Neo4j MCP Server

# MCP Python SDK which python python3 -m venv myenv source myenv/Scripts/activate pip install -r requirements.txt python fast_mcp_server.py # Usage ## to run the client add .env OPENAI_API_KEY= ## to run the server uvicorn ne04j_mcp_server:app --host 0.0.0.0 --port 8000 # Data Prep ## Insert Node: CREATE (p1:Person {name: "Tom Hanks", birthYear: 1956}) CREATE (p2:Person {name: "Kevin Bacon", birthYear: 1958}) CREATE (m1:Movie {title: "Forrest Gump", releaseYear: 1994}) CREATE (m2:Movie {title: "Apollo 13", releaseYear: 1995}) ## Insert Relationship MATCH (p:Person {name: "Tom Hanks"}), (m:Movie {title: "Forrest Gump"}) CREATE (p)-[:ACTED_IN]->(m) MATCH (p:Person {name: "Tom Hanks"}), (m:Movie {title: "Apollo 13"}) CREATE (p)-[:ACTED_IN]->(m) MATCH (p1:Person {name: "Tom Hanks"}), (p2:Person {name: "Kevin Bacon"}) CREATE (p1)-[:FRIENDS_WITH]->(p2) ## Insert properties MATCH (p:Person {name: "Tom Hanks"}) SET p.oscarsWon = 2 MATCH (m:Movie {title: "Forrest Gump"}) SET m.genre = "Drama" MATCH (p:Person {name: "Tom Hanks"})-[r:ACTED_IN]->(m:Movie {title: "Forrest Gump"}) SET r.role = "Forrest Gump" ## Insert Complex Structure // Create a community and then match persons to add them to the community CREATE (c1:Community {name: "Hollywood Stars"}) WITH c1 MATCH (p:Person) WHERE p.name IN ["Tom Hanks", "Kevin Bacon"] CREATE (p)-[:MEMBER_OF]->(c1) # other things - boiler plate - no clue - ignore for now. <div align="center"> <strong>Python implementation of the Model Context Protocol (MCP)</strong> [![PyPI][pypi-badge]][pypi-url] [![MIT licensed][mit-badge]][mit-url] [![Python Version][python-badge]][python-url] [![Documentation][docs-badge]][docs-url] [![Specification][spec-badge]][spec-url] [![GitHub Discussions][discussions-badge]][discussions-url] </div> <!-- omit in toc --> ## Table of Contents - [Overview](#overview) - [Installation](#installation) - [Quickstart](#quickstart) - [What is MCP?](#what-is-mcp) - [Core Concepts](#core-concepts) - [Server](#server) - [Resources](#resources) - [Tools](#tools) - [Prompts](#prompts) - [Images](#images) - [Context](#context) - [Running Your Server](#running-your-server) - [Development Mode](#development-mode) - [Claude Desktop Integration](#claude-desktop-integration) - [Direct Execution](#direct-execution) - [Examples](#examples) - [Echo Server](#echo-server) - [SQLite Explorer](#sqlite-explorer) - [Advanced Usage](#advanced-usage) - [Low-Level Server](#low-level-server) - [Writing MCP Clients](#writing-mcp-clients) - [MCP Primitives](#mcp-primitives) - [Server Capabilities](#server-capabilities) - [Documentation](#documentation) - [Contributing](#contributing) - [License](#license) [pypi-badge]: https://img.shields.io/pypi/v/mcp.svg [pypi-url]: https://pypi.org/project/mcp/ [mit-badge]: https://img.shields.io/pypi/l/mcp.svg [mit-url]: https://github.com/modelcontextprotocol/python-sdk/blob/main/LICENSE [python-badge]: https://img.shields.io/pypi/pyversions/mcp.svg [python-url]: https://www.python.org/downloads/ [docs-badge]: https://img.shields.io/badge/docs-modelcontextprotocol.io-blue.svg [docs-url]: https://modelcontextprotocol.io [spec-badge]: https://img.shields.io/badge/spec-spec.modelcontextprotocol.io-blue.svg [spec-url]: https://spec.modelcontextprotocol.io [discussions-badge]: https://img.shields.io/github/discussions/modelcontextprotocol/python-sdk [discussions-url]: https://github.com/modelcontextprotocol/python-sdk/discussions ## Overview The Model Context Protocol allows applications to provide context for LLMs in a standardized way, separating the concerns of providing context from the actual LLM interaction. This Python SDK implements the full MCP specification, making it easy to: - Build MCP clients that can connect to any MCP server - Create MCP servers that expose resources, prompts and tools - Use standard transports like stdio and SSE - Handle all MCP protocol messages and lifecycle events ## Installation We recommend using [uv](https://docs.astral.sh/uv/) to manage your Python projects: ```bash uv add "mcp[cli]" ``` Alternatively: ```bash pip install mcp ``` ## Quickstart Let's create a simple MCP server that exposes a calculator tool and some data: ```python # server.py from mcp.server.fastmcp import FastMCP # Create an MCP server mcp = FastMCP("Demo") # Add an addition tool @mcp.tool() def add(a: int, b: int) -> int: """Add two numbers""" return a + b # Add a dynamic greeting resource @mcp.resource("greeting://{name}") def get_greeting(name: str) -> str: """Get a personalized greeting""" return f"Hello, {name}!" ``` You can install this server in [Claude Desktop](https://claude.ai/download) and interact with it right away by running: ```bash mcp install server.py ``` Alternatively, you can test it with the MCP Inspector: ```bash mcp dev server.py ``` ## What is MCP? The [Model Context Protocol (MCP)](https://modelcontextprotocol.io) lets you build servers that expose data and functionality to LLM applications in a secure, standardized way. Think of it like a web API, but specifically designed for LLM interactions. MCP servers can: - Expose data through **Resources** (think of these sort of like GET endpoints; they are used to load information into the LLM's context) - Provide functionality through **Tools** (sort of like POST endpoints; they are used to execute code or otherwise produce a side effect) - Define interaction patterns through **Prompts** (reusable templates for LLM interactions) - And more! ## Core Concepts ### Server The FastMCP server is your core interface to the MCP protocol. It handles connection management, protocol compliance, and message routing: ```python # Add lifespan support for startup/shutdown with strong typing from dataclasses import dataclass from typing import AsyncIterator from mcp.server.fastmcp import FastMCP # Create a named server mcp = FastMCP("My App") # Specify dependencies for deployment and development mcp = FastMCP("My App", dependencies=["pandas", "numpy"]) @dataclass class AppContext: db: Database # Replace with your actual DB type @asynccontextmanager async def app_lifespan(server: FastMCP) -> AsyncIterator[AppContext]: """Manage application lifecycle with type-safe context""" try: # Initialize on startup await db.connect() yield AppContext(db=db) finally: # Cleanup on shutdown await db.disconnect() # Pass lifespan to server mcp = FastMCP("My App", lifespan=app_lifespan) # Access type-safe lifespan context in tools @mcp.tool() def query_db(ctx: Context) -> str: """Tool that uses initialized resources""" db = ctx.request_context.lifespan_context["db"] return db.query() ``` ### Resources Resources are how you expose data to LLMs. They're similar to GET endpoints in a REST API - they provide data but shouldn't perform significant computation or have side effects: ```python @mcp.resource("config://app") def get_config() -> str: """Static configuration data""" return "App configuration here" @mcp.resource("users://{user_id}/profile") def get_user_profile(user_id: str) -> str: """Dynamic user data""" return f"Profile data for user {user_id}" ``` ### Tools Tools let LLMs take actions through your server. Unlike resources, tools are expected to perform computation and have side effects: ```python @mcp.tool() def calculate_bmi(weight_kg: float, height_m: float) -> float: """Calculate BMI given weight in kg and height in meters""" return weight_kg / (height_m ** 2) @mcp.tool() async def fetch_weather(city: str) -> str: """Fetch current weather for a city""" async with httpx.AsyncClient() as client: response = await client.get(f"https://api.weather.com/{city}") return response.text ``` ### Prompts Prompts are reusable templates that help LLMs interact with your server effectively: ```python @mcp.prompt() def review_code(code: str) -> str: return f"Please review this code:\n\n{code}" @mcp.prompt() def debug_error(error: str) -> list[Message]: return [ UserMessage("I'm seeing this error:"), UserMessage(error), AssistantMessage("I'll help debug that. What have you tried so far?") ] ``` ### Images FastMCP provides an `Image` class that automatically handles image data: ```python from mcp.server.fastmcp import FastMCP, Image from PIL import Image as PILImage @mcp.tool() def create_thumbnail(image_path: str) -> Image: """Create a thumbnail from an image""" img = PILImage.open(image_path) img.thumbnail((100, 100)) return Image(data=img.tobytes(), format="png") ``` ### Context The Context object gives your tools and resources access to MCP capabilities: ```python from mcp.server.fastmcp import FastMCP, Context @mcp.tool() async def long_task(files: list[str], ctx: Context) -> str: """Process multiple files with progress tracking""" for i, file in enumerate(files): ctx.info(f"Processing {file}") await ctx.report_progress(i, len(files)) data, mime_type = await ctx.read_resource(f"file://{file}") return "Processing complete" ``` ## Running Your Server ### Development Mode The fastest way to test and debug your server is with the MCP Inspector: ```bash mcp dev server.py # Add dependencies mcp dev server.py --with pandas --with numpy # Mount local code mcp dev server.py --with-editable . ``` ### Claude Desktop Integration Once your server is ready, install it in Claude Desktop: ```bash mcp install server.py # Custom name mcp install server.py --name "My Analytics Server" # Environment variables mcp install server.py -v API_KEY=abc123 -v DB_URL=postgres://... mcp install server.py -f .env ``` ### Direct Execution For advanced scenarios like custom deployments: ```python from mcp.server.fastmcp import FastMCP mcp = FastMCP("My App") if __name__ == "__main__": mcp.run() ``` Run it with: ```bash python server.py # or mcp run server.py ``` ## Examples ### Echo Server A simple server demonstrating resources, tools, and prompts: ```python from mcp.server.fastmcp import FastMCP mcp = FastMCP("Echo") @mcp.resource("echo://{message}") def echo_resource(message: str) -> str: """Echo a message as a resource""" return f"Resource echo: {message}" @mcp.tool() def echo_tool(message: str) -> str: """Echo a message as a tool""" return f"Tool echo: {message}" @mcp.prompt() def echo_prompt(message: str) -> str: """Create an echo prompt""" return f"Please process this message: {message}" ``` ### SQLite Explorer A more complex example showing database integration: ```python from mcp.server.fastmcp import FastMCP import sqlite3 mcp = FastMCP("SQLite Explorer") @mcp.resource("schema://main") def get_schema() -> str: """Provide the database schema as a resource""" conn = sqlite3.connect("database.db") schema = conn.execute( "SELECT sql FROM sqlite_master WHERE type='table'" ).fetchall() return "\n".join(sql[0] for sql in schema if sql[0]) @mcp.tool() def query_data(sql: str) -> str: """Execute SQL queries safely""" conn = sqlite3.connect("database.db") try: result = conn.execute(sql).fetchall() return "\n".join(str(row) for row in result) except Exception as e: return f"Error: {str(e)}" ``` ## Advanced Usage ### Low-Level Server For more control, you can use the low-level server implementation directly. This gives you full access to the protocol and allows you to customize every aspect of your server, including lifecycle management through the lifespan API: ```python from contextlib import asynccontextmanager from typing import AsyncIterator @asynccontextmanager async def server_lifespan(server: Server) -> AsyncIterator[dict]: """Manage server startup and shutdown lifecycle.""" try: # Initialize resources on startup await db.connect() yield {"db": db} finally: # Clean up on shutdown await db.disconnect() # Pass lifespan to server server = Server("example-server", lifespan=server_lifespan) # Access lifespan context in handlers @server.call_tool() async def query_db(name: str, arguments: dict) -> list: ctx = server.request_context db = ctx.lifespan_context["db"] return await db.query(arguments["query"]) ``` The lifespan API provides: - A way to initialize resources when the server starts and clean them up when it stops - Access to initialized resources through the request context in handlers - Type-safe context passing between lifespan and request handlers ```python from mcp.server.lowlevel import Server, NotificationOptions from mcp.server.models import InitializationOptions import mcp.server.stdio import mcp.types as types # Create a server instance server = Server("example-server") @server.list_prompts() async def handle_list_prompts() -> list[types.Prompt]: return [ types.Prompt( name="example-prompt", description="An example prompt template", arguments=[ types.PromptArgument( name="arg1", description="Example argument", required=True ) ] ) ] @server.get_prompt() async def handle_get_prompt( name: str, arguments: dict[str, str] | None ) -> types.GetPromptResult: if name != "example-prompt": raise ValueError(f"Unknown prompt: {name}") return types.GetPromptResult( description="Example prompt", messages=[ types.PromptMessage( role="user", content=types.TextContent( type="text", text="Example prompt text" ) ) ] ) async def run(): async with mcp.server.stdio.stdio_server() as (read_stream, write_stream): await server.run( read_stream, write_stream, InitializationOptions( server_name="example", server_version="0.1.0", capabilities=server.get_capabilities( notification_options=NotificationOptions(), experimental_capabilities={}, ) ) ) if __name__ == "__main__": import asyncio asyncio.run(run()) ``` ### Writing MCP Clients The SDK provides a high-level client interface for connecting to MCP servers: ```python from mcp import ClientSession, StdioServerParameters from mcp.client.stdio import stdio_client # Create server parameters for stdio connection server_params = StdioServerParameters( command="python", # Executable args=["example_server.py"], # Optional command line arguments env=None # Optional environment variables ) # Optional: create a sampling callback async def handle_sampling_message(message: types.CreateMessageRequestParams) -> types.CreateMessageResult: return types.CreateMessageResult( role="assistant", content=types.TextContent( type="text", text="Hello, world! from model", ), model="gpt-3.5-turbo", stopReason="endTurn", ) async def run(): async with stdio_client(server_params) as (read, write): async with ClientSession(read, write, sampling_callback=handle_sampling_message) as session: # Initialize the connection await session.initialize() # List available prompts prompts = await session.list_prompts() # Get a prompt prompt = await session.get_prompt("example-prompt", arguments={"arg1": "value"}) # List available resources resources = await session.list_resources() # List available tools tools = await session.list_tools() # Read a resource content, mime_type = await session.read_resource("file://some/path") # Call a tool result = await session.call_tool("tool-name", arguments={"arg1": "value"}) if __name__ == "__main__": import asyncio asyncio.run(run()) ``` ### MCP Primitives The MCP protocol defines three core primitives that servers can implement: | Primitive | Control | Description | Example Use | |-----------|-----------------------|-----------------------------------------------------|------------------------------| | Prompts | User-controlled | Interactive templates invoked by user choice | Slash commands, menu options | | Resources | Application-controlled| Contextual data managed by the client application | File contents, API responses | | Tools | Model-controlled | Functions exposed to the LLM to take actions | API calls, data updates | ### Server Capabilities MCP servers declare capabilities during initialization: | Capability | Feature Flag | Description | |-------------|------------------------------|------------------------------------| | `prompts` | `listChanged` | Prompt template management | | `resources` | `subscribe`<br/>`listChanged`| Resource exposure and updates | | `tools` | `listChanged` | Tool discovery and execution | | `logging` | - | Server logging configuration | | `completion`| - | Argument completion suggestions | ## Documentation - [Model Context Protocol documentation](https://modelcontextprotocol.io) - [Model Context Protocol specification](https://spec.modelcontextprotocol.io) - [Officially supported servers](https://github.com/modelcontextprotocol/servers) ## Contributing We are passionate about supporting contributors of all levels of experience and would love to see you get involved in the project. See the [contributing guide](CONTRIBUTING.md) to get started. ## License This project is licensed under the MIT License - see the LICENSE file for details.