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Clean up logging (#286)

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Stephen Toub 2025-04-14 10:55:45 -04:00 • committed by GitHub
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12 changed files with 401 additions and 570 deletions
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18
src/ModelContextProtocol.AspNetCore/StreamableHttpHandler.cs
View file

@ -9,6 +9,7 @@ using ModelContextProtocol.Protocol.Transport;
using ModelContextProtocol.Server; using ModelContextProtocol.Server;
using ModelContextProtocol.Utils.Json; using ModelContextProtocol.Utils.Json;
using System.Collections.Concurrent; using System.Collections.Concurrent;
using System.Diagnostics;
using System.Security.Cryptography; using System.Security.Cryptography;
namespace ModelContextProtocol.AspNetCore; namespace ModelContextProtocol.AspNetCore;
@ -61,18 +62,19 @@ internal sealed class StreamableHttpHandler(
var httpMcpSession = new HttpMcpSession(transport, context.User); var httpMcpSession = new HttpMcpSession(transport, context.User);
if (!_sessions.TryAdd(sessionId, httpMcpSession)) if (!_sessions.TryAdd(sessionId, httpMcpSession))
{ {
throw new Exception($"Unreachable given good entropy! Session with ID '{sessionId}' has already been created."); Debug.Fail("Unreachable given good entropy!");
} throw new InvalidOperationException($"Session with ID '{sessionId}' has already been created.");
var mcpServerOptions = mcpServerOptionsSnapshot.Value;
if (httpMcpServerOptions.Value.ConfigureSessionOptions is { } configureSessionOptions)
{
mcpServerOptions = mcpServerOptionsFactory.Create(Options.DefaultName);
await configureSessionOptions(context, mcpServerOptions, cancellationToken);
} }
try try
{ {
var mcpServerOptions = mcpServerOptionsSnapshot.Value;
if (httpMcpServerOptions.Value.ConfigureSessionOptions is { } configureSessionOptions)
{
mcpServerOptions = mcpServerOptionsFactory.Create(Options.DefaultName);
await configureSessionOptions(context, mcpServerOptions, cancellationToken);
}
var transportTask = transport.RunAsync(cancellationToken); var transportTask = transport.RunAsync(cancellationToken);
try try

30
src/ModelContextProtocol/Client/McpClient.cs
View file

@ -1,5 +1,4 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Protocol.Transport; using ModelContextProtocol.Protocol.Transport;
using ModelContextProtocol.Protocol.Types; using ModelContextProtocol.Protocol.Types;
@ -10,7 +9,7 @@ using System.Text.Json;
namespace ModelContextProtocol.Client; namespace ModelContextProtocol.Client;
/// <inheritdoc/> /// <inheritdoc/>
internal sealed class McpClient : McpEndpoint, IMcpClient internal sealed partial class McpClient : McpEndpoint, IMcpClient
{ {
private static Implementation DefaultImplementation { get; } = new() private static Implementation DefaultImplementation { get; } = new()
{ {
@ -133,9 +132,12 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
cancellationToken: initializationCts.Token).ConfigureAwait(false); cancellationToken: initializationCts.Token).ConfigureAwait(false);
// Store server information // Store server information
_logger.ServerCapabilitiesReceived(EndpointName, if (_logger.IsEnabled(LogLevel.Information))
capabilities: JsonSerializer.Serialize(initializeResponse.Capabilities, McpJsonUtilities.JsonContext.Default.ServerCapabilities), {
serverInfo: JsonSerializer.Serialize(initializeResponse.ServerInfo, McpJsonUtilities.JsonContext.Default.Implementation)); LogServerCapabilitiesReceived(EndpointName,
capabilities: JsonSerializer.Serialize(initializeResponse.Capabilities, McpJsonUtilities.JsonContext.Default.ServerCapabilities),
serverInfo: JsonSerializer.Serialize(initializeResponse.ServerInfo, McpJsonUtilities.JsonContext.Default.Implementation));
}
_serverCapabilities = initializeResponse.Capabilities; _serverCapabilities = initializeResponse.Capabilities;
_serverInfo = initializeResponse.ServerInfo; _serverInfo = initializeResponse.ServerInfo;
@ -144,7 +146,7 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
// Validate protocol version // Validate protocol version
if (initializeResponse.ProtocolVersion != _options.ProtocolVersion) if (initializeResponse.ProtocolVersion != _options.ProtocolVersion)
{ {
_logger.ServerProtocolVersionMismatch(EndpointName, _options.ProtocolVersion, initializeResponse.ProtocolVersion); LogServerProtocolVersionMismatch(EndpointName, _options.ProtocolVersion, initializeResponse.ProtocolVersion);
throw new McpException($"Server protocol version mismatch. Expected {_options.ProtocolVersion}, got {initializeResponse.ProtocolVersion}"); throw new McpException($"Server protocol version mismatch. Expected {_options.ProtocolVersion}, got {initializeResponse.ProtocolVersion}");
} }
@ -155,13 +157,13 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
} }
catch (OperationCanceledException oce) when (initializationCts.IsCancellationRequested) catch (OperationCanceledException oce) when (initializationCts.IsCancellationRequested)
{ {
_logger.ClientInitializationTimeout(EndpointName); LogClientInitializationTimeout(EndpointName);
throw new McpException("Initialization timed out", oce); throw new McpException("Initialization timed out", oce);
} }
} }
catch (Exception e) catch (Exception e)
{ {
_logger.ClientInitializationError(EndpointName, e); LogClientInitializationError(EndpointName, e);
await DisposeAsync().ConfigureAwait(false); await DisposeAsync().ConfigureAwait(false);
throw; throw;
} }
@ -188,4 +190,16 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
} }
} }
} }
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} client received server '{ServerInfo}' capabilities: '{Capabilities}'.")]
private partial void LogServerCapabilitiesReceived(string endpointName, string capabilities, string serverInfo);
[LoggerMessage(Level = LogLevel.Error, Message = "{EndpointName} client initialization error.")]
private partial void LogClientInitializationError(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Error, Message = "{EndpointName} client initialization timed out.")]
private partial void LogClientInitializationTimeout(string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "{EndpointName} client protocol version mismatch with server. Expected '{Expected}', received '{Received}'.")]
private partial void LogServerProtocolVersionMismatch(string endpointName, string expected, string received);
} }

19
src/ModelContextProtocol/Client/McpClientFactory.cs
View file

@ -1,8 +1,6 @@
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Transport; using ModelContextProtocol.Protocol.Transport;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
namespace ModelContextProtocol.Client; namespace ModelContextProtocol.Client;
@ -14,7 +12,7 @@ namespace ModelContextProtocol.Client;
/// that connect to MCP servers. It handles the creation and connection /// that connect to MCP servers. It handles the creation and connection
/// of appropriate implementations through the supplied transport. /// of appropriate implementations through the supplied transport.
/// </remarks> /// </remarks>
public static class McpClientFactory public static partial class McpClientFactory
{ {
/// <summary>Creates an <see cref="IMcpClient"/>, connecting it to the specified server.</summary> /// <summary>Creates an <see cref="IMcpClient"/>, connecting it to the specified server.</summary>
/// <param name="clientTransport">The transport instance used to communicate with the server.</param> /// <param name="clientTransport">The transport instance used to communicate with the server.</param>
@ -35,21 +33,24 @@ public static class McpClientFactory
{ {
Throw.IfNull(clientTransport); Throw.IfNull(clientTransport);
string endpointName = clientTransport.Name;
var logger = loggerFactory?.CreateLogger(typeof(McpClientFactory)) ?? NullLogger.Instance;
logger.CreatingClient(endpointName);
McpClient client = new(clientTransport, clientOptions, loggerFactory); McpClient client = new(clientTransport, clientOptions, loggerFactory);
try try
{ {
await client.ConnectAsync(cancellationToken).ConfigureAwait(false); await client.ConnectAsync(cancellationToken).ConfigureAwait(false);
logger.ClientCreated(endpointName); if (loggerFactory?.CreateLogger(typeof(McpClientFactory)) is ILogger logger)
return client; {
logger.LogClientCreated(client.EndpointName);
}
} }
catch catch
{ {
await client.DisposeAsync().ConfigureAwait(false); await client.DisposeAsync().ConfigureAwait(false);
throw; throw;
} }
return client;
} }
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} client created and connected.")]
private static partial void LogClientCreated(this ILogger logger, string endpointName);
} }

350
src/ModelContextProtocol/Logging/Log.cs
View file

@ -1,350 +0,0 @@
using ModelContextProtocol.Protocol.Messages;
using Microsoft.Extensions.Logging;
namespace ModelContextProtocol.Logging;
/// <summary>
/// Logging methods for the ModelContextProtocol library.
/// </summary>
internal static partial class Log
{
[LoggerMessage(Level = LogLevel.Information, Message = "Server {endpointName} capabilities received: {capabilities}, server info: {serverInfo}")]
internal static partial void ServerCapabilitiesReceived(this ILogger logger, string endpointName, string capabilities, string serverInfo);
[LoggerMessage(Level = LogLevel.Information, Message = "Creating client for {endpointName}")]
internal static partial void CreatingClient(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Client for {endpointName} created and connected")]
internal static partial void ClientCreated(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Client server {endpointName} initialization error")]
internal static partial void ClientInitializationError(this ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Error, Message = "Server {endpointName} protocol version mismatch, expected {expected}, received {received}")]
internal static partial void ServerProtocolVersionMismatch(this ILogger logger, string endpointName, string expected, string received);
[LoggerMessage(Level = LogLevel.Error, Message = "Client {endpointName} initialization timeout")]
internal static partial void ClientInitializationTimeout(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Endpoint message processing cancelled for {endpointName}")]
internal static partial void EndpointMessageProcessingCancelled(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Request handler called for {endpointName} with method {method}")]
internal static partial void RequestHandlerCalled(this ILogger logger, string endpointName, string method);
[LoggerMessage(Level = LogLevel.Information, Message = "Request handler completed for {endpointName} with method {method}")]
internal static partial void RequestHandlerCompleted(this ILogger logger, string endpointName, string method);
[LoggerMessage(Level = LogLevel.Error, Message = "Request handler error for {endpointName} with method {method}")]
internal static partial void RequestHandlerError(this ILogger logger, string endpointName, string method, Exception exception);
[LoggerMessage(Level = LogLevel.Warning, Message = "No request found for message with ID {messageWithId} for {endpointName}")]
internal static partial void NoRequestFoundForMessageWithId(this ILogger logger, string endpointName, string messageWithId);
[LoggerMessage(Level = LogLevel.Warning, Message = "The request has not valid message ID for {endpointName}")]
internal static partial void RequestHasInvalidId(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Client not connected for {endpointName}")]
internal static partial void ClientNotConnected(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Endpoint not connected for {endpointName}")]
internal static partial void EndpointNotConnected(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Sending request payload for {endpointName}: {payload}")]
internal static partial void SendingRequestPayload(this ILogger logger, string endpointName, string payload);
[LoggerMessage(Level = LogLevel.Information, Message = "Sending request for {endpointName} with method {method}")]
internal static partial void SendingRequest(this ILogger logger, string endpointName, string method);
[LoggerMessage(Level = LogLevel.Error, Message = "Request failed for {endpointName} with method {method}: {message} ({code})")]
internal static partial void RequestFailed(this ILogger logger, string endpointName, string method, string message, int code);
[LoggerMessage(Level = LogLevel.Information, Message = "Request '{requestId}' canceled via client notification with reason '{Reason}'.")]
internal static partial void RequestCanceled(this ILogger logger, RequestId requestId, string? reason);
[LoggerMessage(Level = LogLevel.Information, Message = "Request response received payload for {endpointName}: {payload}")]
internal static partial void RequestResponseReceivedPayload(this ILogger logger, string endpointName, string payload);
[LoggerMessage(Level = LogLevel.Information, Message = "Request response received for {endpointName} with method {method}")]
internal static partial void RequestResponseReceived(this ILogger logger, string endpointName, string method);
[LoggerMessage(Level = LogLevel.Error, Message = "Request invalid response type for {endpointName} with method {method}")]
internal static partial void RequestInvalidResponseType(this ILogger logger, string endpointName, string method);
[LoggerMessage(Level = LogLevel.Information, Message = "Cleaning up endpoint {endpointName}")]
internal static partial void CleaningUpEndpoint(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Endpoint cleaned up for {endpointName}")]
internal static partial void EndpointCleanedUp(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport for {endpointName} already connected")]
internal static partial void TransportAlreadyConnected(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport for {endpointName} connecting")]
internal static partial void TransportConnecting(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Creating process for transport for {endpointName} with command {command}, arguments {arguments}, environment {environment}, working directory {workingDirectory}, shutdown timeout {shutdownTimeout}")]
internal static partial void CreateProcessForTransport(this ILogger logger, string endpointName, string command, string? arguments, string environment, string workingDirectory, string shutdownTimeout);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport for {endpointName} received stderr log: {data}")]
internal static partial void ReadStderr(this ILogger logger, string endpointName, string data);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport process start failed for {endpointName}")]
internal static partial void TransportProcessStartFailed(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport process started for {endpointName} with PID {processId}")]
internal static partial void TransportProcessStarted(this ILogger logger, string endpointName, int processId);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport reading messages for {endpointName}")]
internal static partial void TransportReadingMessages(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport connect failed for {endpointName}")]
internal static partial void TransportConnectFailed(this ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport not connected for {endpointName}")]
internal static partial void TransportNotConnected(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport sending message for {endpointName} with ID {messageId}, JSON {json}")]
internal static partial void TransportSendingMessage(this ILogger logger, string endpointName, string messageId, string? json = null);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport message sent for {endpointName} with ID {messageId}")]
internal static partial void TransportSentMessage(this ILogger logger, string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport send failed for {endpointName} with ID {messageId}")]
internal static partial void TransportSendFailed(this ILogger logger, string endpointName, string messageId, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport entering read messages loop for {endpointName}")]
internal static partial void TransportEnteringReadMessagesLoop(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport waiting for message for {endpointName}")]
internal static partial void TransportWaitingForMessage(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport end of stream for {endpointName}")]
internal static partial void TransportEndOfStream(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport received message for {endpointName}: {line}")]
internal static partial void TransportReceivedMessage(this ILogger logger, string endpointName, string line);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport received message parsed for {endpointName}: {messageId}")]
internal static partial void TransportReceivedMessageParsed(this ILogger logger, string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport message written for {endpointName} with ID {messageId}")]
internal static partial void TransportMessageWritten(this ILogger logger, string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport message parse failed due to unexpected message schema for {endpointName}: {line}")]
internal static partial void TransportMessageParseUnexpectedType(this ILogger logger, string endpointName, string line);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport message parse failed for {endpointName}: {line}")]
internal static partial void TransportMessageParseFailed(this ILogger logger, string endpointName, string line, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport exiting read messages loop for {endpointName}")]
internal static partial void TransportExitingReadMessagesLoop(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport read messages cancelled for {endpointName}")]
internal static partial void TransportReadMessagesCancelled(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport read messages failed for {endpointName}")]
internal static partial void TransportReadMessagesFailed(this ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport cleaning up for {endpointName}")]
internal static partial void TransportCleaningUp(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Debug, Message = "Transport waiting for shutdown for {endpointName}")]
internal static partial void TransportWaitingForShutdown(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport shutdown failed for {endpointName}")]
internal static partial void TransportShutdownFailed(this ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Debug, Message = "Transport waiting for read task for {endpointName}")]
internal static partial void TransportWaitingForReadTask(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "Transport cleanup read task timeout for {endpointName}")]
internal static partial void TransportCleanupReadTaskTimeout(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport cleanup read task cancelled for {endpointName}")]
internal static partial void TransportCleanupReadTaskCancelled(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Error, Message = "Transport cleanup read task failed for {endpointName}")]
internal static partial void TransportCleanupReadTaskFailed(this ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport read task cleaned up for {endpointName}")]
internal static partial void TransportReadTaskCleanedUp(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "Transport cleaned up for {endpointName}")]
internal static partial void TransportCleanedUp(this ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Debug, Message = "Sending message to {endpointName}: {message}")]
internal static partial void SendingMessage(this ILogger logger, string endpointName, string message);
[LoggerMessage(
EventId = 7000,
Level = LogLevel.Error,
Message = "Transport connection error for {endpointName}"
)]
public static partial void TransportConnectionError(
this ILogger logger,
string endpointName,
Exception exception);
[LoggerMessage(
EventId = 7001,
Level = LogLevel.Warning,
Message = "Transport message received before connected for {endpointName}: {data}"
)]
public static partial void TransportMessageReceivedBeforeConnected(
this ILogger logger,
string endpointName,
string data);
[LoggerMessage(
EventId = 7002,
Level = LogLevel.Error,
Message = "Transport endpoint event received out of order for {endpointName}: {data}"
)]
public static partial void TransportEndpointEventInvalid(
this ILogger logger,
string endpointName,
string data);
[LoggerMessage(
EventId = 7003,
Level = LogLevel.Error,
Message = "Transport event parse failed for {endpointName}: {data}"
)]
public static partial void TransportEndpointEventParseFailed(
this ILogger logger,
string endpointName,
string data,
Exception exception);
[LoggerMessage(
EventId = 7008,
Level = LogLevel.Error,
Message = "Message handler error for {endpointName} with message type {messageType}, payload {payload}"
)]
public static partial void MessageHandlerError(
this ILogger logger,
string endpointName,
string messageType,
string payload,
Exception exception);
[LoggerMessage(
EventId = 7009,
Level = LogLevel.Trace,
Message = "Writing message to channel: {message}"
)]
public static partial void TransportWritingMessageToChannel(
this ILogger logger,
IJsonRpcMessage message);
[LoggerMessage(
EventId = 7010,
Level = LogLevel.Trace,
Message = "Message written to channel"
)]
public static partial void TransportMessageWrittenToChannel(this ILogger logger);
[LoggerMessage(
EventId = 7011,
Level = LogLevel.Trace,
Message = "Message read from channel for {endpointName} with type {messageType}"
)]
public static partial void TransportMessageRead(
this ILogger logger,
string endpointName,
string messageType);
[LoggerMessage(
EventId = 7012,
Level = LogLevel.Warning,
Message = "No handler found for request {method} for server {endpointName}"
)]
public static partial void NoHandlerFoundForRequest(
this ILogger logger,
string endpointName,
string method);
[LoggerMessage(
EventId = 7013,
Level = LogLevel.Trace,
Message = "Response matched pending request for {endpointName} with ID {messageId}"
)]
public static partial void ResponseMatchedPendingRequest(
this ILogger logger,
string endpointName,
string messageId);
[LoggerMessage(
EventId = 7014,
Level = LogLevel.Warning,
Message = "Endpoint handler received unexpected message type for {endpointName}: {messageType}"
)]
public static partial void EndpointHandlerUnexpectedMessageType(
this ILogger logger,
string endpointName,
string messageType);
[LoggerMessage(
EventId = 7015,
Level = LogLevel.Debug,
Message = "Request sent for {endpointName} with method {method}, ID {id}. Waiting for response."
)]
public static partial void RequestSentAwaitingResponse(
this ILogger logger,
string endpointName,
string method,
string id);
[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);
/// <summary>
/// Logs the byte representation of a message in UTF-8 encoding.
/// </summary>
/// <param name="logger">The logger to use.</param>
/// <param name="endpointName">The name of the endpoint.</param>
/// <param name="byteRepresentation">The byte representation as a hex string.</param>
[LoggerMessage(EventId = 39000, Level = LogLevel.Trace, Message = "Transport {EndpointName}: Message bytes (UTF-8): {ByteRepresentation}")]
private static partial void TransportMessageBytes(this ILogger logger, string endpointName, string byteRepresentation);
/// <summary>
/// Logs the byte representation of a message for diagnostic purposes.
/// This is useful for diagnosing encoding issues with non-ASCII characters.
/// </summary>
/// <param name="logger">The logger to use.</param>
/// <param name="endpointName">The name of the endpoint.</param>
/// <param name="message">The message to log bytes for.</param>
internal static void TransportMessageBytesUtf8(this ILogger logger, string endpointName, string message)
{
if (logger.IsEnabled(LogLevel.Trace))
{
var bytes = System.Text.Encoding.UTF8.GetBytes(message);
var byteRepresentation =
#if NET
Convert.ToHexString(bytes);
#else
BitConverter.ToString(bytes).Replace("-", " ");
#endif
logger.TransportMessageBytes(endpointName, byteRepresentation);
}
}
}

104
src/ModelContextProtocol/Protocol/Transport/SseClientSessionTransport.cs
View file

@ -1,9 +1,9 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
using ModelContextProtocol.Utils.Json; using ModelContextProtocol.Utils.Json;
using System.Diagnostics;
using System.Net.Http.Headers; using System.Net.Http.Headers;
using System.Net.ServerSentEvents; using System.Net.ServerSentEvents;
using System.Text; using System.Text;
@ -14,9 +14,8 @@ namespace ModelContextProtocol.Protocol.Transport;
/// <summary> /// <summary>
/// The ServerSideEvents client transport implementation /// The ServerSideEvents client transport implementation
/// </summary> /// </summary>
internal sealed class SseClientSessionTransport : TransportBase internal sealed partial class SseClientSessionTransport : TransportBase
{ {
private readonly string _endpointName;
private readonly HttpClient _httpClient; private readonly HttpClient _httpClient;
private readonly SseClientTransportOptions _options; private readonly SseClientTransportOptions _options;
private readonly Uri _sseEndpoint; private readonly Uri _sseEndpoint;
@ -35,7 +34,7 @@ internal sealed class SseClientSessionTransport : TransportBase
/// <param name="loggerFactory">Logger factory for creating loggers.</param> /// <param name="loggerFactory">Logger factory for creating loggers.</param>
/// <param name="endpointName">The endpoint name used for logging purposes.</param> /// <param name="endpointName">The endpoint name used for logging purposes.</param>
public SseClientSessionTransport(SseClientTransportOptions transportOptions, HttpClient httpClient, ILoggerFactory? loggerFactory, string endpointName) public SseClientSessionTransport(SseClientTransportOptions transportOptions, HttpClient httpClient, ILoggerFactory? loggerFactory, string endpointName)
: base(loggerFactory) : base(endpointName, loggerFactory)
{ {
Throw.IfNull(transportOptions); Throw.IfNull(transportOptions);
Throw.IfNull(httpClient); Throw.IfNull(httpClient);
@ -45,36 +44,23 @@ internal sealed class SseClientSessionTransport : TransportBase
_httpClient = httpClient; _httpClient = httpClient;
_connectionCts = new CancellationTokenSource(); _connectionCts = new CancellationTokenSource();
_logger = (ILogger?)loggerFactory?.CreateLogger<SseClientTransport>() ?? NullLogger.Instance; _logger = (ILogger?)loggerFactory?.CreateLogger<SseClientTransport>() ?? NullLogger.Instance;
_connectionEstablished = new TaskCompletionSource<bool>(); _connectionEstablished = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
_endpointName = endpointName;
} }
/// <inheritdoc/> /// <inheritdoc/>
public async Task ConnectAsync(CancellationToken cancellationToken = default) public async Task ConnectAsync(CancellationToken cancellationToken = default)
{ {
Debug.Assert(!IsConnected);
try try
{ {
if (IsConnected)
{
_logger.TransportAlreadyConnected(_endpointName);
throw new McpTransportException("Transport is already connected");
}
// Start message receiving loop // Start message receiving loop
_receiveTask = ReceiveMessagesAsync(_connectionCts.Token); _receiveTask = ReceiveMessagesAsync(_connectionCts.Token);
_logger.TransportReadingMessages(_endpointName);
await _connectionEstablished.Task.WaitAsync(_options.ConnectionTimeout, cancellationToken).ConfigureAwait(false); await _connectionEstablished.Task.WaitAsync(_options.ConnectionTimeout, cancellationToken).ConfigureAwait(false);
} }
catch (McpTransportException) catch (Exception ex) when (ex is not McpTransportException) // propagate transport exceptions
{ {
// Rethrow transport exceptions LogTransportConnectFailed(Name, ex);
throw;
}
catch (Exception ex)
{
_logger.TransportConnectFailed(_endpointName, ex);
await CloseAsync().ConfigureAwait(false); await CloseAsync().ConfigureAwait(false);
throw new McpTransportException("Failed to connect transport", ex); throw new McpTransportException("Failed to connect transport", ex);
} }
@ -118,7 +104,7 @@ internal sealed class SseClientSessionTransport : TransportBase
// If the response is not a JSON-RPC response, it is an SSE message // If the response is not a JSON-RPC response, it is an SSE message
if (string.IsNullOrEmpty(responseContent) || responseContent.Equals("accepted", StringComparison.OrdinalIgnoreCase)) if (string.IsNullOrEmpty(responseContent) || responseContent.Equals("accepted", StringComparison.OrdinalIgnoreCase))
{ {
_logger.SSETransportPostAccepted(_endpointName, messageId); LogAcceptedPost(Name, messageId);
// The response will arrive as an SSE message // The response will arrive as an SSE message
} }
else else
@ -126,21 +112,30 @@ internal sealed class SseClientSessionTransport : TransportBase
JsonRpcResponse initializeResponse = JsonSerializer.Deserialize(responseContent, McpJsonUtilities.JsonContext.Default.JsonRpcResponse) ?? JsonRpcResponse initializeResponse = JsonSerializer.Deserialize(responseContent, McpJsonUtilities.JsonContext.Default.JsonRpcResponse) ??
throw new McpTransportException("Failed to initialize client"); throw new McpTransportException("Failed to initialize client");
_logger.TransportReceivedMessageParsed(_endpointName, messageId); LogTransportReceivedMessage(Name, messageId);
await WriteMessageAsync(initializeResponse, cancellationToken).ConfigureAwait(false); await WriteMessageAsync(initializeResponse, cancellationToken).ConfigureAwait(false);
_logger.TransportMessageWritten(_endpointName, messageId); LogTransportMessageWritten(Name, messageId);
} }
return; return;
} }
// Otherwise, check if the response was accepted (the response will come as an SSE message) // Otherwise, check if the response was accepted (the response will come as an SSE message)
if (string.IsNullOrEmpty(responseContent) || responseContent.Equals("accepted", StringComparison.OrdinalIgnoreCase)) if (string.IsNullOrEmpty(responseContent) || responseContent.Equals("accepted", StringComparison.OrdinalIgnoreCase))
{ {
_logger.SSETransportPostAccepted(_endpointName, messageId); LogAcceptedPost(Name, messageId);
} }
else else
{ {
_logger.SSETransportPostNotAccepted(_endpointName, messageId, responseContent); if (_logger.IsEnabled(LogLevel.Trace))
{
LogRejectedPostSensitive(Name, messageId, responseContent);
}
else
{
LogRejectedPost(Name, messageId);
}
throw new McpTransportException("Failed to send message"); throw new McpTransportException("Failed to send message");
} }
} }
@ -151,12 +146,17 @@ internal sealed class SseClientSessionTransport : TransportBase
{ {
await _connectionCts.CancelAsync().ConfigureAwait(false); await _connectionCts.CancelAsync().ConfigureAwait(false);
if (_receiveTask != null) try
{ {
await _receiveTask.ConfigureAwait(false); if (_receiveTask != null)
{
await _receiveTask.ConfigureAwait(false);
}
}
finally
{
_connectionCts.Dispose();
} }
_connectionCts.Dispose();
} }
finally finally
{ {
@ -216,13 +216,13 @@ internal sealed class SseClientSessionTransport : TransportBase
catch when (cancellationToken.IsCancellationRequested) catch when (cancellationToken.IsCancellationRequested)
{ {
// Normal shutdown // Normal shutdown
LogTransportReadMessagesCancelled(Name);
_connectionEstablished.TrySetCanceled(cancellationToken); _connectionEstablished.TrySetCanceled(cancellationToken);
_logger.TransportReadMessagesCancelled(_endpointName);
} }
catch (Exception ex) when (!cancellationToken.IsCancellationRequested) catch (Exception ex)
{ {
LogTransportReadMessagesFailed(Name, ex);
_connectionEstablished.TrySetException(ex); _connectionEstablished.TrySetException(ex);
_logger.TransportConnectionError(_endpointName, ex);
throw; throw;
} }
finally finally
@ -235,7 +235,7 @@ internal sealed class SseClientSessionTransport : TransportBase
{ {
if (!IsConnected) if (!IsConnected)
{ {
_logger.TransportMessageReceivedBeforeConnected(_endpointName, data); LogTransportMessageReceivedBeforeConnected(Name);
return; return;
} }
@ -244,7 +244,7 @@ internal sealed class SseClientSessionTransport : TransportBase
var message = JsonSerializer.Deserialize(data, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage); var message = JsonSerializer.Deserialize(data, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage);
if (message == null) if (message == null)
{ {
_logger.TransportMessageParseUnexpectedType(_endpointName, data); LogTransportMessageParseUnexpectedTypeSensitive(Name, data);
return; return;
} }
@ -254,13 +254,20 @@ internal sealed class SseClientSessionTransport : TransportBase
messageId = messageWithId.Id.ToString(); messageId = messageWithId.Id.ToString();
} }
_logger.TransportReceivedMessageParsed(_endpointName, messageId); LogTransportReceivedMessage(Name, messageId);
await WriteMessageAsync(message, cancellationToken).ConfigureAwait(false); await WriteMessageAsync(message, cancellationToken).ConfigureAwait(false);
_logger.TransportMessageWritten(_endpointName, messageId); LogTransportMessageWritten(Name, messageId);
} }
catch (JsonException ex) catch (JsonException ex)
{ {
_logger.TransportMessageParseFailed(_endpointName, data, ex); if (_logger.IsEnabled(LogLevel.Trace))
{
LogTransportMessageParseFailedSensitive(Name, data, ex);
}
else
{
LogTransportMessageParseFailed(Name, ex);
}
} }
} }
@ -270,7 +277,7 @@ internal sealed class SseClientSessionTransport : TransportBase
{ {
if (string.IsNullOrEmpty(data)) if (string.IsNullOrEmpty(data))
{ {
_logger.TransportEndpointEventInvalid(_endpointName, data); LogTransportEndpointEventInvalid(Name);
return; return;
} }
@ -283,7 +290,15 @@ internal sealed class SseClientSessionTransport : TransportBase
} }
catch (JsonException ex) catch (JsonException ex)
{ {
_logger.TransportEndpointEventParseFailed(_endpointName, data, ex); if (_logger.IsEnabled(LogLevel.Trace))
{
LogTransportEndpointEventParseFailedSensitive(Name, data, ex);
}
else
{
LogTransportEndpointEventParseFailed(Name, ex);
}
throw new McpTransportException("Failed to parse endpoint event", ex); throw new McpTransportException("Failed to parse endpoint event", ex);
} }
} }
@ -301,4 +316,13 @@ internal sealed class SseClientSessionTransport : TransportBase
} }
} }
} }
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} accepted SSE transport POST for message ID '{MessageId}'.")]
private partial void LogAcceptedPost(string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} rejected SSE transport POST for message ID '{MessageId}'.")]
private partial void LogRejectedPost(string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} rejected SSE transport POST for message ID '{MessageId}'. Server response: '{responseContent}'.")]
private partial void LogRejectedPostSensitive(string endpointName, string messageId, string responseContent);
} }

12
src/ModelContextProtocol/Protocol/Transport/StdioClientSessionTransport.cs
View file

@ -1,6 +1,6 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using System;
using System.Diagnostics; using System.Diagnostics;
namespace ModelContextProtocol.Protocol.Transport; namespace ModelContextProtocol.Protocol.Transport;
@ -49,7 +49,6 @@ internal sealed class StdioClientSessionTransport : StreamClientSessionTransport
if (hasExited) if (hasExited)
{ {
Logger.TransportNotConnected(EndpointName);
throw new McpTransportException("Transport is not connected", processException); throw new McpTransportException("Transport is not connected", processException);
} }
@ -59,7 +58,14 @@ internal sealed class StdioClientSessionTransport : StreamClientSessionTransport
/// <inheritdoc/> /// <inheritdoc/>
protected override ValueTask CleanupAsync(CancellationToken cancellationToken) protected override ValueTask CleanupAsync(CancellationToken cancellationToken)
{ {
StdioClientTransport.DisposeProcess(_process, processRunning: true, Logger, _options.ShutdownTimeout, EndpointName); try
{
StdioClientTransport.DisposeProcess(_process, processRunning: true, _options.ShutdownTimeout, Name);
}
catch (Exception ex)
{
LogTransportShutdownFailed(Name, ex);
}
return base.CleanupAsync(cancellationToken); return base.CleanupAsync(cancellationToken);
} }

69
src/ModelContextProtocol/Protocol/Transport/StdioClientTransport.cs
View file

@ -1,6 +1,5 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
using System.Diagnostics; using System.Diagnostics;
using System.Runtime.InteropServices; using System.Runtime.InteropServices;
@ -24,7 +23,7 @@ namespace ModelContextProtocol.Protocol.Transport;
/// and environment variables, handling output, and properly terminating the process when the transport is closed. /// and environment variables, handling output, and properly terminating the process when the transport is closed.
/// </para> /// </para>
/// </remarks> /// </remarks>
public sealed class StdioClientTransport : IClientTransport public sealed partial class StdioClientTransport : IClientTransport
{ {
private readonly StdioClientTransportOptions _options; private readonly StdioClientTransportOptions _options;
private readonly ILoggerFactory? _loggerFactory; private readonly ILoggerFactory? _loggerFactory;
@ -68,7 +67,7 @@ public sealed class StdioClientTransport : IClientTransport
ILogger logger = (ILogger?)_loggerFactory?.CreateLogger<StdioClientTransport>() ?? NullLogger.Instance; ILogger logger = (ILogger?)_loggerFactory?.CreateLogger<StdioClientTransport>() ?? NullLogger.Instance;
try try
{ {
logger.TransportConnecting(endpointName); LogTransportConnecting(logger, endpointName);
UTF8Encoding noBomUTF8 = new(encoderShouldEmitUTF8Identifier: false); UTF8Encoding noBomUTF8 = new(encoderShouldEmitUTF8Identifier: false);
@ -114,14 +113,22 @@ public sealed class StdioClientTransport : IClientTransport
} }
} }
logger.CreateProcessForTransport(endpointName, _options.Command, if (logger.IsEnabled(LogLevel.Trace))
startInfo.Arguments, string.Join(", ", startInfo.Environment.Select(kvp => kvp.Key + "=" + kvp.Value)), {
startInfo.WorkingDirectory, _options.ShutdownTimeout.ToString()); LogCreateProcessForTransportSensitive(logger, endpointName, _options.Command,
startInfo.Arguments,
string.Join(", ", startInfo.Environment.Select(kvp => $"{kvp.Key}={kvp.Value}")),
startInfo.WorkingDirectory);
}
else
{
LogCreateProcessForTransport(logger, endpointName, _options.Command);
}
process = new() { StartInfo = startInfo }; process = new() { StartInfo = startInfo };
// Set up error logging // Set up error logging
process.ErrorDataReceived += (sender, args) => logger.ReadStderr(endpointName, args.Data ?? "(no data)"); process.ErrorDataReceived += (sender, args) => LogReadStderr(logger, endpointName, args.Data ?? "(no data)");
// We need both stdin and stdout to use a no-BOM UTF-8 encoding. On .NET Core, // We need both stdin and stdout to use a no-BOM UTF-8 encoding. On .NET Core,
// we can use ProcessStartInfo.StandardOutputEncoding/StandardInputEncoding, but // we can use ProcessStartInfo.StandardOutputEncoding/StandardInputEncoding, but
@ -146,11 +153,11 @@ public sealed class StdioClientTransport : IClientTransport
if (!processStarted) if (!processStarted)
{ {
logger.TransportProcessStartFailed(endpointName); LogTransportProcessStartFailed(logger, endpointName);
throw new McpTransportException("Failed to start MCP server process"); throw new McpTransportException("Failed to start MCP server process");
} }
logger.TransportProcessStarted(endpointName, process.Id); LogTransportProcessStarted(logger, endpointName, process.Id);
process.BeginErrorReadLine(); process.BeginErrorReadLine();
@ -158,14 +165,23 @@ public sealed class StdioClientTransport : IClientTransport
} }
catch (Exception ex) catch (Exception ex)
{ {
logger.TransportConnectFailed(endpointName, ex); LogTransportConnectFailed(logger, endpointName, ex);
DisposeProcess(process, processStarted, logger, _options.ShutdownTimeout, endpointName);
try
{
DisposeProcess(process, processStarted, _options.ShutdownTimeout, endpointName);
}
catch (Exception ex2)
{
LogTransportShutdownFailed(logger, endpointName, ex2);
}
throw new McpTransportException("Failed to connect transport", ex); throw new McpTransportException("Failed to connect transport", ex);
} }
} }
internal static void DisposeProcess( internal static void DisposeProcess(
Process? process, bool processRunning, ILogger logger, TimeSpan shutdownTimeout, string endpointName) Process? process, bool processRunning, TimeSpan shutdownTimeout, string endpointName)
{ {
if (process is not null) if (process is not null)
{ {
@ -188,18 +204,37 @@ public sealed class StdioClientTransport : IClientTransport
// Wait for the process to exit. // Wait for the process to exit.
// Kill the while process tree because the process may spawn child processes // Kill the while process tree because the process may spawn child processes
// and Node.js does not kill its children when it exits properly. // and Node.js does not kill its children when it exits properly.
logger.TransportWaitingForShutdown(endpointName);
process.KillTree(shutdownTimeout); process.KillTree(shutdownTimeout);
} }
} }
catch (Exception ex)
{
logger.TransportShutdownFailed(endpointName, ex);
}
finally finally
{ {
process.Dispose(); process.Dispose();
} }
} }
} }
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} connecting.")]
private static partial void LogTransportConnecting(ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} starting server process. Command: '{Command}'.")]
private static partial void LogCreateProcessForTransport(ILogger logger, string endpointName, string command);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} starting server process. Command: '{Command}', Arguments: {Arguments}, Environment: {Environment}, Working directory: {WorkingDirectory}.")]
private static partial void LogCreateProcessForTransportSensitive(ILogger logger, string endpointName, string command, string? arguments, string environment, string workingDirectory);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} failed to start server process.")]
private static partial void LogTransportProcessStartFailed(ILogger logger, string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} received stderr log: '{Data}'.")]
private static partial void LogReadStderr(ILogger logger, string endpointName, string data);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} started server process with PID {ProcessId}.")]
private static partial void LogTransportProcessStarted(ILogger logger, string endpointName, int processId);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} connect failed.")]
private static partial void LogTransportConnectFailed(ILogger logger, string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} shutdown failed.")]
private static partial void LogTransportShutdownFailed(ILogger logger, string endpointName, Exception exception);
} }

75
src/ModelContextProtocol/Protocol/Transport/StreamClientSessionTransport.cs
View file

@ -1,6 +1,4 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
using ModelContextProtocol.Utils.Json; using ModelContextProtocol.Utils.Json;
@ -40,17 +38,14 @@ internal class StreamClientSessionTransport : TransportBase
/// </remarks> /// </remarks>
public StreamClientSessionTransport( public StreamClientSessionTransport(
TextWriter serverInput, TextReader serverOutput, string endpointName, ILoggerFactory? loggerFactory) TextWriter serverInput, TextReader serverOutput, string endpointName, ILoggerFactory? loggerFactory)
: base(loggerFactory) : base(endpointName, loggerFactory)
{ {
Logger = (ILogger?)loggerFactory?.CreateLogger<StdioClientTransport>() ?? NullLogger.Instance;
_serverOutput = serverOutput; _serverOutput = serverOutput;
_serverInput = serverInput; _serverInput = serverInput;
EndpointName = endpointName;
// Start reading messages in the background. We use the rarer pattern of new Task + Start // Start reading messages in the background. We use the rarer pattern of new Task + Start
// in order to ensure that the body of the task will always see _readTask initialized. // in order to ensure that the body of the task will always see _readTask initialized.
// It is then able to reliably null it out on completion. // It is then able to reliably null it out on completion.
Logger.TransportReadingMessages(endpointName);
var readTask = new Task<Task>( var readTask = new Task<Task>(
thisRef => ((StreamClientSessionTransport)thisRef!).ReadMessagesAsync(_shutdownCts.Token), thisRef => ((StreamClientSessionTransport)thisRef!).ReadMessagesAsync(_shutdownCts.Token),
this, this,
@ -61,25 +56,6 @@ internal class StreamClientSessionTransport : TransportBase
SetConnected(true); SetConnected(true);
} }
/// <summary>
/// Gets the logger instance used by this transport for diagnostic output.
/// If no logger factory was provided in the constructor, this will be a NullLogger.
/// </summary>
/// <remarks>
/// Derived classes can use this logger to emit additional diagnostic information
/// specific to their implementation.
/// </remarks>
protected ILogger Logger { get; private set; }
/// <summary>
/// Gets the name that identifies this transport endpoint in logs.
/// </summary>
/// <remarks>
/// This name is provided during construction and is used in log messages to identify
/// the source of transport-related events.
/// </remarks>
protected string EndpointName { get; }
/// <inheritdoc/> /// <inheritdoc/>
/// <remarks> /// <remarks>
/// <para> /// <para>
@ -102,7 +78,6 @@ internal class StreamClientSessionTransport : TransportBase
{ {
if (!IsConnected) if (!IsConnected)
{ {
Logger.TransportNotConnected(EndpointName);
throw new McpTransportException("Transport is not connected"); throw new McpTransportException("Transport is not connected");
} }
@ -117,18 +92,13 @@ internal class StreamClientSessionTransport : TransportBase
using var _ = await _sendLock.LockAsync(cancellationToken).ConfigureAwait(false); using var _ = await _sendLock.LockAsync(cancellationToken).ConfigureAwait(false);
try try
{ {
Logger.TransportSendingMessage(EndpointName, id, json);
Logger.TransportMessageBytesUtf8(EndpointName, json);
// Write the message followed by a newline using our UTF-8 writer // Write the message followed by a newline using our UTF-8 writer
await _serverInput.WriteLineAsync(json).ConfigureAwait(false); await _serverInput.WriteLineAsync(json).ConfigureAwait(false);
await _serverInput.FlushAsync(cancellationToken).ConfigureAwait(false); await _serverInput.FlushAsync(cancellationToken).ConfigureAwait(false);
Logger.TransportSentMessage(EndpointName, id);
} }
catch (Exception ex) catch (Exception ex)
{ {
Logger.TransportSendFailed(EndpointName, id, ex); LogTransportSendFailed(Name, id, ex);
throw new McpTransportException("Failed to send message", ex); throw new McpTransportException("Failed to send message", ex);
} }
} }
@ -151,14 +121,13 @@ internal class StreamClientSessionTransport : TransportBase
{ {
try try
{ {
Logger.TransportEnteringReadMessagesLoop(EndpointName); LogTransportEnteringReadMessagesLoop(Name);
while (!cancellationToken.IsCancellationRequested) while (!cancellationToken.IsCancellationRequested)
{ {
Logger.TransportWaitingForMessage(EndpointName);
if (await _serverOutput.ReadLineAsync(cancellationToken).ConfigureAwait(false) is not string line) if (await _serverOutput.ReadLineAsync(cancellationToken).ConfigureAwait(false) is not string line)
{ {
Logger.TransportEndOfStream(EndpointName); LogTransportEndOfStream(Name);
break; break;
} }
@ -167,20 +136,18 @@ internal class StreamClientSessionTransport : TransportBase
continue; continue;
} }
Logger.TransportReceivedMessage(EndpointName, line); LogTransportReceivedMessageSensitive(Name, line);
Logger.TransportMessageBytesUtf8(EndpointName, line);
await ProcessMessageAsync(line, cancellationToken).ConfigureAwait(false); await ProcessMessageAsync(line, cancellationToken).ConfigureAwait(false);
} }
Logger.TransportExitingReadMessagesLoop(EndpointName);
} }
catch (OperationCanceledException) catch (OperationCanceledException)
{ {
Logger.TransportReadMessagesCancelled(EndpointName); LogTransportReadMessagesCancelled(Name);
} }
catch (Exception ex) catch (Exception ex)
{ {
Logger.TransportReadMessagesFailed(EndpointName, ex); LogTransportReadMessagesFailed(Name, ex);
} }
finally finally
{ {
@ -202,24 +169,31 @@ internal class StreamClientSessionTransport : TransportBase
messageId = messageWithId.Id.ToString(); messageId = messageWithId.Id.ToString();
} }
Logger.TransportReceivedMessageParsed(EndpointName, messageId); LogTransportReceivedMessage(Name, messageId);
await WriteMessageAsync(message, cancellationToken).ConfigureAwait(false); await WriteMessageAsync(message, cancellationToken).ConfigureAwait(false);
Logger.TransportMessageWritten(EndpointName, messageId); LogTransportMessageWritten(Name, messageId);
} }
else else
{ {
Logger.TransportMessageParseUnexpectedType(EndpointName, line); LogTransportMessageParseUnexpectedTypeSensitive(Name, line);
} }
} }
catch (JsonException ex) catch (JsonException ex)
{ {
Logger.TransportMessageParseFailed(EndpointName, line, ex); if (Logger.IsEnabled(LogLevel.Trace))
{
LogTransportMessageParseFailedSensitive(Name, line, ex);
}
else
{
LogTransportMessageParseFailed(Name, ex);
}
} }
} }
protected virtual async ValueTask CleanupAsync(CancellationToken cancellationToken) protected virtual async ValueTask CleanupAsync(CancellationToken cancellationToken)
{ {
Logger.TransportCleaningUp(EndpointName); LogTransportShuttingDown(Name);
if (Interlocked.Exchange(ref _shutdownCts, null) is { } shutdownCts) if (Interlocked.Exchange(ref _shutdownCts, null) is { } shutdownCts)
{ {
@ -231,25 +205,18 @@ internal class StreamClientSessionTransport : TransportBase
{ {
try try
{ {
Logger.TransportWaitingForReadTask(EndpointName);
await readTask.WaitAsync(TimeSpan.FromSeconds(5), cancellationToken).ConfigureAwait(false); await readTask.WaitAsync(TimeSpan.FromSeconds(5), cancellationToken).ConfigureAwait(false);
Logger.TransportReadTaskCleanedUp(EndpointName);
}
catch (TimeoutException)
{
Logger.TransportCleanupReadTaskTimeout(EndpointName);
} }
catch (OperationCanceledException) catch (OperationCanceledException)
{ {
Logger.TransportCleanupReadTaskCancelled(EndpointName);
} }
catch (Exception ex) catch (Exception ex)
{ {
Logger.TransportCleanupReadTaskFailed(EndpointName, ex); LogTransportCleanupReadTaskFailed(Name, ex);
} }
} }
SetConnected(false); SetConnected(false);
Logger.TransportCleanedUp(EndpointName); LogTransportShutDown(Name);
} }
} }

57
src/ModelContextProtocol/Protocol/Transport/StreamServerTransport.cs
View file

@ -1,6 +1,5 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
using ModelContextProtocol.Utils.Json; using ModelContextProtocol.Utils.Json;
@ -25,7 +24,6 @@ public class StreamServerTransport : TransportBase
private readonly TextReader _inputReader; private readonly TextReader _inputReader;
private readonly Stream _outputStream; private readonly Stream _outputStream;
private readonly string _endpointName;
private readonly SemaphoreSlim _sendLock = new(1, 1); private readonly SemaphoreSlim _sendLock = new(1, 1);
private readonly CancellationTokenSource _shutdownCts = new(); private readonly CancellationTokenSource _shutdownCts = new();
@ -43,7 +41,7 @@ public class StreamServerTransport : TransportBase
/// <exception cref="ArgumentNullException"><paramref name="inputStream"/> is <see langword="null"/>.</exception> /// <exception cref="ArgumentNullException"><paramref name="inputStream"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentNullException"><paramref name="outputStream"/> is <see langword="null"/>.</exception> /// <exception cref="ArgumentNullException"><paramref name="outputStream"/> is <see langword="null"/>.</exception>
public StreamServerTransport(Stream inputStream, Stream outputStream, string? serverName = null, ILoggerFactory? loggerFactory = null) public StreamServerTransport(Stream inputStream, Stream outputStream, string? serverName = null, ILoggerFactory? loggerFactory = null)
: base(loggerFactory) : base(serverName is not null ? $"Server (stream) ({serverName})" : "Server (stream)", loggerFactory)
{ {
Throw.IfNull(inputStream); Throw.IfNull(inputStream);
Throw.IfNull(outputStream); Throw.IfNull(outputStream);
@ -55,8 +53,6 @@ public class StreamServerTransport : TransportBase
SetConnected(true); SetConnected(true);
_readLoopCompleted = Task.Run(ReadMessagesAsync, _shutdownCts.Token); _readLoopCompleted = Task.Run(ReadMessagesAsync, _shutdownCts.Token);
_endpointName = serverName is not null ? $"Server (stream) ({serverName})" : "Server (stream)";
} }
/// <inheritdoc/> /// <inheritdoc/>
@ -64,7 +60,6 @@ public class StreamServerTransport : TransportBase
{ {
if (!IsConnected) if (!IsConnected)
{ {
_logger.TransportNotConnected(_endpointName);
throw new McpTransportException("Transport is not connected"); throw new McpTransportException("Transport is not connected");
} }
@ -78,17 +73,13 @@ public class StreamServerTransport : TransportBase
try try
{ {
_logger.TransportSendingMessage(_endpointName, id);
await JsonSerializer.SerializeAsync(_outputStream, message, McpJsonUtilities.DefaultOptions.GetTypeInfo(typeof(IJsonRpcMessage)), cancellationToken).ConfigureAwait(false); await JsonSerializer.SerializeAsync(_outputStream, message, McpJsonUtilities.DefaultOptions.GetTypeInfo(typeof(IJsonRpcMessage)), cancellationToken).ConfigureAwait(false);
await _outputStream.WriteAsync(s_newlineBytes, cancellationToken).ConfigureAwait(false); await _outputStream.WriteAsync(s_newlineBytes, cancellationToken).ConfigureAwait(false);
await _outputStream.FlushAsync(cancellationToken).ConfigureAwait(false); await _outputStream.FlushAsync(cancellationToken).ConfigureAwait(false);
_logger.TransportSentMessage(_endpointName, id);
} }
catch (Exception ex) catch (Exception ex)
{ {
_logger.TransportSendFailed(_endpointName, id, ex); LogTransportSendFailed(Name, id, ex);
throw new McpTransportException("Failed to send message", ex); throw new McpTransportException("Failed to send message", ex);
} }
} }
@ -98,26 +89,23 @@ public class StreamServerTransport : TransportBase
CancellationToken shutdownToken = _shutdownCts.Token; CancellationToken shutdownToken = _shutdownCts.Token;
try try
{ {
_logger.TransportEnteringReadMessagesLoop(_endpointName); LogTransportEnteringReadMessagesLoop(Name);
while (!shutdownToken.IsCancellationRequested) while (!shutdownToken.IsCancellationRequested)
{ {
_logger.TransportWaitingForMessage(_endpointName);
var line = await _inputReader.ReadLineAsync(shutdownToken).ConfigureAwait(false); var line = await _inputReader.ReadLineAsync(shutdownToken).ConfigureAwait(false);
if (string.IsNullOrWhiteSpace(line)) if (string.IsNullOrWhiteSpace(line))
{ {
if (line is null) if (line is null)
{ {
_logger.TransportEndOfStream(_endpointName); LogTransportEndOfStream(Name);
break; break;
} }
continue; continue;
} }
_logger.TransportReceivedMessage(_endpointName, line); LogTransportReceivedMessageSensitive(Name, line);
_logger.TransportMessageBytesUtf8(_endpointName, line);
try try
{ {
@ -128,32 +116,38 @@ public class StreamServerTransport : TransportBase
{ {
messageId = messageWithId.Id.ToString(); messageId = messageWithId.Id.ToString();
} }
_logger.TransportReceivedMessageParsed(_endpointName, messageId);
LogTransportReceivedMessage(Name, messageId);
await WriteMessageAsync(message, shutdownToken).ConfigureAwait(false); await WriteMessageAsync(message, shutdownToken).ConfigureAwait(false);
_logger.TransportMessageWritten(_endpointName, messageId); LogTransportMessageWritten(Name, messageId);
} }
else else
{ {
_logger.TransportMessageParseUnexpectedType(_endpointName, line); LogTransportMessageParseUnexpectedTypeSensitive(Name, line);
} }
} }
catch (JsonException ex) catch (JsonException ex)
{ {
_logger.TransportMessageParseFailed(_endpointName, line, ex); if (Logger.IsEnabled(LogLevel.Trace))
{
LogTransportMessageParseFailedSensitive(Name, line, ex);
}
else
{
LogTransportMessageParseFailed(Name, ex);
}
// Continue reading even if we fail to parse a message // Continue reading even if we fail to parse a message
} }
} }
_logger.TransportExitingReadMessagesLoop(_endpointName);
} }
catch (OperationCanceledException) catch (OperationCanceledException)
{ {
_logger.TransportReadMessagesCancelled(_endpointName); LogTransportReadMessagesCancelled(Name);
} }
catch (Exception ex) catch (Exception ex)
{ {
_logger.TransportReadMessagesFailed(_endpointName, ex); LogTransportReadMessagesFailed(Name, ex);
} }
finally finally
{ {
@ -171,7 +165,7 @@ public class StreamServerTransport : TransportBase
try try
{ {
_logger.TransportCleaningUp(_endpointName); LogTransportShuttingDown(Name);
// Signal to the stdin reading loop to stop. // Signal to the stdin reading loop to stop.
await _shutdownCts.CancelAsync().ConfigureAwait(false); await _shutdownCts.CancelAsync().ConfigureAwait(false);
@ -185,27 +179,20 @@ public class StreamServerTransport : TransportBase
// Make sure the work has quiesced. // Make sure the work has quiesced.
try try
{ {
_logger.TransportWaitingForReadTask(_endpointName);
await _readLoopCompleted.ConfigureAwait(false); await _readLoopCompleted.ConfigureAwait(false);
_logger.TransportReadTaskCleanedUp(_endpointName);
}
catch (TimeoutException)
{
_logger.TransportCleanupReadTaskTimeout(_endpointName);
} }
catch (OperationCanceledException) catch (OperationCanceledException)
{ {
_logger.TransportCleanupReadTaskCancelled(_endpointName);
} }
catch (Exception ex) catch (Exception ex)
{ {
_logger.TransportCleanupReadTaskFailed(_endpointName, ex); LogTransportCleanupReadTaskFailed(Name, ex);
} }
} }
finally finally
{ {
SetConnected(false); SetConnected(false);
_logger.TransportCleanedUp(_endpointName); LogTransportShutDown(Name);
} }
GC.SuppressFinalize(this); GC.SuppressFinalize(this);

82
src/ModelContextProtocol/Protocol/Transport/TransportBase.cs
View file

@ -1,6 +1,5 @@
using System.Threading.Channels; using System.Threading.Channels;
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
@ -20,7 +19,7 @@ namespace ModelContextProtocol.Protocol.Transport;
/// to handle the specific transport mechanism being used. /// to handle the specific transport mechanism being used.
/// </para> /// </para>
/// </remarks> /// </remarks>
public abstract class TransportBase : ITransport public abstract partial class TransportBase : ITransport
{ {
private readonly Channel<IJsonRpcMessage> _messageChannel; private readonly Channel<IJsonRpcMessage> _messageChannel;
private readonly ILogger _logger; private readonly ILogger _logger;
@ -29,17 +28,30 @@ public abstract class TransportBase : ITransport
/// <summary> /// <summary>
/// Initializes a new instance of the <see cref="TransportBase"/> class. /// Initializes a new instance of the <see cref="TransportBase"/> class.
/// </summary> /// </summary>
protected TransportBase(ILoggerFactory? loggerFactory) protected TransportBase(string name, ILoggerFactory? loggerFactory)
{ {
Name = name;
_logger = loggerFactory?.CreateLogger(GetType()) ?? NullLogger.Instance;
// Unbounded channel to prevent blocking on writes // Unbounded channel to prevent blocking on writes
_messageChannel = Channel.CreateUnbounded<IJsonRpcMessage>(new UnboundedChannelOptions _messageChannel = Channel.CreateUnbounded<IJsonRpcMessage>(new UnboundedChannelOptions
{ {
SingleReader = true, SingleReader = true,
SingleWriter = true, SingleWriter = true,
}); });
_logger = loggerFactory?.CreateLogger(GetType()) ?? NullLogger.Instance;
} }
/// <summary>Gets the logger used by this transport.</summary>
private protected ILogger Logger => _logger;
/// <summary>
/// Gets the name that identifies this transport endpoint in logs.
/// </summary>
/// <remarks>
/// This name is used in log messages to identify the source of transport-related events.
/// </remarks>
protected string Name { get; }
/// <inheritdoc/> /// <inheritdoc/>
public bool IsConnected => _isConnected == 1; public bool IsConnected => _isConnected == 1;
@ -64,9 +76,7 @@ public abstract class TransportBase : ITransport
throw new McpTransportException("Transport is not connected"); throw new McpTransportException("Transport is not connected");
} }
_logger.TransportWritingMessageToChannel(message);
await _messageChannel.Writer.WriteAsync(message, cancellationToken).ConfigureAwait(false); await _messageChannel.Writer.WriteAsync(message, cancellationToken).ConfigureAwait(false);
_logger.TransportMessageWrittenToChannel();
} }
/// <summary> /// <summary>
@ -86,4 +96,64 @@ public abstract class TransportBase : ITransport
_messageChannel.Writer.Complete(); _messageChannel.Writer.Complete();
} }
} }
[LoggerMessage(Level = LogLevel.Error, Message = "{EndpointName} transport connect failed.")]
private protected partial void LogTransportConnectFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Error, Message = "{EndpointName} transport send failed for message ID '{MessageId}'.")]
private protected partial void LogTransportSendFailed(string endpointName, string messageId, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} transport reading messages.")]
private protected partial void LogTransportEnteringReadMessagesLoop(string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} transport completed reading messages.")]
private protected partial void LogTransportEndOfStream(string endpointName);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} transport received message. Message: '{Message}'.")]
private protected partial void LogTransportReceivedMessageSensitive(string endpointName, string message);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} transport received message with ID '{MessageId}'.")]
private protected partial void LogTransportReceivedMessage(string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} transport sent message with ID '{MessageId}'.")]
private protected partial void LogTransportMessageWritten(string endpointName, string messageId);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} transport received unexpected message. Message: '{Message}'.")]
private protected partial void LogTransportMessageParseUnexpectedTypeSensitive(string endpointName, string message);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} transport message parsing failed.")]
private protected partial void LogTransportMessageParseFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} transport message parsing failed. Message: '{Message}'.")]
private protected partial void LogTransportMessageParseFailedSensitive(string endpointName, string message, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} transport message reading canceled.")]
private protected partial void LogTransportReadMessagesCancelled(string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} transport message reading failed.")]
private protected partial void LogTransportReadMessagesFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} shutting down.")]
private protected partial void LogTransportShuttingDown(string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} shutdown failed.")]
private protected partial void LogTransportShutdownFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} shutdown failed waiting for message reading completion.")]
private protected partial void LogTransportCleanupReadTaskFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} shut down.")]
private protected partial void LogTransportShutDown(string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} received message before connected.")]
private protected partial void LogTransportMessageReceivedBeforeConnected(string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} endpoint event received out of order.")]
private protected partial void LogTransportEndpointEventInvalid(string endpointName);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} failed to parse event.")]
private protected partial void LogTransportEndpointEventParseFailed(string endpointName, Exception exception);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} failed to parse event. Message: '{Message}'.")]
private protected partial void LogTransportEndpointEventParseFailedSensitive(string endpointName, string message, Exception exception);
} }

13
src/ModelContextProtocol/Shared/McpEndpoint.cs
View file

@ -1,6 +1,5 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Protocol.Transport; using ModelContextProtocol.Protocol.Transport;
using ModelContextProtocol.Server; using ModelContextProtocol.Server;
@ -17,7 +16,7 @@ namespace ModelContextProtocol.Shared;
/// This is especially true as a client represents a connection to one and only one server, and vice versa. /// This is especially true as a client represents a connection to one and only one server, and vice versa.
/// Any multi-client or multi-server functionality should be implemented at a higher level of abstraction. /// Any multi-client or multi-server functionality should be implemented at a higher level of abstraction.
/// </summary> /// </summary>
internal abstract class McpEndpoint : IAsyncDisposable internal abstract partial class McpEndpoint : IAsyncDisposable
{ {
/// <summary>Cached naming information used for name/version when none is specified.</summary> /// <summary>Cached naming information used for name/version when none is specified.</summary>
internal static AssemblyName DefaultAssemblyName { get; } = (Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly()).GetName(); internal static AssemblyName DefaultAssemblyName { get; } = (Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly()).GetName();
@ -95,7 +94,7 @@ internal abstract class McpEndpoint : IAsyncDisposable
/// <returns></returns> /// <returns></returns>
public virtual async ValueTask DisposeUnsynchronizedAsync() public virtual async ValueTask DisposeUnsynchronizedAsync()
{ {
_logger.CleaningUpEndpoint(EndpointName); LogEndpointShuttingDown(EndpointName);
try try
{ {
@ -122,9 +121,15 @@ internal abstract class McpEndpoint : IAsyncDisposable
_sessionCts?.Dispose(); _sessionCts?.Dispose();
} }
_logger.EndpointCleanedUp(EndpointName); LogEndpointShutDown(EndpointName);
} }
protected McpSession GetSessionOrThrow() protected McpSession GetSessionOrThrow()
=> _session ?? throw new InvalidOperationException($"This should be unreachable from public API! Call {nameof(InitializeSession)} before sending messages."); => _session ?? throw new InvalidOperationException($"This should be unreachable from public API! Call {nameof(InitializeSession)} before sending messages.");
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} shutting down.")]
private partial void LogEndpointShuttingDown(string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} shut down.")]
private partial void LogEndpointShutDown(string endpointName);
} }

140
src/ModelContextProtocol/Shared/McpSession.cs
View file

@ -1,6 +1,5 @@
using Microsoft.Extensions.Logging; using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions; using Microsoft.Extensions.Logging.Abstractions;
using ModelContextProtocol.Logging;
using ModelContextProtocol.Protocol.Messages; using ModelContextProtocol.Protocol.Messages;
using ModelContextProtocol.Protocol.Transport; using ModelContextProtocol.Protocol.Transport;
using ModelContextProtocol.Utils; using ModelContextProtocol.Utils;
@ -19,7 +18,7 @@ namespace ModelContextProtocol.Shared;
/// <summary> /// <summary>
/// Class for managing an MCP JSON-RPC session. This covers both MCP clients and servers. /// Class for managing an MCP JSON-RPC session. This covers both MCP clients and servers.
/// </summary> /// </summary>
internal sealed class McpSession : IDisposable internal sealed partial class McpSession : IDisposable
{ {
private static readonly Histogram<double> s_clientSessionDuration = Diagnostics.CreateDurationHistogram( private static readonly Histogram<double> s_clientSessionDuration = Diagnostics.CreateDurationHistogram(
"mcp.client.session.duration", "Measures the duration of a client session.", longBuckets: true); "mcp.client.session.duration", "Measures the duration of a client session.", longBuckets: true);
@ -101,7 +100,7 @@ internal sealed class McpSession : IDisposable
{ {
await foreach (var message in _transport.MessageReader.ReadAllAsync(cancellationToken).ConfigureAwait(false)) await foreach (var message in _transport.MessageReader.ReadAllAsync(cancellationToken).ConfigureAwait(false))
{ {
_logger.TransportMessageRead(EndpointName, message.GetType().Name); LogMessageRead(EndpointName, message.GetType().Name);
_ = ProcessMessageAsync(); _ = ProcessMessageAsync();
async Task ProcessMessageAsync() async Task ProcessMessageAsync()
@ -142,7 +141,7 @@ internal sealed class McpSession : IDisposable
if (!isUserCancellation && message is JsonRpcRequest request) if (!isUserCancellation && message is JsonRpcRequest request)
{ {
_logger.RequestHandlerError(EndpointName, request.Method, ex); LogRequestHandlerException(EndpointName, request.Method, ex);
await _transport.SendMessageAsync(new JsonRpcError await _transport.SendMessageAsync(new JsonRpcError
{ {
Id = request.Id, Id = request.Id,
@ -156,8 +155,14 @@ internal sealed class McpSession : IDisposable
} }
else if (ex is not OperationCanceledException) else if (ex is not OperationCanceledException)
{ {
var payload = JsonSerializer.Serialize(message, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage); if (_logger.IsEnabled(LogLevel.Trace))
_logger.MessageHandlerError(EndpointName, message.GetType().Name, payload, ex); {
LogMessageHandlerExceptionSensitive(EndpointName, message.GetType().Name, JsonSerializer.Serialize(message, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage), ex);
}
else
{
LogMessageHandlerException(EndpointName, message.GetType().Name, ex);
}
} }
} }
finally finally
@ -174,7 +179,7 @@ internal sealed class McpSession : IDisposable
catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested) catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
{ {
// Normal shutdown // Normal shutdown
_logger.EndpointMessageProcessingCancelled(EndpointName); LogEndpointMessageProcessingCanceled(EndpointName);
} }
finally finally
{ {
@ -226,7 +231,7 @@ internal sealed class McpSession : IDisposable
break; break;
default: default:
_logger.EndpointHandlerUnexpectedMessageType(EndpointName, message.GetType().Name); LogEndpointHandlerUnexpectedMessageType(EndpointName, message.GetType().Name);
break; break;
} }
} }
@ -252,7 +257,7 @@ internal sealed class McpSession : IDisposable
_handlingRequests.TryGetValue(cn.RequestId, out var cts)) _handlingRequests.TryGetValue(cn.RequestId, out var cts))
{ {
await cts.CancelAsync().ConfigureAwait(false); await cts.CancelAsync().ConfigureAwait(false);
_logger.RequestCanceled(cn.RequestId, cn.Reason); LogRequestCanceled(EndpointName, cn.RequestId, cn.Reason);
} }
} }
catch catch
@ -267,18 +272,13 @@ internal sealed class McpSession : IDisposable
private void HandleMessageWithId(IJsonRpcMessage message, IJsonRpcMessageWithId messageWithId) private void HandleMessageWithId(IJsonRpcMessage message, IJsonRpcMessageWithId messageWithId)
{ {
if (messageWithId.Id.Id is null) if (_pendingRequests.TryRemove(messageWithId.Id, out var tcs))
{ {
_logger.RequestHasInvalidId(EndpointName);
}
else if (_pendingRequests.TryRemove(messageWithId.Id, out var tcs))
{
_logger.ResponseMatchedPendingRequest(EndpointName, messageWithId.Id.ToString());
tcs.TrySetResult(message); tcs.TrySetResult(message);
} }
else else
{ {
_logger.NoRequestFoundForMessageWithId(EndpointName, messageWithId.Id.ToString()); LogNoRequestFoundForMessageWithId(EndpointName, messageWithId.Id);
} }
} }
@ -286,13 +286,14 @@ internal sealed class McpSession : IDisposable
{ {
if (!_requestHandlers.TryGetValue(request.Method, out var handler)) if (!_requestHandlers.TryGetValue(request.Method, out var handler))
{ {
_logger.NoHandlerFoundForRequest(EndpointName, request.Method); LogNoHandlerFoundForRequest(EndpointName, request.Method);
throw new McpException("The method does not exist or is not available.", ErrorCodes.MethodNotFound); throw new McpException("The method does not exist or is not available.", ErrorCodes.MethodNotFound);
} }
_logger.RequestHandlerCalled(EndpointName, request.Method); LogRequestHandlerCalled(EndpointName, request.Method);
JsonNode? result = await handler(request, cancellationToken).ConfigureAwait(false); JsonNode? result = await handler(request, cancellationToken).ConfigureAwait(false);
_logger.RequestHandlerCompleted(EndpointName, request.Method); LogRequestHandlerCompleted(EndpointName, request.Method);
await _transport.SendMessageAsync(new JsonRpcResponse await _transport.SendMessageAsync(new JsonRpcResponse
{ {
Id = request.Id, Id = request.Id,
@ -341,7 +342,6 @@ internal sealed class McpSession : IDisposable
{ {
if (!_transport.IsConnected) if (!_transport.IsConnected)
{ {
_logger.EndpointNotConnected(EndpointName);
throw new McpException("Transport is not connected"); throw new McpException("Transport is not connected");
} }
@ -375,21 +375,21 @@ internal sealed class McpSession : IDisposable
AddTags(ref tags, activity, request, method); AddTags(ref tags, activity, request, method);
} }
// Expensive logging, use the logging framework to check if the logger is enabled if (_logger.IsEnabled(LogLevel.Trace))
if (_logger.IsEnabled(LogLevel.Debug))
{ {
_logger.SendingRequestPayload(EndpointName, JsonSerializer.Serialize(request, McpJsonUtilities.JsonContext.Default.JsonRpcRequest)); LogSendingRequestSensitive(EndpointName, request.Method, JsonSerializer.Serialize(request, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage));
}
else
{
LogSendingRequest(EndpointName, request.Method);
} }
// Less expensive information logging
_logger.SendingRequest(EndpointName, request.Method);
await _transport.SendMessageAsync(request, cancellationToken).ConfigureAwait(false); await _transport.SendMessageAsync(request, cancellationToken).ConfigureAwait(false);
_logger.RequestSentAwaitingResponse(EndpointName, request.Method, request.Id.ToString());
// Now that the request has been sent, register for cancellation. If we registered before, // Now that the request has been sent, register for cancellation. If we registered before,
// a cancellation request could arrive before the server knew about that request ID, in which // a cancellation request could arrive before the server knew about that request ID, in which
// case the server could ignore it. // case the server could ignore it.
LogRequestSentAwaitingResponse(EndpointName, request.Method, request.Id);
IJsonRpcMessage? response; IJsonRpcMessage? response;
using (var registration = RegisterCancellation(cancellationToken, request.Id)) using (var registration = RegisterCancellation(cancellationToken, request.Id))
{ {
@ -398,8 +398,8 @@ internal sealed class McpSession : IDisposable
if (response is JsonRpcError error) if (response is JsonRpcError error)
{ {
_logger.RequestFailed(EndpointName, request.Method, error.Error.Message, error.Error.Code); LogSendingRequestFailed(EndpointName, request.Method, error.Error.Message, error.Error.Code);
throw new McpException($"Request failed (server side): {error.Error.Message}", error.Error.Code); throw new McpException($"Request failed (remote): {error.Error.Message}", error.Error.Code);
} }
if (response is JsonRpcResponse success) if (response is JsonRpcResponse success)
@ -409,13 +409,20 @@ internal sealed class McpSession : IDisposable
AddResponseTags(ref tags, activity, success.Result, method); AddResponseTags(ref tags, activity, success.Result, method);
} }
_logger.RequestResponseReceivedPayload(EndpointName, success.Result?.ToJsonString() ?? "null"); if (_logger.IsEnabled(LogLevel.Trace))
_logger.RequestResponseReceived(EndpointName, request.Method); {
LogRequestResponseReceivedSensitive(EndpointName, request.Method, success.Result?.ToJsonString() ?? "null");
}
else
{
LogRequestResponseReceived(EndpointName, request.Method);
}
return success; return success;
} }
// Unexpected response type // Unexpected response type
_logger.RequestInvalidResponseType(EndpointName, request.Method); LogSendingRequestInvalidResponseType(EndpointName, request.Method);
throw new McpException("Invalid response type"); throw new McpException("Invalid response type");
} }
catch (Exception ex) when (addTags) catch (Exception ex) when (addTags)
@ -436,7 +443,6 @@ internal sealed class McpSession : IDisposable
if (!_transport.IsConnected) if (!_transport.IsConnected)
{ {
_logger.ClientNotConnected(EndpointName);
throw new McpException("Transport is not connected"); throw new McpException("Transport is not connected");
} }
@ -463,9 +469,13 @@ internal sealed class McpSession : IDisposable
AddTags(ref tags, activity, message, method); AddTags(ref tags, activity, message, method);
} }
if (_logger.IsEnabled(LogLevel.Debug)) if (_logger.IsEnabled(LogLevel.Trace))
{ {
_logger.SendingMessage(EndpointName, JsonSerializer.Serialize(message, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage)); LogSendingMessageSensitive(EndpointName, JsonSerializer.Serialize(message, McpJsonUtilities.JsonContext.Default.IJsonRpcMessage));
}
else
{
LogSendingMessage(EndpointName);
} }
await _transport.SendMessageAsync(message, cancellationToken).ConfigureAwait(false); await _transport.SendMessageAsync(message, cancellationToken).ConfigureAwait(false);
@ -683,4 +693,64 @@ internal sealed class McpSession : IDisposable
return null; return null;
} }
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} message processing canceled.")]
private partial void LogEndpointMessageProcessingCanceled(string endpointName);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} method '{Method}' request handler called.")]
private partial void LogRequestHandlerCalled(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} method '{Method}' request handler completed.")]
private partial void LogRequestHandlerCompleted(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} method '{Method}' request handler failed.")]
private partial void LogRequestHandlerException(string endpointName, string method, Exception exception);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} received request for unknown request ID '{RequestId}'.")]
private partial void LogNoRequestFoundForMessageWithId(string endpointName, RequestId requestId);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} request failed for method '{Method}': {ErrorMessage} ({ErrorCode}).")]
private partial void LogSendingRequestFailed(string endpointName, string method, string errorMessage, int errorCode);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} received invalid response for method '{Method}'.")]
private partial void LogSendingRequestInvalidResponseType(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} sending method '{Method}' request.")]
private partial void LogSendingRequest(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} sending method '{Method}' request. Request: '{Request}'.")]
private partial void LogSendingRequestSensitive(string endpointName, string method, string request);
[LoggerMessage(Level = LogLevel.Information, Message = "{EndpointName} canceled request '{RequestId}' per client notification. Reason: '{Reason}'.")]
private partial void LogRequestCanceled(string endpointName, RequestId requestId, string? reason);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} Request response received for method {method}")]
private partial void LogRequestResponseReceived(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} Request response received for method {method}. Response: '{Response}'.")]
private partial void LogRequestResponseReceivedSensitive(string endpointName, string method, string response);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} read {MessageType} message from channel.")]
private partial void LogMessageRead(string endpointName, string messageType);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} message handler {MessageType} failed.")]
private partial void LogMessageHandlerException(string endpointName, string messageType, Exception exception);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} message handler {MessageType} failed. Message: '{Message}'.")]
private partial void LogMessageHandlerExceptionSensitive(string endpointName, string messageType, string message, Exception exception);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} received unexpected {MessageType} message type.")]
private partial void LogEndpointHandlerUnexpectedMessageType(string endpointName, string messageType);
[LoggerMessage(Level = LogLevel.Warning, Message = "{EndpointName} received request for method '{Method}', but not handler is available.")]
private partial void LogNoHandlerFoundForRequest(string endpointName, string method);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} waiting for response to request '{RequestId}' for method '{Method}'.")]
private partial void LogRequestSentAwaitingResponse(string endpointName, string method, RequestId requestId);
[LoggerMessage(Level = LogLevel.Debug, Message = "{EndpointName} sending message.")]
private partial void LogSendingMessage(string endpointName);
[LoggerMessage(Level = LogLevel.Trace, Message = "{EndpointName} sending message. Message: '{Message}'.")]
private partial void LogSendingMessageSensitive(string endpointName, string message);
} }