josiah-hester/mysql-mcp

MySQL MCP Server

A Model Context Protocol (MCP) server that provides tools for interacting with MySQL databases.

Features

The server provides the following tools:

connect

Connect to a MySQL database using a Data Source Name (DSN).

Parameters:

• dsn (string): MySQL connection string (e.g., user:password@tcp(localhost:3306)/database)

Example:

{
  "dsn": "root:password@tcp(localhost:3306)/"
}

list_databases

List all databases on the MySQL server.

Parameters: None

list_tables

List all tables in a specific database.

Parameters:

• database (string): Database name

Example:

{
  "database": "myapp"
}

describe_table

Describe the structure of a specific table, including columns, data types, and constraints.

Parameters:

• database (string): Database name
• table (string): Table name

Example:

{
  "database": "myapp",
  "table": "users"
}

execute_query

Execute a SQL query. SELECT queries return data, while other queries return the number of affected rows.

Parameters:

• query (string): SQL query to execute

Example:

{
  "query": "SELECT * FROM users WHERE active = 1 LIMIT 10"
}

Building

go build -o mysql-mcp-server

Usage

The server runs over stdin/stdout and communicates using the MCP protocol.

Command Line Options

• -dsn string: MySQL DSN for automatic connection on startup (optional)

Examples

Basic usage (connect manually via MCP tools):

./mysql-mcp-server

Auto-connect on startup:

./mysql-mcp-server -dsn="readonly_user:password@tcp(localhost:3306)/myapp"

Example with Claude Desktop

Add to your MCP configuration:

{
  "mcpServers": {
    "mysql": {
      "command": "/path/to/mysql-mcp-server",
      "args": ["-dsn=readonly_user:password@tcp(localhost:3306)/myapp"]
    }
  }
}

Or without auto-connect:

{
  "mcpServers": {
    "mysql": {
      "command": "/path/to/mysql-mcp-server"
    }
  }
}

Security Considerations

• Always use the principle of least privilege when configuring database connections
• Consider using read-only database users for query operations
• Be cautious with execute_query tool as it can run any SQL statement
• Never commit database credentials to version control

Dependencies

• Go 1.24+
• go-sql-driver/mysql - MySQL driver
• modelcontextprotocol/go-sdk - MCP SDK

Error Handling

The server includes comprehensive error handling for:

• Database connection failures
• Invalid SQL queries
• Missing parameters
• Network timeouts
• Permission errors

All errors are returned as MCP tool call results with appropriate error messages.