Remove McpServerConfig and have McpClientFactory accept IClientTransport instances directly. (#230)

* Remove McpServerConfig and have McpClientFactory accept IClientTransport instances directly.

* Address feedback and use lists when representing stdio arguments.

* Use "Name" for transport descriptors and "EndpointName" for MCP clients and servers.

* Update code samples.

* Fix source file naming
This commit is contained in:
Eirik Tsarpalis 2025-04-08 17:37:41 +01:00 • committed by GitHub
commit 3e21f3594a
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2 changed files with 315 additions and 527 deletions

View file

@ -33,9 +33,8 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
/// </summary>
/// <param name="clientTransport">The transport to use for communication with the server.</param>
/// <param name="options">Options for the client, defining protocol version and capabilities.</param>
/// <param name="serverConfig">The server configuration.</param>
/// <param name="loggerFactory">The logger factory.</param>
public McpClient(IClientTransport clientTransport, McpClientOptions? options, McpServerConfig serverConfig, ILoggerFactory? loggerFactory)
public McpClient(IClientTransport clientTransport, McpClientOptions? options, ILoggerFactory? loggerFactory)
: base(loggerFactory)
{
options ??= new();
@ -43,7 +42,7 @@ internal sealed class McpClient : McpEndpoint, IMcpClient
_clientTransport = clientTransport;
_options = options;
EndpointName = $"Client ({serverConfig.Id}: {serverConfig.Name})";
EndpointName = clientTransport.Name;
if (options.Capabilities is { } capabilities)
{

View file

@ -12,128 +12,39 @@ namespace ModelContextProtocol.Client;
public static class McpClientFactory
{
/// <summary>Creates an <see cref="IMcpClient"/>, connecting it to the specified server.</summary>
/// <param name="serverConfig">Configuration for the target server to which the client should connect.</param>
/// <param name="clientTransport">The transport instance used to communicate with the server.</param>
/// <param name="clientOptions">
/// A client configuration object which specifies client capabilities and protocol version.
/// If <see langword="null"/>, details based on the current process will be employed.
/// </param>
/// <param name="createTransportFunc">An optional factory method which returns transport implementations based on a server configuration.</param>
/// <param name="loggerFactory">A logger factory for creating loggers for clients.</param>
/// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
/// <returns>An <see cref="IMcpClient"/> that's connected to the specified server.</returns>
/// <exception cref="ArgumentNullException"><paramref name="serverConfig"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentNullException"><paramref name="clientTransport"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentNullException"><paramref name="clientOptions"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentException"><paramref name="serverConfig"/> contains invalid information.</exception>
/// <exception cref="InvalidOperationException"><paramref name="createTransportFunc"/> returns an invalid transport.</exception>
public static async Task<IMcpClient> CreateAsync(
McpServerConfig serverConfig,
IClientTransport clientTransport,
McpClientOptions? clientOptions = null,
Func<McpServerConfig, ILoggerFactory?, IClientTransport>? createTransportFunc = null,
ILoggerFactory? loggerFactory = null,
CancellationToken cancellationToken = default)
{
Throw.IfNull(serverConfig);
createTransportFunc ??= CreateTransport;
string endpointName = $"Client ({serverConfig.Id}: {serverConfig.Name})";
Throw.IfNull(clientTransport);
string endpointName = clientTransport.Name;
var logger = loggerFactory?.CreateLogger(typeof(McpClientFactory)) ?? NullLogger.Instance;
logger.CreatingClient(endpointName);
var transport =
createTransportFunc(serverConfig, loggerFactory) ??
throw new InvalidOperationException($"{nameof(createTransportFunc)} returned a null transport.");
McpClient client = new(clientTransport, clientOptions, loggerFactory);
try
{
McpClient client = new(transport, clientOptions, serverConfig, loggerFactory);
try
{
await client.ConnectAsync(cancellationToken).ConfigureAwait(false);
logger.ClientCreated(endpointName);
return client;
}
catch
{
await client.DisposeAsync().ConfigureAwait(false);
throw;
}
await client.ConnectAsync(cancellationToken).ConfigureAwait(false);
logger.ClientCreated(endpointName);
return client;
}
catch
{
if (transport is IAsyncDisposable asyncDisposableTransport)
{
await asyncDisposableTransport.DisposeAsync().ConfigureAwait(false);
}
else if (transport is IDisposable disposableTransport)
{
disposableTransport.Dispose();
}
await client.DisposeAsync().ConfigureAwait(false);
throw;
}
}
private static IClientTransport CreateTransport(McpServerConfig serverConfig, ILoggerFactory? loggerFactory)
{
if (string.Equals(serverConfig.TransportType, TransportTypes.StdIo, StringComparison.OrdinalIgnoreCase))
{
string? command = serverConfig.TransportOptions?.GetValueOrDefault("command");
if (string.IsNullOrWhiteSpace(command))
{
command = serverConfig.Location;
if (string.IsNullOrWhiteSpace(command))
{
throw new ArgumentException("Command is required for stdio transport.", nameof(serverConfig));
}
}
string? arguments = serverConfig.TransportOptions?.GetValueOrDefault("arguments");
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) &&
serverConfig.TransportType.Equals(TransportTypes.StdIo, StringComparison.OrdinalIgnoreCase) &&
!string.IsNullOrEmpty(command) &&
!string.Equals(Path.GetFileName(command), "cmd.exe", StringComparison.OrdinalIgnoreCase))
{
// On Windows, for stdio, we need to wrap non-shell commands with cmd.exe /c {command} (usually npx or uvicorn).
// The stdio transport will not work correctly if the command is not run in a shell.
arguments = string.IsNullOrWhiteSpace(arguments) ?
$"/c {command}" :
$"/c {command} {arguments}";
command = "cmd.exe";
}
return new StdioClientTransport(new StdioClientTransportOptions
{
Command = command!,
Arguments = arguments,
WorkingDirectory = serverConfig.TransportOptions?.GetValueOrDefault("workingDirectory"),
EnvironmentVariables = serverConfig.TransportOptions?
.Where(kv => kv.Key.StartsWith("env:", StringComparison.Ordinal))
.ToDictionary(kv => kv.Key.Substring("env:".Length), kv => kv.Value),
ShutdownTimeout = TimeSpan.TryParse(serverConfig.TransportOptions?.GetValueOrDefault("shutdownTimeout"), CultureInfo.InvariantCulture, out var timespan) ? timespan : StdioClientTransportOptions.DefaultShutdownTimeout
}, serverConfig, loggerFactory);
}
if (string.Equals(serverConfig.TransportType, TransportTypes.Sse, StringComparison.OrdinalIgnoreCase) ||
string.Equals(serverConfig.TransportType, "http", StringComparison.OrdinalIgnoreCase))
{
return new SseClientTransport(new SseClientTransportOptions
{
ConnectionTimeout = TimeSpan.FromSeconds(ParseInt32OrDefault(serverConfig.TransportOptions, "connectionTimeout", 30)),
MaxReconnectAttempts = ParseInt32OrDefault(serverConfig.TransportOptions, "maxReconnectAttempts", 3),
ReconnectDelay = TimeSpan.FromSeconds(ParseInt32OrDefault(serverConfig.TransportOptions, "reconnectDelay", 5)),
AdditionalHeaders = serverConfig.TransportOptions?
.Where(kv => kv.Key.StartsWith("header.", StringComparison.Ordinal))
.ToDictionary(kv => kv.Key.Substring("header.".Length), kv => kv.Value)
}, serverConfig, loggerFactory);
static int ParseInt32OrDefault(Dictionary<string, string>? options, string key, int defaultValue) =>
options?.TryGetValue(key, out var value) is not true ? defaultValue :
int.TryParse(value, out var result) ? result :
throw new ArgumentException($"Invalid value '{value}' for option '{key}' in transport options.", nameof(serverConfig));
}
throw new ArgumentException($"Unsupported transport type '{serverConfig.TransportType}'.", nameof(serverConfig));
}
}