modelcontextprotocol · mikekistler · Aug 14, 2025 · Aug 15, 2025 · Aug 15, 2025 · Aug 15, 2025
diff --git a/samples/EverythingServer/EverythingServer.csproj b/samples/EverythingServer/EverythingServer.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>net9.0</TargetFramework>
@@ -8,14 +8,13 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Hosting" />
     <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
     <PackageReference Include="OpenTelemetry.Extensions.Hosting" />
     <PackageReference Include="OpenTelemetry.Instrumentation.Http" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\..\src\ModelContextProtocol\ModelContextProtocol.csproj" />
+    <ProjectReference Include="..\..\src\ModelContextProtocol.AspNetCore\ModelContextProtocol.AspNetCore.csproj" />
   </ItemGroup>
 
 </Project>
diff --git a/samples/EverythingServer/EverythingServer.http b/samples/EverythingServer/EverythingServer.http
@@ -0,0 +1,77 @@
+@HostAddress = http://localhost:3001
+
+POST {{HostAddress}}/
+Accept: application/json, text/event-stream
+Content-Type: application/json
+
+{
+    "jsonrpc": "2.0",
+    "id": 1,
+    "method": "initialize",
+    "params": {
+        "clientInfo": {
+            "name": "RestClient",
+            "version": "0.1.0"
+        },
+        "capabilities": {},
+        "protocolVersion": "2025-06-18"
+    }
+}
+
+###
+
+@SessionId = ZwwM0VFEtKNOMBsP8D2VzQ
+
+POST {{HostAddress}}/
+Accept: application/json, text/event-stream
+Content-Type: application/json
+MCP-Protocol-Version: 2025-06-18
+Mcp-Session-Id: {{SessionId}}
+
+{
+    "jsonrpc": "2.0",
+    "id": 2,
+    "method": "resources/list"
+}
+
+###
+
+@resource_uri = test://direct/text/resource
+
+POST {{HostAddress}}/
+Accept: application/json, text/event-stream
+Content-Type: application/json
+MCP-Protocol-Version: 2025-06-18
+Mcp-Session-Id: {{SessionId}}
+
+{
+    "jsonrpc": "2.0",
+    "id": 3,
+    "method": "resources/subscribe",
+    "params": {
+        "uri": "{{resource_uri}}"
+    }
+}
+
+###
+
+POST {{HostAddress}}/
+Accept: application/json, text/event-stream
+Content-Type: application/json
+MCP-Protocol-Version: 2025-06-18
+Mcp-Session-Id: {{SessionId}}
+
+{
+    "jsonrpc": "2.0",
+    "id": 4,
+    "method": "resources/unsubscribe",
+    "params": {
+        "uri": "{{resource_uri}}"
+    }
+}
+
+###
+
+DELETE {{HostAddress}}/
+MCP-Protocol-Version: 2025-06-18
+Mcp-Session-Id: {{SessionId}}
diff --git a/samples/EverythingServer/LoggingUpdateMessageSender.cs b/samples/EverythingServer/LoggingUpdateMessageSender.cs
@@ -1,11 +1,10 @@
-using Microsoft.Extensions.Hosting;
-using ModelContextProtocol;
+using ModelContextProtocol;
 using ModelContextProtocol.Protocol;
 using ModelContextProtocol.Server;
 
 namespace EverythingServer;
 
-public class LoggingUpdateMessageSender(IMcpServer server, Func<LoggingLevel> getMinLevel) : BackgroundService
+public class LoggingUpdateMessageSender(IServiceProvider serviceProvider) : BackgroundService
 {
     readonly Dictionary<LoggingLevel, string> _loggingLevelMap = new()
     {
@@ -21,19 +20,35 @@ public class LoggingUpdateMessageSender(IMcpServer server, Func<LoggingLevel> ge
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
+        // Wait for the application to fully start before trying to access the MCP server
+        await Task.Delay(2000, stoppingToken);
+
         while (!stoppingToken.IsCancellationRequested)
         {
-            var newLevel = (LoggingLevel)Random.Shared.Next(_loggingLevelMap.Count);
-
-            var message = new
+            try
+            {
+                // Try to get the server from the service provider
+                var server = serviceProvider.GetService<IMcpServer>();
+                if (server != null)
                 {
-                    Level = newLevel.ToString().ToLower(),
-                    Data = _loggingLevelMap[newLevel],
-                };
+                    var newLevel = (LoggingLevel)Random.Shared.Next(_loggingLevelMap.Count);
 
-            if (newLevel > getMinLevel())
+                    var message = new
+                        {
+                            Level = newLevel.ToString().ToLower(),
+                            Data = _loggingLevelMap[newLevel],
+                        };
+
+                    if (newLevel > server.LoggingLevel)
+                    {
+                        await server.SendNotificationAsync("notifications/message", message, cancellationToken: stoppingToken);
+                    }
+                }
+            }
+            catch (Exception ex)
             {
-                await server.SendNotificationAsync("notifications/message", message, cancellationToken: stoppingToken);
+                // Log the exception but don't crash the service
+                Console.WriteLine($"Error in LoggingUpdateMessageSender: {ex.Message}");
             }
 
             await Task.Delay(15000, stoppingToken);

diff --git a/samples/EverythingServer/Program.cs b/samples/EverythingServer/Program.cs
@@ -3,9 +3,6 @@
 using EverythingServer.Resources;
 using EverythingServer.Tools;
 using Microsoft.Extensions.AI;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Logging;
 using ModelContextProtocol;
 using ModelContextProtocol.Protocol;
 using ModelContextProtocol.Server;
@@ -14,20 +11,28 @@
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
+using System.Collections.Concurrent;
 
-var builder = Host.CreateApplicationBuilder(args);
-builder.Logging.AddConsole(consoleLogOptions =>
-{
-    // Configure all logs to go to stderr
-    consoleLogOptions.LogToStandardErrorThreshold = LogLevel.Trace;
-});
-
-HashSet<string> subscriptions = [];
-var _minimumLoggingLevel = LoggingLevel.Debug;
+var builder = WebApplication.CreateBuilder(args);
 
 builder.Services
     .AddMcpServer()
-    .WithStdioServerTransport()
+    .WithHttpTransport(options =>
+    {
+        // Add a RunSessionHandler to remove all subscriptions for the session when it ends
+        options.RunSessionHandler = async (httpContext, mcpServer, token) =>
+        {
+            try
+            {
+                await mcpServer.RunAsync(token);
+            }
+            finally
+            {
+                // This code runs when the session ends
+                SubscriptionManager.RemoveAllSubscriptions(mcpServer);
+            }
+        };
+    })
     .WithTools<AddTool>()
     .WithTools<AnnotatedMessageTool>()
     .WithTools<EchoTool>()
@@ -40,11 +45,13 @@
     .WithResources<SimpleResourceType>()
     .WithSubscribeToResourcesHandler(async (ctx, ct) =>
     {
-        var uri = ctx.Params?.Uri;
-
-        if (uri is not null)
+        if (ctx.Server.SessionId == null)
+        {
+            throw new McpException("Cannot add subscription for server with null SessionId");
+        }
+        if (ctx.Params?.Uri is { } uri)
         {
-            subscriptions.Add(uri);
+            SubscriptionManager.AddSubscription(uri, ctx.Server);
 
             await ctx.Server.SampleAsync([
                 new ChatMessage(ChatRole.System, "You are a helpful test server"),
@@ -62,10 +69,13 @@ await ctx.Server.SampleAsync([
     })
     .WithUnsubscribeFromResourcesHandler(async (ctx, ct) =>
     {
-        var uri = ctx.Params?.Uri;
-        if (uri is not null)
+        if (ctx.Server.SessionId == null)
         {
-            subscriptions.Remove(uri);
+            throw new McpException("Cannot remove subscription for server with null SessionId");
+        }
+        if (ctx.Params?.Uri is { } uri)
+        {
+            SubscriptionManager.RemoveSubscription(uri, ctx.Server);
         }
         return new EmptyResult();
     })
@@ -126,13 +136,13 @@ await ctx.Server.SampleAsync([
             throw new McpException("Missing required argument 'level'", McpErrorCode.InvalidParams);
         }
 
-        _minimumLoggingLevel = ctx.Params.Level;
+        // The SDK updates the LoggingLevel field of the IMcpServer
 
         await ctx.Server.SendNotificationAsync("notifications/message", new
         {
             Level = "debug",
             Logger = "test-server",
-            Data = $"Logging level set to {_minimumLoggingLevel}",
+            Data = $"Logging level set to {ctx.Params.Level}",
         }, cancellationToken: ct);
 
         return new EmptyResult();
@@ -145,10 +155,13 @@ await ctx.Server.SampleAsync([
     .WithLogging(b => b.SetResourceBuilder(resource))
     .UseOtlpExporter();
 
-builder.Services.AddSingleton(subscriptions);
 builder.Services.AddHostedService<SubscriptionMessageSender>();
 builder.Services.AddHostedService<LoggingUpdateMessageSender>();
 
-builder.Services.AddSingleton<Func<LoggingLevel>>(_ => () => _minimumLoggingLevel);
+var app = builder.Build();
+
+app.UseHttpsRedirection();
+
+app.MapMcp();
 
-await builder.Build().RunAsync();
+app.Run();
diff --git a/samples/EverythingServer/Properties/launchSettings.json b/samples/EverythingServer/Properties/launchSettings.json
@@ -0,0 +1,21 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "applicationUrl": "http://localhost:3001",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "applicationUrl": "https://localhost:7133;http://localhost:3001",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+      }
+    }
+  }
+}
diff --git a/samples/EverythingServer/SubscriptionManager.cs b/samples/EverythingServer/SubscriptionManager.cs
@@ -0,0 +1,91 @@
+using ModelContextProtocol;
+using ModelContextProtocol.Server;
+
+// This class manages subscriptions to resources by McpServer instances.
+// The subscription information must be accessed in a thread-safe manner since handlers
+// can run in parallel even in the context of a single session.
+static class SubscriptionManager
+{
+    // Subscriptions tracks resource URIs to bags of McpServer instances (thread-safe via locking)
+    private static Dictionary<string, List<IMcpServer>> subscriptions = new();
+
+    // SessionSubscriptions is a secondary index to subscriptions to allow efficient removal of all
+    // subscriptions for a given session when it ends. (thread-safe via locking)
+    private static Dictionary<string /* sessionId */, List<string> /* uris */> sessionSubscriptions = new();
+
+    private static readonly object _subscriptionsLock = new();
+
+    public static void AddSubscription(string uri, IMcpServer server)
+    {
+        if (server.SessionId == null)
+        {
+            throw new McpException("Cannot add subscription for server with null SessionId");
+        }
+        lock (_subscriptionsLock)
+        {
+            subscriptions[uri] ??= new List<IMcpServer>();
+            subscriptions[uri].Add(server);
+            sessionSubscriptions[server.SessionId] ??= new List<string>();
+            sessionSubscriptions[server.SessionId].Add(uri);
+        }
+    }
+
+    public static void RemoveSubscription(string uri, IMcpServer server)
+    {
+        if (server.SessionId == null)
+        {
+            throw new McpException("Cannot remove subscription for server with null SessionId");
+        }
+        lock (_subscriptionsLock)
+        {
+            if (subscriptions.ContainsKey(uri))
+            {
+                // Remove the server from the list of subscriptions for the URI
+                subscriptions[uri] = subscriptions[uri].Where(s => s.SessionId != server.SessionId).ToList();
+                if (subscriptions[uri]?.Count == 0)
+                {
+                    subscriptions.Remove(uri);
+                }
+            }
+            // Remove the URI from the list of subscriptions for the session
+            sessionSubscriptions[server.SessionId]?.Remove(uri);
+            if (sessionSubscriptions[server.SessionId]?.Count == 0)
+            {
+                sessionSubscriptions.Remove(server.SessionId);
+            }
+        }
+    }
+
+    public static IDictionary<string, List<IMcpServer>> GetSubscriptions()
+    {
+        lock (_subscriptionsLock)
+        {
+            // Return a copy of the subscriptions dictionary to avoid external modification
+            return subscriptions.ToDictionary(entry => entry.Key,
+                                             entry => entry.Value.ToList());
+        }
+    }
+
+    public static void RemoveAllSubscriptions(IMcpServer server)
+    {
+        if (server.SessionId is { } sessionId)
+        {
+            lock (_subscriptionsLock)
+            {
+                // Remove all subscriptions for the session
+                if (sessionSubscriptions.TryGetValue(sessionId, out var uris))
+                {
+                    foreach (var uri in uris)
+                    {
+                        subscriptions[uri] = subscriptions[uri].Where(s => s.SessionId != sessionId).ToList();
+                        if (subscriptions[uri]?.Count == 0)
+                        {
+                            subscriptions.Remove(uri);
+                        }
+                    }
+                    sessionSubscriptions.Remove(sessionId);
+                }
+            }
+        }
+    }
+}