MCP MySQL Lens

A Model Context Protocol (MCP) server that enables Claude Desktop to interact with MySQL databases directly. This server allows Claude to query, analyze, and manage your MySQL databases through natural language.

Features

• 🔍 Query Execution: Run SQL queries directly from Claude Desktop
• 📊 Schema Inspection: Explore database structure, tables, and relationships
• 🔄 Data Analysis: Analyze and visualize data patterns
• 🛡️ Safe Operations: Built-in safeguards for database operations
• 🚀 Easy Setup: Simple configuration with environment variables

Prerequisites

• Claude Desktop installed
• Node.js (v16 or higher)
• MySQL Server (v5.7 or higher)
• install npm
• Valid MySQL credentials with appropriate permissions

NPM Link

Visit npm package mcp-mysql-lens

Installation

1. Install the MCP Server

npm install -g mcp-mysql-lens

2. Configure Claude Desktop

Add this configuration to your Claude Desktop config file:

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": [
        "mcp-mysql-lens"
      ],
      "env": {
        "MYSQL_HOST": "<YOUR_MYSQL_HOST>",
        "MYSQL_PORT": "<YOUR_MYSQL_PORT>",
        "MYSQL_USER": "<YOUR_MYSQL_USERNAME>",
        "MYSQL_PASSWORD": "<YOUR_MYSQL_PASSWORD>",
        "MYSQL_DATABASE": "<YOUR_MYSQL_DEFAULT_DB>"
      }
    }
  }
}

Configuration File Location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

3. Restart Claude Desktop

After saving the configuration, restart Claude Desktop for the changes to take effect.

Configuration Parameters

Parameter	Description	Default	Required
MYSQL_HOST	MySQL server hostname	-	Yes
MYSQL_PORT	MySQL server port	3306	Yes
MYSQL_USER	Database username	-	Yes
MYSQL_PASSWORD	Database password	-	Yes
MYSQL_DATABASE	Default database to connect to	-	Yes

Usage Examples

Once configured, you can interact with your MySQL database through Claude Desktop:

Query Data

"Show me all users from the users table"
"What are the top 10 products by sales?"
"Find all orders from the last 30 days"

Analyze Schema

"What tables are in my database?"
"Describe the structure of the customers table"
"Show me the relationships between tables"

Data Analysis

"Calculate the average order value by month"
"Find duplicate records in the products table"
"Show me user registration trends"

Security Best Practices

⚠️ Important Security Considerations:

1. Use Read-Only Credentials: Create a dedicated MySQL user with read-only permissions for data analysis tasks

2. Never Commit Credentials: Don't commit the claude_desktop_config.json file with actual credentials to version control

3. Use Environment Variables: For production environments, consider using environment variable substitution

4. Limit Database Access: Only grant access to specific databases that Claude needs to work with

5. Use Strong Passwords: Ensure your MySQL password is strong and unique

6. Enable SSL/TLS: For remote connections, always use SSL/TLS encryption

7. Regular Auditing: Monitor database access logs regularly

Troubleshooting

Connection Issues

Problem: "Cannot connect to MySQL server"

• Verify MySQL server is running: systemctl status mysql (Linux) or check Services (Windows)
• Check host and port are correct
• Ensure firewall allows connections on MySQL port (default 3306)
• Verify credentials are correct

Problem: "Access denied for user"

• Confirm username and password are correct
• Check user has appropriate permissions: SHOW GRANTS FOR 'your_user'@'localhost';
• Verify user can connect from the specified host

Configuration Issues

Problem: Claude Desktop doesn't show the MySQL server

• Ensure the config file is in the correct location
• Check JSON syntax is valid (use a JSON validator)
• Restart Claude Desktop after making changes
• Check Claude Desktop logs for errors

Performance Issues

Problem: Queries are slow

• Add appropriate indexes to frequently queried columns
• Optimize complex queries
• Consider increasing MySQL connection timeout
• Check database server resources (CPU, memory)

Limitations

• Query Timeout: Long-running queries may timeout (default: 30 seconds)
• Result Size: Large result sets may be truncated
• Write Operations: Currently not supported
• Concurrent Connections: Limited by MySQL server's max_connections setting

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built on the Model Context Protocol
• Powered by Claude by Anthropic
• MySQL connector by mysql2
• Inspired by dpflucas mysql server

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