Add an in-memory transport sample (#664)

* Add an in-memory transport sample

* Rename sample

Author: stephentoub

ModelContextProtocol.slnx

@@ -12,6 +12,7 @@
     <Project Path="samples/AspNetCoreSseServer/AspNetCoreSseServer.csproj" />
     <Project Path="samples/ChatWithTools/ChatWithTools.csproj" />
     <Project Path="samples/EverythingServer/EverythingServer.csproj" />
+    <Project Path="samples/InMemoryTransport/InMemoryTransport.csproj" />
     <Project Path="samples/ProtectedMCPClient/ProtectedMCPClient.csproj" />
     <Project Path="samples/ProtectedMCPServer/ProtectedMCPServer.csproj" />
     <Project Path="samples/QuickstartClient/QuickstartClient.csproj" />

samples/InMemoryTransport/InMemoryTransport.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <PublishAot>true</PublishAot>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\ModelContextProtocol\ModelContextProtocol.csproj" />
+  </ItemGroup>
+
+</Project>

samples/InMemoryTransport/Program.cs

@@ -0,0 +1,40 @@
+using ModelContextProtocol.Client;
+using ModelContextProtocol.Protocol;
+using ModelContextProtocol.Server;
+using System.IO.Pipelines;
+
+Pipe clientToServerPipe = new(), serverToClientPipe = new();
+
+// Create a server using a stream-based transport over an in-memory pipe.
+await using IMcpServer server = McpServerFactory.Create(
+    new StreamServerTransport(clientToServerPipe.Reader.AsStream(), serverToClientPipe.Writer.AsStream()),
+    new McpServerOptions()
+    {
+        Capabilities = new()
+        {
+            Tools = new()
+            {
+                ToolCollection = [McpServerTool.Create((string arg) => $"Echo: {arg}", new() { Name = "Echo" })]
+            }
+        }
+    });
+_ = server.RunAsync();
+
+// Connect a client using a stream-based transport over the same in-memory pipe.
+await using IMcpClient client = await McpClientFactory.CreateAsync(
+    new StreamClientTransport(clientToServerPipe.Writer.AsStream(), serverToClientPipe.Reader.AsStream()));
+
+// List all tools.
+var tools = await client.ListToolsAsync();
+foreach (var tool in tools)
+{
+    Console.WriteLine($"Tool Name: {tool.Name}");
+}
+Console.WriteLine();
+
+// Invoke a tool.
+var echo = tools.First(t => t.Name == "Echo");
+Console.WriteLine(await echo.InvokeAsync(new()
+{
+    ["arg"] = "Hello World"
+}));