. Add the Trigger for the tag, give it a descriptive name, and click Save.

How to test and troubleshoot the Postscript tag setup

You can test the configurations in Google Tag Manager. Click on Preview, trigger the event, and check whether the tag has fired.

Find out more about debugging and monitoring server-side tracking configuration in our guide.