# Custom Event (Version 3.x)

A custom event lets you track unique user interactions and send data that isn't covered by standard events. You can include a flexible payload of user-defined attributes to capture the specific details of an interaction. You can then map these attributes to a Custom Event Schema in Data 360 using the Mobile Schema naming conventions.

## Custom Event Example for iOS

Here's an example of a custom event that captures a user's gift preferences.

> **Note:** In this example, `mobileAppEvent` is a sample name parameter value. Set the `name` parameter to a value that matches the `developerName` defined in your [Custom Event Schema](https://developer.salesforce.com/docs/data/data-cloud-int/guide/c360-a-mobile-web-sdk-schema-quick-guide.md#event) in Data 360.

```nolang
CustomEvent(
    name: "mobileAppEvent",
    attributes: [
        "giftWrap" : true,
        "giftMessage" : "Happy Birthday",
        "giftWrapOptions": [
            "paperColor": "green",
            "ribbon": false
  ]
    ]
)
```

To see how a schema maps, see [Custom Event Schema](https://developer.salesforce.com/docs/data/data-cloud-engagement-mobile-sdk/guide/c360a-api-engagement-mobile-sdk-custom-event-schema.md).

## Custom Event Example for Android

Here's an example showing the same custom event for capturing a user's gift preferences on Android.

```nolang
EventManager.customEvent(
    name = "mobileAppEvent",
    attributes = mapOf(
        "gift" to mapOf(
            "message" to "Happy Birthday",
            "wrap" to true,
            "wrapOptions" to mapOf(
                "paper-color" to "green",
                "ribbon" to false
            )
        )
    )
)?.track()
```

Nested attribute keys are flattened using parent-child naming (for example, `gift.message` becomes `giftMessage`) per the schema mapping rules.