EventBridge sending duplicate events — deduplication strategy

Struggling to figure out why EventBridge is triggering my Lambda twice for a single Genesys interaction. My security audit pipeline is double-counting access reviews, causing SCIM sync errors.

Here is the event payload:

{"detail": {"interactionId": "123"}, "id": "evt-456"}

Is there a native deduplication header I should check? How do I write the Lambda handler to ignore duplicates?