From 6a7e83e986702dbde470a5a4b63aaf3df7df51d8 Mon Sep 17 00:00:00 2001 From: Luis Rodriguez <25299418+luisangelrod@users.noreply.github.com> Date: Mon, 10 Aug 2026 11:18:38 -0400 Subject: [PATCH 1/3] Fix protocol version tag for stateless server spans --- .../McpSessionHandler.cs | 5 +-- .../MapMcpStatelessTests.cs | 34 +++++++++++++++++++ 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/src/ModelContextProtocol.Core/McpSessionHandler.cs b/src/ModelContextProtocol.Core/McpSessionHandler.cs index 61a1872f2..92b42de5d 100644 --- a/src/ModelContextProtocol.Core/McpSessionHandler.cs +++ b/src/ModelContextProtocol.Core/McpSessionHandler.cs @@ -962,9 +962,10 @@ private void AddTags(ref TagList tags, Activity? activity, JsonRpcMessage messag tags.Add("network.protocol.name", "http"); } - if (NegotiatedProtocolVersion is not null) + string? protocolVersion = (message as JsonRpcRequest)?.Context?.ProtocolVersion ?? NegotiatedProtocolVersion; + if (protocolVersion is not null) { - tags.Add("mcp.protocol.version", NegotiatedProtocolVersion); + tags.Add("mcp.protocol.version", protocolVersion); } if (activity is { IsAllDataRequested: true }) diff --git a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs index ac19953bf..83597b7b5 100644 --- a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs +++ b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs @@ -2,6 +2,8 @@ using Microsoft.Extensions.DependencyInjection; using ModelContextProtocol.Protocol; using ModelContextProtocol.Server; +using OpenTelemetry.Trace; +using System.Diagnostics; namespace ModelContextProtocol.AspNetCore.Tests; @@ -10,6 +12,38 @@ public class MapMcpStatelessTests(ITestOutputHelper outputHelper) : MapMcpStream protected override bool UseStreamableHttp => true; protected override bool Stateless => true; + [Fact] + public async Task ServerActivity_IncludesPerRequestProtocolVersion() + { + var activities = new List(); + + using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder() + .AddSource("Experimental.ModelContextProtocol") + .AddInMemoryExporter(activities) + .Build(); + + Builder.Services.AddMcpServer() + .WithHttpTransport(ConfigureStateless) + .WithTools([McpServerTool.Create(() => "ok", new() { Name = "test-tool" })]); + + await using var app = Builder.Build(); + app.MapMcp(); + await app.StartAsync(TestContext.Current.CancellationToken); + + await using var client = await ConnectAsync(configureClient: options => + options.ProtocolVersion = McpProtocolVersions.July2026ProtocolVersion); + + await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken); + tracerProvider.ForceFlush(); + + var serverListToolsActivity = Assert.Single(activities, activity => + activity.DisplayName == "tools/list" && activity.Kind == ActivityKind.Server); + + Assert.Contains(serverListToolsActivity.Tags, tag => + tag.Key == "mcp.protocol.version" && + tag.Value == McpProtocolVersions.July2026ProtocolVersion); + } + [Fact] public async Task EnablePollingAsync_ThrowsInvalidOperationException_InStatelessMode() { From 2a27e8513a5aa084249ff091315748dec1c0e9b6 Mon Sep 17 00:00:00 2001 From: Luis Rodriguez <25299418+luisangelrod@users.noreply.github.com> Date: Mon, 10 Aug 2026 11:39:44 -0400 Subject: [PATCH 2/3] Stabilize protocol version activity test --- .../MapMcpStatelessTests.cs | 26 +++++++++---------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs index 83597b7b5..e3f007049 100644 --- a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs +++ b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs @@ -17,24 +17,24 @@ public async Task ServerActivity_IncludesPerRequestProtocolVersion() { var activities = new List(); - using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder() + using (var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder() .AddSource("Experimental.ModelContextProtocol") .AddInMemoryExporter(activities) - .Build(); - - Builder.Services.AddMcpServer() - .WithHttpTransport(ConfigureStateless) - .WithTools([McpServerTool.Create(() => "ok", new() { Name = "test-tool" })]); + .Build()) + { + Builder.Services.AddMcpServer() + .WithHttpTransport(ConfigureStateless) + .WithTools([McpServerTool.Create(() => "ok", new() { Name = "test-tool" })]); - await using var app = Builder.Build(); - app.MapMcp(); - await app.StartAsync(TestContext.Current.CancellationToken); + await using var app = Builder.Build(); + app.MapMcp(); + await app.StartAsync(TestContext.Current.CancellationToken); - await using var client = await ConnectAsync(configureClient: options => - options.ProtocolVersion = McpProtocolVersions.July2026ProtocolVersion); + await using var client = await ConnectAsync(configureClient: options => + options.ProtocolVersion = McpProtocolVersions.July2026ProtocolVersion); - await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken); - tracerProvider.ForceFlush(); + await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken); + } var serverListToolsActivity = Assert.Single(activities, activity => activity.DisplayName == "tools/list" && activity.Kind == ActivityKind.Server); From 5109182ccee64656eea878736b932dbf79377d64 Mon Sep 17 00:00:00 2001 From: Luis Rodriguez <25299418+luisangelrod@users.noreply.github.com> Date: Mon, 10 Aug 2026 14:51:30 -0400 Subject: [PATCH 3/3] test: make protocol version activity assertion parallel-safe --- .../MapMcpStatelessTests.cs | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs index e3f007049..dbbfc6ef0 100644 --- a/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs +++ b/tests/ModelContextProtocol.AspNetCore.Tests/MapMcpStatelessTests.cs @@ -36,12 +36,10 @@ public async Task ServerActivity_IncludesPerRequestProtocolVersion() await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken); } - var serverListToolsActivity = Assert.Single(activities, activity => - activity.DisplayName == "tools/list" && activity.Kind == ActivityKind.Server); - - Assert.Contains(serverListToolsActivity.Tags, tag => - tag.Key == "mcp.protocol.version" && - tag.Value == McpProtocolVersions.July2026ProtocolVersion); + Assert.Contains(activities, activity => + activity.DisplayName == "tools/list" && + activity.Kind == ActivityKind.Server && + activity.GetTagItem("mcp.protocol.version") as string == McpProtocolVersions.July2026ProtocolVersion); } [Fact]