read-only-local-mysql

This MCP server exposes a read-only interface to a MySQL database, enabling Claude Desktop to translate natural language queries into safe, read-only SQL against the configured database. It validates queries to ensure only SELECT statements are executed and returns results in JSON format. To use it, configure Claude to connect to the MCP server via a MySQL MCP entry (the example uses the server name 'mysql'). Once connected, you can issue natural language questions such as requesting table lists, table schemas, or sample data, and Claude will generate and run the corresponding read-only SQL through the MCP server.

The MCP server exposes three core tools for Claude users:

• connect: Establish or change the active MySQL connection using a connection string. This persists for subsequent queries until you disconnect or change it.
• disconnect: End the current runtime connection and revert to the environment-configured defaults.
• query: Submit a read-only SQL query against the currently connected database. Claude will map your natural language request to a safe SELECT statement and return JSON results.

Prerequisites:

• Node.js (v16 or higher)
• MySQL server accessible with credentials
• Claude Desktop or Claude Code setup ready to configure MCP servers

Option A: Install from MCP Registry (Recommended)

1. Install the MCP server via npx (automated):

claude mcp add mysql -s user -- npx -y @hovecapital/read-only-mysql-mcp-server@latest

2. Set environment variables for your database credentials in Claude Desktop or Claude Code configuration as shown in the examples:

export DB_HOST=localhost
export DB_PORT=3306
export DB_DATABASE=your_database_name
export DB_USERNAME=your_username
export DB_PASSWORD=your_password

Option B: Manual JSON Configuration (Claude Desktop)

Edit Claude Desktop config:

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": ["-y", "@hovecapital/read-only-mysql-mcp-server@latest"],
      "env": {
        "DB_HOST": "localhost",
        "DB_PORT": "3306",
        "DB_DATABASE": "your_database_name",
        "DB_USERNAME": "your_username",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

Option C: Install from npm (local development)

npm install -g @hovecapital/read-only-mysql-mcp-server

Option D: Manual Installation (source)

# Clone the repository
mkdir -p ~/mcp-servers/mysql
cd ~/mcp-servers/mysql
git clone https://github.com/hovecapital/read-only-local-mysql-mcp-server.git .

# Install dependencies and build
npm install
npm run build

Then point Claude to the produced entry point as shown in the manual Claude Code configuration example.

Environment variables:

• DB_HOST defaults to localhost if not set by your configuration
• DB_PORT defaults to 3306
• DB_DATABASE, DB_USERNAME, DB_PASSWORD are required for establishing a connection
• The server only allows read-only queries; attempts to run non-SELECT statements will be blocked for safety. If you need to switch databases, update the environment variables or reconnect using the connect tool. Common issues:
• Incorrect connection string or credentials causing authentication failures
• Network/firewall blocks preventing MySQL host/port access
• Claude tool misconfiguration pointing to the wrong MCP server name If you encounter issues, ensure the MCP server is reachable from Claude, and verify the environment variables are correctly set in the client configuration.