mcp-mysql

MySQL MCP Server

An MCP server for interacting with MySQL databases.

This server supports executing read-only queries (query) and write queries that are ultimately rolled back (test_execute).

Setup

Environment Variables

Add the following environment variables to ~/.mcp/.env:

MYSQL_HOST=host.docker.internal  # Hostname to access host services from Docker container
MYSQL_PORT=3306
MYSQL_USER=root
MYSQL_PASSWORD=your_password

Note: host.docker.internal is a special DNS name for accessing host machine services from Docker containers. Use this setting when connecting to a MySQL server running on your host machine. If connecting to a different MySQL server, change to the appropriate hostname.

mcp.json Configuration

{
  "mcpServers": {
    "mysql": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "--add-host=host.docker.internal:host-gateway",
        "--env-file",
        "/Users/username/.mcp/.env",
        "my-mcp/mysql"
      ]
    }
  }
}

Usage

Starting the Server

docker run -i --rm --add-host=host.docker.internal:host-gateway --env-file ~/.mcp/.env my-mcp/mysql

Note: If you're using OrbStack, host.docker.internal is automatically supported, so the --add-host option can be omitted. While Docker Desktop also typically supports this automatically, adding the --add-host option is recommended for better reliability.

Available Commands

1. Execute Read-only Query

{
  "type": "query",
  "payload": {
    "sql": "SELECT * FROM your_table"
  }
}

Response:

{
  "success": true,
  "data": [
    {
      "id": 1,
      "name": "example"
    }
  ]
}

2. Test Query Execution

{
  "type": "test_execute",
  "payload": {
    "sql": "UPDATE your_table SET name = 'updated' WHERE id = 1"
  }
}

Response:

{
  "success": true,
  "data": "The UPDATE SQL query can be executed."
}

3. List Tables

{
  "type": "list_tables"
}

Response:

{
  "success": true,
  "data": ["table1", "table2", "table3"]
}

4. Describe Table

{
  "type": "describe_table",
  "payload": {
    "table": "your_table"
  }
}

Response:

{
  "success": true,
  "data": [
    {
      "Field": "id",
      "Type": "int(11)",
      "Null": "NO",
      "Key": "PRI",
      "Default": null,
      "Extra": ""
    },
    {
      "Field": "name",
      "Type": "varchar(255)",
      "Null": "YES",
      "Key": "",
      "Default": null,
      "Extra": ""
    }
  ]
}

Implementation Details

• Implemented in TypeScript
• Uses mysql2 package
• Runs as a Docker container
• Accepts JSON commands through standard input
• Returns JSON responses through standard output
• Uses host.docker.internal to connect to host MySQL (compatible with both OrbStack and Docker Desktop)

Security Considerations

• Uses environment variables for sensitive information management
• SQL injection prevention is the implementer's responsibility
• Proper network configuration required for production use
• Appropriate firewall settings needed when connecting to host machine services