.NET: feat: Microsoft.Extensions.AI.Agents.Hosting.A2A package (#390)

* add timeout handling for message send * prepare a2a proj * fix it finally * add a holder for selected protocol * init types ; * see discoveredAgentCardJson * prettify json * correct usage * client setup for card * setp? * message:send * init task based communication * try call it via the agent thread * okay i got back the message wooooow! * nit * fix duplicates * yea matey! * fix knights-knaves for A2A-Task-based communication * fix a2a agents csproj * AI feedback * a2a does not support netstandard / netfx * try fix build + refactor * bump a2a for net9 only * rollback System.Net.ServerSentEvents & Microsoft.Bcl.AsyncInterfaces version upgrade; override in-place and retarget to net9;net8 for A2A * address PR comments x1 * refactor a2a interfaces * address PR comments x2 * fix cancel usage * separate project for A2A.AspNetCore * simplify * cleanup * cleanup dependencies * generate convertor tests / fix namespaces etc * setup actor client! * fix build * backoff conversations * fix duplicate message streaming * address PR comments x1 * remove internalsvisibleto * dont implement agent card query on my own: give it to the user * nit * rename and move projects * fix dotnet-format * address PR comments x1 * remove unreferenced project * rollback * rename * nit --------- Co-authored-by: Chris <66376200+crickman@users.noreply.github.com>
2026-06-16 21:04:09 +08:00 · 2025-08-25 11:14:55 +00:00
parent a40eda48f1
commit 6ec21859cf
18 changed files with 1897 additions and 136 deletions
@@ -14,6 +14,7 @@
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Runtime.Abstractions\Microsoft.Extensions.AI.Agents.Runtime.Abstractions.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Runtime\Microsoft.Extensions.AI.Agents.Runtime.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents\Microsoft.Extensions.AI.Agents.csproj" />
+    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Hosting.A2A.AspNetCore\Microsoft.Extensions.AI.Agents.Hosting.A2A.AspNetCore.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Runtime.Storage.CosmosDB\Microsoft.Extensions.AI.Agents.Runtime.Storage.CosmosDB.csproj" />
    <ProjectReference Include="..\AgentWebChat.ServiceDefaults\AgentWebChat.ServiceDefaults.csproj" />
  </ItemGroup>
@@ -29,7 +30,13 @@
    <PackageReference Include="Microsoft.Extensions.AI.OpenAI" />
    <PackageReference Include="Microsoft.AspNetCore.OpenAPI" />
    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" />
-    <PackageReference Include="System.Net.ServerSentEvents" />
  </ItemGroup>

+  <!-- A2A dependency -->
+  <ItemGroup>
+    <PackageReference Include="System.Net.ServerSentEvents" VersionOverride="10.0.0-preview.5.25277.114" />
+    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" VersionOverride="10.0.0-preview.5.25277.114" />
+  </ItemGroup>
+  <!-- A2A dependency -->
+
 </Project>
@@ -8,6 +8,7 @@ using Microsoft.Azure.Cosmos;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.AI.Agents;
 using Microsoft.Extensions.AI.Agents.Hosting;
+using Microsoft.Extensions.AI.Agents.Hosting.A2A.AspNetCore;
 using Microsoft.Extensions.AI.Agents.Runtime.Storage.CosmosDB;

 var builder = WebApplication.CreateBuilder(args);
@@ -92,6 +93,18 @@ app.UseExceptionHandler();

 app.MapActors();

+// attach a2a with simple message communication
+app.AttachA2A(agentName: "pirate", path: "/a2a/pirate");
+app.AttachA2A(agentName: "knights-and-knaves", path: "/a2a/knights-and-knaves", agentCard: new()
+{
+    Name = "Knights and Knaves",
+    Description = "An agent that helps you solve the knights and knaves puzzle.",
+    Version = "1.0",
+
+    // Url can be not set, and SDK will help assign it.
+    // Url = "http://localhost:5390/a2a/knights-and-knaves"
+});
+
 // Map the agents HTTP endpoints
 app.MapAgentDiscovery("/agents");

@@ -0,0 +1,127 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using A2A;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.AI.Agents.Hosting;
+using Microsoft.Extensions.AI.Agents.Hosting.A2A.Converters;
+using Microsoft.Extensions.AI.Agents.Runtime;
+
+namespace AgentWebChat.Web;
+
+internal sealed class A2AActorClient : IActorClient
+{
+    private readonly ILogger _logger;
+    private readonly Uri _uri;
+
+    // because A2A sdk does not provide a client which can handle multiple agents, we need a client per agent
+    // for this app the convention is "baseUri/<agentname>"
+    private readonly ConcurrentDictionary<string, (A2AClient, A2ACardResolver)> _clients = new();
+
+    public A2AActorClient(ILogger logger, Uri baseUri)
+    {
+        this._logger = logger;
+        this._uri = baseUri;
+    }
+
+    public Task<AgentCard> GetAgentCardAsync(string agent, CancellationToken cancellationToken = default)
+    {
+        this._logger.LogInformation("Retrieving agent card for {Agent}", agent);
+
+        var (_, a2aCardResolver) = this.ResolveClient(agent);
+        return a2aCardResolver.GetAgentCardAsync(cancellationToken);
+    }
+
+    public ValueTask<ActorResponseHandle> GetResponseAsync(ActorId actorId, string messageId, CancellationToken cancellationToken)
+    {
+        throw new NotImplementedException();
+    }
+
+    public ValueTask<ActorResponseHandle> SendRequestAsync(ActorRequest request, CancellationToken cancellationToken)
+    {
+        var agentName = request.ActorId.Type;
+        var (a2aClient, _) = this.ResolveClient(agentName);
+
+        return new ValueTask<ActorResponseHandle>(new A2AActorResponseHandle(a2aClient, request));
+    }
+
+    private (A2AClient, A2ACardResolver) ResolveClient(ActorType agentName)
+        => this.ResolveClient(agentName.Name);
+
+    private (A2AClient, A2ACardResolver) ResolveClient(string agentName)
+    {
+        return this._clients.GetOrAdd(agentName, name =>
+        {
+            var uri = new Uri($"{this._uri}/{name}/");
+            var a2aClient = new A2AClient(uri);
+
+            // /v1/card is a default path for A2A agent card discovery
+            var a2aCardResolver = new A2ACardResolver(uri, agentCardPath: "/v1/card/");
+
+            this._logger.LogInformation("Built clients for agent {Agent} with baseUri {Uri}", name, uri);
+            return (a2aClient, a2aCardResolver);
+        });
+    }
+
+    private sealed class A2AActorResponseHandle : ActorResponseHandle
+    {
+        private readonly A2AClient _a2aClient;
+        private readonly ActorRequest _request;
+
+        public A2AActorResponseHandle(A2AClient a2aClient, ActorRequest request)
+        {
+            this._a2aClient = a2aClient;
+            this._request = request;
+        }
+
+        public override ValueTask CancelAsync(CancellationToken cancellationToken)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override ValueTask<ActorResponse> GetResponseAsync(CancellationToken cancellationToken)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override bool TryGetResponse([NotNullWhen(true)] out ActorResponse? response)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override async IAsyncEnumerable<ActorRequestUpdate> WatchUpdatesAsync([EnumeratorCancellation] CancellationToken cancellationToken)
+        {
+            var agentRunRequestData = this._request.Params.Deserialize(AgentHostingJsonUtilities.DefaultOptions.GetTypeInfo(typeof(AgentRunRequest))) as AgentRunRequest;
+            var messageTexts = agentRunRequestData!.Messages!.SelectMany(x => x.Contents.OfType<TextContent>()).Select(x => x.Text);
+            var parts = messageTexts.Select(text => new TextPart { Text = text });
+            var messageSendParams = new MessageSendParams
+            {
+                Message = new()
+                {
+                    Role = MessageRole.User,
+                    MessageId = this._request.MessageId,
+                    ContextId = this._request.ActorId.Key,
+                    Parts = [.. parts]
+                }
+            };
+
+            await foreach (var upd in this._a2aClient.SendMessageStreamAsync(messageSendParams, cancellationToken))
+            {
+                var @event = upd.Data;
+                if (@event is not Message message)
+                {
+                    throw new NotSupportedException("Only message is supported in A2A processing, but got: " + @event.GetType());
+                }
+
+                // handling of message on agentProxy side expects the 
+                yield return message.ToActorRequestUpdate(status: RequestStatus.Pending);
+            }
+
+            // complete request after all updates are sent
+            yield return new ActorRequestUpdate(status: RequestStatus.Completed, data: default);
+        }
+    }
+}
@@ -5,15 +5,19 @@
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
-
-  <ItemGroup>
-    <PackageReference Include="System.Net.ServerSentEvents" />
-  </ItemGroup>
-
+  
  <ItemGroup>
+    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Hosting.A2A\Microsoft.Extensions.AI.Agents.Hosting.A2A.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Hosting\Microsoft.Extensions.AI.Agents.Hosting.csproj" />
    <ProjectReference Include="..\AgentWebChat.ServiceDefaults\AgentWebChat.ServiceDefaults.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.Extensions.AI.Agents.Abstractions\Microsoft.Extensions.AI.Agents.Abstractions.csproj" />
  </ItemGroup>

+  <!-- A2A dependency -->
+  <ItemGroup>
+    <PackageReference Include="System.Net.ServerSentEvents" VersionOverride="10.0.0-preview.5.25277.114" />
+    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" VersionOverride="10.0.0-preview.5.25277.114" />
+  </ItemGroup>
+  <!-- A2A dependency -->
+
 </Project>
@@ -4,6 +4,7 @@
@inject IJSRuntime JSRuntime
@inject ILogger<Home> Logger
@inject IActorClient ActorClient
+@inject A2AActorClient A2AActorClient
@rendermode InteractiveServer
@using System.Text
@using System.Text.Json
@@ -11,6 +12,7 @@
@using Microsoft.Extensions.AI.Agents
@using Microsoft.Extensions.AI.Agents.Hosting
@using Microsoft.Extensions.AI.Agents.Runtime
+@using A2A

 <PageTitle>Agent Web Chat</PageTitle>

@@ -48,7 +50,105 @@
        </div>
    </div>

-    @if (conversations.Any())
+    <div class="protocol-selection-card">
+        <label for="protocol-select" class="protocol-select-label">Choose communication protocol:</label>
+        <div class="protocol-select-wrapper">
+            <select id="protocol-select" class="protocol-select" @bind="selectedProtocol" disabled="@(isStreaming)">
+                <option value="AgenticFramework">Agentic Framework</option>
+                <option value="A2A">A2A (Agent-to-Agent)</option>
+            </select>
+            <div class="protocol-info">
+                @switch (selectedProtocol)
+                {
+                    case Protocol.A2A:
+                        <span class="protocol-description">🔗 A2A protocol supports long-running agentic processes</span>
+                        break;
+                    case Protocol.AgenticFramework:
+                    default:
+                        <span class="protocol-description">⚡ Direct agentic framework communication</span>
+                        break;
+                }
+            </div>
+        </div>
+    </div>
+
+    @if (selectedProtocol == Protocol.A2A)
+    {
+        <div class="a2a-configuration-card">
+            <div class="a2a-header" @onclick="ToggleA2AExpanded">
+                <h3 class="a2a-title">
+                    <svg class="a2a-toggle-icon @(isA2AExpanded ? "expanded" : "")" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <polyline points="6,9 12,15 18,9"></polyline>
+                    </svg>
+                    A2A Configuration
+                </h3>
+                <span class="a2a-subtitle">Discover and configure agent cards</span>
+            </div>
+            
+            @if (isA2AExpanded)
+            {
+                <div class="a2a-content">
+                    <div class="discover-section">
+                        <button class="discover-btn" 
+                                @onclick="DiscoverAgentCard" 
+                                disabled="@(string.IsNullOrEmpty(selectedAgentName) || isDiscoveringCard)">
+                            @if (isDiscoveringCard)
+                            {
+                                <div class="spinner-small"></div>
+                                <span>Discovering...</span>
+                            }
+                            else
+                            {
+                                <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                                    <circle cx="11" cy="11" r="8"></circle>
+                                    <path d="m21 21-4.35-4.35"></path>
+                                </svg>
+                                <span>Discover Agent Card</span>
+                            }
+                        </button>
+                        
+                        @if (!string.IsNullOrEmpty(selectedAgentName))
+                        {
+                            <span class="discover-info">for agent: <strong>@GetAgentDisplayName(selectedAgentName)</strong></span>
+                        }
+                        else
+                        {
+                            <span class="discover-info text-muted">Please select an agent first</span>
+                        }
+                    </div>
+
+                    @if (discoveredAgentCardJson != null)
+                    {
+                        <div class="agent-card-display">
+                            <h4 class="card-title">🔗 Discovered Agent Card</h4>
+                            <div class="card-details">
+                                <div class="json-container">
+                                    <div class="json-header">
+                                        <span class="json-label">Agent Card JSON:</span>
+                                    </div>
+                                    <pre class="json-display"><code>@discoveredAgentCardJson</code></pre>
+                                </div>
+                            </div>
+                        </div>
+                    }
+
+                    @if (!string.IsNullOrEmpty(discoveryError))
+                    {
+                        <div class="error-display">
+                            <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                                <circle cx="12" cy="12" r="10"></circle>
+                                <line x1="15" y1="9" x2="9" y2="15"></line>
+                                <line x1="9" y1="9" x2="15" y2="15"></line>
+                            </svg>
+                            <span>@discoveryError</span>
+                        </div>
+                    }
+                </div>
+            }
+        </div>
+    }
+
+	@if (conversations.Any())
    {
        <div class="conversations-section">
            <div class="conversation-tabs">
@@ -175,7 +275,7 @@
        margin: 0;
    }

-    .agent-selection-card {
+    .agent-selection-card, .protocol-selection-card, .a2a-configuration-card {
        background: white;
        border-radius: 12px;
        padding: 1.5rem;
@@ -183,20 +283,20 @@
        margin-bottom: 2rem;
    }

-    .agent-select-label {
+    .agent-select-label, .protocol-select-label {
        display: block;
        font-weight: 600;
        color: #374151;
        margin-bottom: 0.75rem;
    }

-    .agent-select-wrapper {
+    .agent-select-wrapper, .protocol-select-wrapper {
        display: flex;
        gap: 1rem;
        align-items: center;
    }

-    .agent-select {
+    .agent-select, .protocol-select {
        flex: 1;
        padding: 0.75rem 1rem;
        font-size: 1rem;
@@ -208,21 +308,281 @@
        transition: all 0.2s;
    }

-    .agent-select:hover:not(:disabled) {
+    .agent-select:hover:not(:disabled), .protocol-select:hover:not(:disabled) {
        border-color: #6366f1;
    }

-    .agent-select:focus {
+    .agent-select:focus, .protocol-select:focus {
        outline: none;
        border-color: #6366f1;
        box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    }

-    .agent-select:disabled {
+    .agent-select:disabled, .protocol-select:disabled {
        opacity: 0.5;
        cursor: not-allowed;
    }

+    .protocol-info {
+        flex: 1;
+        min-width: 200px;
+    }
+
+    .protocol-description {
+        font-size: 0.875rem;
+        color: #6b7280;
+        font-style: italic;
+    }
+
+    /* A2A Configuration Card Styles */
+    .a2a-header {
+        cursor: pointer;
+        display: flex;
+        flex-direction: column;
+        gap: 0.25rem;
+        padding: 0.5rem 0;
+        transition: all 0.2s;
+    }
+
+    .a2a-header:hover {
+        background: rgba(99, 102, 241, 0.05);
+        border-radius: 8px;
+        padding: 0.5rem;
+        margin: -0.5rem;
+    }
+
+    .a2a-title {
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+        margin: 0;
+        font-size: 1.125rem;
+        font-weight: 600;
+        color: #374151;
+    }
+
+    .a2a-toggle-icon {
+        transition: transform 0.2s;
+    }
+
+    .a2a-toggle-icon.expanded {
+        transform: rotate(180deg);
+    }
+
+    .a2a-subtitle {
+        font-size: 0.875rem;
+        color: #6b7280;
+        margin-left: 1.25rem;
+    }
+
+    .a2a-content {
+        margin-top: 1rem;
+        padding-top: 1rem;
+        border-top: 1px solid #e5e7eb;
+    }
+
+    .discover-section {
+        display: flex;
+        align-items: center;
+        gap: 1rem;
+        margin-bottom: 1.5rem;
+    }
+
+    .discover-btn {
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+        padding: 0.75rem 1.5rem;
+        background: #059669;
+        color: white;
+        border: none;
+        border-radius: 8px;
+        font-weight: 600;
+        cursor: pointer;
+        transition: all 0.2s;
+    }
+
+    .discover-btn:hover:not(:disabled) {
+        background: #047857;
+        transform: translateY(-1px);
+        box-shadow: 0 4px 12px rgba(5, 150, 105, 0.3);
+    }
+
+    .discover-btn:disabled {
+        opacity: 0.5;
+        cursor: not-allowed;
+        transform: none;
+        box-shadow: none;
+    }
+
+    .discover-info {
+        font-size: 0.875rem;
+        color: #6b7280;
+    }
+
+    .text-muted {
+        color: #9ca3af !important;
+    }
+
+    .spinner-small {
+        width: 16px;
+        height: 16px;
+        border: 2px solid rgba(255, 255, 255, 0.3);
+        border-top-color: white;
+        border-radius: 50%;
+        animation: spin 0.8s linear infinite;
+    }
+
+    /* Agent Card Display */
+    .agent-card-display {
+        background: #f9fafb;
+        border: 1px solid #e5e7eb;
+        border-radius: 8px;
+        padding: 1rem;
+        margin-top: 1rem;
+    }
+
+    .card-title {
+        margin: 0 0 1rem 0;
+        font-size: 1rem;
+        font-weight: 600;
+        color: #374151;
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+    }
+
+    .card-details {
+        display: flex;
+        flex-direction: column;
+        gap: 0.75rem;
+    }
+
+    /* JSON Display Styles */
+    .json-container {
+        background: #1e293b;
+        border-radius: 8px;
+        overflow: hidden;
+        border: 1px solid #334155;
+    }
+
+    .json-header {
+        display: flex;
+        justify-content: space-between;
+        align-items: center;
+        padding: 0.75rem 1rem;
+        background: #334155;
+        border-bottom: 1px solid #475569;
+    }
+
+    .json-label {
+        font-size: 0.875rem;
+        font-weight: 600;
+        color: #e2e8f0;
+    }
+
+    .copy-btn {
+        display: flex;
+        align-items: center;
+        gap: 0.375rem;
+        padding: 0.375rem 0.75rem;
+        background: #475569;
+        color: #e2e8f0;
+        border: none;
+        border-radius: 4px;
+        font-size: 0.75rem;
+        font-weight: 500;
+        cursor: pointer;
+        transition: all 0.2s;
+    }
+
+    .copy-btn:hover {
+        background: #64748b;
+        color: white;
+    }
+
+    .json-display {
+        margin: 0;
+        padding: 1rem;
+        background: #1e293b;
+        color: #e2e8f0;
+        font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
+        font-size: 0.875rem;
+        line-height: 1.5;
+        overflow-x: auto;
+        white-space: pre-wrap;
+        word-wrap: break-word;
+    }
+
+    .json-display code {
+        background: none;
+        color: inherit;
+        font-family: inherit;
+        padding: 0;
+    }
+
+    /* JSON Syntax Highlighting */
+    .json-display {
+        /* JSON strings */
+        --json-string: #a3d977;
+        /* JSON numbers */
+        --json-number: #ffc777;
+        /* JSON booleans */
+        --json-boolean: #ff966c;
+        /* JSON null */
+        --json-null: #c53030;
+        /* JSON keys */
+        --json-key: #82aaff;
+        /* JSON punctuation */
+        --json-punctuation: #c792ea;
+    }
+
+    .card-property {
+        display: flex;
+        gap: 0.75rem;
+        align-items: flex-start;
+    }
+
+    .card-property label {
+        font-weight: 600;
+        color: #374151;
+        min-width: 100px;
+        flex-shrink: 0;
+    }
+
+    .card-property span {
+        color: #6b7280;
+        flex: 1;
+    }
+
+    .capabilities-list {
+        display: flex;
+        flex-wrap: wrap;
+        gap: 0.5rem;
+    }
+
+    .capability-tag {
+        background: #dbeafe;
+        color: #1e40af;
+        padding: 0.25rem 0.5rem;
+        border-radius: 4px;
+        font-size: 0.75rem;
+        font-weight: 500;
+    }
+
+    /* Error Display */
+    .error-display {
+        background: #fef2f2;
+        border: 1px solid #fecaca;
+        color: #dc2626;
+        padding: 0.75rem;
+        border-radius: 8px;
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+        margin-top: 1rem;
+    }
+
    .start-chat-btn {
        display: flex;
        align-items: center;
@@ -494,190 +854,287 @@
        .chat-container {
            height: 500px;
        }
+
+        .protocol-select-wrapper {
+            flex-direction: column;
+            align-items: flex-start;
+            gap: 0.5rem;
+        }
+
+        .protocol-info {
+            min-width: auto;
+        }
+
+        .discover-section {
+            flex-direction: column;
+            align-items: flex-start;
+            gap: 0.75rem;
+        }
+
+        .card-property {
+            flex-direction: column;
+            gap: 0.25rem;
+        }
+
+        .card-property label {
+            min-width: auto;
+        }
    }
 </style>

@code {
+	private string currentMessage = "";
+	private bool isStreaming = false;
+	private bool isLoadingAgents = true;
+	private string currentStreamedMessage = "";
+	private string selectedAgentName = "";
+	private List<AgentDiscoveryClient.AgentDiscoveryCard> availableAgents = new();
+	private List<Conversation> conversations = new();
+	private Conversation? currentConversation;

+	// protocol
+	private Protocol selectedProtocol;

+	// a2a agent card
+	private bool isA2AExpanded = false;
+	private bool isDiscoveringCard = false;
+	private string? discoveredAgentCardJson = null;
+	private string? discoveryError = null;

-    private string currentMessage = "";
-    private bool isStreaming = false;
-    private bool isLoadingAgents = true;
-    private string currentStreamedMessage = "";
-    private string selectedAgentName = "";
-    private List<AgentDiscoveryClient.AgentDiscoveryCard> availableAgents = new();
-    private List<Conversation> conversations = new();
-    private Conversation? currentConversation;
+	private enum Protocol
+	{
+		AgenticFramework,
+		A2A // Agent-to-Agent protocol
+	}

-    private class Conversation
-    {
-        public string SessionId { get; set; } = Guid.NewGuid().ToString();
-        public string AgentName { get; set; } = "";
-        public List<ChatMessage> Messages { get; set; } = new();
-    }
+	private class Conversation
+	{
+		public string SessionId { get; set; } = Guid.NewGuid().ToString();
+		public string AgentName { get; set; } = "";
+		public List<ChatMessage> Messages { get; set; } = new();
+	}

-    protected override async Task OnInitializedAsync()
-    {
-        Logger.LogDebug("Initializing Agent Chat component");
+	protected override async Task OnInitializedAsync()
+	{
+		Logger.LogDebug("Initializing Agent Chat component");

-        // Load agents
-        try
-        {
-            availableAgents = await AgentClient.GetAgentsAsync();
-            Logger.LogInformation("Loaded {AgentCount} agents", availableAgents.Count);
+		// Load agents
+		try
+		{
+			availableAgents = await AgentClient.GetAgentsAsync();
+			Logger.LogInformation("Loaded {AgentCount} agents", availableAgents.Count);
+			Logger.LogInformation("Loaded Agents info: {AgentData}", JsonSerializer.Serialize(availableAgents, new JsonSerializerOptions() { WriteIndented = true }));

-            // Default to first agent and start a conversation
-            if (availableAgents.Any())
-            {
-                selectedAgentName = availableAgents.First().Name!;
-                StartNewConversation();
-            }
-        }
-        catch (Exception ex)
-        {
-            Logger.LogError(ex, "Failed to load agents");
-        }
-        finally
-        {
-            isLoadingAgents = false;
-        }
+			// Default to first agent and start a conversation
+			if (availableAgents.Any())
+			{
+				selectedAgentName = availableAgents.First().Name!;
+				StartNewConversation();
+			}
+		}
+		catch (Exception ex)
+		{
+			Logger.LogError(ex, "Failed to load agents");
+		}
+		finally
+		{
+			isLoadingAgents = false;
+		}

-        // Conversations start fresh on page load
-    }
+		// Conversations start fresh on page load
+	}

-    private string GetAgentIcon(string agentName)
-    {
-        return agentName?.ToLower() switch
-        {
-            "pirate" => "🏴‍☠️",
-            "knights-and-knaves" => "⚔️",
-            _ => "🤖"
-        };
-    }
+	private string GetAgentIcon(string agentName)
+	{
+		return agentName?.ToLower() switch
+		{
+			"pirate" => "🏴‍☠️",
+			"knights-and-knaves" => "⚔️",
+			_ => "🤖"
+		};
+	}

-    private string GetAgentDisplayName(string agentName)
-    {
-        return agentName?.ToLower() switch
-        {
-            "pirate" => "Pirate",
-            "knights-and-knaves" => "Knights & Knaves",
-            _ => agentName ?? "Agent"
-        };
-    }
+	private string GetAgentDisplayName(string agentName)
+	{
+		return agentName?.ToLower() switch
+		{
+			"pirate" => "Pirate",
+			"knights-and-knaves" => "Knights & Knaves",
+			_ => agentName ?? "Agent"
+		};
+	}

+	private void ToggleA2AExpanded()
+	{
+		isA2AExpanded = !isA2AExpanded;
+	}

+	private async Task DiscoverAgentCard()
+	{
+		if (string.IsNullOrEmpty(selectedAgentName) || isDiscoveringCard)
+			return;

-    private void StartNewConversation()
-    {
-        if (string.IsNullOrEmpty(selectedAgentName))
-            return;
+		isDiscoveringCard = true;
+		discoveryError = null;
+		discoveredAgentCardJson = null;
+		StateHasChanged();

-        var newConversation = new Conversation
+		try
+		{
+			Logger.LogInformation("Discovering agent card for agent: {AgentName}", selectedAgentName);
+			var agentCard = await A2AActorClient.GetAgentCardAsync(selectedAgentName);
+			discoveredAgentCardJson = JsonSerializer.Serialize(agentCard, new JsonSerializerOptions() { WriteIndented = true });
+			Logger.LogInformation("Successfully discovered agent card for {AgentName}: {CardData}", selectedAgentName, discoveredAgentCardJson);
+		}
+		catch (Exception ex)
+		{
+			Logger.LogError(ex, "Failed to discover agent card for {AgentName}", selectedAgentName);
+			discoveryError = $"Failed to discover agent card: {ex.Message}";
+		}
+		finally
+		{
+			isDiscoveringCard = false;
+			StateHasChanged();
+		}
+	}
+
+	private void StartNewConversation()
+	{
+		if (string.IsNullOrEmpty(selectedAgentName))
+			return;
+
+		var newConversation = new Conversation
        {
            AgentName = selectedAgentName
        };

-        conversations.Add(newConversation);
-        currentConversation = newConversation;
+		conversations.Add(newConversation);
+		currentConversation = newConversation;

-        Logger.LogInformation("Started new conversation with agent: {AgentName}, session: {SessionId}", 
-            newConversation.AgentName, newConversation.SessionId);
+		Logger.LogInformation("Started new conversation with agent: {AgentName}, session: {SessionId}", 
+			newConversation.AgentName, newConversation.SessionId);

-        StateHasChanged();
-    }
+		StateHasChanged();
+	}

-    private void SelectConversation(string sessionId)
-    {
-        currentConversation = conversations.FirstOrDefault(c => c.SessionId == sessionId);
-        if (currentConversation != null)
-        {
-            selectedAgentName = currentConversation.AgentName;
-            Logger.LogDebug("Selected conversation with session: {SessionId}", sessionId);
-        }
-        StateHasChanged();
-    }
+	private void SelectConversation(string sessionId)
+	{
+		currentConversation = conversations.FirstOrDefault(c => c.SessionId == sessionId);
+		if (currentConversation != null)
+		{
+			selectedAgentName = currentConversation.AgentName;
+			Logger.LogDebug("Selected conversation with session: {SessionId}", sessionId);
+		}
+		StateHasChanged();
+	}

-    private void CloseConversation(string sessionId)
-    {
-        var conversationToRemove = conversations.FirstOrDefault(c => c.SessionId == sessionId);
-        if (conversationToRemove != null)
-        {
-            conversations.Remove(conversationToRemove);
+	private void CloseConversation(string sessionId)
+	{
+		var conversationToRemove = conversations.FirstOrDefault(c => c.SessionId == sessionId);
+		if (conversationToRemove != null)
+		{
+			conversations.Remove(conversationToRemove);

-            if (currentConversation?.SessionId == sessionId)
-            {
-                currentConversation = conversations.FirstOrDefault();
-                if (currentConversation != null)
-                {
-                    selectedAgentName = currentConversation.AgentName;
-                }
-            }
+			if (currentConversation?.SessionId == sessionId)
+			{
+				currentConversation = conversations.FirstOrDefault();
+				if (currentConversation != null)
+				{
+					selectedAgentName = currentConversation.AgentName;
+				}
+			}

-            Logger.LogInformation("Closed conversation with session: {SessionId}", sessionId);
-        }
-        StateHasChanged();
-    }
+			Logger.LogInformation("Closed conversation with session: {SessionId}", sessionId);
+		}
+		StateHasChanged();
+	}

-    private async Task SendMessage()
-    {
-        if (string.IsNullOrWhiteSpace(currentMessage) || isStreaming || currentConversation == null)
-            return;
+	private async Task SendMessage()
+	{
+		if (string.IsNullOrWhiteSpace(currentMessage) || isStreaming || currentConversation == null)
+			return;

-        var userMessage = currentMessage.Trim();
-        currentMessage = "";
+		var userMessage = currentMessage.Trim();
+		currentMessage = "";

-        Logger.LogInformation("User sending message: '{UserMessage}' to agent {AgentName} in session {SessionId}", 
-            userMessage, currentConversation.AgentName, currentConversation.SessionId);
+		Logger.LogInformation("User sending message: '{UserMessage}' to agent {AgentName} in session {SessionId}",
+			userMessage, currentConversation.AgentName, currentConversation.SessionId);

-        // Add user message to chat
-        currentConversation.Messages.Add(new ChatMessage(ChatRole.User, userMessage));
-        StateHasChanged();
-        await ScrollToBottom();
+		// Add user message to chat
+		currentConversation.Messages.Add(new ChatMessage(ChatRole.User, userMessage));
+		StateHasChanged();
+		await ScrollToBottom();

-        // Start streaming response
-        isStreaming = true;
-        currentStreamedMessage = "";
-        StateHasChanged();
+		// Start streaming response
+		isStreaming = true;
+		currentStreamedMessage = "";
+		StateHasChanged();

-        try
-        {
-            var responseContent = new StringBuilder();
-            var agent = new AgentProxy(currentConversation.AgentName, ActorClient);
+		StringBuilder responseContent = new();
+		var hasReceivedContent = false;
+
+		using var timeoutCts = new CancellationTokenSource(
+#if DEBUG
+            TimeSpan.FromSeconds(120)
+#else
+			TimeSpan.FromSeconds(20)
+#endif
+		);
+
+		try
+		{
+			var actorClient = (selectedProtocol is Protocol.A2A) ? A2AActorClient : ActorClient;
+            var agent = new AgentProxy(currentConversation.AgentName, actorClient);
            var thread = agent.GetNewThread();
            thread.ConversationId = currentConversation.SessionId;

            await foreach (var update in agent.RunStreamingAsync(
-                [new ChatMessage(ChatRole.User, userMessage)], 
+            [new ChatMessage(ChatRole.User, userMessage)],
                thread,
-                cancellationToken: CancellationToken.None))
+                cancellationToken: timeoutCts.Token))
            {
                var content = update.Text ?? "";
                if (!string.IsNullOrEmpty(content))
                {
+                    hasReceivedContent = true;
                    responseContent.Append(content);
                    currentStreamedMessage = responseContent.ToString();
                    StateHasChanged();
                    await ScrollToBottom();
+
+                    Logger.LogDebug("Received streaming content: {ContentLength} characters", content.Length);
                }
            }

+            Logger.LogInformation("Streaming completed for session {SessionId}, total content length: {ContentLength}",
+                currentConversation.SessionId, responseContent.Length);
+
            // Add the complete agent response to chat messages
            if (responseContent.Length > 0)
            {
                currentConversation.Messages.Add(new ChatMessage(ChatRole.Assistant, responseContent.ToString()));
            }
+            else if (!hasReceivedContent)
+            {
+                Logger.LogWarning("No content received during streaming for session {SessionId}", currentConversation.SessionId);
+                currentConversation.Messages.Add(new ChatMessage(ChatRole.Assistant, "No response received from the agent."));
+            }
            else
            {
                currentConversation.Messages.Add(new ChatMessage(ChatRole.Assistant, "Sorry, I couldn't generate a response."));
            }
        }
+        catch (OperationCanceledException) when (isStreaming)
+        {
+            Logger.LogWarning("Streaming operation timed out for session {SessionId}", currentConversation.SessionId);
+            currentConversation.Messages.Add(new ChatMessage(ChatRole.Assistant, "Request timed out. Please try again."));
+        }
        catch (Exception ex)
        {
-            Logger.LogError(ex, "Error occurred while processing message in session {SessionId}: {ErrorMessage}", 
+            Logger.LogError(ex, "Error occurred while processing message in session {SessionId}: {ErrorMessage}",
                currentConversation.SessionId, ex.Message);
            currentConversation.Messages.Add(new ChatMessage(ChatRole.Assistant, $"Error: {ex.Message}"));
-            }
+        }
        finally
        {
            isStreaming = false;
@@ -15,8 +15,19 @@ builder.Services.AddRazorComponents()

 builder.Services.AddOutputCache();

-builder.Services.AddHttpClient<IActorClient, HttpActorClient>(client => client.BaseAddress = new("https+http://agenthost"));
-builder.Services.AddHttpClient<AgentDiscoveryClient>(client => client.BaseAddress = new("https+http://agenthost"));
+// This URL uses "https+http://" to indicate HTTPS is preferred over HTTP.
+// Learn more about service discovery scheme resolution at https://aka.ms/dotnet/sdschemes.
+Uri baseAddress = new("https+http://agenthost");
+
+// for some reason does not resolve with `apiservice` url
+Uri a2aAddress = new("http://localhost:5390/a2a");
+
+builder.Services.AddHttpClient<AgentDiscoveryClient>(client => client.BaseAddress = baseAddress);
+builder.Services.AddHttpClient<IActorClient, HttpActorClient>(client => client.BaseAddress = baseAddress);
+builder.Services.AddSingleton<A2AActorClient>(sp =>
+{
+    return new A2AActorClient(sp.GetRequiredService<ILogger<A2AActorClient>>(), a2aAddress);
+});

 var app = builder.Build();