.NET: [Breaking] Structured Output improvements

dotnet/samples/AGUIClientServer/AGUIDojoServer/SharedState/SharedStateAgent.cs

@@ -78,7 +78,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
 
         var response = allUpdates.ToAgentResponse();
 
-        if (response.TryDeserialize(this._jsonSerializerOptions, out JsonElement stateSnapshot))
+        if (TryDeserialize(response.Text, this._jsonSerializerOptions, out JsonElement stateSnapshot))
         {
             byte[] stateBytes = JsonSerializer.SerializeToUtf8Bytes(
                 stateSnapshot,
@@ -103,4 +103,25 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
             yield return update;
         }
     }
+
+    private static bool TryDeserialize<T>(string json, JsonSerializerOptions jsonSerializerOptions, out T structuredOutput)
+    {
+        try
+        {
+            T? result = JsonSerializer.Deserialize<T>(json, jsonSerializerOptions);
+            if (result is null)
+            {
+                structuredOutput = default!;
+                return false;
+            }
+
+            structuredOutput = result;
+            return true;
+        }
+        catch
+        {
+            structuredOutput = default!;
+            return false;
+        }
+    }
 }

dotnet/samples/GettingStarted/AGUI/Step05_StateManagement/Server/SharedStateAgent.cs

@@ -107,7 +107,7 @@ stateObj is not JsonElement state ||
         var response = allUpdates.ToAgentResponse();
 
         // Try to deserialize the structured state response
-        if (response.TryDeserialize(this._jsonSerializerOptions, out JsonElement stateSnapshot))
+        if (TryDeserialize(response.Text, this._jsonSerializerOptions, out JsonElement stateSnapshot))
         {
             // Serialize and emit as STATE_SNAPSHOT via DataContent
             byte[] stateBytes = JsonSerializer.SerializeToUtf8Bytes(
@@ -134,4 +134,25 @@ stateObj is not JsonElement state ||
             yield return update;
         }
     }
+
+    private static bool TryDeserialize<T>(string json, JsonSerializerOptions jsonSerializerOptions, out T structuredOutput)
+    {
+        try
+        {
+            T? deserialized = JsonSerializer.Deserialize<T>(json, jsonSerializerOptions);
+            if (deserialized is null)
+            {
+                structuredOutput = default!;
+                return false;
+            }
+
+            structuredOutput = deserialized;
+            return true;
+        }
+        catch
+        {
+            structuredOutput = default!;
+            return false;
+        }
+    }
 }

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/Program.cs

@@ -8,64 +8,164 @@
 using Azure.AI.OpenAI;
 using Azure.Identity;
 using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
 using OpenAI.Chat;
 using SampleApp;
+using ChatMessage = Microsoft.Extensions.AI.ChatMessage;
 
-var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
-var deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
+string endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
+string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
 
 // Create chat client to be used by chat client agents.
 ChatClient chatClient = new AzureOpenAIClient(
     new Uri(endpoint),
     new AzureCliCredential())
         .GetChatClient(deploymentName);
 
-// Create the ChatClientAgent with the specified name and instructions.
-ChatClientAgent agent = chatClient.AsAIAgent(name: "HelpfulAssistant", instructions: "You are a helpful assistant.");
+// Demonstrates how to work with structured output via ResponseFormat with the non-generic RunAsync method.
+// This approach is useful when:
+// a. Structured output is used for inter-agent communication, where one agent produces structured output
+//    and passes it as text to another agent as input, without the need for the caller to directly work with the structured output.
+// b. The type of the structured output is not known at compile time, so the generic RunAsync<T> method cannot be used.
+// c. The type of the structured output is represented by JSON schema only, without a corresponding class or type in the code.
+await UseStructuredOutputWithResponseFormatAsync(chatClient);
 
-// Set PersonInfo as the type parameter of RunAsync method to specify the expected structured output from the agent and invoke the agent with some unstructured input.
-AgentResponse<PersonInfo> response = await agent.RunAsync<PersonInfo>("Please provide information about John Smith, who is a 35-year-old software engineer.");
+// Demonstrates how to work with structured output via the generic RunAsync<T> method.
+// This approach is useful when the caller needs to directly work with the structured output in the code
+// via an instance of the corresponding class or type and the type is known at compile time.
+await UseStructuredOutputWithRunAsync(chatClient);
 
-// Access the structured output via the Result property of the agent response.
-Console.WriteLine("Assistant Output:");
-Console.WriteLine($"Name: {response.Result.Name}");
-Console.WriteLine($"Age: {response.Result.Age}");
-Console.WriteLine($"Occupation: {response.Result.Occupation}");
+// Demonstrates how to work with structured output when streaming using the RunStreamingAsync method.
+await UseStructuredOutputWithRunStreamingAsync(chatClient);
 
-// Create the ChatClientAgent with the specified name, instructions, and expected structured output the agent should produce.
-ChatClientAgent agentWithPersonInfo = chatClient.AsAIAgent(new ChatClientAgentOptions()
+// Demonstrates how to add structured output support to agents that don't natively support it using the structured output middleware.
+// This approach is useful when working with agents that don't support structured output natively, like A2A, or agents using models
+// that don't have the capability to produce structured output, allowing you to still leverage structured output features by transforming
+// the text output from the agent into structured data using a chat client.
+await UseStructuredOutputWithMiddlewareAsync(chatClient);
+
+static async Task UseStructuredOutputWithResponseFormatAsync(ChatClient chatClient)
+{
+    Console.WriteLine("=== Structured Output with ResponseFormat ===");
+
+    // Create the agent
+    AIAgent agent = chatClient.AsAIAgent(new ChatClientAgentOptions()
+    {
+        Name = "HelpfulAssistant",
+        ChatOptions = new()
+        {
+            Instructions = "You are a helpful assistant.",
+            // Specify CityInfo as the type parameter of ForJsonSchema to indicate the expected structured output from the agent.
+            ResponseFormat = Microsoft.Extensions.AI.ChatResponseFormat.ForJsonSchema<CityInfo>()
+        }
+    });
+
+    // Invoke the agent with some unstructured input to extract the structured information from.
+    AgentResponse response = await agent.RunAsync("Provide information about the capital of France.");
+
+    // Access the structured output via the Text property of the agent response.
+    Console.WriteLine("Assistant Output:");
+    Console.WriteLine(response.Text);
+    Console.WriteLine();
+}
+
+static async Task UseStructuredOutputWithRunAsync(ChatClient chatClient)
+{
+    Console.WriteLine("=== Structured Output with RunAsync<T> ===");
+
+    // Create the agent
+    AIAgent agent = chatClient.AsAIAgent(name: "HelpfulAssistant", instructions: "You are a helpful assistant.");
+
+    // Set CityInfo as the type parameter of RunAsync method to specify the expected structured output from the agent and invoke it with some unstructured input.
+    AgentResponse<CityInfo> response = await agent.RunAsync<CityInfo>("Provide information about the capital of France.");
+
+    // Access the structured output via the Result property of the agent response.
+    CityInfo cityInfo = response.Result;
+
+    Console.WriteLine("Assistant Output:");
+    Console.WriteLine($"Name: {cityInfo.Name}");
+    Console.WriteLine();
+}
+
+static async Task UseStructuredOutputWithRunStreamingAsync(ChatClient chatClient)
+{
+    Console.WriteLine("=== Structured Output with RunStreamingAsync ===");
+
+    // Create the agent
+    AIAgent agent = chatClient.AsAIAgent(new ChatClientAgentOptions()
+    {
+        Name = "HelpfulAssistant",
+        ChatOptions = new()
+        {
+            Instructions = "You are a helpful assistant.",
+            // Specify CityInfo as the type parameter of ForJsonSchema to indicate the expected structured output from the agent.
+            ResponseFormat = Microsoft.Extensions.AI.ChatResponseFormat.ForJsonSchema<CityInfo>()
+        }
+    });
+
+    // Invoke the agent with some unstructured input while streaming, to extract the structured information from.
+    IAsyncEnumerable<AgentResponseUpdate> updates = agent.RunStreamingAsync("Provide information about the capital of France.");
+
+    // Assemble all the parts of the streamed output.
+    AgentResponse nonGenericResponse = await updates.ToAgentResponseAsync();
+
+    // Access the structured output by deserializing JSON in the Text property.
+    CityInfo cityInfo = JsonSerializer.Deserialize<CityInfo>(nonGenericResponse.Text)!;
+
+    Console.WriteLine("Assistant Output:");
+    Console.WriteLine($"Name: {cityInfo.Name}");
+    Console.WriteLine();
+}
+
+static async Task UseStructuredOutputWithMiddlewareAsync(ChatClient chatClient)
 {
-    Name = "HelpfulAssistant",
-    ChatOptions = new() { Instructions = "You are a helpful assistant.", ResponseFormat = Microsoft.Extensions.AI.ChatResponseFormat.ForJsonSchema<PersonInfo>() }
-});
+    Console.WriteLine("=== Structured Output with UseStructuredOutput Middleware ===");
+
+    // Create chat client that will transform the agent text response into structured output.
+    IChatClient meaiChatClient = chatClient.AsIChatClient();
+
+    // Create the agent
+    AIAgent agent = meaiChatClient.AsAIAgent(name: "HelpfulAssistant", instructions: "You are a helpful assistant.");
 
-// Invoke the agent with some unstructured input while streaming, to extract the structured information from.
-var updates = agentWithPersonInfo.RunStreamingAsync("Please provide information about John Smith, who is a 35-year-old software engineer.");
+    // Add structured output middleware via UseStructuredOutput method to add structured output support to the agent.
+    // This middleware transforms the agent's text response into structured data using a chat client.
+    // Since our agent does support structured output natively, we will add a middleware that removes ResponseFormat
+    //  from the AgentRunOptions to emulate an agent that doesn't support structured output natively
+    agent = agent
+        .AsBuilder()
+        .UseStructuredOutput(meaiChatClient)
+        .Use(ResponseFormatRemovalMiddleware, null)
+        .Build();
 
-// Assemble all the parts of the streamed output, since we can only deserialize once we have the full json,
-// then deserialize the response into the PersonInfo class.
-PersonInfo personInfo = (await updates.ToAgentResponseAsync()).Deserialize<PersonInfo>(JsonSerializerOptions.Web);
+    // Set CityInfo as the type parameter of RunAsync method to specify the expected structured output from the agent and invoke it with some unstructured input.
+    AgentResponse<CityInfo> response = await agent.RunAsync<CityInfo>("Provide information about the capital of France.");
 
-Console.WriteLine("Assistant Output:");
-Console.WriteLine($"Name: {personInfo.Name}");
-Console.WriteLine($"Age: {personInfo.Age}");
-Console.WriteLine($"Occupation: {personInfo.Occupation}");
+    // Access the structured output via the Result property of the agent response.
+    CityInfo cityInfo = response.Result;
+
+    Console.WriteLine("Assistant Output:");
+    Console.WriteLine($"Name: {cityInfo.Name}");
+    Console.WriteLine();
+}
+
+static Task<AgentResponse> ResponseFormatRemovalMiddleware(IEnumerable<ChatMessage> messages, AgentSession? session, AgentRunOptions? options, AIAgent innerAgent, CancellationToken cancellationToken)
+{
+    // Remove any ResponseFormat from the options to emulate an agent that doesn't support structured output natively.
+    options = options?.Clone();
+    options?.ResponseFormat = null;
+
+    return innerAgent.RunAsync(messages, session, options, cancellationToken);
+}
 
 namespace SampleApp
 {
     /// <summary>
-    /// Represents information about a person, including their name, age, and occupation, matched to the JSON schema used in the agent.
+    /// Represents information about a city, including its name.
     /// </summary>
-    [Description("Information about a person including their name, age, and occupation")]
-    public class PersonInfo
+    [Description("Information about a city")]
+    public sealed class CityInfo
     {
         [JsonPropertyName("name")]
         public string? Name { get; set; }
-
-        [JsonPropertyName("age")]
-        public int? Age { get; set; }
-
-        [JsonPropertyName("occupation")]
-        public string? Occupation { get; set; }
     }
 }

dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput/README.md

@@ -0,0 +1,52 @@
+# Structured Output with ChatClientAgent
+
+This sample demonstrates how to configure ChatClientAgent to produce structured output in JSON format using various approaches.
+
+## What this sample demonstrates
+
+- **ResponseFormat approach**: Configuring agents with JSON schema response format via `ChatResponseFormat.ForJsonSchema<T>()` for inter-agent communication or when the type is not known at compile time
+- **Generic RunAsync<T> method**: Using the generic `RunAsync<T>` method for structured output when the caller needs to work directly with typed objects
+- **Structured output with Streaming**: Using `RunStreamingAsync` to stream responses while still obtaining structured output by assembling and deserializing the streamed content
+- **StructuredOutput middleware**: Adding structured output support to agents that don't natively support it (like A2A agents or models without structured output capability) by transforming text output into structured data using a chat client
+
+## Prerequisites
+
+Before you begin, ensure you have the following prerequisites:
+
+- .NET 10 SDK or later
+- Azure OpenAI service endpoint and deployment configured
+- Azure CLI installed and authenticated (for Azure credential authentication)
+- User has the `Cognitive Services OpenAI Contributor` role for the Azure OpenAI resource
+
+**Note**: This sample uses Azure OpenAI models. For more information, see [how to deploy Azure OpenAI models with Azure AI Foundry](https://learn.microsoft.com/en-us/azure/ai-foundry/how-to/deploy-models-openai).
+
+**Note**: This demo uses Azure CLI credentials for authentication. Make sure you're logged in with `az login` and have access to the Azure OpenAI resource and have the `Cognitive Services OpenAI Contributor` role. For more information, see the [Azure CLI documentation](https://learn.microsoft.com/cli/azure/authenticate-azure-cli-interactively).
+
+## Environment Variables
+
+Set the following environment variables:
+
+```powershell
+$env:AZURE_OPENAI_ENDPOINT="https://your-resource.openai.azure.com/" # Replace with your Azure OpenAI resource endpoint
+$env:AZURE_OPENAI_DEPLOYMENT_NAME="gpt-4o-mini"  # Optional, defaults to gpt-4o-mini
+```
+
+## Run the sample
+
+Navigate to the sample directory and run:
+
+```powershell
+cd dotnet/samples/GettingStarted/Agents/Agent_Step05_StructuredOutput
+dotnet run
+```
+
+## Expected behavior
+
+The sample will demonstrate four different approaches to structured output:
+
+1. **Structured Output with ResponseFormat**: Creates an agent with `ResponseFormat` set to `ForJsonSchema<CityInfo>()`, invokes it with unstructured input, and accesses the structured output via the `Text` property
+2. **Structured Output with RunAsync<T>**: Creates an agent and uses the generic `RunAsync<CityInfo>()` method to get a typed `AgentResponse<CityInfo>` with the result accessible via the `Result` property
+3. **Structured Output with RunStreamingAsync**: Creates an agent with JSON schema response format, streams the response using `RunStreamingAsync`, assembles the updates using `ToAgentResponseAsync()`, and deserializes the JSON text into a typed object
+4. **Structured Output with StructuredOutput Middleware**: Uses the `UseStructuredOutput` method on `AIAgentBuilder` to add structured output support to agents that don't natively support it
+
+Each approach will output information about the capital of France (Paris) in a structured format.

dotnet/samples/GettingStarted/FoundryAgents/FoundryAgents_Step05_StructuredOutput/Program.cs

@@ -61,7 +61,8 @@
 
 // Assemble all the parts of the streamed output, since we can only deserialize once we have the full json,
 // then deserialize the response into the PersonInfo class.
-PersonInfo personInfo = (await updates.ToAgentResponseAsync()).Deserialize<PersonInfo>(JsonSerializerOptions.Web);
+PersonInfo personInfo = JsonSerializer.Deserialize<PersonInfo>((await updates.ToAgentResponseAsync()).Text, JsonSerializerOptions.Web)
+    ?? throw new InvalidOperationException("Failed to deserialize the streamed response into PersonInfo.");
 
 Console.WriteLine("Assistant Output:");
 Console.WriteLine($"Name: {personInfo.Name}");

dotnet/samples/GettingStarted/Workflows/_Foundational/08_WriterCriticWorkflow/Program.cs

@@ -327,7 +327,8 @@ public override async ValueTask<CriticDecision> HandleAsync(
 
         // Convert the stream to a response and deserialize the structured output
         AgentResponse response = await updates.ToAgentResponseAsync(cancellationToken);
-        CriticDecision decision = response.Deserialize<CriticDecision>(JsonSerializerOptions.Web);
+        CriticDecision decision = JsonSerializer.Deserialize<CriticDecision>(response.Text, JsonSerializerOptions.Web)
+            ?? throw new JsonException("Failed to deserialize CriticDecision from response text.");
 
         Console.WriteLine($"Decision: {(decision.Approved ? "✅ APPROVED" : "❌ NEEDS REVISION")}");
         if (!string.IsNullOrEmpty(decision.Feedback))

dotnet/samples/M365Agent/Agents/WeatherForecastAgent.cs

@@ -54,7 +54,7 @@ protected override async Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessag
 
         // If the agent returned a valid structured output response
         // we might be able to enhance the response with an adaptive card.
-        if (response.TryDeserialize<WeatherForecastAgentResponse>(JsonSerializerOptions.Web, out var structuredOutput))
+        if (TryDeserialize<WeatherForecastAgentResponse>(response.Text, JsonSerializerOptions.Web, out var structuredOutput))
         {
             var textContentMessage = response.Messages.FirstOrDefault(x => x.Contents.OfType<TextContent>().Any());
             if (textContentMessage is not null)
@@ -112,4 +112,25 @@ private static AdaptiveCard CreateWeatherCard(string? location, string? conditio
         });
         return card;
     }
+
+    private static bool TryDeserialize<T>(string json, JsonSerializerOptions jsonSerializerOptions, out T structuredOutput)
+    {
+        try
+        {
+            T? result = JsonSerializer.Deserialize<T>(json, jsonSerializerOptions);
+            if (result is null)
+            {
+                structuredOutput = default!;
+                return false;
+            }
+
+            structuredOutput = result;
+            return true;
+        }
+        catch
+        {
+            structuredOutput = default!;
+            return false;
+        }
+    }
 }

dotnet/src/Microsoft.Agents.AI.Abstractions/AIAgent.cs

@@ -22,7 +22,7 @@ namespace Microsoft.Agents.AI;
 /// may involve multiple agents working together.
 /// </remarks>
 [DebuggerDisplay("{DebuggerDisplay,nq}")]
-public abstract class AIAgent
+public abstract partial class AIAgent
 {
     private static readonly AsyncLocal<AgentRunContext?> s_currentContext = new();