SQLx MCP Server

A Model Context Protocol (MCP) server implementation in Rust that provides comprehensive database management tools using SQLx.

🚀 Features

This server provides 6 powerful MCP tools for database management:

1. 🔍 get_database_info - Get basic database information
2. 📋 list_tables - List all tables with metadata (comments, row counts, etc.)
3. 🏗️ get_table_structure - Get detailed table structure information
4. 📜 get_table_ddl - Export table DDL (CREATE TABLE statements)
5. 👁️ execute_readonly_query - Execute read-only SQL queries safely
6. ✏️ execute_write_query - Execute write SQL operations

🎯 Smart Configuration Management

• Auto-Configuration Detection: Server automatically detects and reports database configuration at startup
• Client Notification: Clients receive configuration status via MCP protocol initialization
• Flexible URL Management: Optional database URL parameters when server is pre-configured
• Secure Display: Database credentials are automatically masked for security

🗄️ Supported Databases

• PostgreSQL - Full support with native features
• MySQL - Complete functionality including engine-specific features
• SQLite - Comprehensive support for embedded database operations

🔧 Installation

Option 1: NPM (Recommended)

Install globally via npm:

npm install -g @sqlx-mcp/sqlx-mcp

Or use directly with npx (no installation needed):

npx @sqlx-mcp/sqlx-mcp --database-url "postgresql://user:pass@localhost/mydb"

Option 2: Build from Source

Prerequisites

• Rust 1.70 or later
• Git

Build Steps

git clone https://github.com/lihongjie0209/sqlx-mcp.git
cd sqlx-mcp
cargo build --release

🚀 Quick Start

1. Run as Standalone Server

Using NPM/npx (Recommended):

# Install globally and run
npm install -g @sqlx-mcp/sqlx-mcp
sqlx-mcp --database-url "postgresql://user:pass@localhost/mydb"

# Or run directly with npx (no installation needed)
npx @sqlx-mcp/sqlx-mcp --database-url "postgresql://user:pass@localhost/mydb"

# With environment variable
export DATABASE_URL="postgresql://user:pass@localhost/mydb"
npx @sqlx-mcp/sqlx-mcp

Using Built Binary:

# With environment variable
export DATABASE_URL="postgresql://user:pass@localhost/mydb"
./target/release/sqlx-mcp

# With command line argument
./target/release/sqlx-mcp --database-url "postgresql://user:pass@localhost/mydb"

2. Integrate with Claude Desktop

Add to your Claude Desktop configuration. The server will automatically notify Claude about the current database configuration status.

Using NPM Package (Recommended):

With Environment Variable (Recommended):

{
  "mcpServers": {
    "sqlx-mcp": {
      "command": "npx",
      "args": ["@sqlx-mcp/sqlx-mcp"],
      "env": {
        "DATABASE_URL": "postgresql://user:pass@localhost/mydb"
      }
    }
  }
}

With Command Line Argument:

{
  "mcpServers": {
    "sqlx-mcp": {
      "command": "npx",
      "args": ["@sqlx-mcp/sqlx-mcp", "--database-url", "postgresql://user:pass@localhost/mydb"]
    }
  }
}

Without Pre-configuration (require database_url in each tool call):

{
  "mcpServers": {
    "sqlx-mcp": {
      "command": "npx",
      "args": ["@sqlx-mcp/sqlx-mcp"]
    }
  }
}

Using Built Binary:

Windows (%APPDATA%\Claude\claude_desktop_config.json):

{
  "mcpServers": {
    "sqlx-mcp": {
      "command": "D:\\path\\to\\sqlx-mcp\\target\\release\\sqlx-mcp.exe",
      "args": ["--database-url", "postgresql://user:pass@localhost/mydb"]
    }
  }
}

macOS/Linux:

{
  "mcpServers": {
    "sqlx-mcp": {
      "command": "/path/to/sqlx-mcp/target/release/sqlx-mcp",
      "args": ["--database-url", "postgresql://user:pass@localhost/mydb"]
    }
  }
}

🔗 Database Configuration

The server provides intelligent database configuration management with automatic detection and client notification.

Configuration Priority

The server resolves database connections with the following priority:

1. Tool Parameter (highest) - database_url parameter in individual tool calls
2. Command Line - --database-url argument at server startup
3. Environment Variable (lowest) - DATABASE_URL environment variable

Auto-Detection & Client Notification

When clients connect to the MCP server, they automatically receive configuration information:

• Configuration Status: Whether a database is pre-configured
• Connection Source: How the database was configured (command line, environment, or none)
• Masked URL: Database connection string with credentials safely hidden
• Usage Guidance: Whether database_url parameter is required in tool calls

Example Client Notifications:

No Configuration:

Current database configuration: No database configured. Please provide database_url parameter in tool calls or set DATABASE_URL environment variable.

Environment Variable Configuration:

Current database configuration: Database configured via environment variable: postgresql://user:***@localhost:5432/mydb

If a database is already configured, you can omit the database_url parameter in tool calls.

Command Line Configuration:

Current database configuration: Database configured via command line: mysql://root:***@localhost:3306/testdb

If a database is already configured, you can omit the database_url parameter in tool calls.

Flexible Usage Patterns

Pre-configured Server (Recommended)

# Set up database via environment variable
export DATABASE_URL="postgresql://user:pass@localhost/mydb"
npx @sqlx-mcp/sqlx-mcp

# Or via command line
npx @sqlx-mcp/sqlx-mcp --database-url "postgresql://user:pass@localhost/mydb"

Then use tools without database_url parameter:

{
  "name": "list_tables",
  "arguments": {}
}

Per-Tool Database URLs

{
  "name": "list_tables", 
  "arguments": {
    "database_url": "postgresql://user:pass@different-host/other-db"
  }
}

This allows flexible connection management for multiple databases.

🛠️ Tool Usage Examples

Get Database Information

{
  "name": "get_database_info",
  "arguments": {
    "database_url": "postgresql://user:pass@localhost/mydb"  // Optional if server is pre-configured
  }
}

List Tables with Metadata

{
  "name": "list_tables",
  "arguments": {
    "database_url": "postgresql://user:pass@localhost/mydb"  // Optional if server is pre-configured
  }
}

Export Table DDL

{
  "name": "get_table_ddl",
  "arguments": {
    "database_url": "postgresql://user:pass@localhost/mydb",  // Optional if server is pre-configured
    "table_name": "users"
  }
}

Execute Safe Read-Only Queries

Supports SELECT, WITH (CTE), SHOW, DESCRIBE, EXPLAIN:

{
  "name": "execute_readonly_query",
  "arguments": {
    "database_url": "postgresql://user:pass@localhost/mydb",  // Optional if server is pre-configured
    "query": "WITH recent_users AS (SELECT * FROM users WHERE created_at > '2024-01-01') SELECT count(*) FROM recent_users"
  }
}

Note: When the server is pre-configured with a database (via command line or environment variable), the database_url parameter becomes optional in all tool calls. The server will notify clients about the current configuration status during MCP initialization.

🔒 Security Features

• Query Validation: Strict read-only query enforcement for safe operations
• SQL Injection Protection: Parameterized queries where possible
• Connection Security: Supports SSL/TLS encrypted connections
• Access Control: Respects database user permissions
• Credential Protection: Database passwords automatically masked in logs and client notifications
• Secure Configuration Display: Connection strings shown with sensitive information hidden

🏗️ Architecture

Built with modern Rust ecosystem:

• rmcp - Rust MCP SDK for protocol compliance
• SQLx - Async SQL toolkit with compile-time checked queries
• Tokio - Async runtime for high performance
• Serde - Serialization framework for JSON handling
• Tracing - Structured logging and debugging

📚 Documentation

• Detailed Usage Guide
• Database Configuration Guide
• DDL Export Feature
• List Tables Feature
• Improvements Summary
• Deployment Guide
• PowerShell Environment Setup

🔧 Development & Release

This project includes an advanced automated release system powered by AI:

Environment Setup

For Windows PowerShell users who want to use the automated release features:

# Quick setup using .env file (recommended)
Copy-Item ".env.template" ".env"
notepad .env  # Add your OPENROUTER_API_KEY

# Or set environment variable for current session
$env:OPENROUTER_API_KEY = "your-api-key-here"

For detailed PowerShell environment setup, see PowerShell Environment Setup Guide.

Release Management

The project includes a comprehensive release script with AI-powered commit message generation:

# Create automated release with AI-generated commit messages
npm run release

# The script will:
# - Bump version numbers
# - Generate intelligent commit messages using AI
# - Update package files
# - Create git commits and tags
# - Push to repository

Features:

• 🤖 AI-powered commit message generation using OpenRouter
• 📦 Automatic version management
• 🔄 Multi-file synchronization (Cargo.toml ↔ package.json)
• 🚀 Git automation (commit, tag, push)
• 🖥️ Cross-platform support (Windows, macOS, Linux)

🤝 Contributing

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

📄 License

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

🙏 Acknowledgments

• Model Context Protocol for the protocol specification
• SQLx for the excellent SQL toolkit
• rmcp for the Rust MCP SDK

📞 Support

• Create an Issue for bug reports
• Start a Discussion for questions
• Check the Documentation for detailed guides

---

Made with ❤️ and 🦀 (Rust)