diff --git a/fundamentals/aot/diagnostics/Rdg11/Program.cs b/fundamentals/aot/diagnostics/Rdg11/Program.cs
new file mode 100644
index 0000000..aaad063
--- /dev/null
+++ b/fundamentals/aot/diagnostics/Rdg11/Program.cs
@@ -0,0 +1,57 @@
+#define RDG11F //   RDG11 RDG11F
+#if NEVER
+#elif RDG11
+// <snippet_1>
+var builder = WebApplication.CreateSlimBuilder(args);
+
+var app = builder.Build();
+app.MapEndpoints<Todo>();
+app.Run();
+
+public static class RouteBuilderExtensions
+{
+    public static IEndpointRouteBuilder MapEndpoints<T>(this IEndpointRouteBuilder app) where T : class, new()
+    {
+        app.MapPost("/input", (T value) => value);
+        app.MapGet("/result", () => new T());
+        app.MapPost("/input-with-wrapper", (Wrapper<T> value) => value);
+        app.MapGet("/async", async () =>
+        {
+            await Task.CompletedTask;
+            return new T();
+        });
+        return app;
+    }
+}
+
+record Todo();
+record Wrapper<T> { }
+// </snippet_1>
+#elif RDG11F
+// <snippet_1f>
+var builder = WebApplication.CreateSlimBuilder(args);
+
+var app = builder.Build();
+app.MapTodoEndpoints();
+app.Run();
+
+public static class TodoRouteBuilderExtensions
+{
+    public static IEndpointRouteBuilder MapTodoEndpoints(this IEndpointRouteBuilder app)
+    {
+        app.MapPost("/input", (Todo value) => value);
+        app.MapGet("/result", () => new Todo());
+        app.MapPost("/input-with-wrapper", (Wrapper<Todo> value) => value);
+        app.MapGet("/async", async () =>
+        {
+            await Task.CompletedTask;
+            return new Todo();
+        });
+        return app;
+    }
+}
+
+record Todo();
+record Wrapper<T> { }
+// </snippet_1f>
+#endif
diff --git a/fundamentals/aot/diagnostics/Rdg11/Rdg11.csproj b/fundamentals/aot/diagnostics/Rdg11/Rdg11.csproj
new file mode 100644
index 0000000..c12d03b
--- /dev/null
+++ b/fundamentals/aot/diagnostics/Rdg11/Rdg11.csproj
@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <EnableRequestDelegateGenerator>true</EnableRequestDelegateGenerator>
+    <LangVersion>preview</LangVersion>
+  </PropertyGroup>
+
+</Project>
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