> 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/track-purchases-from-a-specific-collection.md).

# Track purchases from a specific collection

### What you'll build

A custom event based on purchase, scoped with a trigger condition so it fires only when the order contains a product from one collection.

A collection often maps to a business line: a new range you're launching, a brand within your store, a category with different margins. A dedicated event lets a destination report on, trigger from, or optimize toward that line, while the standard purchase event keeps flowing untouched.

### What you need

* A Shopify collection, product type, or tag that identifies the product line
* At least one Littledata destination connected, for example Meta Conversions API or Google Analytics
* Access to the Event Editor in the Littledata app

### Steps

{% stepper %}
{% step %}

#### Add a custom event

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

Click **Add event**.
{% endstep %}

{% step %}

#### Name it and pick the base event

Name the event after the line, e.g. `SkincarePurchase`.

Select **Purchase** as the base event. The custom event inherits the complete field mappings of its base, so it sends a full, valid payload from the start. See Derive a new custom event.
{% endstep %}

{% step %}

#### Scope it with a trigger condition

Without a condition, the new event fires on every purchase. Add a condition so it only fires when the order contains a product from the collection:

| Field                   | Operation        | Value      |
| ----------------------- | ---------------- | ---------- |
| `products.collections`  | `contains`       | `skincare` |
| `products.category`     | `does not equal` | `Health`   |
| `products.product_type` | `does not equal` | `Health`   |

The event fires when any product in the order matches, so a mixed cart with one skincare item still counts. See Trigger conditions.
{% endstep %}

{% step %}

#### Preview and save

Use the event preview to check the payload, then click **Save**.
{% endstep %}
{% endstepper %}

### Destination notes

* **Meta**: in Events Manager, mark the event as a custom conversion to run campaigns optimized for the range, for example a launch campaign bidding toward `SkincarePurchase` rather than any purchase.
* **GA4**: mark the event as a key event to compare which channels drive the line, without segmenting every purchase report by item.
* **Klaviyo**: use the event as a flow trigger for line-specific post-purchase journeys, for example replenishment reminders for consumables.

### Verify it's working

1. Place a test order containing a product from the collection.
2. Confirm the new event arrives alongside the standard purchase event, for example in Meta **Events Manager** or GA4 **DebugView**.
3. Orders without a product from the collection should fire purchase only.

### Make it yours

This setup is a custom event conditioned on what's in the order. Any product attribute your store maintains can define a line:

* Condition on product type, vendor, tag, or a SKU prefix instead of a collection.
* The order value still reflects the whole cart. If the destination should only see the line's revenue, adjust the event's field mappings.
* Custom events exist per connection. To use the same event in another destination, create it there as well.