modelcontextprotocol--python-sdk/examples/servers/simple-tool

A simple MCP server that exposes a website fetching tool.

Usage

Start the server using either stdio (default) or Streamable HTTP transport:

# Using stdio transport (default)
uv run mcp-simple-tool

# Using Streamable HTTP transport on custom port
uv run mcp-simple-tool --transport streamable-http --port 8000

The server exposes a tool named "fetch" that accepts one required argument:

• url: The URL of the website to fetch

Example

Using the MCP client, you can use the tool like this using the STDIO transport:

import asyncio
from mcp.client.session import ClientSession
from mcp.client.stdio import StdioServerParameters, stdio_client


async def main():
    async with stdio_client(
        StdioServerParameters(command="uv", args=["run", "mcp-simple-tool"])
    ) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()

            # List available tools
            tools = await session.list_tools()
            print(tools)

            # Call the fetch tool
            result = await session.call_tool("fetch", {"url": "https://example.com"})
            print(result)


asyncio.run(main())