MCP Server Example

A simple MCP (Model Context Protocol) server for learning the core primitives: Tools, Resources, and Prompts.

Setup

Prerequisites

• Python 3.10+
• uv

Install

uv sync

Test

Option 1 — MCP Inspector (recommended)

uv run mcp dev server.py

Opens a browser UI at http://localhost:6274. From there you can:

• Tools tab: call add, multiply, save_note, delete_note with custom inputs
• Resources tab: read notes://list or notes://{name}
• Prompts tab: run summarize_notes or brainstorm with arguments

Option 2 — CLI with mcp client

List all available tools:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}' | uv run python server.py

Call a tool (e.g. add 3 + 4):

echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"add","arguments":{"a":3,"b":4}}}' | uv run python server.py

Connect to Claude Code (CLI)

Add the server to your Claude Code session:

claude mcp add learning-mcp -- uv run --directory /Users/binod/projects/mcp-example python server.py

Verify it's connected:

claude mcp list

Once added, Claude Code can call your tools directly in the chat — just ask it to, e.g. "save a note called 'ideas'" or "what is 3 + 5?".

Connect to Claude Desktop

Add this to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "learning-mcp": {
      "command": "uv",
      "args": [
        "run",
        "--directory", "/Users/binod/projects/mcp-example",
        "python", "server.py"
      ]
    }
  }
}

Then restart Claude Desktop.

Use programmatically (Python)

Use the mcp library to call tools, read resources, and fetch prompts from your own code:

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

async def main():
    server = StdioServerParameters(
        command="uv", args=["run", "python", "server.py"]
    )
    async with stdio_client(server) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()

            # Call a tool
            result = await session.call_tool("add", {"a": 3, "b": 4})
            print(result)  # 7.0

            # Read a resource
            notes = await session.read_resource("notes://list")
            print(notes)

            # Get a prompt
            prompt = await session.get_prompt("brainstorm", {"topic": "side projects"})
            print(prompt)

asyncio.run(main())

To let Claude (via Anthropic API) call your tools, add anthropic[mcp] to your dependencies and convert the tools:

from anthropic.lib.tools.mcp import async_mcp_tool
import anthropic

client = anthropic.AsyncAnthropic()
tools = [async_mcp_tool(t, session) for t in (await session.list_tools()).tools]

runner = client.beta.messages.tool_runner(
    model="claude-opus-4-6",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Save a note called ideas"}],
    tools=tools,
)
async for message in runner:
    for block in message.content:
        if hasattr(block, "text"):
            print(block.text)

What's inside

File	Description
server.py	MCP server with tools, resources, and prompts
pyproject.toml	Project dependencies

Tools (Claude can call these)

Tool	Description
add(a, b)	Add two numbers
multiply(a, b)	Multiply two numbers
save_note(name, content)	Save a note
delete_note(name)	Delete a note

Resources (Claude can read these)

URI	Description
notes://list	List all saved notes
notes://{name}	Read a specific note

Prompts (reusable templates)

Prompt	Description
summarize_notes	Summarize all saved notes
brainstorm(topic)	Brainstorm ideas on a topic