Class StdioTransport

Namespace: LMKit.Mcp.Transport

Assembly: LM-Kit.NET.dll

MCP transport implementation using stdio (standard input/output) communication with a subprocess.

public sealed class StdioTransport : IMcpTransport, IDisposable

Inheritance: object

StdioTransport

Implements: IMcpTransport

IDisposable

Inherited Members: object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// Using the filesystem MCP server
var options = new StdioTransportOptions
{
    Command = "npx",
    Arguments = "@modelcontextprotocol/server-filesystem /path/to/dir",
    StderrHandler = line => Console.WriteLine($"[Server] {line}")
};

using var transport = new StdioTransport(options);
await transport.ConnectAsync();

// Send initialize request
var response = await transport.SendRequestAsync(1, "initialize", new { ... });

Remarks

The stdio transport spawns a subprocess and communicates via JSON-RPC 2.0 messages over stdin/stdout using newline-delimited JSON (JSONL) format. This is the standard transport for local MCP servers as defined in the MCP specification.

Message Format: Each JSON-RPC message is written as a single line of JSON followed by a newline character. The transport handles message framing automatically.

Thread Safety: This transport is thread-safe. Multiple concurrent requests can be sent, and responses are correlated by request ID.

Process Lifecycle: The transport manages the subprocess lifecycle including startup, health monitoring, and graceful/forceful termination.

Constructors

StdioTransport(StdioTransportOptions): Initializes a new stdio transport with detailed options.

StdioTransport(string, string): Initializes a new stdio transport with the specified command.

Properties

IsConnected: Gets whether the transport connection is currently established and ready for communication.

TransportType: Gets the transport type identifier for logging and diagnostics.

Methods

CloseAsync(CancellationToken): Closes the transport connection gracefully.

ConnectAsync(CancellationToken): Establishes the transport connection asynchronously.

Dispose()

SendNotificationAsync(string, object, CancellationToken): Sends a JSON-RPC notification (fire-and-forget, no response expected).

SendRequestAsync(long, string, object, CancellationToken): Sends a JSON-RPC request and waits for the corresponding response.

Events

Disconnected: Raised when the transport connection is unexpectedly lost.

ServerNotificationReceived: Raised when a server-initiated notification is received.

StderrReceived: Raised when the subprocess writes to stderr.