Add public subscriptions/listen server handler (SEP-2575) (#1775)
Co-authored-by: Tarek Mahmoud Sayed <tarekms@ntdev.microsoft.com> Copilot-Session: 80653343-5dcb-43cb-89b0-8ac8e572c4f7
This commit is contained in:
Tarek Mahmoud Sayed
GitHub
parent
79e13b3e2c
commit
81ae6ec6c7
1 changed files with 689 additions and 13 deletions
|
|
@ -380,6 +380,196 @@ public class StatelessServerTests(ITestOutputHelper outputHelper) : KestrelInMem
|
|||
Assert.Null(grantedNotifications["resourceSubscriptions"]);
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task SubscriptionsListen_WithCustomHandler_InStatelessMode_StreamsNotificationOverHeldOpenPost()
|
||||
{
|
||||
// The built-in stateless handler grants nothing and returns immediately because there is no
|
||||
// session-wide channel. A custom SubscriptionsListenHandler can instead stream notifications over the
|
||||
// held-open POST response (the listen request's RelatedTransport), which is the solicited
|
||||
// server-to-client stream. This is the core scenario of issue #1662.
|
||||
const string subscribedUri = "resource://test";
|
||||
|
||||
Builder.Services.AddMcpServer()
|
||||
.WithHttpTransport(options =>
|
||||
{
|
||||
options.Stateless = true;
|
||||
})
|
||||
.WithSubscriptionsListenHandler(async (request, cancellationToken) =>
|
||||
{
|
||||
var subscriptionId = request.JsonRpcRequest.Id;
|
||||
|
||||
var ack = new JsonRpcNotification
|
||||
{
|
||||
Method = NotificationMethods.SubscriptionsAcknowledgedNotification,
|
||||
Params = JsonSerializer.SerializeToNode(
|
||||
new SubscriptionsAcknowledgedNotificationParams
|
||||
{
|
||||
Notifications = new SubscriptionsListenNotifications
|
||||
{
|
||||
ResourceSubscriptions = request.Params.Notifications.ResourceSubscriptions,
|
||||
},
|
||||
},
|
||||
McpJsonUtilities.DefaultOptions),
|
||||
};
|
||||
TagWithSubscriptionId(ack, subscriptionId);
|
||||
await request.Server.SendMessageAsync(ack, cancellationToken);
|
||||
|
||||
var updated = new JsonRpcNotification
|
||||
{
|
||||
Method = NotificationMethods.ResourceUpdatedNotification,
|
||||
Params = new JsonObject { ["uri"] = subscribedUri },
|
||||
};
|
||||
TagWithSubscriptionId(updated, subscriptionId);
|
||||
await request.Server.SendMessageAsync(updated, cancellationToken);
|
||||
|
||||
// Complete the stream so the POST response finishes; the buffered notifications flush to the client.
|
||||
return new EmptyResult();
|
||||
});
|
||||
|
||||
_app = Builder.Build();
|
||||
_app.MapMcp();
|
||||
await _app.StartAsync(TestContext.Current.CancellationToken);
|
||||
|
||||
HttpClient.DefaultRequestHeaders.Accept.Add(new("application/json"));
|
||||
HttpClient.DefaultRequestHeaders.Accept.Add(new("text/event-stream"));
|
||||
|
||||
await using var client = await ConnectMcpClientAsync();
|
||||
|
||||
var ackChannel = Channel.CreateUnbounded<JsonRpcNotification>();
|
||||
var updatedChannel = Channel.CreateUnbounded<JsonRpcNotification>();
|
||||
await using var ackReg = client.RegisterNotificationHandler(NotificationMethods.SubscriptionsAcknowledgedNotification,
|
||||
(notification, _) => { ackChannel.Writer.TryWrite(notification); return default; });
|
||||
await using var updatedReg = client.RegisterNotificationHandler(NotificationMethods.ResourceUpdatedNotification,
|
||||
(notification, _) => { updatedChannel.Writer.TryWrite(notification); return default; });
|
||||
|
||||
var listenRequest = new JsonRpcRequest
|
||||
{
|
||||
Method = RequestMethods.SubscriptionsListen,
|
||||
Params = JsonSerializer.SerializeToNode(
|
||||
new SubscriptionsListenRequestParams
|
||||
{
|
||||
Notifications = new SubscriptionsListenNotifications { ResourceSubscriptions = [subscribedUri] },
|
||||
},
|
||||
McpJsonUtilities.DefaultOptions),
|
||||
};
|
||||
|
||||
await client.SendRequestAsync(listenRequest, TestContext.Current.CancellationToken)
|
||||
.WaitAsync(TestConstants.DefaultTimeout, TestContext.Current.CancellationToken);
|
||||
|
||||
var ack = await ackChannel.Reader.ReadAsync(TestContext.Current.CancellationToken);
|
||||
var subscriptionId = GetSubscriptionId(ack);
|
||||
Assert.NotNull(subscriptionId);
|
||||
|
||||
var updated = await updatedChannel.Reader.ReadAsync(TestContext.Current.CancellationToken);
|
||||
Assert.Equal(subscriptionId, GetSubscriptionId(updated));
|
||||
Assert.Equal(subscribedUri, Assert.IsType<JsonObject>(updated.Params)["uri"]?.GetValue<string>());
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public async Task SubscriptionsListen_WithCustomHandler_InStatelessMode_AdvertisesAndStreamsListChanged()
|
||||
{
|
||||
// resources/updated rides on resources.subscribe, which is never suppressed, so it cannot prove the
|
||||
// listChanged capability is advertised. A custom SubscriptionsListenHandler gives a stateless server a
|
||||
// way to deliver */list_changed over the held-open POST, so server/discover (the only path a
|
||||
// 2026-07-28+ client uses) must advertise tools.listChanged rather than dropping it (issue #1662).
|
||||
Builder.Services.AddMcpServer()
|
||||
.WithHttpTransport(options =>
|
||||
{
|
||||
options.Stateless = true;
|
||||
})
|
||||
.WithTools([McpServerTool.Create(() => "result", new() { Name = "myTool" })])
|
||||
.WithSubscriptionsListenHandler(async (request, cancellationToken) =>
|
||||
{
|
||||
var subscriptionId = request.JsonRpcRequest.Id;
|
||||
|
||||
var ack = new JsonRpcNotification
|
||||
{
|
||||
Method = NotificationMethods.SubscriptionsAcknowledgedNotification,
|
||||
Params = JsonSerializer.SerializeToNode(
|
||||
new SubscriptionsAcknowledgedNotificationParams
|
||||
{
|
||||
Notifications = new SubscriptionsListenNotifications
|
||||
{
|
||||
ToolsListChanged = request.Params.Notifications.ToolsListChanged,
|
||||
},
|
||||
},
|
||||
McpJsonUtilities.DefaultOptions),
|
||||
};
|
||||
TagWithSubscriptionId(ack, subscriptionId);
|
||||
await request.Server.SendMessageAsync(ack, cancellationToken);
|
||||
|
||||
var listChanged = new JsonRpcNotification { Method = NotificationMethods.ToolListChangedNotification };
|
||||
TagWithSubscriptionId(listChanged, subscriptionId);
|
||||
await request.Server.SendMessageAsync(listChanged, cancellationToken);
|
||||
|
||||
return new EmptyResult();
|
||||
});
|
||||
|
||||
// Advertise tools.listChanged so the per-response capability decision has something to preserve.
|
||||
Builder.Services.Configure<McpServerOptions>(options =>
|
||||
{
|
||||
options.Capabilities ??= new();
|
||||
options.Capabilities.Tools ??= new();
|
||||
options.Capabilities.Tools.ListChanged = true;
|
||||
});
|
||||
|
||||
_app = Builder.Build();
|
||||
_app.MapMcp();
|
||||
await _app.StartAsync(TestContext.Current.CancellationToken);
|
||||
|
||||
HttpClient.DefaultRequestHeaders.Accept.Add(new("application/json"));
|
||||
HttpClient.DefaultRequestHeaders.Accept.Add(new("text/event-stream"));
|
||||
|
||||
await using var client = await ConnectMcpClientAsync();
|
||||
|
||||
// The stateless server can now deliver tools/list_changed over the custom listen stream, so the
|
||||
// capability must survive on the server/discover response instead of being cleared.
|
||||
Assert.True(client.ServerCapabilities.Tools?.ListChanged);
|
||||
|
||||
var listChangedChannel = Channel.CreateUnbounded<JsonRpcNotification>();
|
||||
await using var listChangedReg = client.RegisterNotificationHandler(NotificationMethods.ToolListChangedNotification,
|
||||
(notification, _) => { listChangedChannel.Writer.TryWrite(notification); return default; });
|
||||
|
||||
var listenRequest = new JsonRpcRequest
|
||||
{
|
||||
Method = RequestMethods.SubscriptionsListen,
|
||||
Params = JsonSerializer.SerializeToNode(
|
||||
new SubscriptionsListenRequestParams
|
||||
{
|
||||
Notifications = new SubscriptionsListenNotifications { ToolsListChanged = true },
|
||||
},
|
||||
McpJsonUtilities.DefaultOptions),
|
||||
};
|
||||
|
||||
await client.SendRequestAsync(listenRequest, TestContext.Current.CancellationToken)
|
||||
.WaitAsync(TestConstants.DefaultTimeout, TestContext.Current.CancellationToken);
|
||||
|
||||
var listChangedNotification = await listChangedChannel.Reader.ReadAsync(TestContext.Current.CancellationToken);
|
||||
Assert.NotNull(GetSubscriptionId(listChangedNotification));
|
||||
}
|
||||
|
||||
private static string? GetSubscriptionId(JsonRpcNotification notification)
|
||||
=> ((notification.Params as JsonObject)?["_meta"] as JsonObject)?[MetaKeys.SubscriptionId]?.ToJsonString();
|
||||
|
||||
private static void TagWithSubscriptionId(JsonRpcNotification notification, RequestId subscriptionId)
|
||||
{
|
||||
var paramsObject = notification.Params as JsonObject ?? new JsonObject();
|
||||
if (paramsObject["_meta"] is not JsonObject meta)
|
||||
{
|
||||
meta = new JsonObject();
|
||||
paramsObject["_meta"] = meta;
|
||||
}
|
||||
|
||||
meta[MetaKeys.SubscriptionId] = subscriptionId.Id switch
|
||||
{
|
||||
string stringId => JsonValue.Create(stringId),
|
||||
long longId => JsonValue.Create(longId),
|
||||
_ => null,
|
||||
};
|
||||
|
||||
notification.Params = paramsObject;
|
||||
}
|
||||
|
||||
[McpServerTool(Name = "testSamplingErrors")]
|
||||
public static async Task<string> TestSamplingErrors(McpServer server)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in a new issue