Document external product links feature

Add documentation for the new feature that allows products to link to external URLs using href instead of path. This enables users to include links to separate applications or third-party documentation in their product switcher.

Changes:
- Add new section 'Link to external products' with configuration examples
- Document external product properties (href, display-name, subtitle, icon, image, audiences)
- Add changelog entry for 2025-11-03
- Clarify that products can be internal or external

Co-Authored-By: Catherine Deskur <[email protected]>

Author: devin-ai-integration[bot]

fern/products/docs/pages/changelog/2025-11-03.mdx

@@ -0,0 +1,23 @@
+## External product links
+
+You can now configure products to link to external URLs instead of hosting documentation on your site. This is useful when you want to include links to separate applications, third-party documentation, or other external resources in your product switcher.
+
+External products appear in the product switcher alongside internal products but navigate users to the specified URL when selected.
+
+To define an external product, add an item to the `products` list in `docs.yml` with an `href` instead of a `path`:
+
+```yaml title="docs.yml"
+products:
+  - display-name: API Documentation
+    path: ./products/api-docs.yml
+    icon: fa-solid fa-book
+    slug: api-docs
+    subtitle: Complete API reference
+
+  - display-name: Dashboard
+    href: https://dashboard.example.com
+    icon: fa-solid fa-chart-line
+    subtitle: Analytics and insights
+```
+
+Visit the [product switching documentation](/learn/docs/navigation/products#link-to-external-products) to learn more.

fern/products/docs/pages/navigation/products.mdx

@@ -26,6 +26,8 @@ subtitle: Allow users to seamlessly navigate between different products you offe
 
 Each product can contain its own distinct versions, tabs, sections, pages, and API references. Products can share content as well. 
 
+Products can be either internal (with their own navigation structure hosted on your docs site) or external (linking to an external URL like a separate application or third-party documentation).
+
 ## Add products to your docs
 
 <Steps toc={true}>
@@ -119,9 +121,50 @@ If your `docs.yml` file includes a `navigation` field or a `tabs` field, be sure
 </Step>
 </Steps>
 
+## Link to external products
+
+You can configure a product to link to an external URL instead of hosting documentation on your site. This is useful when you want to include links to separate applications, third-party documentation, or other external resources in your product switcher.
+
+External products appear in the product switcher alongside internal products but navigate users to the specified URL when selected.
+
+### Configure an external product
+
+To define an external product, add an item to the `products` list in `docs.yml` with an `href` instead of a `path`. You can still include optional parameters like `image`, `icon`, and `subtitle`.
+
+<CodeBlock title="docs.yml">
+```yaml
+products:
+  - display-name: API Documentation
+    path: ./products/api-docs.yml
+    icon: fa-solid fa-book
+    slug: api-docs
+    subtitle: Complete API reference
+
+  - display-name: Dashboard
+    href: https://dashboard.example.com
+    icon: fa-solid fa-chart-line
+    subtitle: Analytics and insights
+```
+</CodeBlock>
+
+In this example, "API Documentation" is an internal product with its own navigation structure, while "Dashboard" is an external product that links to `https://dashboard.example.com`.
+
+### External product properties
+
+External products support the following properties in `docs.yml`:
+
+- `display-name` (required) - The title displayed in the product switcher
+- `href` (required) - External URL to navigate to when the product is selected
+- `subtitle` (optional) - Brief description of the product
+- `icon` (optional) - Icon to display in the product switcher
+- `image` (optional) - Image to display in the product switcher (takes precedence over `icon`)
+- `audiences` (optional) - Control visibility across different documentation instances
+
+<Note>External products cannot have versions, tabs, or navigation structures since they link to external URLs.</Note>
+
 ### Add versioning to your products
 
-You can optionally add versions to your products. Versioned and unversioned products can live next to each other in your site. 
+You can optionally add versions to your products. Versioned and unversioned products can live next to each other in your site.
 
 <Note>For standalone versioning without products, see our [Versioning guide](/docs/configuration/versions).</Note>
 
@@ -324,4 +367,4 @@ The dropdown menus for product and version selectors can be customized using the
       <img src="webflow-version-selector.avif" alt="Example of a styled version selector" />
     </Frame>
   </Tab>
-</Tabs> 
+</Tabs>