MCP Server for MySQL based on NodeJS

A Model Context Protocol server that provides access to MySQL databases with fine-grained access control. Supports multiple databases, access modes, and table-level permissions.

Features

• Multi-database support: Connect to multiple MySQL databases simultaneously
• Access control: readonly, readwrite, full modes per database
• Table-level permissions: Whitelist/blacklist with wildcards and regex
• Read-only transaction protection: Database-level safety for readonly mode
• Backward compatible: Works with single database environment variables

Components

Tools

Tool	Description
mysql_query	Read-only SELECT queries (always available)
mysql_execute	Write operations (only visible when writable databases exist)

Resources

• mysql://connections: List of database connections with access modes
• mysql://{db}/tables/{table}/schema: Table schema

Prompts

• mysql_usage_guide: Dynamic guide based on configured databases

Configuration

Config File

Create ~/.mcp_mysql/databases.json:

{
  "databases": [
    {
      "name": "prod",
      "host": "prod-db.example.com",
      "port": 3306,
      "user": "readonly_user",
      "password": "***",
      "database": "production",
      "accessMode": "readonly"
    },
    {
      "name": "dev",
      "host": "localhost",
      "port": 3306,
      "user": "dev_user",
      "password": "***",
      "database": "development",
      "accessMode": "readwrite",
      "allowedTables": ["log_*", "tmp_*", "/^test_.*/i"]
    }
  ]
}

Access Modes

Mode	SELECT	INSERT/UPDATE/DELETE	DDL
readonly (default)	✅	❌	❌
readwrite	✅	✅	❌
full	✅	✅	✅

Table Patterns

Format	Example	Matches
Exact	log_table	Only log_table
Wildcard	log_*	log_ prefix
Regex	/^test_\d+$/i	test_ + digits

Environment Variables

Variable	Description
MYSQL_CONFIG_PATH	Custom config file path
MYSQL_HOST	Legacy single-database host
MYSQL_PORT	Legacy single-database port
MYSQL_USER	Legacy single-database user
MYSQL_PASS	Legacy single-database password
MYSQL_DB	Legacy single-database name

Usage with Claude Desktop

Multi-database configuration (Recommended)

First, create ~/.mcp_mysql/databases.json with your database configurations.

Then add to your claude_desktop_config.json:

{
  "mcpServers": {
    "mcp_server_mysql": {
      "command": "npx",
      "args": [
        "-y",
        "@zhengyun1008/mcp-server-mysql"
      ]
    }
  }
}

Single database (Legacy, backward compatible)

{
  "mcpServers": {
    "mcp_server_mysql": {
      "command": "npx",
      "args": [
        "-y",
        "@zhengyun1008/mcp-server-mysql"
      ],
      "env": {
        "MYSQL_HOST": "127.0.0.1",
        "MYSQL_PORT": "3306",
        "MYSQL_USER": "root",
        "MYSQL_PASS": "",
        "MYSQL_DB": "db_name"
      }
    }
  }
}

Usage Examples

User: "查询 prod 库中的用户表"
→ mysql_query(database="prod", sql="SELECT * FROM users")

User: "在 dev 库的 log_test 表插入一条记录"
→ mysql_execute(database="dev", sql="INSERT INTO log_test ...", confirm=true)

Security

• readonly mode: Uses SET SESSION TRANSACTION READ ONLY for database-level protection
• SQL validation: Validates statement type before execution
• Table validation: Checks whitelist/blacklist before write operations
• Confirmation required: Write operations require confirm=true

Troubleshooting

If you encounter an error "Could not connect to MCP server mcp-server-mysql", you may need to explicitly set the path of all required binaries such as the configuration below:

{
  "mcpServers": {
    "mcp_server_mysql": {
      "command": "/path/to/npx/binary/npx",
      "args": [
        "-y",
        "@zhengyun1008/mcp-server-mysql"
      ],
      "env": {
        "MYSQL_HOST": "127.0.0.1",
        "MYSQL_PORT": "3306",
        "MYSQL_USER": "root",
        "MYSQL_PASS": "",
        "MYSQL_DB": "db_name",
        "PATH": "/path/to/node/bin:/usr/bin:/bin"
      }
    }
  }
}

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.