Pipe isolation through Hosting helper extension methods

dotnet/src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/Microsoft.Agents.AI.Hosting.A2A.AspNetCore.csproj

@@ -27,6 +27,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Microsoft.Agents.AI.Hosting.A2A\Microsoft.Agents.AI.Hosting.A2A.csproj" />
+    <ProjectReference Include="..\Microsoft.Agents.AI.Hosting.AspNetCore\Microsoft.Agents.AI.Hosting.AspNetCore.csproj" />
   </ItemGroup>
 
   <PropertyGroup>

dotnet/src/Microsoft.Agents.AI.Hosting.AspNetCore/ServiceCollectionExtensions.cs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Microsoft.Agents.AI.Hosting;
+
+/// <summary>
+/// Extension methods for configuring AI hosting services in an <see cref="IServiceCollection"/>.
+/// </summary>
+public static class ServiceCollectionExtensions
+{
+    /// <summary>
+    /// Registers a <see cref="SessionIsolationKeyProvider"/> that uses claims from the current user's identity
+    /// to generate session isolation keys.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add services to.</param>
+    /// <param name="options"> Optional configuration for the claims-based session isolation key provider.</param>
+    /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
+    /// <remarks>
+    /// This method requires <see cref="IHttpContextAccessor"/> to be registered in the service collection.
+    /// Ensure that <c>services.AddHttpContextAccessor()</c> has been called before using this method.
+    /// </remarks>
+    public static IServiceCollection UseClaimsBasedSessionIsolation(
+        this IServiceCollection services,
+        ClaimsIdentitySessionIsolationKeyProviderOptions? options = null)
+    {
+        options ??= new();
+        ServiceDescriptor descriptor = new(typeof(SessionIsolationKeyProvider), CreateIsolationKeyProvider, ServiceLifetime.Scoped);
+        services.Add(descriptor);
+
+        return services;
+
+        object CreateIsolationKeyProvider(IServiceProvider serviceProvider)
+        {
+            IHttpContextAccessor contextAccessor = serviceProvider.GetRequiredService<IHttpContextAccessor>();
+
+            return new ClaimsIdentitySessionIsolationKeyProvider(contextAccessor, options);
+        }
+    }
+}

dotnet/src/Microsoft.Agents.AI.Hosting/HostedAgentBuilderExtensions.cs

@@ -3,6 +3,7 @@
 using System;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.AI.Hosting;
@@ -16,12 +17,11 @@ public static class HostedAgentBuilderExtensions
     /// Configures the host agent builder to use an in-memory session store for agent session management.
     /// </summary>
     /// <param name="builder">The host agent builder to configure with the in-memory session store.</param>
+    /// <param name="withIsolation">When <see langword="true"/>, wraps the session store with an <see cref="IsolationKeyScopedAgentSessionStore"/>
+    /// to provide isolation-key-based scoping for sessions. Defaults to <see langword="true"/>.</param>
     /// <returns>The same <paramref name="builder"/> instance, configured to use an in-memory session store.</returns>
-    public static IHostedAgentBuilder WithInMemorySessionStore(this IHostedAgentBuilder builder)
-    {
-        builder.ServiceCollection.AddKeyedSingleton<AgentSessionStore>(builder.Name, new InMemoryAgentSessionStore());
-        return builder;
-    }
+    public static IHostedAgentBuilder WithInMemorySessionStore(this IHostedAgentBuilder builder, bool withIsolation = true)
+        => builder.WithSessionStore(new InMemoryAgentSessionStore(), withIsolation);
 
     /// <summary>
     /// Registers the specified agent session store with the host agent builder, enabling session-specific storage for
@@ -29,12 +29,11 @@ public static class HostedAgentBuilderExtensions
     /// </summary>
     /// <param name="builder">The host agent builder to configure with the session store. Cannot be null.</param>
     /// <param name="store">The agent session store instance to register. Cannot be null.</param>
+    /// <param name="withIsolation">When <see langword="true"/>, wraps the session store with an <see cref="IsolationKeyScopedAgentSessionStore"/>
+    /// to provide isolation-key-based scoping for sessions. Defaults to <see langword="true"/>.</param>
     /// <returns>The same host agent builder instance, allowing for method chaining.</returns>
-    public static IHostedAgentBuilder WithSessionStore(this IHostedAgentBuilder builder, AgentSessionStore store)
-    {
-        builder.ServiceCollection.AddKeyedSingleton(builder.Name, store);
-        return builder;
-    }
+    public static IHostedAgentBuilder WithSessionStore(this IHostedAgentBuilder builder, AgentSessionStore store, bool withIsolation = true)
+        => builder.WithSessionStore((sp, key) => store, ServiceLifetime.Singleton, withIsolation);
 
     /// <summary>
     /// Configures the host agent builder to use a custom session store implementation for agent sessions.
@@ -44,16 +43,36 @@ public static class HostedAgentBuilderExtensions
     /// name.</param>
     /// <param name="lifetime">The DI service lifetime for the session store registration. Defaults to <see cref="ServiceLifetime.Singleton"/>
     /// because session stores persist conversation state across requests and are consumed independently of the agent's lifetime.</param>
+    /// <param name="withIsolation">When <see langword="true"/>, wraps the session store with an <see cref="IsolationKeyScopedAgentSessionStore"/>
+    /// to provide isolation-key-based scoping for sessions. Defaults to <see langword="true"/>.</param>
     /// <returns>The same host agent builder instance, enabling further configuration.</returns>
-    public static IHostedAgentBuilder WithSessionStore(this IHostedAgentBuilder builder, Func<IServiceProvider, string, AgentSessionStore> createAgentSessionStore, ServiceLifetime lifetime = ServiceLifetime.Singleton)
+    public static IHostedAgentBuilder WithSessionStore(this IHostedAgentBuilder builder, Func<IServiceProvider, string, AgentSessionStore> createAgentSessionStore, ServiceLifetime lifetime = ServiceLifetime.Singleton, bool withIsolation = true)
     {
         builder.ServiceCollection.AddKeyedService(builder.Name, (sp, key) =>
         {
             Throw.IfNull(key);
             var keyString = key as string;
             Throw.IfNullOrEmpty(keyString);
-            return createAgentSessionStore(sp, keyString) ??
+
+            AgentSessionStore store = createAgentSessionStore(sp, keyString) ??
                 throw new InvalidOperationException($"The agent session store factory did not return a valid {nameof(AgentSessionStore)} instance for key '{keyString}'.");
+
+            if (withIsolation && store.GetService<IsolationKeyScopedAgentSessionStore>() is null)
+            {
+                var isolationKeyProvider = sp.GetService<SessionIsolationKeyProvider>();
+
+                // Best efforts options getting
+                IsolationKeyScopedAgentSessionStoreOptions? options = sp.GetService<IsolationKeyScopedAgentSessionStoreOptions>();
+                if (options is null)
+                {
+                    var optionsProvider = sp.GetService<IOptions<IsolationKeyScopedAgentSessionStoreOptions>>();
+                    options = optionsProvider?.Value;
+                }
+
+                store = new IsolationKeyScopedAgentSessionStore(store, isolationKeyProvider, options ?? new());
+            }
+
+            return store;
         }, lifetime);
         return builder;
     }