diff --git a/fern/products/openapi-def/openapi-def.yml b/fern/products/openapi-def/openapi-def.yml
index 419d75e5b..a843620a7 100644
--- a/fern/products/openapi-def/openapi-def.yml
+++ b/fern/products/openapi-def/openapi-def.yml
@@ -4,7 +4,7 @@ navigation:
   - page: Authentication
     path: ./pages/auth.mdx
   - page: Servers
-    path: ./pages/servers.mdx            
+    path: ./pages/servers.mdx
   - section: Endpoints
     slug: endpoints
     contents:
@@ -17,6 +17,9 @@ navigation:
       - page: Server-Sent Events
         path: ./pages/endpoints/sse.mdx
         slug: sse
+      - page: others
+        title: Other
+        path: ./pages/extensions/others.mdx
   - section: Extensions
     slug: extensions
     contents:
@@ -38,7 +41,7 @@ navigation:
       - page: Overlay Customizations
         path: ./pages/overrides.mdx
       - page: Sync your OpenAPI Specification
-        path: ./pages/automation.mdx            
+        path: ./pages/automation.mdx
   - section: Integrate your Server Framework
     slug: frameworks
     contents:
diff --git a/fern/products/openapi-definition/pages/extensions/others.mdx b/fern/products/openapi-definition/pages/extensions/others.mdx
new file mode 100644
index 000000000..16e32d15b
--- /dev/null
+++ b/fern/products/openapi-definition/pages/extensions/others.mdx
@@ -0,0 +1,79 @@
+---
+title: 'Other OpenAPI Extensions'
+description: 'Reference of Fern-supported OpenAPI extensions'
+---
+
+# Fern OpenAPI Extensions
+
+Below is a comprehensive list of all OpenAPI extensions supported by Fern:
+
+## x-fern-sdk-variables
+
+Defines variables that can be passed into SDK client constructors. Variables defined here can be referenced in operation paths.
+
+```yaml
+x-fern-sdk-variables:
+  project_id:
+    type: string
+    description: The ID of the project
+    pattern: "^proj_[a-zA-Z0-9]+$"
+```
+
+## x-fern-sdk-group-name
+
+Groups operations together in generated SDKs under a common namespace/class.
+
+```yaml
+x-fern-sdk-group-name: accounts
+```
+
+## x-fern-sdk-method-name 
+
+Specifies the method name to use in generated SDKs.
+
+```yaml
+x-fern-sdk-method-name: retrieve
+```
+
+## x-fern-sdk-return-value
+
+Indicates which part of the response should be returned from SDK methods.
+
+```yaml
+x-fern-sdk-return-value: data
+```
+
+## x-fern-pagination
+
+Configures pagination for list endpoints.
+
+```yaml
+x-fern-pagination:
+  cursor: "$request.after"
+  next_cursor: "$response.page_info.end_cursor"
+  results: "$response.data"
+```
+
+## x-fern-ignore
+
+Excludes an operation from SDK generation.
+
+```yaml
+x-fern-ignore: true
+```
+
+## x-fern-sdk-variable
+
+References a variable defined in x-fern-sdk-variables.
+
+```yaml
+x-fern-sdk-variable: project_id
+```
+
+<Note>
+All extensions are optional. Only include the ones needed for your specific use case.
+</Note>
+
+<Warning>
+Extensions must be properly formatted according to OpenAPI specification rules. Invalid extension formatting may cause SDK generation to fail.
+</Warning>
\ No newline at end of file
diff --git a/fern/products/sdks/overview/python/configuration.mdx b/fern/products/sdks/overview/python/configuration.mdx
index 1c0eb6af7..ecb5042d3 100644
--- a/fern/products/sdks/overview/python/configuration.mdx
+++ b/fern/products/sdks/overview/python/configuration.mdx
@@ -15,7 +15,30 @@ groups:
         config:
           package_name: "your_package"
           client:
-            class_name: "YourClient" 
+            class_name: "YourClient"
+```
+
+## Extension Headers
+
+You can configure SDK variables in your OpenAPI spec using the `x-fern-sdk-variables` extension. These variables will be injected into the SDK client constructor.
+
+For example, to add a `project_id` variable that gets automatically injected into path parameters:
+
+```yaml
+components:
+  x-fern-sdk-variables:
+    project_id:
+      type: string
+      description: The ID of the project
+      pattern: "^proj_[a-zA-Z0-9]+$"
+```
+
+The variable will be available in the client constructor:
+
+```python
+from my_package import Client
+
+client = Client(project_id="proj_123")
 ```
 
 ## SDK Configuration Options
@@ -72,7 +95,6 @@ groups:
 </ParamField>
 
 <ParamField path="package_name" type="string" default="null" required={false} toc={true}>
-
 Specifies the Python package name that users will import your generated client
 from.
   
@@ -112,8 +134,8 @@ groups:
   # Visit every case in the union
   shape = get_shape()
   shape.visit(
-    circle: lambda circle: do_something_with_circle(circle),
-    triangle: lambda triangle: do_something_with_triangle(triangle),
+    circle=lambda circle: do_something_with_circle(circle),
+    triangle=lambda triangle: do_something_with_triangle(triangle),
   )
   ```