**Data Modeling Hub > Events > Add event**.
3. In the **Name** field, enter `product.backInStock`.
In the API and SDK, the name parameter is usually called `action` or `action name`.
4. Optionally, define a human-friendly display name that will be shown in the **Data Modeling Hub** and **Decision Hub**.
5. Optionally, in the **Description** field, enter the description of the event.
6. Enable the **Make this event available to anonymous profiles without JWT** toggle.
7. Click **Apply**.
8. In the list of events, find the event you just created.
9. On the right side of the screen, click **Add property**.
10. In the **Source parameter** field, enter `sku`.
11. In the **Property name** field, enter a human-readable label for display in the Synerise platform.
12. Optionally, in the **Description** field, you can add an explanation about the purpose of this parameter.
13. To complete the process, click **Save**.
## Create an aggregate with products for which the customer has signed up for notifications
---
The aggregate created will later be used in workflow to check which products have returned to stock.
**Behavioral Data Hub > Live Aggregates > Create aggregate**.
2. As the aggregate type, select **Profile**.
2. Enter the name of the aggregate.
3. Click **Analyze profiles by** and select **Last multi** and in the **Size** field, enter `100`.
5. From the **Choose event** dropdown list, select the **form.submit** event.
6. As the event parameter, select **sku**.
7. Click **+ where** button.
8. From the **Choose parameter** dropdown list, select the **formType** parameter.
9. From the **Choose operator** dropdown list, select **Equal**.
10. Enter the name of the form. In our case it's `back_in_stock_alert`.
11. Set the period from which the aggregate will analyze the results to the last **30 days**.
12. Save the aggregate.
**Behavioral Data Hub > Live Aggregates > Create aggregate**.
2. As the aggregate type, select **Profile**.
2. Enter the name of the aggregate.
3. Click **Analyze profiles by** and select **Last multi** and in the **Size** field, enter `100`.
5. From the **Choose event** dropdown list, select the **product.backInStock** event.
6. As the event parameter, select **sku**.
7. Set the period from which the aggregate will analyze results to the last **30 days**.
8. Save the aggregate.
Great news, the product:
{%set eventParams = event.params%}
{%set sku = eventParams.sku|split(',')|last%}
{%catalogitemv2.items-demo(sku)%}
{%set itemObject=catalog_result%}
{{itemObject.title}}
{%endcatalogitemv2%}
you were waiting for is back in stock!{%set eventParams = event.params%}
{%set sku = eventParams.sku|split(',')|last%}
{%catalogitemv2.items-demo(sku)%}
{%set itemObject=catalog_result%}
{{itemObject.link}}
{%endcatalogitemv2%}
{
"sku": "{% set signedProducts=[] %}{% set receivedProducts=[] %}{% set finalSku=[] %}{% aggregate b4173b56-cf83-3ce8-90c8-f35f36a91368 %}{% for sku in aggregate_result|reverse %}{% do signedProducts.append(sku) %}{% endfor %}{% endaggregate %}{% aggregate e55cae5e-2d48-3e29-a2a2-5122913e4e96 %}{% for sku in aggregate_result|reverse %}{% do receivedProducts.append(sku) %}{% endfor %}{% endaggregate %}{% for sku in signedProducts %}{% catalogvar.items-demo(sku).availability %}{% if catalog_result=='in stock' %}{% if sku in receivedProducts|join(',') %}{% else %}{% do finalSku.append(sku) %}{% endif%}{% endif %}{% endcatalogvar %}{% endfor %}{% set counter=0 %}{% for sku in finalSku %}{% set counter=counter + 1 %}{{sku}}{% if counter < finalSku|length%},{% endif %}{%endfor%}"
}
