MCP-Server

This repository contains MCP server projects. It currently includes:

• mysql-mcp-server: a Python-based Model Context Protocol server that gives MCP clients controlled access to a MySQL database.

MySQL MCP Server

mysql-mcp-server exposes MySQL operations to Claude Desktop or any other MCP-compatible client over stdio. It is designed for practical database work while keeping the server surface constrained and predictable.

It can:

• inspect databases with read tools such as query, list_tables, describe_table, and server_info
• perform controlled writes with insert, update, and delete
• inspect and manage schema with explain, list_indexes, table_stats, and execute_ddl
• run multiple statements atomically with execute_transaction

Key Behaviors

• Reads and writes are separated into dedicated tools.
• SQL operations are validated against an allowlist before execution.
• Single-statement tools reject stacked queries and obvious comment-based injection patterns.
• Parameterized execution is supported through %s placeholders plus params.
• UPDATE and DELETE are refused unless they include a WHERE clause.
• Bare SELECT statements receive an automatic row limit by default.
• A connection pool is used for database access, with retry handling for transient MySQL failures.
• MYSQL_READ_ONLY=true can lock the server down for exploratory use.

Requirements

• Python 3.10+
• A reachable MySQL server
• The database name supplied through MYSQL_DB

By default, the server uses:

• host: localhost
• port: 3306
• user: root
• password: root

Those defaults can be changed with environment variables.

Install

From the repository root:

pip install -e .\mysql-mcp-server

Run

$env:MYSQL_DB = "your_database"
python -m mysql_mcp.server

The server stays in the foreground and communicates through MCP over stdio.

Claude Desktop Example

{
  "mcpServers": {
    "mysql": {
      "command": "python",
      "args": ["-m", "mysql_mcp.server"],
      "cwd": "C:\\path\\to\\MCP-Server\\mysql-mcp-server",
      "env": {
        "MYSQL_DB": "your_database"
      }
    }
  }
}

Configuration

Variable	Default	Purpose
MYSQL_DB	required	Database name to connect to
MYSQL_HOST	localhost	MySQL host
MYSQL_PORT	3306	MySQL port
MYSQL_USER	root	MySQL user
MYSQL_PASSWORD	root	MySQL password
MYSQL_POOL_SIZE	5	Connection pool size
MYSQL_TIMEOUT	10	Connection timeout in seconds
MYSQL_MAX_ROWS	1000	Auto-limit for bare SELECT queries; 0 disables it
MYSQL_READ_ONLY	false	Blocks write operations when enabled
ALLOWED_OPERATIONS	common MySQL verbs	Comma-separated SQL operation allowlist

Tool Summary

Read Tools

• query(sql, params?)
• list_tables()
• describe_table(table)
• server_info()

Write Tools

• insert(sql, params?)
• update(sql, params?)
• delete(sql, params?)

Advanced Tools

• explain(sql)
• list_indexes(table)
• table_stats(table)
• execute_ddl(sql)

Transaction Tool

• execute_transaction(statements)

Safety Notes

This project adds guardrails, but it is still a database-access server. Use a least-privilege MySQL account in real environments, narrow ALLOWED_OPERATIONS to the actions you actually need, and enable read-only mode whenever writes are unnecessary.

For the full package-specific documentation, see mysql-mcp-server/README.md.