MSSQL MCP Server

Enterprise-grade Model Context Protocol server for Microsoft SQL Server.

A production-ready MCP server built for real-world database work: exploring unfamiliar schemas, profiling data shape, validating pipelines in UAT, and moving confidently to production. If you work with SQL Server and want AI tooling that understands enterprise database workflows, this is for you.

Package Tiers

Choose the tier that matches your security requirements. All tiers share the same governance controls, audit logging, and multi-environment support.

Why This Exists

Most SQL + AI demos stop at "generate a query." That's table stakes. Real database work means:

• Navigating massive schemas you didn't design, often with cryptic naming conventions
• Understanding data shape before writing anything
• Working safely in regulated environments where one bad UPDATE can trigger an incident
• Moving fast in UAT so you can validate changes before they hit production

This server is built around those realities. It's stable, secure by default, and designed to make AI assistants genuinely useful on enterprise SQL Server instances.

What's here today

• Semantic schema discovery – search_schema finds tables/columns via wildcards with fuzzy matching and paginated results so large databases don’t blow up your context window.
• Table profiling – profile_table summarizes column shape (null %, cardinality, min/max/avg/median/p90) and can return a capped sample of rows.
• Relationship mapping – inspect_relationships enumerates inbound/outbound FKs with column mappings, so you can follow dependencies before touching data.
• Flexible authentication – SQL auth, Windows auth, and Azure AD are supported; pick what matches your infra.
• Safe data operations – read_data, describe_table, list_table, plus write tools (insert_data, update_data, delete_data, create_table, create_index, drop_table) when you need full agent-mode workflows.
• Preview + Confirm for mutations – update_data and delete_data show affected rows before execution; require explicit confirmation to proceed.
• Multi-environment support – Define named database environments (prod, staging, dev) in a JSON config; switch between them per request.
• Audit logging – Every tool invocation logged to JSON Lines format with timestamps, arguments (auto-redacted), and results.
• MCP-native – Works with Windsurf, Claude Desktop, and any MCP-compatible client.

Key tools at a glance

Discovery & Schema:

• search_schema – Wildcard/fuzzy search across tables and columns with pagination.
• describe_table – Column definitions, types, nullability, keys.
• list_table – List all tables in a database with optional filtering.
• list_databases – List databases on server-level environments.
• list_environments – Show configured environments and their policies.

Profiling & Analysis:

• profile_table – Column stats (null %, cardinality, min/max/avg/median/p90) with optional sample rows.
• inspect_relationships – FK mappings in both directions.
• inspect_dependencies – Full dependency analysis (views, procs, functions, triggers referencing an object).
• explain_query – Execution plan analysis via SHOWPLAN.

Data Operations:

• read_data – Safe SELECT with automatic row limits.
• insert_data – Parameterized inserts (single or batch).
• update_data – Preview affected rows, require confirmation.
• delete_data – Preview affected rows, require confirmation.

DDL Operations:

• create_table – Create tables with column definitions.
• create_index – Create indexes on existing tables.
• drop_table – Drop tables (requires confirmation).

Named Scripts:

• list_scripts – Show available pre-approved SQL scripts.
• run_script – Execute named scripts with parameters and governance controls.
• Scripts directory – Point the server at a folder containing scripts.json + .sql files by setting SCRIPTS_PATH (env var) or "scriptsPath" inside your environment entry. list_scripts/run_script remain disabled until this location is configured.

Operations:

• test_connection – Verify connectivity and latency.
• validate_environment_config – Check environment configuration for errors.

Prerequisites

You’ll need a current Node.js runtime (minimum 18, recommended 20 LTS). The tooling now shims legacy APIs so it also works on the newest Node releases, but installing an LTS build avoids surprises on fresh machines.

Verify with node -v (should show v20.x). If you already have a newer Node version installed, the server will still run thanks to the built-in SlowBuffer shim.

Quick start

Option 1: Install from npm (recommended)

npm install -g @connorbritain/mssql-mcp-server@latest

Then configure your MCP client:

{

  "mcpServers": {

    "mssql": {

      "command": "npx",

      "args": ["@connorbritain/mssql-mcp-server@latest"],

      "env": { "SERVER_NAME": "localhost", "DATABASE_NAME": "mydb", "READONLY": "true" }

    }

  }

}

Option 2: Build from source

git clone https://github.com/ConnorBritain/mssql-mcp-server.git

cd mssql-mcp-server/src/node

npm install

npm run build

Then point your MCP client to src/node/dist/index.js with your connection env vars.

Configuration

Environment variables

Authentication modes

SQL Server Authentication (SQL_AUTH_MODE=sql)
Standard username/password auth against SQL Server. Works with local instances, Docker containers, and Azure SQL with SQL auth enabled.

"env": {

  "SERVER_NAME": "127.0.0.1",

  "DATABASE_NAME": "mydb",

  "SQL_AUTH_MODE": "sql",

  "SQL_USERNAME": "sa",

  "SQL_PASSWORD": "YourPassword123",

  "SQL_PORT": "1433",

  "TRUST_SERVER_CERTIFICATE": "true"

}

Windows Authentication (SQL_AUTH_MODE=windows) NTLM-based auth using domain credentials. Ideal for on-prem SQL Server in Active Directory environments.

The server auto-parses DOMAIN\username format — you can provide the domain either as a separate SQL_DOMAIN field or embedded in SQL_USERNAME (e.g., CORP\svc_account). If both are present, the explicit SQL_DOMAIN takes precedence and the prefix is stripped from the username.

"env": {

  "SERVER_NAME": "sqlserver.corp.local",

  "DATABASE_NAME": "mydb",

  "SQL_AUTH_MODE": "windows",

  "SQL_USERNAME": "CORP\\svc_account",

  "SQL_PASSWORD": "YourPassword123",

  "SQL_DOMAIN": "CORP"

}

Azure AD Authentication (SQL_AUTH_MODE=aad or omit) Interactive browser-based Azure AD authentication. Opens a browser window on first connection to authenticate. Best for Azure SQL Database with AAD-only auth.

"env": {