Extensions.Bedrock.MEAI: Fix reading/writing ReasoningContent for tool use (#4080)

1. The `RedactedContent` property of `TextReasoningContent` is optional and not required for Claude 4 models. Don't throw new it's not found in `AdditionalProperties`.
2. Use `ProtectedData` for the "Signature" of the reasoning content so that it round trips. See: dotnet/extensions#6784
3. In `GetStreamingResponseAsync`, the final `ReasoningContentBlockDelta` may not have text, but it will have `Signature` and possibly `RedactedContent`

These fix a scenario where thinking + tool use fails because the reasoning content sent back with the tool response is invalid.

Author: jdaigle

extensions/src/AWSSDK.Extensions.Bedrock.MEAI/AWSSDK.Extensions.Bedrock.MEAI.NetFramework.csproj

@@ -37,7 +37,7 @@
   </Choose>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.0" />
+    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.1" />
   </ItemGroup>
 
   <ItemGroup>

extensions/src/AWSSDK.Extensions.Bedrock.MEAI/AWSSDK.Extensions.Bedrock.MEAI.NetStandard.csproj

@@ -41,7 +41,7 @@
   </Choose>
 
   <ItemGroup>
-  <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.0" />
+  <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.1" />
   </ItemGroup>
 
   <ItemGroup>

extensions/src/AWSSDK.Extensions.Bedrock.MEAI/AWSSDK.Extensions.Bedrock.MEAI.nuspec

@@ -15,17 +15,17 @@
       <group targetFramework="net472">
         <dependency id="AWSSDK.Core" version="4.0.1.3" />
         <dependency id="AWSSDK.BedrockRuntime" version="4.0.7.7" />
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.1" />
       </group>
       <group targetFramework="netstandard2.0">
         <dependency id="AWSSDK.Core" version="4.0.1.3" />
         <dependency id="AWSSDK.BedrockRuntime" version="4.0.7.7" />
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.1" />
       </group>
       <group targetFramework="net8.0">
         <dependency id="AWSSDK.Core" version="4.0.1.3" />
         <dependency id="AWSSDK.BedrockRuntime" version="4.0.7.7" />
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.9.1" />
       </group>
     </dependencies>
   </metadata>

extensions/src/AWSSDK.Extensions.Bedrock.MEAI/BedrockChatClient.cs

@@ -121,7 +121,7 @@ public async Task<ChatResponse> GetResponseAsync(
 
                     if (reasoningContent.ReasoningText.Signature is string signature)
                     {
-                        (trc.AdditionalProperties ??= [])[nameof(reasoningContent.ReasoningText.Signature)] = signature;
+                        trc.ProtectedData = signature;
                     }
 
                     if (reasoningContent.RedactedContent is { } redactedContent)
@@ -249,13 +249,13 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                         yield return textUpdate;
                     }
 
-                    if (contentBlockDelta.Delta.ReasoningContent is { Text: not null } reasoningContent)
+                    if (contentBlockDelta.Delta.ReasoningContent is { } reasoningContent)
                     {
                         TextReasoningContent trc = new(reasoningContent.Text);
 
                         if (reasoningContent.Signature is not null)
                         {
-                            (trc.AdditionalProperties ??= [])[nameof(reasoningContent.Signature)] = reasoningContent.Signature;
+                            trc.ProtectedData = reasoningContent.Signature;
                         }
 
                         if (reasoningContent.RedactedContent is { } redactedContent)
@@ -516,16 +516,18 @@ private static List<ContentBlock> CreateContents(ChatMessage message)
                     break;
 
                 case TextReasoningContent trc:
+                    object? redactedContent = null;
+                    trc.AdditionalProperties?.TryGetValue(nameof(ReasoningContentBlock.RedactedContent), out redactedContent);
                     contents.Add(new()
                     {
                         ReasoningContent = new()
                         {
                             ReasoningText = new()
                             {
                                 Text = trc.Text,
-                                Signature = trc.AdditionalProperties?[nameof(ReasoningContentBlock.ReasoningText.Signature)] as string,
+                                Signature = trc.ProtectedData,
                             },
-                            RedactedContent = trc.AdditionalProperties?[nameof(ReasoningContentBlock.RedactedContent)] is byte[] array ? new(array) : null,
+                            RedactedContent = redactedContent is byte[] array ? new(array) : null,
                         }
                     });
                     break;

extensions/test/BedrockMEAITests/BedrockMEAITests.NetFramework.csproj

@@ -18,7 +18,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.0" />
+    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.9.1" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
   </ItemGroup>

generator/.DevConfigs/6c035145-4fe4-42cd-9339-4f10256de2e7.json

@@ -0,0 +1,11 @@
+{
+  "extensions": [
+    {
+      "extensionName": "Extensions.Bedrock.MEAI",
+      "type": "patch",
+      "changeLogMessages": [
+        "Fix reading/writing ReasoningContent for tool use."
+      ]
+    }
+  ]
+}