Merge pull request #36578 from dotnet/main

Merge to Live

Author: wadepickett

aspnetcore/fundamentals/openapi/aspnetcore-openapi.md

@@ -1,11 +1,12 @@
 ---
 title: Generate OpenAPI documents
+ai-usage: ai-assisted
 author: captainsafia
 description: Learn how to generate and customize OpenAPI documents in an ASP.NET Core app.
-ms.author: safia
 monikerRange: '>= aspnetcore-6.0'
+ms.author: safia
 ms.custom: mvc
-ms.date: 12/10/2025
+ms.date: 12/17/2025
 uid: fundamentals/openapi/aspnetcore-openapi
 ---
 # Generate OpenAPI documents
@@ -183,6 +184,11 @@ You can customize the <xref:Microsoft.AspNetCore.OpenApi.OpenApiOptions.ShouldIn
 
 ## Generate OpenAPI documents at build time
 
+> [!NOTE]
+> Starting with .NET 9, ASP.NET Core includes built-in OpenAPI support. The [`Microsoft.AspNetCore.OpenApi`](https://www.nuget.org/packages/Microsoft.AspNetCore.OpenApi) package provides OpenAPI document generation at runtime, and adding the [`Microsoft.Extensions.ApiDescription.Server` ](https://www.nuget.org/packages/Microsoft.Extensions.ApiDescription.Server) package enables build-time document generation. 
+>
+>ASP.NET Core generates OpenAPI documents only. Interactive UIs such as **Swagger UI** or **Scalar** are not included by default and must be added separately. For guidance on using these UI options, see <xref:fundamentals/openapi/using-openapi-documents>.
+
 In typical web apps, OpenAPI documents are generated at runtime and served via an HTTP request to the app server.
 
 In some scenarios, it's helpful to generate the OpenAPI document during the app's build step. These scenarios include generating OpenAPI documentation that is:

aspnetcore/fundamentals/static-files.md

@@ -5,7 +5,7 @@ description: Learn how to serve and secure static files and configure Map Static
 monikerRange: '>= aspnetcore-3.1'
 ms.author: wpickett
 ms.custom: mvc
-ms.date: 09/17/2025
+ms.date: 01/05/2026
 uid: fundamentals/static-files
 ---
 # Static files in ASP.NET Core
@@ -1123,7 +1123,7 @@ Property | Description
 
 Item group | Description | Metadata
 --- | ---
-`StaticWebAssetContentTypeMapping` | Maps file patterns to content types and cache headers for endpoints. | `Pattern`, `Cache`
+`StaticWebAssetContentTypeMapping` | Maps file patterns to content types and cache headers for endpoints. | `Pattern`, `Cache`, `Priority`
 `StaticWebAssetFingerprintPattern` | Defines patterns for applying fingerprints to static web assets for cache busting. | `Pattern`, `Expression`
 
 Metadata Descriptions:
@@ -1132,13 +1132,16 @@ Metadata Descriptions:
 
 * **`Cache`**: Specifies the `Cache-Control` header value for the matched content type. This controls browser caching behavior (for example, `max-age=3600, must-revalidate` for media files).
 
+* **`Priority`**: Controls precedence when multiple `StaticWebAssetContentTypeMapping` items match the same file. Higher numeric values take precedence over lower ones. `Priority` is required.
+
 * **`Expression`**: Defines how the fingerprint is inserted into the filename. The default is `#[.{FINGERPRINT}]`, which inserts the fingerprint (`{FINGERPRINT}` placeholder) before the extension.
 
 The following example maps the bitmap file pattern (`.bmp`) to the `image/bmp` content type with the `{CACHE HEADER}` placeholder representing the `Cache-Control` header to use for non-fingerprinted endpoints:
 
 ```xml
 <ItemGroup>
-  <StaticWebAssetContentTypeMapping Include="image/bmp" Cache="{CACHE HEADER}" Pattern="*.bmp" />
+  <StaticWebAssetContentTypeMapping Include="image/bmp" Cache="{CACHE HEADER}"
+    Pattern="*.bmp" Priority="1" />
 </ItemGroup>
 ```