MCP Server

• In the last session we have used existing mcp Servers with Claude Desktop.
• Goal:
  • Today lets try to write our own mcp server and call it from claude
  • Introduce mcp inspector.
• MCP Server has 3 components
  • tools
  • resources
  • prompts

Steps

• Refer Here for mcp server quick start with python.
• Create a new directory demo
• Now execute

cd demo 
uv init .

• open this folder in vs code code .
• Now create a virtual environment and activate

uv venv .venv
.venv\Scripts\activate

• Select python interpretor ctrl+shift+p in vscode to the virtual environment
• Now add a package uv add "mcp[cli]"
• Now make changes in main.py

from mcp.server.fastmcp import FastMCP

mcp = FastMCP(name="Demo")

@mcp.tool()
def add(a:int, b: int) -> int:
    """Adds two numbers

    Args:
        a (int): a
        b (int): b

    Returns:
        int: a + b
    """
    return a + b

@mcp.tool()
def sub(a:int, b: int) -> int:
    """Subtracts two numbers

    Args:
        a (int): a
        b (int): b

    Returns:
        int: a - b
    """
    return a - b


if __name__ == "__main__":
    mcp.run(transport='stdio')

• Now for testing the mcp server lets add the configuration of the current mcp in claude_desktop_config.json

{
  "mcpServers": {
    "demo": {
      "command": "uv",
      "args": [
        "--directory",
        "C:\\khajaclassroom\\GenerativeAI\\agenticai\\june25\\mcp\\servers\\demo",
        "run",
        "main.py"
      ]
    }
  }
}

• Ensure claude is relaunched
  
• Now write a prompt add 1 and 5
  
  
• Refer Here for all the changes done to build a simple mcp server with add and subtract

Lets build an mcp server which takes notes

• Refer Here for official docs
• Resources are identified by uris Refer Here
• Refer Here for the changes done
• We can run mcp inspector mcp dev <filename>.py
•