EDU-14600: Creating the Newsletter data entity in VTEX Master Data

docs/faststore/components/organisms/newsletter.mdx

 Uses `NewsletterForm`, `NewsletterHeader` and `NewsletterContent` as compound components. 
 excerpt: The `Newsletter` component is a section with at least one input text with an action allowing users to submit their input. 
 Uses `NewsletterForm`, `NewsletterHeader` and `NewsletterContent` as compound components. 
@@ -331,3 +331,113 @@ For further customization, you can use the following data attributes:
 `data-fs-newsletter-content`
 
 `data-fs-newsletter-addendum`
+
+## Creating the Newsletter data entity in VTEX Master Data
+
+The Newsletter data entity, also known as the `NL` acronym, is a [Master Data](https://help.vtex.com/en/tutorial/master-data--4otjBnR27u4WUIciQsmkAw?&utm_source=autocomplete) entity that stores subscription information for the Newsletter component. This entity enables the newsletter subscription feature for stores using FastStore.
+
+When customers subscribe to the store newsletter, their information is saved in the `NL` entity. For the newsletter to operate, such as when a user subscribes, the `NL` entity must be set up in the Master Data.
+
+To create the `NL` entity, follow the instructions below based on the method you prefer: [creating via Admin](#creating-via-admin) or [creating via API](#creating-via-api).
+
+> ℹ For more details about Master Data data entities, see the [data entity](https://help.vtex.com/en/tutorial/data-entity--tutorials_1265) article.
+
+### Creating via Admin
+
+1. In the VTEX Admin, go to **Store Settings > Storefront > Master Data**.
+2. In Master Data, click **Applications > Advanced Settings > Data structure**.
+3. Click the **Data Entities** tab.
+4. Click `Add new`.
+5. Complete the fields of the **Data Entity** section with the following information:
+
+    | **Field name**             | **Value**              |
+    | -------------------------- | ---------------------- |
+    | **Acronym**                | `NL`                   |
+    | **Name**                   | Newsletter             |
+    | **Primary key type**       | Generate a unique GUID |
+
+6. In the **Fields** tab, create three new fields:
+
+    <details>
+    <summary><b>Field 1</b></summary>
+
+    This field will store the customer's email address for newsletter subscription. 
+
+    1. Click `New Field` and complete the field with the following values:
+
+        | **Name**   | **Display Name** | **Type** |
+        | ---------- | ---------------- | -------- |
+        | email      | Email            | Email    |
+
+    2. Click the gear icon (⚙️) to open the field configuration options and check all the following options:
+
+        - **Is nullable?**
+        - **Make readable without credentials**
+        - **Allow editing without credentials**
+        - **Allow filtering without credentials**
+
+    3. In the **Search and filter settings** section, check the **Is searchable?** and **Is filterable?** options.
+
+      ![newsletter-field-1](https://vtexhelp.vtexassets.com/assets/docs/src/newsletter-field-1___61c595999569e52175f1de93d9ecd8f0.png)
+
+    </details>
+
+    <details>
+    <summary><b>Field 2</b></summary>
+
+    This field will indicate whether the user chooses to receive the newsletter or not.
+
+    1. Click `New Field` and complete the field with the following values:
+
+        | **Name**          | **Display Name**    | **Type** |
+        | ----------------- | ------------------- | -------- |
+        | isNewsletterOptIn | Receive newsletter? | Boolean  |
+
+    2. Click the gear icon (⚙️) to open the field configuration options and check all the following options:
+
+        - **Make readable without credentials**
+        - **Allow editing without credentials**
+        - **Allow filtering without credentials**
+
+    3. In the **Search and filter settings** section, check the **Is searchable?** and **Is filterable?** options.
+
+      ![newsletter-field-2](https://vtexhelp.vtexassets.com/assets/docs/src/newsletter-field-2___62281c88b10436ce052707080cc5173e.png)
+
+    </details>
+
+    <details>
+    <summary><b>Field 3</b></summary>
+
+    This field will store the user’s name. 
+
+    1. Click `New Field` and complete the field with the following values:
+
+        | **Name** | **Display Name** | **Type**     |
+        | -------- | ---------------- | ------------ |
+        | name     | Name             | Varchar 750  |
+
+    2. Click the gear icon (⚙️) to open the field configuration options and check all the following options:
+
+        - **Make readable without credentials**
+        - **Allow editing without credentials**
+        - **Allow filtering without credentials**
+
+    3. In the **Search and filter settings** section, check the **Is searchable?** and **Is filterable?** options.
+
+      ![newsletter-field-3](https://vtexhelp.vtexassets.com/assets/docs/src/newsletter-field-3___4e7d9fec7f0a827c5d49908df0e2f20b.png)
+
+    </details>
+
+7. Click `Save` and you will be redirected back to the Data Entity tab.
+8. In the row of the new `NL` entity, click the diskette (💾) to publish the created data entity.
+9. Click `OK`.
+10. Click the **Applications** tab to return to the Master Data homepage.
+11. Click `Reload Applications`.
+
+### Creating via API
+
+You can also create the Newsletter data entity using the [Create partial document](https://developers.vtex.com/docs/api-reference/masterdata-api#patch-/api/dataentities/-acronym-/documents) endpoint.
+
+To create the three fields for the Newsletter data entity, see the [Create document with custom ID or update entire document](https://developers.vtex.com/docs/api-reference/masterdata-api#put-/api/dataentities/-acronym-/documents/-id-) endpoint reference. 
+
+> ⚠️ The field information must be the same as described in [Creating via Admin](#creating-via-admin).

docs/faststore/docs/sdk/analytics/implementing-custom-newsletter-analytics-events.mdx

 2. Run `yarn cms-sync` to sync the new section you created with CMS. 
 - `Submit newsletter`: Triggered when a user clicks `Subscribe`. 
 - `Submit newsletter success`: Triggered upon successful subscription. 
 - `Submit newsletter success` event: Tracks if the subscription was successful. 
 2. Run `yarn cms-sync` to sync the new section you created with CMS. 
@@ -19,6 +19,8 @@ To follow this guide, you should be familiar with the following topics:
 - [Sending custom events](https://developers.vtex.com/docs/guides/faststore/analytics-sending-custom-events)
 - [Creating a new section](https://developers.vtex.com/docs/guides/faststore/building-sections-creating-a-new-section)
 
+Also, make sure you have created the Newsletter data entity that stores use subscription information. For more details, see the [Creating the Newsletter data entity in VTEX Master Data](https://developers.vtex.com/docs/guides/faststore/organisms-newsletter#creating-the-newsletter-data-entity-in-vtex-master-data) instructions.
+
 ## Instructions
 
 <CH.Scrollycoding>

docs/faststore/docs/sdk/analytics/sending-custom-events.mdx

 If you have multiple custom events, such as adding/removing items from the cart or viewing products, you can define a unified type to handle them all. This approach simplifies firing multiple events from the same interface. 
 | `name`            | `string` | The name of the event that appears in Analytics reports. The `name` doesn't need to follow any event name conventions related to natively supported events. | 
 This custom event interface captures when a user adds a product to their wishlist, logging details like `productId`, `productName`, and whether the user is logged in (`isLoggedIn`). This data can then be sent to your analytics tool to better understand customer behavior, such as which products are popular on wishlists and how engagement varies between logged-in and anonymous users. 
 The following example extends the `AddToCartEvent` interface to include the `couponCode` property, which is useful for tracking if a customer applied a coupon code when adding an item to the cart: 
 If you have multiple custom events, such as adding/removing items from the cart or viewing products, you can define a unified type to handle them all. This approach simplifies firing multiple events from the same interface. 
@@ -4,6 +4,8 @@ title: "Sending custom events"
 
 Even though the [Analytics](https://developers.vtex.com/docs/guides/faststore/analytics-overview) module natively supports [Google Analytics ecommerce events](https://support.google.com/analytics/answer/14434488?hl=en), you may need to track customer activity not covered by default events. In such cases, you can trigger and intercept custom events using the [`sendAnalyticsEvent`](https://developers.vtex.com/docs/guides/faststore/analytics-send-analytics-event) and [`useAnalyticsEvent`](https://developers.vtex.com/docs/guides/faststore/analytics-use-analytics-event) functions. In this guide, learn how to define and send custom events.
 
+> ℹ️ For a practical example of sending custom events, see the [Implementing custom newsletter analytics events](https://developers.vtex.com/docs/guides/faststore/analytics-implementing-custom-newsletter-analytics-events) guide.
+
 ## Instructions
 
 ### Step 1 - Declaring an interface for your custom event