MCP Server (Go)

A Go implementation of a Model Context Protocol (MCP) server that provides database querying capabilities through a JSON-RPC interface.

Features

• JSON-RPC 2.0 protocol implementation
• Server-Sent Events (SSE) for real-time communication
• SQLite database integration
• Tool-based architecture for extensible functionality
• Authentication support

Available Tools

1. Query Tool

   • Execute SQL queries against the database
   • Returns results in tabular format

2. List Tables Tool

   • List all available tables in the database

Getting Started

Prerequisites

• Go 1.x
• SQLite3

Installation

1. Clone the repository:

git clone <repository-url>
cd mcp_server_go

2. Install dependencies:

go mod download

Configuration

The server uses a simple token-based authentication system. The expected token is hardcoded as "abcd" in the server configuration.

Running the Server

go run main.go

The server will start on port 8777.

API Documentation

Authentication

All requests must include an Authorization header with the format:

Authorization: Bearer <token>

Endpoints

1. Root Endpoint (/)

• Method: GET
• Purpose: Establishes a Server-Sent Events (SSE) connection
• Response: Returns an endpoint URL for message communication

2. Messages Endpoint (/messages/{sessionID})

• Method: POST
• Purpose: Handle client requests
• Supported Methods:
  • initialize: Initialize the connection
  • tools/list: List available tools
  • tools/call: Execute a specific tool

Example Usage

1. Initialize connection:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {}
}

2. List available tools:

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/list",
  "params": {}
}

3. Execute a query:

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "tools/call",
  "params": {
    "name": "query",
    "arguments": {
      "query": "SELECT * FROM your_table"
    }
  }
}

Project Structure

mcp_server_go/
├── main.go              # Main server implementation
├── pkg/
│   ├── messages/        # Message structures
│   ├── methods/         # Request handling methods
│   └── tools/           # Tool implementations
└── mcp.db              # SQLite database file