What is Mcp With D1 Data

mcp-with-d1-data is a demonstration project for building an MCP (Model Context Protocol) server that utilizes Cloudflare’s MCPAgent Durable Objects and a D1 database to access and query database information.

Use cases

Use cases for mcp-with-d1-data include building web applications that require real-time data updates, developing data analysis tools that query databases, and creating APIs that manage and serve data efficiently.

How to use

To use mcp-with-d1-data, clone the repository, install dependencies using npm, and run the server. You can interact with the database using the provided query tool and manage the schema with SQL migration files.

Key features

Key features include integration with a D1 database for data retrieval, schema management through SQL migration files, a Durable Object implementation for stateful interactions, a query tool for executing SQL queries, and an introspection tool for understanding database structure.

Where to use

mcp-with-d1-data can be used in various fields that require database interactions, such as web applications, data analysis tools, and any project needing a robust backend server for managing data.

MCP Server: Demo

Overview

This repository serves as a demonstration of building an MCP (Model Context Protocol) server that can access and query actual database information. Uses
the @modelcontextprotocol/sdk library leveraging Cloudflare’s MCPAgent to implement tools, manage resources, and a D1 database.

Features

Database

The project integrates with a D1 database (mcp-agent-d1-data) to retrieve data but you should be able to work with any database with some minor adjustments on the tools. Also included some niceties:

• Schema Management: SQL migration files (up.sql, down.sql, seed.sql) in the db/ directory manage the database schema and seed data.

MCP Server (MyMCP)

The MyMCP class extends the McpAgent class from the @modelcontextprotocol/sdk library. It acts as the core server implementation, providing server sent events (SSE) as a foundational transport.

• Durable Object: The server is implemented as a Durable Object, which allows stateful interactions and long process operations. It also comes with hibernation built-in when idle.

Query Tool

The query tool is designed to interact with the database by providing an interface where the LLM can send SQL queries onto the database. Use with care in production environments and practice proper authorization safeguards.

Introspection Tool

The schema-introspection tool is particularly useful to help the LLM understand the structure of the database to produce a more accurate query design.

Integration Tests

Included integration tests in the tests/ directory to get started. Validate the functionality of the MCP server and its tools, or use the tests for TDD.

npm run test

Project Structure

📦 d1-mcp
├── package.json
├── README.md
├── tsconfig.json
├── vitest.config.js
├── worker-configuration.d.ts
├── wrangler.jsonc
├── db
│   ├── down.sql
│   ├── seed.sql
│   └── up.sql
├── public
│   └── index.html
├── src
│   ├── index.ts
│   ├── metadata.ts
│   ├── tools.ts
│   └── utils.ts
└── tests
    ├── index.test.ts
    └── tsconfig.json

Getting Started

Prerequisites

• Node.js
• Cloudflare Workers CLI (wrangler)

Installation

1. Clone the repository.
2. Install dependencies:

   npm install
   

Development

• Start the development server:

  npm run dev
  

Deployment

• Deploy to Cloudflare Workers:

  npm run deploy
  

License

This project is licensed under the MIT License.