MCP Microsoft SQL Server

A configurable Model Context Protocol (MCP) server for Microsoft SQL Server integration with Claude Code and other MCP clients. Enables AI assistants to securely interact with SQL Server databases through project-based configurations with full read/write capabilities.

🌟 Features

🔧 Project-Based Configuration

• Multiple database connections - Switch between different projects and databases
• Schema-specific access - Restrict access to specific schemas per project
• Configurable permissions - Fine-grained control over read/write/delete operations
• Environment-based setup - Different configurations for dev, staging, and production

🛡️ Security & Safety

• Transaction management - Automatic rollback on errors for write operations
• Query validation - Prevent SQL injection and validate all operations
• WHERE clause enforcement - Mandatory WHERE clauses for UPDATE/DELETE operations
• Row limit restrictions - Configurable limits to prevent accidental mass operations
• Audit logging - Track all database operations for accountability

🔍 Database Operations

• Read Operations: SELECT queries with pagination and filtering
• Write Operations: INSERT, UPDATE, DELETE with transaction safety
• Schema Exploration: Browse tables, columns, relationships, and indexes
• Table Management: Get metadata, statistics, and sample data
• Configuration Management: Switch between project configurations dynamically

🚀 AI Integration

• Claude Desktop integration - Seamless setup with Claude Desktop app
• MCP protocol compliance - Works with any MCP-compatible client
• Natural language interface - Interact with databases using plain English
• Error handling - Clear, actionable error messages for AI and humans

📋 Prerequisites

• .NET 9.0 or later
• Microsoft SQL Server (any supported version)
• Claude Desktop (for Claude integration)
• Appropriate database permissions for the operations you want to perform

🚀 Quick Start

1. Installation

# Clone the repository
git clone https://github.com/yourusername/mcp-ms-sql-server.git
cd mcp-ms-sql-server

# Build the project
dotnet build -c Release

2. Create Project Configuration

Create a configuration file for your project in the Configurations/ directory:

// Configurations/my-project.json
{
  "name": "My E-Commerce Project",
  "connectionString": "Server=localhost;Database=ECommerceDB;Integrated Security=true;",
  "allowedSchema": "dbo",
  "permissions": {
    "allowRead": true,
    "allowWrite": true,
    "allowDelete": false
  },
  "security": {
    "requireWhereClause": true,
    "maxRowsPerQuery": 1000,
    "auditOperations": true
  }
}

3. Configure Claude Desktop

Add to your Claude Desktop configuration:

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

{
  "mcpServers": {
    "sql-server": {
      "type": "stdio",
      "command": "C:\\Git\\mcp-ms-sql-server\\McpMsSqlServer\\bin\\Release\\net9.0\\McpMsSqlServer.exe",
      "env": {
        "MCP_CONFIG_NAME": "my-project"
      }
    }
  }
}

Note: First build the project with dotnet build -c Release to create the executable.

4. Start Using

In Claude Desktop, you can now ask:

• "Show me all tables in the database"
• "Insert a new customer with name 'John Doe' and email 'john@example.com'"
• "What are the top 10 products by sales?"
• "Update the price of product with ID 123 to $29.99"

📖 Configuration Guide

Project Configuration Structure

{
  "name": "Project Display Name",
  "connectionString": "Your SQL Server connection string",
  "allowedSchema": "schema_name",
  "permissions": {
    "allowRead": true,
    "allowWrite": true,
    "allowDelete": false,
    "allowSchemaChanges": false
  },
  "security": {
    "requireWhereClause": true,
    "maxRowsPerQuery": 1000,
    "maxRowsPerUpdate": 100,
    "maxRowsPerDelete": 10,
    "auditOperations": true
  },
  "querySettings": {
    "timeoutSeconds": 30,
    "enableQueryPlan": false,
    "allowJoins": true,
    "allowSubqueries": true
  },
  "restrictedTables": ["sensitive_table", "audit_log"],
  "allowedOperations": ["SELECT", "INSERT", "UPDATE", "DELETE"]
}

Example Configurations

{
  "name": "Development Database",
  "connectionString": "Server=dev-server;Database=DevDB;Integrated Security=true;",
  "allowedSchema": "dbo",
  "permissions": {
    "allowRead": true,
    "allowWrite": true,
    "allowDelete": true,
    "allowSchemaChanges": true
  },
  "security": {
    "requireWhereClause": false,
    "maxRowsPerQuery": 5000,
    "auditOperations": false
  }
}

{
  "name": "Production Database",
  "connectionString": "Server=prod-server;Database=ProdDB;User Id=app_user;Password=secure_password;",
  "allowedSchema": "app",
  "permissions": {
    "allowRead": true,
    "allowWrite": true,
    "allowDelete": false,
    "allowSchemaChanges": false
  },
  "security": {
    "requireWhereClause": true,
    "maxRowsPerQuery": 100,
    "maxRowsPerUpdate": 10,
    "auditOperations": true
  },
  "restrictedTables": ["user_passwords", "payment_info"]
}

🛠️ Available Tools

Configuration Management (4 tools)

• ListConfigurations - Show all available project configurations
• SwitchConfiguration - Switch to a different project configuration
• GetCurrentConfiguration - View current configuration details
• TestConnection - Test database connectivity

Core Database Operations (6 tools)

• ExecuteQuery - Run SELECT queries within allowed schema
• GetSchemaInfo - Explore database structure and objects
• GetTableInfo - Get table metadata and sample data
• InsertRecords - Insert new records with transaction support
• UpdateRecords - Update existing records (requires WHERE clause)
• DeleteRecords - Delete records (requires WHERE clause)

Advanced Features (6 tools)

• BuildQuery - Generate SQL queries from natural language
• AnalyzeQueryPerformance - Analyze query execution plans
• GetDatabasePerformanceStats - Database performance metrics
• DiscoverData - Search tables/columns by patterns
• AnalyzeTableRelationships - Find table relationships
• ProfileDataQuality - Analyze data quality and statistics

🔒 Security Considerations

Best Practices

• Use dedicated database users with minimal required permissions
• Enable audit logging for production environments
• Set appropriate row limits to prevent accidental mass operations
• Restrict sensitive tables using the restrictedTables configuration
• Use WHERE clause requirements for UPDATE/DELETE operations
• Regular security reviews of configurations and permissions

Connection String Security

# Use environment variables for sensitive data
export DB_PASSWORD="your_secure_password"

{
  "connectionString": "Server=myserver;Database=mydb;User Id=myuser;Password=${DB_PASSWORD};"
}

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

# Clone the repo
git clone https://github.com/yourusername/mcp-ms-sql-server.git
cd mcp-ms-sql-server

# Install dependencies
dotnet restore

# Run tests
dotnet test

# Build and test
dotnet build -c Release

📚 Documentation

• Configuration Guide
• Claude Desktop Setup
• Security Best Practices
• API Reference
• Troubleshooting

🐛 Troubleshooting

Common Issues

Connection Failed

# Test your connection string
dotnet run -- --test-connection --config your-project

Permission Denied

• Check your database user permissions
• Verify the allowedSchema configuration
• Ensure the user has access to the specified schema

Configuration Not Found

• Verify the configuration file exists in Configurations/
• Check the MCP_CONFIG_NAME environment variable
• Ensure the JSON syntax is valid

📄 License

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

🌟 Acknowledgments

• Model Context Protocol by Anthropic
• MCP C# SDK by Microsoft and Anthropic
• The open-source community for inspiration and feedback

📞 Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Documentation: Wiki

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