Add Mintlify integration page for Fern

- Create new integration page at fern/products/docs/pages/integrations/sdks/fern.mdx
- Add navigation entry in docs.yml
- Add Fern card to integrations overview page
- Follow pattern from Speakeasy and Stainless integration pages

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

Author: devin-ai-integration[bot]

fern/products/docs/docs.yml

@@ -269,6 +269,9 @@ navigation:
         slug: analytics/mixpanel
       - page: Postman
         path: ./pages/integrations/postman.mdx
+      - page: Fern
+        path: ./pages/integrations/sdks/fern.mdx
+        slug: sdks/fern
       - page: LaunchDarkly feature flags 
         path: ./pages/integrations/feature-flags.mdx
         hidden: true

fern/products/docs/pages/integrations/overview.mdx

@@ -47,6 +47,14 @@ description: "Integrate with third party platforms for analytics, support, etc."
   iconSize={12}
 />
 
+<Card
+  title="Fern"
+  href="/docs/integrations/sdks/fern"
+  horizontal
+  icon={<img src="https://buildwithfern.com/_next/image?url=%2Fimages%2Flogo-green.png&w=48&q=75" />}
+  iconSize={12}
+/>
+
 </CardGroup>
 
 ## Enabling Analytics
@@ -99,4 +107,4 @@ are available during the workflow run.
 
 <Markdown src="/snippets/enterprise-plan.mdx"/>
 
-If you want to integrate with a third-party analytics or support platforms that Fern doesn't directly support, you can do so [using custom JS](/docs/customization/custom-css-js#custom-javascript). 
+If you want to integrate with a third-party analytics or support platforms that Fern doesn't directly support, you can do so [using custom JS](/docs/customization/custom-css-js#custom-javascript).  

fern/products/docs/pages/integrations/sdks/fern.mdx

@@ -0,0 +1,64 @@
+---
+title: "Fern"
+description: "Automate SDK code snippets in your API playground"
+---
+
+Fern offers a publicly accessible URL with an OpenAPI spec enriched with code samples from generated SDKs. SDK usage snippets are automatically included in the [interactive playground](/docs/api-references/api-explorer) of Mintlify-powered documentation sites.
+
+## Prerequisites
+
+To integrate Mintlify with Fern, you'll need the following:
+
+- A [Mintlify documentation repository](/docs/quickstart#creating-the-repository).
+- A Fern-generated API definition with SDK generators configured in [`generators.yml`](/sdks/reference/generators-yml).
+
+## Setting up the integration
+
+To integrate Fern with Mintlify, you must get your API's OpenAPI spec URL from Fern and update your `docs.json` configuration file.
+
+### Get your OpenAPI spec URL from Fern
+
+Fern automatically generates a publicly accessible OpenAPI spec enriched with SDK code samples. The URL follows this pattern:
+
+```
+https://registry.buildwithfern.com/api-name/openapi/openapi.json
+```
+
+Replace `api-name` with your Fern API name. You can find your API name in your `fern.config.json` file.
+
+### Update your `docs.json` configuration file
+
+Add the Fern OpenAPI spec URL to an **Anchors** or **Tabs** section in your `docs.json` file.
+
+Add the OpenAPI spec URL to an anchor by updating the `anchor` field in your `docs.json` file as follows:
+
+```json docs.json
+{
+  "anchors": [
+    {
+      "name": "API Reference",
+      // !mark
+      "openapi": "https://registry.buildwithfern.com/api-name/openapi/openapi.json",
+      "url": "api-reference",
+      "icon": "square-terminal"
+    }
+  ]
+}
+```
+
+Add the OpenAPI spec URL to a tab by updating the `tab` field in the `docs.json` file as follows:
+
+```json docs.json
+{
+  "tabs": [
+    {
+      "name": "API Reference",
+      "url": "api-reference",
+      // !mark
+      "openapi": "https://registry.buildwithfern.com/api-name/openapi/openapi.json"
+    }
+  ]
+}
+```
+
+Fern-generated code snippets can now be viewed in your API docs and interacted with in the playground.