# FastMCP MySQL Server

A FastMCP server implementation for MySQL database operations, providing secure and efficient access to MySQL databases for LLM applications.

## Features

- 🔒 **Secure by Default**: Read-only access with optional write permissions
- ⚡ **High Performance**: Connection pooling and async operations
- 🛡️ **SQL Injection Protection**: Built-in query validation and prepared statements
- 📊 **Comprehensive Monitoring**: Structured JSON logging
- 🔧 **Flexible Configuration**: Environment variable based configuration
- 🚀 **Easy Deployment**: Install and run with `uvx`

## Installation

### Using uvx (Recommended)

```bash
# Run directly with uvx
uvx fastmcp-mysql

# With environment variables
MYSQL_HOST=localhost MYSQL_USER=myuser MYSQL_PASSWORD=mypass MYSQL_DB=mydb uvx fastmcp-mysql
```

### Using pip

```bash
pip install fastmcp-mysql
```

### From source

```bash
git clone https://github.com/jinto/fastmcp-mysql
cd fastmcp-mysql
uv sync --all-extras
```

## Configuration

Configure the server using environment variables:

### Required Variables

| Variable         | Description       | Default |
| ---------------- | ----------------- | ------- |
| `MYSQL_USER`     | Database username | -       |
| `MYSQL_PASSWORD` | Database password | -       |

### Optional Variables

| Variable                        | Description                             | Default     |
| ------------------------------- | --------------------------------------- | ----------- |
| `MYSQL_HOST`                    | Database host                           | "127.0.0.1" |
| `MYSQL_PORT`                    | Database port                           | "3306"      |
| `MYSQL_DB`                      | Database name (optional)                | None        |
| `MYSQL_ALLOW_INSERT`            | Enable INSERT queries                   | false       |
| `MYSQL_ALLOW_UPDATE`            | Enable UPDATE queries                   | false       |
| `MYSQL_ALLOW_DELETE`            | Enable DELETE queries                   | false       |
| `MYSQL_POOL_SIZE`               | Connection pool size                    | 10          |
| `MYSQL_QUERY_TIMEOUT`           | Query timeout (ms)                      | 30000       |
| `MYSQL_LOG_LEVEL`               | Log level (DEBUG, INFO, WARNING, ERROR) | INFO        |
| `MYSQL_CACHE_ENABLED`           | Enable query result caching             | true        |
| `MYSQL_CACHE_MAX_SIZE`          | Maximum cache entries                   | 1000        |
| `MYSQL_CACHE_TTL`               | Cache TTL (ms)                          | 60000       |
| `MYSQL_CACHE_EVICTION_POLICY`   | Cache eviction policy (lru/ttl/fifo)    | lru         |
| `MYSQL_CACHE_CLEANUP_INTERVAL`  | Cache cleanup interval (seconds)        | 60.0        |
| `MYSQL_CACHE_INVALIDATION_MODE` | Cache invalidation strategy             | aggressive  |
| `MYSQL_STREAMING_CHUNK_SIZE`    | Streaming query chunk size              | 1000        |
| `MYSQL_PAGINATION_DEFAULT_SIZE` | Default page size                       | 10          |
| `MYSQL_PAGINATION_MAX_SIZE`     | Maximum page size                       | 1000        |

## Usage

### Claude Desktop Configuration

#### Using Claude MCP CLI (Recommended)

```bash
# Install from PyPI (when published)
claude mcp add fastmcp-mysql \
  -e MYSQL_HOST="127.0.0.1" \
  -e MYSQL_PORT="3306" \
  -e MYSQL_USER="your_username" \
  -e MYSQL_PASSWORD="your_password" \
  -e MYSQL_DB="your_database" \
  -- uvx fastmcp-mysql

# Without specifying a database (use USE command)
claude mcp add fastmcp-mysql \
  -e MYSQL_HOST="127.0.0.1" \
  -e MYSQL_USER="your_username" \
  -e MYSQL_PASSWORD="your_password" \
  -- uvx fastmcp-mysql

# For local development
claude mcp add fastmcp-mysql \
  -e MYSQL_HOST="127.0.0.1" \
  -e MYSQL_PORT="3306" \
  -e MYSQL_USER="your_username" \
  -e MYSQL_PASSWORD="your_password" \
  -e MYSQL_DB="your_database" \
  -- uv run --project /path/to/fastmcp-mysql fastmcp-mysql
```

#### Manual Configuration

Add to your Claude Desktop configuration file:

```json
{
  "mcpServers": {
    "mysql": {
      "command": "uvx",
      "args": ["fastmcp-mysql"],
      "env": {
        "MYSQL_HOST": "localhost",
        "MYSQL_PORT": "3306",
        "MYSQL_USER": "your_username",
        "MYSQL_PASSWORD": "your_password",
        "MYSQL_DB": "your_database",
        "MYSQL_ENABLE_SECURITY": "true",
        "MYSQL_RATE_LIMIT_RPM": "60",
        "MYSQL_RATE_LIMIT_BURST": "10"
      }
    }
  }
}
```

### Available Tools

#### mysql_query

Execute SQL queries against the configured MySQL database.

**Parameters:**

- `query` (string, required): The SQL query to execute
- `params` (array, optional): Query parameters for prepared statements
- `database` (string, optional): Target database (for multi-db mode)

**Example:**

```python
# Simple query
result = await mysql_query("SELECT * FROM users WHERE active = 1")

# With parameters (SQL injection safe)
result = await mysql_query(
    "SELECT * FROM users WHERE age > %s AND city = %s",
    params=[18, "New York"]
)

# When no database is specified initially
result = await mysql_query("USE mydb")
result = await mysql_query("SHOW TABLES")
result = await mysql_query("SHOW DATABASES")
```

## Security

### Default Security Features

FastMCP MySQL includes comprehensive security features:

- **Read-only by default**: Write operations must be explicitly enabled
- **SQL injection prevention**:
  - Advanced pattern detection for SQL injection attempts
  - Parameter validation for all queries
  - Detection of encoded injection attempts (URL, Unicode, Hex)
- **Query filtering**:
  - Blacklist mode: Blocks dangerous operations (DDL, system tables, file operations)
  - Whitelist mode: Only allows explicitly approved query patterns
  - Customizable filtering rules
- **Rate limiting**:
  - Per-user request throttling
  - Configurable algorithms (Token Bucket, Sliding Window, Fixed Window)
  - Burst protection

### Security Configuration

Configure security features via environment variables:

| Variable                           | Description                                                        | Default      |
| ---------------------------------- | ------------------------------------------------------------------ | ------------ |
| `MYSQL_ENABLE_SECURITY`            | Enable all security features                                       | true         |
| `MYSQL_ENABLE_INJECTION_DETECTION` | Enable SQL injection detection                                     | true         |
| `MYSQL_ENABLE_RATE_LIMITING`       | Enable rate limiting                                               | true         |
| `MYSQL_FILTER_MODE`                | Filter mode (blacklist/whitelist/combined)                         | blacklist    |
| `MYSQL_RATE_LIMIT_RPM`             | Rate limit requests per minute                                     | 60           |
| `MYSQL_RATE_LIMIT_BURST`           | Burst size for rate limiting                                       | 10           |
| `MYSQL_RATE_LIMIT_ALGORITHM`       | Rate limiting algorithm (token_bucket/sliding_window/fixed_window) | token_bucket |
| `MYSQL_MAX_QUERY_LENGTH`           | Maximum query length in characters                                 | 10000        |
| `MYSQL_MAX_PARAMETER_LENGTH`       | Maximum parameter length                                           | 1000         |
| `MYSQL_LOG_SECURITY_EVENTS`        | Log security violations                                            | true         |
| `MYSQL_LOG_REJECTED_QUERIES`       | Log rejected queries                                               | true         |
| `MYSQL_AUDIT_ALL_QUERIES`          | Audit all queries (performance impact)                             | false        |

### Enabling Write Operations

Write operations are disabled by default. Enable them with caution:

```bash
# Enable specific write operations
MYSQL_ALLOW_INSERT=true \
MYSQL_ALLOW_UPDATE=true \
MYSQL_ALLOW_DELETE=true \
uvx fastmcp-mysql
```

### Security Best Practices

1. **Use Prepared Statements**: Always use parameters instead of string concatenation
2. **Principle of Least Privilege**: Only enable write operations when necessary
3. **Monitor Security Events**: Check logs for security violations
4. **Rate Limiting**: Adjust limits based on your application needs
5. **Whitelist Mode**: Use whitelist mode for production environments when possible

## Development

### Setup Development Environment

```bash
# Clone the repository
git clone https://github.com/jinto/fastmcp-mysql
cd fastmcp-mysql

# Create virtual environment with uv
uv venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate

# Install dependencies
uv sync --all-extras

# Install pre-commit hooks
pre-commit install
```

### Running Tests

```bash
# Run all tests
uv run pytest tests/

# Run with coverage
uv run pytest tests/ --cov=fastmcp_mysql

# Run specific test file
uv run pytest tests/unit/test_query.py

# Run integration tests only
uv run pytest tests/integration/
```

### Code Quality

```bash
# Format code
uv run black src tests

# Lint code
uv run ruff check src tests

# Type checking
uv run mypy src
```

## Architecture

The server follows Clean Architecture principles:

```
src/fastmcp_mysql/
├── __init__.py                 # Package initialization
├── __main__.py                 # Entry point for uvx
├── config.py                   # Configuration management
├── server.py                   # FastMCP server setup
├── connection.py               # Database connection management
├── security/                   # Security module (Clean Architecture)
│   ├── __init__.py
│   ├── manager.py              # Security orchestration
│   ├── config.py               # Security configuration
│   ├── exceptions.py           # Security exceptions
│   ├── interfaces/             # Abstract interfaces
│   │   ├── injection_detector.py
│   │   ├── query_filter.py
│   │   └── rate_limiter.py
│   ├── injection/              # SQL injection detection
│   │   ├── detector.py
│   │   └── patterns.py
│   ├── filtering/              # Query filtering
│   │   ├── blacklist.py
│   │   ├── whitelist.py
│   │   └── combined.py
│   └── rate_limiting/          # Rate limiting
│       ├── token_bucket.py
│       ├── sliding_window.py
│       ├── fixed_window.py
│       └── factory.py
└── tools/                      # MCP tools
    ├── __init__.py
    └── query.py                # Query execution tool
```

## Contributing

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

Please ensure:

- All tests pass
- Code is formatted with black
- Type hints are added
- Documentation is updated

## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

## Acknowledgments

- Based on the [MCP Server MySQL](https://github.com/benborla/mcp-server-mysql) Node.js implementation
- Built with [FastMCP](https://github.com/jlowin/fastmcp) framework
- MySQL connectivity via [aiomysql](https://github.com/aio-libs/aiomysql)

## Support

- 📖 [Documentation](https://github.com/jinto/fastmcp-mysql/wiki)
- 🐛 [Issue Tracker](https://github.com/jinto/fastmcp-mysql/issues)
- 💬 [Discussions](https://github.com/jinto/fastmcp-mysql/discussions)
