Per Session Tools Sample (#724)

samples/AspNetCoreMcpPerSessionTools/Program.cs

@@ -0,0 +1,86 @@
+using AspNetCoreMcpPerSessionTools.Tools;
+using ModelContextProtocol.Server;
+using System.Collections.Concurrent;
+using System.Reflection;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Create and populate the tool dictionary at startup
+var toolDictionary = new ConcurrentDictionary<string, McpServerTool[]>();
+PopulateToolDictionary(toolDictionary);
+
+// Register all MCP server tools - they will be filtered per session based on route
+builder.Services.AddMcpServer()
+    .WithHttpTransport(options =>
+    {
+        // Configure per-session options to filter tools based on route category
+        options.ConfigureSessionOptions = async (httpContext, mcpOptions, cancellationToken) =>
+        {
+            // Determine tool category from route parameters
+            var toolCategory = httpContext.Request.RouteValues["toolCategory"]?.ToString()?.ToLower() ?? "all";
+
+            // Get pre-populated tools for the requested category
+            if (toolDictionary.TryGetValue(toolCategory, out var tools))
+            {
+                mcpOptions.Capabilities = new();
+                mcpOptions.Capabilities.Tools = new();
+                var toolCollection = mcpOptions.Capabilities.Tools.ToolCollection = new();
+
+                foreach (var tool in tools)
+                {
+                    toolCollection.Add(tool);
+                }
+            }
+        };
+    });
+
+var app = builder.Build();
+
+// Map MCP with route parameter for tool category filtering
+app.MapMcp("/{toolCategory?}");
+
+app.Run();
+
+// Helper method to populate the tool dictionary at startup
+static void PopulateToolDictionary(ConcurrentDictionary<string, McpServerTool[]> toolDictionary)
+{
+    // Get tools for each category
+    var clockTools = GetToolsForType<ClockTool>();
+    var calculatorTools = GetToolsForType<CalculatorTool>();
+    var userInfoTools = GetToolsForType<UserInfoTool>();
+    McpServerTool[] allTools = [.. clockTools,
+                                .. calculatorTools,
+                                .. userInfoTools];
+
+    // Populate the dictionary with tools for each category
+    toolDictionary.TryAdd("clock", clockTools);
+    toolDictionary.TryAdd("calculator", calculatorTools);
+    toolDictionary.TryAdd("userinfo", userInfoTools);
+    toolDictionary.TryAdd("all", allTools);
+}
+
+// Helper method to get tools for a specific type using reflection
+static McpServerTool[] GetToolsForType<[System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(
+    System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicMethods)] T>()
+{
+    var tools = new List<McpServerTool>();
+    var toolType = typeof(T);
+    var methods = toolType.GetMethods(BindingFlags.Public | BindingFlags.Static)
+        .Where(m => m.GetCustomAttributes(typeof(McpServerToolAttribute), false).Any());
+
+    foreach (var method in methods)
+    {
+        try
+        {
+            var tool = McpServerTool.Create(method, target: null, new McpServerToolCreateOptions());
+            tools.Add(tool);
+        }
+        catch (Exception ex)
+        {
+            // Log error but continue with other tools
+            Console.WriteLine($"Failed to add tool {toolType.Name}.{method.Name}: {ex.Message}");
+        }
+    }
+
+    return [.. tools];
+}