diff --git a/codegen/generator/src/OpenAI.Library.Plugin.csproj b/codegen/generator/src/OpenAI.Library.Plugin.csproj
index 27dd54f8..97bf3bd1 100644
--- a/codegen/generator/src/OpenAI.Library.Plugin.csproj
+++ b/codegen/generator/src/OpenAI.Library.Plugin.csproj
@@ -8,7 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="Microsoft.TypeSpec.Generator.ClientModel" Version="1.0.0-alpha.20250829.4" />
+      <PackageReference Include="Microsoft.TypeSpec.Generator.ClientModel" Version="1.0.0-alpha.20250903.1" />
     </ItemGroup>
 
   <!-- Copy output to package dist path for local execution and  -->
diff --git a/codegen/generator/src/Visitors/ExperimentalAttributeVisitor.cs b/codegen/generator/src/Visitors/ExperimentalAttributeVisitor.cs
index a0c5fbe1..8b095979 100644
--- a/codegen/generator/src/Visitors/ExperimentalAttributeVisitor.cs
+++ b/codegen/generator/src/Visitors/ExperimentalAttributeVisitor.cs
@@ -664,8 +664,8 @@ public class ExperimentalAttributeVisitor : ScmLibraryVisitor
 
             if (!_stableMethods.Contains(lookupName))
             {
-                methodProvider.Update(
-                    attributes: [.. methodProvider.Attributes,
+                methodProvider.Signature.Update(
+                    attributes: [.. methodProvider.Signature.Attributes,
                         methodProvider.EnclosingType.Type.Namespace.StartsWith(_realtimeNamespace) || (methodProvider.Signature.ReturnType?.Namespace.StartsWith(_realtimeNamespace) ?? false) ?
                             _experimental002Attribute :
                             _experimental001Attribute]);
diff --git a/codegen/package.json b/codegen/package.json
index f3e6a5b6..dd68766b 100644
--- a/codegen/package.json
+++ b/codegen/package.json
@@ -31,7 +31,7 @@
     "@open-ai/plugin": "file:",
     "@azure-tools/typespec-client-generator-core": "0.59.0",
     "@azure-tools/typespec-azure-core": "0.59.0",
-    "@typespec/http-client-csharp": "1.0.0-alpha.20250829.4",
+    "@typespec/http-client-csharp": "1.0.0-alpha.20250903.1",
     "@typespec/http": "1.3.0",
     "@typespec/openapi": "1.3.0"
   },
diff --git a/package-lock.json b/package-lock.json
index 627915e7..1b2fd17f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -23,7 +23,7 @@
         "@azure-tools/typespec-client-generator-core": "0.59.0",
         "@open-ai/plugin": "file:",
         "@typespec/http": "1.3.0",
-        "@typespec/http-client-csharp": "1.0.0-alpha.20250829.4",
+        "@typespec/http-client-csharp": "1.0.0-alpha.20250903.1",
         "@typespec/openapi": "1.3.0"
       },
       "devDependencies": {
@@ -1531,9 +1531,9 @@
       }
     },
     "node_modules/@typespec/http-client-csharp": {
-      "version": "1.0.0-alpha.20250829.4",
-      "resolved": "https://registry.npmjs.org/@typespec/http-client-csharp/-/http-client-csharp-1.0.0-alpha.20250829.4.tgz",
-      "integrity": "sha512-SxOwdLrI5sJ4dPC3j0jLn5DQHQg0g4qm5q4cZCsLMzHbT1Jiio5Z8kDZWlx9UrhfGeNaJ53WWHcccXKowlFw/A==",
+      "version": "1.0.0-alpha.20250903.1",
+      "resolved": "https://registry.npmjs.org/@typespec/http-client-csharp/-/http-client-csharp-1.0.0-alpha.20250903.1.tgz",
+      "integrity": "sha512-W3vbpxUhVJYBSoYPE4seMsDp/nvcqEwxsuYjVxBWMDliOOtO8ED05PYLvY5N4h+vKF2j30iT2d23NqpPo2qxeA==",
       "license": "MIT",
       "peerDependencies": {
         "@azure-tools/typespec-azure-core": ">=0.59.0 <0.60.0 || ~0.60.0-0",
diff --git a/scripts/Invoke-CodeGen.ps1 b/scripts/Invoke-CodeGen.ps1
index 16696181..83fb5108 100644
--- a/scripts/Invoke-CodeGen.ps1
+++ b/scripts/Invoke-CodeGen.ps1
@@ -269,10 +269,17 @@ Push-Location $repoRootPath
 
 try {
     Invoke-ScriptWithLogging { npm ci }
+    if ($LASTEXITCODE -ne 0) {
+        exit $LASTEXITCODE
+    }
+
     Invoke-ScriptWithLogging { npm run build -w $codegenFolderPath }
+    if ($LASTEXITCODE -ne 0) {
+        exit $LASTEXITCODE
+    }
 
     Set-Location $specificationFolderPath
-    Invoke-ScriptWithLogging { npm exec --no -- tsp compile . }
+    Invoke-ScriptWithLogging { npx tsp compile . --trace @typespec/http-client-csharp }
 }
 finally {
     Pop-Location