Overview

An event-based rule defines which catalog items are eligible for personalization based on a user's behavioral signals, the events they trigger, and the properties associated with those events.

Unlike catalog-based rules, which filter items based on static catalog attributes, event-based rules incorporate user behavior to dynamically shape the item pool. Recommendations for each user are resolved from their own event history, so two users in the same campaign can receive entirely different outputs.

Event-based rules can work alongside catalog-based rules in the recommendation pipeline: catalog-based rules define the base item pool using static attributes; event-based rules refine or exclude from that pool using behavioral context.

How Event-Based Rules Work

Event-based rules operate in two phases: a background pre-computation phase and a runtime filtering phase.

Background Pre-Computation

When a user triggers an event, a background process (the populator) evaluates the rule continuously:

1. Checks whether the event matches the rule's criteria (event name and filter conditions).
2. Uses the Catalog and Event Property Mapping section to identify which catalog item is associated with the event.
3. Writes the matched product ID to a per-user feature store, keyed by rule and timestamp.
4. Retains only the most recent N entries, where N is the Interaction Count you set on the rule.

The eligible item set for each user is built continuously in the background. When a recommendation request arrives, the engine reads from this store; it does not process event history at that point.

The following fields control how the populator builds the store:

Runtime Filtering

When a recommendation request arrives, the recommendation pool is assembled first; event-based rule filters shape it as follows:

1. The engine reads each user's pre-computed product IDs for the referenced rules.
2. Per-user filtering is then applied to that pool:    
   • Inclusion rule: Keep only items that appear in the user's resolved include set    
   • Exclusion rule: Remove items that appear in the user's resolved exclude set

The final ranked output is returned.

Inclusion vs. Exclusion

Inclusion and Exclusion are not properties of a rule. The same rule can act as an inclusion in one strategy and an exclusion in another.

The designation is made when you attach the rule to a recommendation strategy, not when you create the rule. When creating a rule, you define the matching criteria and item association. How the resolved item set is applied (i.e., whether to include or exclude it) is a strategy-level decision.

Use Cases

Create Event-Based Rule

To create a new rule, go to Recommendations > Event-Based Rules and click Create Rule. The Create Event-Based Rule page opens.

To create a rule, perform the following steps:

1. Click Create to save the rule.
2. Enter the following details to identify and describe the rule:

3. Click Add Condition to add a condition block. Each rule supports one event.

4. Select an Event: Click the event field to choose from the available events in your account, such as Added to Cart, Product Viewed, or Charged.

5. (Optional) Filter the Event: Click + Filter to narrow the event using event properties. A filter row appears with the following fields:

   

6. Click + to add additional values for the same property (OR logic within the filter row). You can click × to remove a value. To delete the filter row, click the trash icon on the right.

   Multiple filter rows on the same event are combined with AND logic: all conditions must match for the event to qualify. For example: Event: Product Viewed AND Brand = Nike AND Category = Footwear

   This applies only to Product Viewed events where Brand is Nike, and Category is Footwear.

Catalog and Event Property Mapping

This section maps a catalog column to an event property so the engine knows which catalog item to associate with a qualifying event.

In this example, the Catalog column: product_id maps to Event property: item_id

This tells the engine: when a qualifying event triggers, read the item_id from that event and match it against the catalog column product_id to identify which item is associated.

Manage Event-Based Rules

The Event-Based Rules list page provides a central view of all rules, with tools for searching, sorting, filtering, and managing them.

Each rule displays the following columns by default:

From the rules list, you can perform the following actions on any rule:

• Edit: Modify the rule's name, description, criteria, interaction count, date range, or event mapping.
• Clone: Select the rule to open it and then click to create a copy of the rule. You can use this as a starting point for a new rule with a similar configuration.
• Delete: Select the rule and confirm deletion. A rule cannot be deleted while it is
  referenced by one or more active engagements. CleverTap displays the list of campaigns
  and journeys blocking the deletion, so you know what to update before retrying.

Search Rules

Use the search bar to find rules by name. Click any column header to sort by that column. A sort indicator appears in the toolbar when a sort is active.

Filter Rules

Click the icon to open the Filters panel:

Edit Columns

Click the icon to open the Edit Columns panel. Toggle columns on or off and drag rows to reorder them. Click Apply Changes to save, or Reset to restore the default layout.