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73d2a06
Initial check-in for the A2A Agent implementation
markwallace-microsoft May 14, 2025
1f90951
Merge branch 'main' into users/markwallace/a2a_agent
markwallace-microsoft May 14, 2025
21c1858
Fix warning
markwallace-microsoft May 14, 2025
b8b3bf6
Add A2A Client and Server samples
markwallace-microsoft May 14, 2025
0196641
Mark assembly as experimental
markwallace-microsoft May 14, 2025
aba8ada
Fix warnings
markwallace-microsoft May 14, 2025
d1297dd
Fix warnings
markwallace-microsoft May 14, 2025
384de1d
Skip .net8.0 build for A2AClientServer
markwallace-microsoft May 14, 2025
8469ddc
Skip .net8.0 build for A2AClientServer
markwallace-microsoft May 14, 2025
192ebee
Skip .net8.0 build for A2AClientServer
markwallace-microsoft May 14, 2025
908af44
Undo changes
markwallace-microsoft May 14, 2025
f2516dd
Bump package versions and add readme
markwallace-microsoft May 14, 2025
d2ba0d8
Revert to just net8.0
markwallace-microsoft May 14, 2025
4edfb35
Merge Shawn's changes and support ChatCompletion or AzureAI agents
markwallace-microsoft May 17, 2025
7d6ce75
Merge branch 'main' into users/markwallace/a2a_agent
markwallace-microsoft May 17, 2025
84acb02
Fix formatting
markwallace-microsoft May 17, 2025
bec3c2d
Fix formatting
markwallace-microsoft May 17, 2025
41a1d31
Merge branch 'main' into users/markwallace/a2a_agent
markwallace-microsoft May 19, 2025
7940e93
Rename configu property
markwallace-microsoft May 19, 2025
2244207
Merge branch 'users/markwallace/a2a_agent' of https://github.com/mark…
markwallace-microsoft May 19, 2025
b2439f5
Start work on streaming support
markwallace-microsoft May 19, 2025
2ba30e3
Merge latest from main and resolve merge conflicts
markwallace-microsoft Jun 10, 2025
3898ebe
Merge branch 'main' into users/markwallace/a2a_agent
markwallace-microsoft Jun 10, 2025
9458511
Update the .slnx file
markwallace-microsoft Jun 10, 2025
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3 changes: 3 additions & 0 deletions dotnet/Directory.Packages.props
Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,9 @@
<PackageVersion Include="System.Text.Json" Version="8.0.5" />
<PackageVersion Include="System.ValueTuple" Version="4.6.1" />
<PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.6.3" />
<PackageVersion Include="SharpA2A.Core" Version="0.1.0-preview.4" />
<PackageVersion Include="SharpA2A.AspNetCore" Version="0.1.0-preview.4" />
<PackageVersion Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
<!-- Tokenizers -->
<PackageVersion Include="Microsoft.ML.Tokenizers" Version="1.0.2" />
<PackageVersion Include="Microsoft.DeepDev.TokenizerLib" Version="1.3.3" />
Expand Down
5 changes: 5 additions & 0 deletions dotnet/SK-dotnet.slnx
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,10 @@
<Project Path="samples/Demos/TimePlugin/TimePlugin.csproj" />
<Project Path="samples/Demos/VectorStoreRAG/VectorStoreRAG.csproj" />
</Folder>
<Folder Name="/samples/Demos/A2AClientServer/">
<Project Path="samples/Demos/A2AClientServer/A2AClient/A2AClient.csproj" />
<Project Path="samples/Demos/A2AClientServer/A2AServer/A2AServer.csproj" />
</Folder>
<Folder Name="/samples/Demos/AgentFrameworkWithAspire/">
<File Path="samples/Demos/AgentFrameworkWithAspire/README.md" />
<Project Path="samples/Demos/AgentFrameworkWithAspire/ChatWithAgent.ApiService/ChatWithAgent.ApiService.csproj" />
Expand Down Expand Up @@ -85,6 +89,7 @@
<Project Path="src/SemanticKernel.UnitTests/SemanticKernel.UnitTests.csproj" />
</Folder>
<Folder Name="/src/agents/">
<Project Path="src/Agents/A2A/Agents.A2A.csproj" />
<Project Path="src/Agents/Abstractions/Agents.Abstractions.csproj" />
<Project Path="src/Agents/AzureAI/Agents.AzureAI.csproj" />
<Project Path="src/Agents/Bedrock/Agents.Bedrock.csproj" />
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25 changes: 25 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AClient/A2AClient.csproj
Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net8.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
<UserSecretsId>5ee045b0-aea3-4f08-8d31-32d1a6f8fed0</UserSecretsId>
<NoWarn>$(NoWarn);CS1591;VSTHRD111;CA2007;SKEXP0110</NoWarn>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="SharpA2A.Core" />
<PackageReference Include="SharpA2A.AspNetCore" />
<PackageReference Include="System.CommandLine" />
<PackageReference Include="Microsoft.Extensions.Hosting" />
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\..\..\..\src\Agents\A2A\Agents.A2A.csproj" />
<ProjectReference Include="..\..\..\..\src\Agents\Core\Agents.Core.csproj" />
<ProjectReference Include="..\..\..\..\src\Connectors\Connectors.OpenAI\Connectors.OpenAI.csproj" />
</ItemGroup>

</Project>
120 changes: 120 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AClient/HostClientAgent.cs
Original file line number Diff line number Diff line change
@@ -0,0 +1,120 @@
// Copyright (c) Microsoft. All rights reserved.

using Microsoft.Extensions.Logging;
using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.Agents;
using Microsoft.SemanticKernel.Agents.A2A;
using SharpA2A.Core;

namespace A2A;

internal sealed class HostClientAgent
{
internal HostClientAgent(ILogger logger)
{
this._logger = logger;
}
internal async Task InitializeAgentAsync(string modelId, string apiKey, string[] agentUrls)
{
try
{
this._logger.LogInformation("Initializing Semantic Kernel agent with model: {ModelId}", modelId);

// Connect to the remote agents via A2A
var createAgentTasks = agentUrls.Select(agentUrl => this.CreateAgentAsync(agentUrl));
var agents = await Task.WhenAll(createAgentTasks);
var agentFunctions = agents.Select(agent => AgentKernelFunctionFactory.CreateFromAgent(agent)).ToList();
var agentPlugin = KernelPluginFactory.CreateFromFunctions("AgentPlugin", agentFunctions);

// Define the Host agent
var builder = Kernel.CreateBuilder();
builder.AddOpenAIChatCompletion(modelId, apiKey);
builder.Plugins.Add(agentPlugin);
var kernel = builder.Build();
kernel.FunctionInvocationFilters.Add(new ConsoleOutputFunctionInvocationFilter());

this.Agent = new ChatCompletionAgent()
{
Kernel = kernel,
Name = "HostClient",
Instructions =
"""
You specialize in handling queries for users and using your tools to provide answers.
""",
Arguments = new KernelArguments(new PromptExecutionSettings() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() }),
};
}
catch (Exception ex)
{
this._logger.LogError(ex, "Failed to initialize HostClientAgent");
throw;
}
}

/// <summary>
/// The associated <see cref="Agent"/>
/// </summary>
public Agent? Agent { get; private set; }

#region private
private readonly ILogger _logger;

private async Task<A2AAgent> CreateAgentAsync(string agentUri)
{
var httpClient = new HttpClient
{
BaseAddress = new Uri(agentUri),
Timeout = TimeSpan.FromSeconds(60)
};

var client = new A2AClient(httpClient);
var cardResolver = new A2ACardResolver(httpClient);
var agentCard = await cardResolver.GetAgentCardAsync();

return new A2AAgent(client, agentCard!);
}
#endregion
}

internal sealed class ConsoleOutputFunctionInvocationFilter() : IFunctionInvocationFilter
{
private static string IndentMultilineString(string multilineText, int indentLevel = 1, int spacesPerIndent = 4)
{
// Create the indentation string
var indentation = new string(' ', indentLevel * spacesPerIndent);

// Split the text into lines, add indentation, and rejoin
char[] NewLineChars = { '\r', '\n' };
string[] lines = multilineText.Split(NewLineChars, StringSplitOptions.None);

return string.Join(Environment.NewLine, lines.Select(line => indentation + line));
}
public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
{
Console.ForegroundColor = ConsoleColor.DarkGray;

Console.WriteLine($"\nCalling Agent {context.Function.Name} with arguments:");
Console.ForegroundColor = ConsoleColor.Gray;

foreach (var kvp in context.Arguments)
{
Console.WriteLine(IndentMultilineString($" {kvp.Key}: {kvp.Value}"));
}

await next(context);

if (context.Result.GetValue<object>() is ChatMessageContent[] chatMessages)
{
Console.ForegroundColor = ConsoleColor.DarkGray;

Console.WriteLine($"Got Response from Agent {context.Function.Name}:");
foreach (var message in chatMessages)
{
Console.ForegroundColor = ConsoleColor.Gray;

Console.WriteLine(IndentMultilineString($"{message}"));
}
}
Console.ResetColor();
}
}
89 changes: 89 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AClient/Program.cs
Original file line number Diff line number Diff line change
@@ -0,0 +1,89 @@
// Copyright (c) Microsoft. All rights reserved.

using System.CommandLine;
using System.CommandLine.Invocation;
using System.Reflection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.Agents;

namespace A2A;

public static class Program
{
public static async Task<int> Main(string[] args)
{
// Create root command with options
var rootCommand = new RootCommand("A2AClient");
rootCommand.SetHandler(HandleCommandsAsync);

// Run the command
return await rootCommand.InvokeAsync(args);
}

public static async System.Threading.Tasks.Task HandleCommandsAsync(InvocationContext context)
{
await RunCliAsync();
}

#region private
private static async System.Threading.Tasks.Task RunCliAsync()
{
// Set up the logging
using var loggerFactory = LoggerFactory.Create(builder =>
{
builder.AddConsole();
builder.SetMinimumLevel(LogLevel.Information);
});
var logger = loggerFactory.CreateLogger("A2AClient");

// Retrieve configuration settings
IConfigurationRoot configRoot = new ConfigurationBuilder()
.AddEnvironmentVariables()
.AddUserSecrets(Assembly.GetExecutingAssembly())
.Build();
var apiKey = configRoot["A2AClient:ApiKey"] ?? throw new ArgumentException("A2AClient:ApiKey must be provided");
var modelId = configRoot["A2AClient:ModelId"] ?? "gpt-4.1";
var agentUrls = configRoot["A2AClient:AgentUrls"] ?? "http://localhost:5000/policy/ http://localhost:5000/invoice/ http://localhost:5000/logistics/";

// Create the Host agent
var hostAgent = new HostClientAgent(logger);
await hostAgent.InitializeAgentAsync(modelId, apiKey, agentUrls!.Split(" "));
AgentThread thread = new ChatHistoryAgentThread();
try
{
while (true)
{
// Get user message
Console.Write("\nUser (:q or quit to exit): ");
string? message = Console.ReadLine();
if (string.IsNullOrWhiteSpace(message))
{
Console.WriteLine("Request cannot be empty.");
continue;
}

if (message == ":q" || message == "quit")
{
break;
}

await foreach (AgentResponseItem<ChatMessageContent> response in hostAgent.Agent!.InvokeAsync(message, thread))
{
Console.ForegroundColor = ConsoleColor.Cyan;
Console.WriteLine($"Agent: {response.Message.Content}");
Console.ResetColor();

thread = response.Thread;
}
}
}
catch (Exception ex)
{
logger.LogError(ex, "An error occurred while running the A2AClient");
return;
}
}
#endregion
}
26 changes: 26 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AClient/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,26 @@

# A2A Client Sample
Show how to create an A2A Client with a command line interface which invokes agents using the A2A protocol.

## Run the Sample

To run the sample, follow these steps:

1. Run the A2A client:
```bash
cd A2AClient
dotnet run
```
2. Enter your request e.g. "Show me all invoices for Contoso?"

## Set Secrets with Secret Manager

The agent urls are provided as a ` ` delimited list of strings

```text
cd dotnet/samples/Demos/A2AClientServer/A2AClient
dotnet user-secrets set "A2AClient:ModelId" "..."
dotnet user-secrets set "A2AClient":ApiKey" "..."
dotnet user-secrets set "A2AClient:AgentUrls" "http://localhost:5000/policy http://localhost:5000/invoice http://localhost:5000/logistics"
```
24 changes: 24 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AServer/A2AServer.csproj
Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net8.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
<UserSecretsId>5ee045b0-aea3-4f08-8d31-32d1a6f8fed0</UserSecretsId>
<NoWarn>$(NoWarn);CS1591;VSTHRD111;CA2007;SKEXP0110</NoWarn>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="SharpA2A.Core" />
<PackageReference Include="SharpA2A.AspNetCore" />
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\..\..\..\src\Agents\A2A\Agents.A2A.csproj" />
<ProjectReference Include="..\..\..\..\src\Agents\AzureAI\Agents.AzureAI.csproj" />
<ProjectReference Include="..\..\..\..\src\Agents\Core\Agents.Core.csproj" />
<ProjectReference Include="..\..\..\..\src\Connectors\Connectors.OpenAI\Connectors.OpenAI.csproj" />
</ItemGroup>

</Project>
76 changes: 76 additions & 0 deletions dotnet/samples/Demos/A2AClientServer/A2AServer/A2AServer.http
Original file line number Diff line number Diff line change
@@ -0,0 +1,76 @@
@host = http://localhost:5000

### Query agent card for the invoice agent
GET {{host}}/invoice/.well-known/agent.json

### Send a task to the invoice agent
POST {{host}}/invoice
Content-Type: application/json

{
"id": "1",
"jsonrpc": "2.0",
"method": "task/send",
"params": {
"id": "12345",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "Show me all invoices for Contoso?"
}
]
}
}
}

### Query agent card for the policy agent
GET {{host}}/policy/.well-known/agent.json

### Send a task to the policy agent
POST {{host}}/policy
Content-Type: application/json

{
"id": "1",
"jsonrpc": "2.0",
"method": "task/send",
"params": {
"id": "12345",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "What is the policy for short shipments?"
}
]
}
}
}

### Query agent card for the logistics agent
GET {{host}}/logistics/.well-known/agent.json

### Send a task to the logistics agent
POST {{host}}/logistics
Content-Type: application/json

{
"id": "1",
"jsonrpc": "2.0",
"method": "task/send",
"params": {
"id": "12345",
"message": {
"role": "user",
"parts": [
{
"type": "text",
"text": "What is the status for SHPMT-SAP-001"
}
]
}
}
}
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