# Create the CpqAppHandlerHook Implementation

In this task, Felix needs to create the interface implementation hook. The hook interface provides a hook to the implementation method for pre-invoke and post-invoke handling.

1. Navigate to the **Interface Implementations** tab in the Industries CPQ app.

2. Click **New**.

3. In the **Interface Name** field, type `CpqAppHandlerHook`.

   :::note
   The maximum length for a hook interface name is 36 characters.
   :::

4. In the Active Implementation Class field, type `CpqAppHandlerHookImplementation`.

   ![](https://a.sfdcstatic.com/developer-website/sfdocs/industries/media/image91.png)

5. Click **Save**.

6. From the Related tab, click **New** next to **Interface Implementation Detail (0)**.

7. In the New Interface Implementation Detail window, type `CpqAppHandlerHookImplementation` in the **Available Implementation** field.

8. Check the **Active** and **Default** box and **Save**.

   ![](https://a.sfdcstatic.com/developer-website/sfdocs/industries/media/image92.png)

See [Add a New Column to Industries CPQ Cart](/docs/industries/cme/guide/comms-add-a-new-column-to-industries-cpq-cart.md).