Stdio Transport

Stdio transport communicates with a server via standard input/output.

Server-side

use rust_mcp_sdk::{
    mcp_server::{server_runtime, McpServerOptions},
    StdioTransport, ToMcpServerHandler, TransportOptions,
};

let transport = StdioTransport::new(TransportOptions::default())?;

// create the MCP server (`handler` implements `ServerHandler`)
let server = server_runtime::create_server(McpServerOptions {
    server_details,
    transport,
    handler: handler.to_mcp_server_handler(),
    task_store: None,
    client_task_store: None,
    message_observer: None,
});
server.start().await?;

Client-side

use rust_mcp_sdk::{
    mcp_client::{client_runtime, McpClientOptions},
    ToMcpClientHandler, TransportOptions, StdioTransport,
};

// Launch and connect to a server subprocess
let transport = StdioTransport::create_with_server_launch(
    "npx",
    vec!["-y".to_string(), "@modelcontextprotocol/server-everything@latest".to_string()],
    None, // environment variables
    TransportOptions::default(),
)?;

// create the MCP client (`handler` implements `ClientHandler`)
let client = client_runtime::create_client(McpClientOptions {
    client_details,
    transport,
    handler: handler.to_mcp_client_handler(),
    task_store: None,
    server_task_store: None,
    message_observer: None,
});
client.clone().start().await?;

Process Lifecycle

The SDK handles spawning, monitoring, and cleaning up the child process. Tune message handling via the TransportOptions fields (timeout, max_line_length, channel_capacity).