ZAP onEvent Handler.js

// A script which listens for events generated by the ProxyListenerLogEventPublisher.
// You can change this to listen for events generated by any other event publisher

var consumer;

function install(helper) {
  var ConsumerClass = Java.extend(
    Java.type("org.zaproxy.zap.eventBus.EventConsumer")
  );
  consumer = new ConsumerClass({
    eventReceived: function (event) {
      // Print in one statement to prevent threads interleaving
      var target = "---";
      if (event.getTarget()) {
        target = event.getTarget().getDisplayName();
      }
      print(
        "Event received: \n" +
          "  Publisher: " +
          event.getPublisher().getPublisherName() +
          "\n" +
          "  Type:      " +
          event.getEventType() +
          "\n" +
          "  Target:    " +
          target +
          "\n" +
          "  Params:    " +
          event.getParameters()
      );
    },
  });

  org.zaproxy.zap.ZAP.getEventBus().registerConsumer(
    consumer,
    "org.parosproxy.paros.extension.history.ProxyListenerLogEventPublisher"
  );
}

function uninstall(helper) {
  org.zaproxy.zap.ZAP.getEventBus().unregisterConsumer(consumer);
}