Issue

You are experiencing duplicate events within Segment that are sent to downstream destinations because the tracking event is triggered simultaneously from both a browser library and a server-side library.

Product

Twilio Segment

Environment

Segment Console

Cause

This duplication happens when the same event name is implemented across multiple connected tracking sources or libraries. By default, Segment routes all successfully tracked events from every source to your enabled destinations unless a filter explicitly stops them.

Resolution

You can eliminate duplicate events by creating a Destination Filter that checks the context.library.name field to block browser-side tracking while allowing server-side tracking to pass through.

Follow these steps to configure your Destination Filter:

1. Log in to your Segment workspace.

2. Navigate to Destinations and select the destination receiving the duplicate data.

3. Click the Filters tab and select Add Filter.

4. Define the filter criteria to identify the browser library:

   • Select context.library.name as the property.

   • Set the operator to equal the library, such as analytics.js.

   • Add additional logic as needed.

5. Set the filter action to drop or block the matching events.

6. Save and toggle the filter to active status.

Additional Information

Using Destination Filters allows you to manage data delivery dynamically on a per-destination basis without needing to modify your deployed application source code.