In the context of Buy with Prime analytics, a user event is a specific action or occurrence within your e-commerce platform. User events can include various shopper interactions such as page views, clicks, and so on. Every user event has a name (such as page-load), an associated schema, and a unique event ID.

There are two ways to track user events, as shown in the following figure.

• Server-side: This is the tracking method we recommend. In this method, your server sends user events to your Buy with Prime account by using the Buy with Prime API. This approach is the most reliable and the easiest to maintain, because the server is an environment that you control. As such, you can add tracking in one place (your servers) rather than in diverse places (web, iOS, Android). However, server-side tracking has limitations with respect to capturing certain shopper interactions. A server-side user event can be captured when a page loads, but it might not be able to determine if the page was actually rendered. Similarly, not every click, hover, or scrolling action leads to a back-end service call, and therefore can’t be captured with server-side tracking alone.
• Client-side: In this method, user events are generated on the shopper's desktop or mobile device and sent to your Buy with Prime account by using the Buy with Prime API. It can capture granular interactions like clicks, hovers, and scrolling. Client-side tracking is less reliable than server-side because it might be obstructed by ad blockers, browser settings, and network issues. It's also harder to maintain across multiple platforms, because it might involve redeploying your app to web and mobile clients. We therefore recommend that you track everything you can by using your servers, and only supplement that with client-side tracking when necessary.

Regardless of whether you send server-side or client-side user events, we recommend that you call the sendUserEvents mutation asynchronously so that you can track user events in a non-blocking way. The following example shows a non-blocking API call.

// Async client
sendUserEventsMutation = async(mutation) => {
   const res = await fetch(buyWithPrimeUrl,  {
    method: "POST",
    headers: buyWithPrimeHeaders,
    mutation
   });
   return res.json();
}

A schema defines the fields of the user event. Every user event has its own schema, which contains a list of fields that the user event can capture based on the user event type. Because schemas can evolve, each schema has a name and a version. If you don't specify a schema name and a schema version, the event is validated against the latest default schema, which contains all possible fields.

For the schema of user events, see User Event Schema. Some fields are provided by default. You can emit additional optional properties in the additionalProperties list within the event.

The event time of a user event is a date-time field that captures the UTC time when the user event was generated.