Converting to proper background services

Author: aaronpowell

samples/EverythingServer/LoggingUpdateMessageSender.cs

@@ -1,13 +1,12 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using ModelContextProtocol;
-using ModelContextProtocol.Protocol.Messages;
 using ModelContextProtocol.Protocol.Types;
 using ModelContextProtocol.Server;
 
 namespace EverythingServer;
 
-public class LoggingUpdateMessageSender(IMcpServer server) : IHostedService
+public class LoggingUpdateMessageSender(IMcpServer server) : BackgroundService
 {
     readonly Dictionary<LoggingLevel, string> _loggingLevelMap = new()
     {
@@ -21,11 +20,11 @@ public class LoggingUpdateMessageSender(IMcpServer server) : IHostedService
         { LoggingLevel.Emergency, "Emergency-level message" }
     };
 
-    public async Task StartAsync(CancellationToken cancellationToken)
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
         var currentLevel = server.Services!.GetRequiredService<Func<LoggingLevel>>();
 
-        while (!cancellationToken.IsCancellationRequested)
+        while (!stoppingToken.IsCancellationRequested)
         {
             var newLevel = (LoggingLevel)Random.Shared.Next(_loggingLevelMap.Count);
 
@@ -37,15 +36,10 @@ public async Task StartAsync(CancellationToken cancellationToken)
 
             if (newLevel > currentLevel())
             {
-                await server.SendNotificationAsync("notifications/message", message, cancellationToken: cancellationToken);
+                await server.SendNotificationAsync("notifications/message", message, cancellationToken: stoppingToken);
             }
 
-            await Task.Delay(15000, cancellationToken);
+            await Task.Delay(15000, stoppingToken);
         }
     }
-
-    public Task StopAsync(CancellationToken cancellationToken)
-    {
-        return Task.CompletedTask;
-    }
 }

samples/EverythingServer/Program.cs

@@ -1,14 +1,20 @@
-using Microsoft.Extensions.Hosting;
-using ModelContextProtocol.Protocol.Types;
-using EverythingServer;
-using ModelContextProtocol.Server;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.DependencyInjection;
+using EverythingServer;
 using EverythingServer.Prompts;
 using EverythingServer.Tools;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using ModelContextProtocol;
+using ModelContextProtocol.Protocol.Types;
+using ModelContextProtocol.Server;
 
 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;

samples/EverythingServer/SubscriptionMessageSender.cs

@@ -2,27 +2,22 @@
 using ModelContextProtocol;
 using ModelContextProtocol.Server;
 
-internal class SubscriptionMessageSender(IMcpServer server, HashSet<string> subscriptions) : IHostedService
+internal class SubscriptionMessageSender(IMcpServer server, HashSet<string> subscriptions) : BackgroundService
 {
-    public async Task StartAsync(CancellationToken cancellationToken)
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
-        while (!cancellationToken.IsCancellationRequested)
+        while (!stoppingToken.IsCancellationRequested)
         {
             foreach (var uri in subscriptions)
             {
                 await server.SendNotificationAsync("notifications/resource/updated",
                     new
                     {
                         Uri = uri,
-                    }, cancellationToken: cancellationToken);
+                    }, cancellationToken: stoppingToken);
             }
 
-            await Task.Delay(5000, cancellationToken);
+            await Task.Delay(5000, stoppingToken);
         }
     }
-
-    public Task StopAsync(CancellationToken cancellationToken)
-    {
-        return Task.CompletedTask;
-    }
 }