MySQL MCP Server

A Model Context Protocol (MCP) server that provides AI assistants with read-only access to MySQL databases. The server validates all queries to ensure only SELECT statements are executed.

Features

• Read-only access - Only SELECT queries are allowed
• Query validation - Blocks dangerous SQL operations (INSERT, UPDATE, DELETE, DROP, etc.)
• SSL/TLS support - Works with cloud databases like PlanetScale
• Secure credentials - Database credentials stay on the server, never exposed to AI clients

Prerequisites

• Bun runtime
• MySQL database with a read-only user

Installation

git clone <your-repo-url>
cd mysql-mcp
bun install

Configuration

Create a .env file in the project root:

DB_HOST=localhost
DB_USER=ai_readonly
DB_PASSWORD=your_password
DB_NAME=your_database

Creating a Read-Only MySQL User

For security, create a dedicated read-only user for the AI:

CREATE USER 'ai_readonly'@'%' IDENTIFIED BY 'STRONG_PASSWORD_HERE';
GRANT SELECT ON your_database.* TO 'ai_readonly'@'%';
FLUSH PRIVILEGES;

Usage

With Claude Desktop

Add to your claude_desktop_config.json (located at ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "mysql": {
      "command": "bun",
      "args": ["run", "/absolute/path/to/mysql-mcp/src/index.ts"]
    }
  }
}

With Cursor

Add to your MCP server settings:

{
  "mcpServers": {
    "mysql": {
      "command": "bun",
      "args": ["run", "/absolute/path/to/mysql-mcp/src/index.ts"]
    }
  }
}

Manual Testing

bun run start

Available Tools

execute_sql

Executes a SELECT-only SQL query on the MySQL database.

Input:

{
  "query": "SELECT * FROM users LIMIT 10"
}

Output:

{
  "rows": [
    { "id": 1, "name": "Alice" },
    { "id": 2, "name": "Bob" }
  ]
}

Security

The server implements multiple layers of protection:

1. Query validation - Must start with SELECT
2. Keyword blocking - Blocks: INSERT, UPDATE, DELETE, DROP, CREATE, ALTER, TRUNCATE, REPLACE, GRANT, REVOKE, COMMIT, ROLLBACK, LOCK, CALL, EXECUTE, PREPARE, LOAD, INTO OUTFILE, INTO DUMPFILE
3. Injection prevention - Blocks semicolons (;) and SQL comments (--, /*)
4. Database-level enforcement - Use a MySQL user with only SELECT privileges

License

MIT