MCP SQL Server

A Model Context Protocol (MCP) server for SQL Server integration with Claude Code. Query, monitor, and analyze your SQL Server databases directly from Claude.

Features

Query Execution - Execute SELECT queries with parameterized inputs
Schema Exploration - Browse tables, columns, procedures, and indexes
Database Monitoring - Track active queries, blocking sessions, wait stats, and connections
Performance Analysis - Identify missing indexes, unused indexes, and fragmentation
Write Operations - INSERT, UPDATE, DELETE when enabled (READONLY=false)

Installation

Option 1: From npm (recommended)

npx @fabriciofs/mcp-sql-server

Option 2: Global installation

npm install -g @fabriciofs/mcp-sql-server

Option 3: Clone and build locally

git clone https://github.com/fabriciofs/mcp-sql-server.git
cd mcp-sql-server
npm install
npm run build

Configuration

Claude Code Integration

Add to your Claude Code MCP settings (~/.claude/settings.json or project .claude/settings.json):

{
  "mcpServers": {
    "sqlserver": {
      "command": "npx",
      "args": ["-y", "@fabriciofs/mcp-sql-server"],
      "env": {
        "SQL_CONNECTION_URL": "sqlserver://user:password@localhost:1433/database",
        "READONLY": "true"
      }
    }
  }
}

Or with individual connection parameters:

{
  "mcpServers": {
    "sqlserver": {
      "command": "npx",
      "args": ["-y", "@fabriciofs/mcp-sql-server"],
      "env": {
        "SQL_SERVER": "localhost",
        "SQL_DATABASE": "mydb",
        "SQL_USER": "sa",
        "SQL_PASSWORD": "yourpassword",
        "SQL_PORT": "1433",
        "SQL_TRUST_CERT": "true",
        "READONLY": "true"
      }
    }
  }
}

Environment Variables

Connection (choose one method)

Method 1: Connection URL

SQL_CONNECTION_URL=sqlserver://user:password@host:port/database?TrustServerCertificate=true

Method 2: Individual Parameters

SQL_SERVER=localhost
SQL_DATABASE=mydb
SQL_USER=sa
SQL_PASSWORD=yourpassword
SQL_PORT=1433              # Optional, default: 1433
SQL_ENCRYPT=true           # Optional, default: true
SQL_TRUST_CERT=false       # Optional, default: false

Required Settings

Variable	Description
`READONLY`	Required. Set to `true` for read-only mode or `false` to enable write operations

Optional Settings

Variable	Default	Description
`QUERY_TIMEOUT`	`30000`	Query timeout in milliseconds (max: 120000)
`MAX_ROWS`	`1000`	Maximum rows to return (max: 5000)
`POOL_MIN`	`2`	Minimum connection pool size
`POOL_MAX`	`10`	Maximum connection pool size
`LOG_LEVEL`	`info`	Log level: debug, info, warn, error

Available Tools

Query Tools

Tool	Description
`sql_execute`	Execute SELECT queries with parameterized inputs

Schema Tools

Tool	Description
`schema_list_tables`	List all tables and views in the database
`schema_describe_table`	Get detailed table information (columns, indexes, foreign keys)
`schema_list_columns`	Search for columns across all tables
`schema_list_procedures`	List stored procedures
`schema_list_indexes`	List indexes with usage statistics

Monitor Tools

Tool	Description
`monitor_active_queries`	Monitor currently running queries
`monitor_blocking`	Monitor blocking sessions and lock chains
`monitor_wait_stats`	Monitor wait statistics for performance bottlenecks
`monitor_database_size`	Monitor database size and file usage
`monitor_connections`	Monitor active connections
`monitor_performance_counters`	Monitor SQL Server performance counters

Analysis Tools

Tool	Description
`analyze_query`	Analyze query execution plan and statistics
`analyze_suggest_indexes`	Suggest missing indexes based on query patterns
`analyze_unused_indexes`	Find indexes that are not being used
`analyze_duplicate_indexes`	Find duplicate or overlapping indexes
`analyze_fragmentation`	Analyze index fragmentation levels
`analyze_statistics`	Analyze table statistics for stale data

Write Tools (READONLY=false only)

Tool	Description
`sql_insert`	Insert a row into a table
`sql_update`	Update rows in a table
`sql_delete`	Delete rows from a table

Usage Examples

Once configured, you can ask Claude to interact with your database:

"List all tables in the database"
"Describe the Users table"
"Show me active queries running for more than 5 seconds"
"Find unused indexes in the Orders table"
"Analyze the fragmentation of all indexes"
"What are the top wait statistics?"

Security Considerations

Always use READONLY=true in production unless write access is explicitly required
Store credentials securely using environment variables
Use SQL Server accounts with minimal required permissions
Consider network security (VPN, firewall rules) for remote connections

Requirements

Node.js >= 20.0.0
SQL Server 2016 or later
Appropriate SQL Server permissions for the operations you want to perform

Development

# Install dependencies
npm install

# Build
npm run build

# Development mode (watch)
npm run dev

# Type check
npm run typecheck

# Run MCP Inspector
npm run inspector

License

MIT License - see LICENSE file for details.