capital.hove/read-only-local-mysql-mcp-server

Official

by hovecapital · JavaScript

MCP server for read-only MySQL database queries in Claude Desktop

Enables read-only MySQL database queries through Claude Desktop.

MySQL MCP Server

A Model Context Protocol (MCP) server that enables Claude Desktop to interact with MySQL databases through natural language queries.

Features

Execute read-only SQL queries through Claude Desktop
Dynamic connection configuration — connect to any MySQL database at runtime via connection string
Built-in security with query validation (only SELECT statements allowed)
Easy integration with Claude Desktop
JSON formatted query results
Environment-based configuration for database credentials

Quick Start

For Claude Code Users (Recommended - Easiest Method)

bash

claude mcp add mysql -s user -- npx -y @hovecapital/read-only-mysql-mcp-server@latest

Then set your database environment variables:

bash

export DB_HOST=localhost
export DB_PORT=3306
export DB_DATABASE=your_database_name
export DB_USERNAME=your_username
export DB_PASSWORD=your_password

Done! Restart Claude Code and ask: "What tables are in my database?"

For Claude Desktop Users (Manual Configuration)

1. Open your config file:

bash

# macOS
open ~/Library/Application\ Support/Claude/claude_desktop_config.json

# Windows
notepad %APPDATA%\Claude\claude_desktop_config.json

2. Add this configuration:

json

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": ["-y", "@hovecapital/read-only-mysql-mcp-server@latest"],
      "env": {
        "DB_HOST": "localhost",
        "DB_PORT": "3306",
        "DB_DATABASE": "your_database_name",
        "DB_USERNAME": "your_username",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

3. Save, restart Claude Desktop, and test!

Prerequisites

Node.js (v16 or higher) - If using mise, update the command path accordingly
MySQL database server
Claude Desktop application

Installation

Option 1: Install from MCP Registry (Recommended)

This server is published in the Model Context Protocol Registry as capital.hove/read-only-local-mysql-mcp-server.

Method A: Claude Code CLI (Easiest!)

bash

claude mcp add mysql -s user -- npx -y @hovecapital/read-only-mysql-mcp-server@latest

Then configure your database credentials using environment variables. Restart Claude Code and you're done!

Benefits:

One command installation
No manual JSON editing
Automatic configuration

Method B: Manual JSON Configuration

For Claude Desktop:

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

json

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": ["-y", "@hovecapital/read-only-mysql-mcp-server@latest"],
      "env": {
        "DB_HOST": "localhost",
        "DB_PORT": "3306",
        "DB_DATABASE": "your_database_name",
        "DB_USERNAME": "your_username",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

For Claude Code:

Edit ~/.config/claude-code/settings.json (macOS/Linux) or %APPDATA%\claude-code\settings.json (Windows):

json

{
  "mcp": {
    "servers": {
      "mysql": {
        "command": "npx",
        "args": ["-y", "@hovecapital/read-only-mysql-mcp-server@latest"],
        "env": {
          "DB_HOST": "localhost",
          "DB_PORT": "3306",
          "DB_DATABASE": "your_database_name",
          "DB_USERNAME": "your_username",
          "DB_PASSWORD": "your_password"
        }
      }
    }
  }
}

Option 2: Install from npm

bash

npm install -g @hovecapital/read-only-mysql-mcp-server

Option 3: Installation with Claude Code

If you're using Claude Code, you can easily install this MCP server:

bash

# Clone the repository
git clone https://github.com/hovecapital/read-only-local-mysql-mcp-server.git
cd read-only-local-mysql-mcp-server

# Install dependencies and build
npm install
npm run build

Then configure Claude Code by adding to your MCP settings.

Option 4: Manual Installation

1. Clone or Download

Save the repository to a directory on your system:

bash

mkdir ~/mcp-servers/mysql
cd ~/mcp-servers/mysql
git clone https://github.com/hovecapital/read-only-local-mysql-mcp-server.git .

2. Install Dependencies

bash

npm install
npm run build

Configuration

Note: If you installed via Option 1 (MCP Registry with npx), you've already configured everything! This section is for users who chose Options 2, 3, or 4 (npm or manual installation).

Claude Code Configuration

If you're using Claude Code with a manual installation, add the MySQL server to your MCP settings:

Open your Claude Code settings (typically in ~/.config/claude-code/settings.json on macOS/Linux or %APPDATA%\claude-code\settings.json on Windows)
Add the MySQL MCP server configuration:

json

{
  "mcp": {
    "servers": {
      "mysql": {
        "command": "node",
        "args": ["/absolute/path/to/read-only-local-mysql-mcp-server/dist/index.js"],
        "env": {
          "DB_HOST": "localhost",
          "DB_PORT": "3306",
          "DB_DATABASE": "your_database_name",
          "DB_USERNAME": "your_username",
          "DB_PASSWORD": "your_password"
        }
      }
    }
  }
}

Restart Claude Code for the changes to take effect.

Claude Desktop Configuration

If you're using Claude Desktop with a manual installation, open your Claude Desktop configuration file:

macOS:

bash

~/Library/Application Support/Claude/claude_desktop_config.json

Windows:

bash

%APPDATA%\Claude\claude_desktop_config.json

Add the MySQL server configuration:

json

{
  "mcpServers": {
    "mysql": {
      "command": "node",
      "args": ["/absolute/path/to/read-only-local-mysql-mcp-server/dist/index.js"],
      "env": {
        "DB_HOST": "localhost",
        "DB_PORT": "3306",
        "DB_DATABASE": "your_database_name",
        "DB_USERNAME": "your_username",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

Using mise for Node.js

If you're using mise for Node.js version management, make sure to use the full path to the Node.js executable in your configuration.

Environment Variables

Variable	Description	Default
`DB_HOST`	MySQL server hostname	`mysql`
`DB_PORT`	MySQL server port	`3306`
`DB_DATABASE`	Database name	`database`
`DB_USERNAME`	MySQL username	`root`
`DB_PASSWORD`	MySQL password	(empty)

Usage

Restart Claude Desktop after updating the configuration
Start chatting with Claude about your database

Example Queries

bash

"Show me all tables in my database"
"What's the structure of the users table?"
"Get the first 10 records from the products table"
"How many orders were placed last month?"
"Show me users with email addresses ending in @gmail.com"

Claude will automatically convert your natural language requests into appropriate SQL queries and execute them against your database.

Tools

`connect`

Connect to a MySQL database using a connection string. The connection persists for subsequent queries until changed or disconnected.

Parameters:

Parameter	Required	Description
`connectionString`	Yes	MySQL connection string (e.g., `mysql://user:password@host:port/database`)

`disconnect`

Disconnect from the current runtime database and revert to the default environment-configured connection. Takes no parameters.

`query`

Run a read-only SQL query against the currently connected database.

Parameters:

Parameter	Required	Description
`sql`	Yes	SQL query to execute (read-only)
`connectionString`	No	MySQL connection string to override the current connection for this query only

Dynamic Connection

The server supports switching databases at runtime without restarting. Connection priority:

Per-query connectionString — overrides everything for a single query
Runtime connection (from connect tool) — persists until disconnect is called
Environment variables — the default fallback

Connection string format:

code

mysql://username:password@hostname:port/database_name

Example workflow:

code

1. connect → mysql://analyst:pass@prod-db:3306/analytics
2. query   → SELECT COUNT(*) FROM events
3. query   → SELECT * FROM users LIMIT 5 (uses the same analytics connection)
4. query   → SELECT * FROM orders LIMIT 5, connectionString: mysql://analyst:pass@prod-db:3306/sales
              (one-off override — does not change the stored connection)
5. disconnect → reverts to env var defaults

Security Features

Read-Only Operations

The server only allows SELECT queries. The following operations are blocked:

INSERT - Adding new records
UPDATE - Modifying existing records
DELETE - Removing records
DROP - Removing tables/databases
ALTER - Modifying table structure
CREATE - Creating new tables/databases

Recommended Database Setup

For enhanced security, create a dedicated read-only user for the MCP server:

sql

-- Create a read-only user
CREATE USER 'claude_readonly'@'localhost' IDENTIFIED BY 'secure_password';

-- Grant only SELECT permissions on your specific database
GRANT SELECT ON your_database_name.* TO 'claude_readonly'@'localhost';

-- Apply the changes
FLUSH PRIVILEGES;

Troubleshooting

Connection Issues

Verify MySQL is running: Check if your MySQL server is active
Check credentials: Ensure username/password are correct
Network connectivity: Confirm Claude Desktop can reach your MySQL server

Configuration Issues

Restart required: Always restart Claude Desktop after configuration changes
Path accuracy: Ensure the absolute path to dist/index.js is correct
JSON syntax: Validate your claude_desktop_config.json format

Debug Mode

To see server logs, you can run the server manually:

bash

node dist/index.js

File Structure

bash

~/mcp-servers/mysql/
├── src/
│   └── index.ts
├── dist/
│   ├── index.js
│   └── index.d.ts
├── package.json
├── tsconfig.json
└── node_modules/

Dependencies

@modelcontextprotocol/sdk: MCP protocol implementation
mysql2: Modern MySQL client for Node.js with Promise support

Contributing

Feel free to submit issues and enhancement requests!

License

This project is open source and available under the MIT License.

Support

If you encounter issues:

Check the troubleshooting section above
Verify your MySQL connection independently
Ensure Claude Desktop is updated to the latest version
Review the Claude Desktop MCP documentation

Note: This server is designed for development and analysis purposes. For production use, consider additional security measures and monitoring.

Install

claude_desktop_config.json

{
  "mcpServers": {
    "read-only-local-mysql-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@hovecapital/read-only-mysql-mcp-server@0.1.1"
      ]
    }
  }
}