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SSE ClientTransport fixes and tests (#27)

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SSE fixes
Additional SSE integration tests with everything server
This commit is contained in:
Peder Holdgaard Pedersen 2025-02-27 21:14:20 +01:00 • committed by GitHub
commit 30f3f192ca
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GPG key ID: B5690EEEBB952194
3 changed files with 381 additions and 81 deletions
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21
src/mcpdotnet/Logging/Log.cs
View file

@ -480,4 +480,25 @@ internal static partial class Log
this ILogger logger,
string endpointName,
Exception e);
[LoggerMessage(
EventId = 7018,
Level = LogLevel.Debug,
Message = "SSE transport POST accepted for {endpointName} with message ID {messageId}"
)]
public static partial void SSETransportPostAccepted(
this ILogger logger,
string endpointName,
string messageId);
[LoggerMessage(
EventId = 7019,
Level = LogLevel.Error,
Message = "SSE transport POST not accepted for {endpointName} with message ID {messageId} and server response {responseContent}"
)]
public static partial void SSETransportPostNotAccepted(
this ILogger logger,
string endpointName,
string messageId,
string responseContent);
}

103
src/mcpdotnet/Protocol/Transport/SseClientTransport.cs
View file

@ -99,6 +99,13 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
"application/json"
);
string messageId = "(no id)";
RequestId? requestId = null;
if (message is IJsonRpcMessageWithId messageWithId)
{
messageId = messageWithId.Id.ToString();
}
var response = await _httpClient.PostAsync(
_messageEndpoint,
content,
@ -107,31 +114,40 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
response.EnsureSuccessStatusCode();
var responseContent = await response.Content.ReadAsStringAsync();
// Handle notifications, which don't have responses
if (message is JsonRpcNotification)
// Check if the message was an initialize request
if (message is JsonRpcRequest request && request.Method == "initialize")
{
await HandleNotificationResponseAsync(message, responseContent, cancellationToken);
// If the response is not a JSON-RPC response, it is an SSE message
if (responseContent.ToLowerInvariant() == "accepted")
{
_logger.SSETransportPostAccepted(EndpointName, messageId);
// The response will arrive as an SSE message
}
else
{
JsonRpcResponse initializeResponse = JsonSerializer.Deserialize<JsonRpcResponse>(responseContent, _jsonOptions);
if (initializeResponse == null)
{
throw new McpTransportException("Failed to initialize client");
}
_logger.TransportReceivedMessageParsed(EndpointName, messageId);
await WriteMessageAsync(initializeResponse, cancellationToken);
_logger.TransportMessageWritten(EndpointName, messageId);
}
return;
}
var responseMessage = JsonSerializer.Deserialize<IJsonRpcMessage>(responseContent, _jsonOptions);
if (responseMessage != null)
// Otherwise, check if the response was accepted (the response will come as an SSE message)
if (responseContent.ToLowerInvariant() == "accepted")
{
string messageId = "(no id)";
if (responseMessage is IJsonRpcMessageWithId messageWithId)
{
messageId = messageWithId.Id.ToString();
}
_logger.TransportReceivedMessageParsed(EndpointName, messageId);
await WriteMessageAsync(responseMessage, cancellationToken);
_logger.TransportMessageWritten(EndpointName, messageId);
_logger.SSETransportPostAccepted(EndpointName, messageId);
}
else
{
_logger.TransportMessageParseUnexpectedType(EndpointName, responseContent);
_logger.SSETransportPostNotAccepted(EndpointName, messageId, responseContent);
throw new McpTransportException("Failed to send message");
}
}
@ -154,28 +170,6 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
GC.SuppressFinalize(this);
}
private async Task HandleNotificationResponseAsync(
IJsonRpcMessage message,
string responseContent,
CancellationToken cancellationToken)
{
// Check for error response, but don't require one
try
{
var errorResponse = JsonSerializer.Deserialize<JsonRpcError>(responseContent, _jsonOptions);
if (errorResponse is not null)
{
await WriteMessageAsync(errorResponse, cancellationToken);
return;
}
}
catch (JsonException)
{
// Ignore deserialization errors for notifications
// This is expected as most notifications won't have responses
}
}
internal Uri? MessageEndpoint => _messageEndpoint;
internal SseClientTransportOptions Options => _options;
@ -207,7 +201,7 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
string? currentEvent = null;
string? line;
while ((line = await reader.ReadLineAsync()) != null)
while ((line = await reader.ReadLineAsync(cancellationToken)) != null)
{
if (line.StartsWith("event: "))
{
@ -227,6 +221,16 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
}
}
}
catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
{
_logger.TransportReadMessagesCancelled(EndpointName);
// Normal shutdown
}
catch (IOException) when (cancellationToken.IsCancellationRequested)
{
_logger.TransportReadMessagesCancelled(EndpointName);
// Normal shutdown
}
catch (Exception ex) when (!cancellationToken.IsCancellationRequested)
{
_logger.TransportConnectionError(EndpointName, ex);
@ -279,14 +283,31 @@ public sealed class SseClientTransport : TransportBase, IClientTransport
{
try
{
var endpointData = JsonSerializer.Deserialize<EndpointEventData>(data, _jsonOptions);
if (endpointData?.Uri == null)
if (string.IsNullOrEmpty(data))
{
_logger.TransportEndpointEventInvalid(EndpointName, data);
return;
}
_messageEndpoint = new Uri(endpointData.Uri);
// Check if data is absolute URI
if (data.ToLowerInvariant().StartsWith("http://") || data.ToLowerInvariant().StartsWith("https://"))
{
// Since the endpoint is an absolute URI, we can use it directly
_messageEndpoint = new Uri(data);
}
else
{
// If the endpoint is a relative URI, we need to combine it with the relative path of the SSE endpoint
var hostUrl = _sseEndpoint.AbsoluteUri;
if (hostUrl.EndsWith("/sse"))
hostUrl = hostUrl[..^4];
var endpointUri = hostUrl + data;
_messageEndpoint = new Uri(endpointUri);
}
// Set connected state
SetConnected(true);
_connectionEstablished.TrySetResult(true);
}

2
src/mcpdotnet/mcpdotnet.csproj
View file

@ -9,7 +9,7 @@
<PropertyGroup>
<!-- license and package properties -->
<PackageId>mcpdotnet</PackageId>
<Version>1.0.1.1</Version>
<Version>1.0.1.3</Version>
<Authors>PederHP</Authors>
<Description>.NET client library for the Model Context Protocol (MCP)</Description>
<PackageProjectUrl>https://github.com/PederHP/mcpdotnet</PackageProjectUrl>