MSSqlMcpDotNet

MsSqlMcpDotNet

Microsoft SQL Server MCP Server

MsSqlMcpDotNet is a Model Context Protocol (MCP) server that enables secure interaction with Microsoft SQL Server databases.
It allows AI assistants—such as GitHub Copilot Agent—to generate and execute SQL queries in a controlled and safe manner.

Features

• Implements an MCP server for Microsoft SQL Server.

• SQL injection protection via parameterized queries.

• Compatible with GitHub Copilot Agent.

• Retrieves server-level metadata:

  • Databases

• Retrieves detailed schema and database metadata:

  • Tables
  • Views
  • Columns
  • Keys (Primary / Foreign)

• Stores the database connection string securely using Windows DPAPI (Data Protection API).

• Fully asynchronous database operations using async/await.

• Structured logging with Serilog.

Prerequisites

• .NET 9.0 SDK or later to build and run the project.

SQL Server Secure Configuration

A SQL script is provided to create a dedicated secure login in SQL Server for use by the MCP server.
The MCP login is granted minimal read-only permissions on the target database.

⚠️ IMPORTANT:
The MCP user is explicitly restricted from writing or modifying data in the database or SQL Server instance. This ensures that the MCP server can only read data and cannot alter the database in any way.

/* ----------------------------------------------------------------------------------------------
   Use this script to create a login for the MCP user in SQL Server.
   Replace <yourStrongPassword123!> with the desired password for the login.
   ---------------------------------------------------------------------------------------------- */

USE [master]
GO
CREATE LOGIN [mcpUser]  
WITH  
    PASSWORD = N'<yourStrongPassword123!>',  
    DEFAULT_DATABASE = [master],  
    CHECK_EXPIRATION = OFF,  
    CHECK_POLICY = OFF
GO

GRANT CONNECT ANY DATABASE TO [mcpUser]
GO
GRANT CONNECT SQL TO [mcpUser]
GO
GRANT VIEW ANY DATABASE TO [mcpUser]
GO
GRANT VIEW ANY DEFINITION TO [mcpUser]
GO
GRANT VIEW ANY ERROR LOG TO [mcpUser]
GO
GRANT VIEW ANY PERFORMANCE DEFINITION TO [mcpUser]
GO
GRANT VIEW SERVER STATE TO [mcpUser]
GO

-- Read permission in the specific database
USE [<MyDatabase>]
GO
CREATE USER [mcpUser] FOR LOGIN [mcpUser]
GO
ALTER ROLE [db_datareader] ADD MEMBER [mcpUser]
GO

MCP Server Configuration

To set the connection string and configure the MCP server, simply run MSSqlMcpDotNet.exe.
The program will prompt for:

• SQL Server instance name
• Trusted connection option
• User credentials (if required)

This process will generate a sqlserver.secured.json file containing the connection string encrypted using DPAPI.

If you wish to change the access credentials, simply delete the existing sqlserver.secured.json file and repeat the configuration process.

Visual Studio Code Configuration

Edit your App.Settings file and add the MCP server configuration under the mcp section.
Remember to start the server before using it from Visual Studio Code.

"mcp": {
    "servers": {
        "MSSqlMcpDotNet": {
            "type": "stdio",
            "command": "C:\\bin\\mcp\\MSSqlMcpDotNet\\MSSqlMcpDotNet.exe",
            "args": []
        }
    }
}

mcp.json

This file is used in Visual Studio 2022 or in any MCP Client Application.

The mcp.json file defines the MCP server configuration.

{
  "servers": {
    "MSSqlMcpDotNet": {
      "type": "stdio",
      "command": "C:\\bin\\mcp\\MSSqlMcpDotNet\\MSSqlMcpDotNet.exe",
      "args": []
    }
  }
}

License

This project is licensed under the MIT License.
See the LICENSE file for more details.