LocalDB MCP Server

An MCP (Model Context Protocol) server that enables AI assistants to query and interact with Microsoft SQL Server LocalDB (MSSQLLocalDB).

Features

This MCP server provides the following tools:

Tool	Description
list_databases	List all databases on the LocalDB instance
connect_database	Connect to a specific database
list_tables	List all tables in the current database
describe_table	Get detailed schema information (columns, keys, indexes)
query	Execute SELECT queries (read-only, safe)
execute_sql	Execute any SQL statement (INSERT, UPDATE, DELETE, DDL)
database_info	Get database metadata and statistics
list_stored_procedures	List all stored procedures
get_procedure_definition	Get the source code of a stored procedure
sample_data	Get sample rows from a table

Prerequisites

• Node.js 18 or higher
• Microsoft SQL Server LocalDB installed
• LocalDB instance named MSSQLLocalDB (default)

Installation

npm install
npm run build

Usage

With VS Code (GitHub Copilot)

The .vscode/mcp.json file is already configured. Just open VS Code in this directory and the MCP server will be available.

With Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "localdb-mcp": {
      "command": "node",
      "args": ["d:/MCP HOLE/localdb-mcp/build/index.js"]
    }
  }
}

Manual Testing

npm start

Example Queries

Once connected, you can ask your AI assistant:

• "List all databases on LocalDB"
• "Connect to the AdventureWorks database"
• "Show me all tables in the current database"
• "Describe the Customers table"
• "Show me the first 10 rows from the Orders table"
• "How many records are in the Products table?"
• "What stored procedures exist in this database?"

Security Notes

• The query tool only allows SELECT statements for safety
• The execute_sql tool allows any SQL - use with caution
• Connections use Windows Authentication by default
• Only connects to LocalDB on the local machine

Development

# Watch mode for development
npm run dev

# Build for production
npm run build

Troubleshooting

Connection Issues

1. Ensure LocalDB is installed:

   sqllocaldb info
   

2. Start the LocalDB instance if not running:

   sqllocaldb start MSSQLLocalDB
   

3. Verify the instance is accessible:

   sqllocaldb info MSSQLLocalDB
   

Common Errors

• "Cannot connect to LocalDB": Make sure the MSSQLLocalDB instance exists and is running
• "Login failed": LocalDB uses Windows Authentication - ensure you have access
• "Database not found": Use list_databases to see available databases

License

MIT