> For the complete documentation index, see [llms.txt](https://help.littledata.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.littledata.io/event-editor/common-setups/personalise-klaviyo-flows-with-product-metafields.md).

# Send product metafields to a destination

### What you'll build

Events enriched with product metafield data, for example skin type, material, or a clean category taxonomy. You'll expose the metafield with a [custom data source](/event-editor/custom-data-sources.md), then use [field mappings](/event-editor/field-mappings.md) to put the value where your destination reads it: either a new custom parameter or the new source of an existing field.

Product attributes work as a proxy for customer preferences: you don't need a survey to know a customer cares about sensitive skin, the products they browse tell you. And one controlled metafield beats a drifting product type, so category reports become trustworthy.

### What you need

* Product metafields populated with the attributes you care about
* At least one Littledata destination connected, for example [Klaviyo](/integrations/shopify-klaviyo/littledata-klaviyo-installation-guide.md) or [Google Analytics](/integrations/shopify-to-google-analytics/littledata-shopify-install-guide.md)
* Access to the Event Editor in the Littledata app

{% hint style="info" %}
The metafield namespace and key depend on how your store is set up. Common sources are Shopify's category metafields, your theme's custom fields, or an app that writes metafields, for example a PIM. You'll find them in the metafield list in step 1.
{% endhint %}

### Steps

{% stepper %}
{% step %}

#### Expose the product metafields

Go to **Settings → Custom Data Sources**.

Under **Products**, find and select the metafields you want, for example your skin type attribute.

If they don't appear, click **Refresh metafields** and check back in a few minutes. See [Custom data sources](/event-editor/custom-data-sources.md).
{% endstep %}

{% step %}

#### Open the event

Go to **Settings** for your destination, then open **Events**.

Click the event you want to enrich, for example **Added to Cart** for Klaviyo or **purchase** for GA4. You can repeat the same mapping for other funnel events afterwards so the data stays consistent.
{% endstep %}

{% step %}

#### Map the metafield

In the field mappings, you have two options.

Add the metafield as a new custom parameter:

| Source                   | Destination |
| ------------------------ | ----------- |
| Your skin type metafield | `skin_type` |

Or repoint an existing field at the metafield, for example replacing the default product type with a clean category taxonomy:

| Source                  | Destination     |
| ----------------------- | --------------- |
| Your category metafield | `item_category` |

The metafields you exposed in step 1 appear in the source dropdown. See [Remap existing events](/event-editor/field-mappings.md).
{% endstep %}

{% step %}

#### Preview and save

Use the [event preview](/event-editor/event-preview.md) to check the value appears in the payload, then click **Save**.
{% endstep %}
{% endstepper %}

### Destination notes

* **Klaviyo**: the property appears on the Littledata event, ready for conditional splits in flows and for segments, for example everyone who carted a sensitive-skin product in the last 90 days.
* **GA4**: register each custom parameter as an event-scoped custom dimension (**Admin → Custom definitions**); data appears in reports within 24 to 48 hours. Remapped standard fields like `item_category` work in reports immediately.
* **Meta**: custom parameters are available for refining custom audiences.

### Verify it's working

1. Trigger the event with a product that has the metafield set, for example add it to your cart as a test customer.
2. Check the destination received the value: the profile's activity feed in Klaviyo, or **DebugView** in GA4.

### Make it yours

Any metafield can flow to any destination field:

* Customer metafields work the same way: expose them under **Customers** to send who the customer is rather than what they browsed. See [Build audiences from quiz answers](/event-editor/common-setups/quiz-answer-lookalikes-meta-ads.md).
* Send deeper taxonomy levels as `item_category2` through `item_category5` to mirror a full taxonomy path in GA4.
* Food and supplement stores: map dietary attributes like `vegan` or `gluten_free` and branch replenishment flows on them.