StdioTransport

Reference for connecting to local MCP servers over stdio.

Connect to local MCP servers over stdio

Use stdio(...) for new applications. It creates a StdioTransport that launches a local MCP server process and communicates over stdio.

Quick Start

import { mcp, stdio } from "@fentaris/core";

const filesystem = mcp("filesystem", {
  transport: stdio({
    command: "npx",
    args: ["-y", "@modelcontextprotocol/server-filesystem", "./demo-files"],
  }),
});

Options

command

Executable to spawn.

command: "npx"

args

Argument list passed to the spawned process.

args: ["-y", "@modelcontextprotocol/server-filesystem", "./demo-files"]

env

Extra environment variables for the upstream process.

stderr

How to handle stderr from the spawned process.

Allowed values:

• inherit
• pipe
• overlapped
• ignore

clientName

MCP client name.

Default: fentaris-core

clientVersion

MCP client version.

Default: 0.1.0

Methods

listTools(params?)

Lists tools exposed by the MCP server.

callTool(params)

Calls a tool on the MCP server.

close()

Closes the underlying client connection.

Low-Level Constructor

The class constructor is available for advanced integrations:

import { StdioTransport } from "@fentaris/core";

const transport = new StdioTransport({
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-filesystem", "./demo-files"],
});

For normal applications, prefer stdio(options).

Related Documentation

• McpServer reference
• Servers and transports
• Setup