mcp-sqlserver

A powerful Model Context Protocol (MCP) server for Microsoft SQL Server. Connects AI assistants (Claude, Gemini, Kiro, OpenAI, Copilot, Cursor) directly to your SQL Server databases with enterprise-grade security controls.

39 tools across 7 categories: schema discovery, query execution, DDL, stored procedures, performance/DBA diagnostics, developer utilities, and server management.

Changelog: See CHANGELOG.md for version history or GitHub Releases for detailed release notes.

What's New in v1.3

• Multi-server support — Define dev/staging/prod servers in one config, switch with server parameter
• list_servers tool — See all configured connections at a glance
• Per-server security — Each server gets its own security mode, row limits, and blocked databases
• Backward compatible — Existing single-server configs work without any changes

What's New in v1.2

• 16 new tools — DBA diagnostics, code generation, ER diagrams, schema diff, data sampling, and more
• SQL injection protection — All queries now use parameterized inputs and escaped identifiers
• ISO date formatting — Dates display as 2025-01-27 instead of raw JavaScript Date strings
• Streamable HTTP transport — Host the MCP server remotely with --http <port>
• Health check — Verify connection status and server responsiveness

Features

Server Management (1 tool)

| Tool | Description | |------|-------------| | list_servers | List all configured server connections with host, database, auth, and security mode |

Multi-server: Every tool accepts an optional server parameter to target a specific named server. Omit it to use the default server.

Schema Discovery (9 tools)

| Tool | Description | |------|-------------| | list_databases | List all accessible databases on the instance | | list_schemas | List schemas in a database | | list_tables | List tables with row counts and sizes | | list_views | List views in a database | | describe_table | Detailed column info: types, defaults, nullability, identity, computed | | get_foreign_keys | Foreign key relationships for a table | | get_indexes | Index information with included columns | | get_constraints | PK, unique, check, and default constraints | | get_triggers | Trigger definitions on a table |

Query Execution (3 tools)

| Tool | Description | |------|-------------| | execute_query | Run SELECT queries with automatic row limits | | execute_mutation | Run INSERT/UPDATE/DELETE/MERGE (requires readwrite mode) | | export_query | Export query results as CSV or JSON format |

DDL Operations (1 tool)

| Tool | Description | |------|-------------| | execute_ddl | Run CREATE/ALTER/DROP statements (requires admin mode) |

Stored Procedures (3 tools)

| Tool | Description | |------|-------------| | list_procedures | List stored procedures in a database | | describe_procedure | View parameters and source code of a procedure | | execute_procedure | Execute with named parameters (requires readwrite mode) |

Performance & DBA (16 tools)

| Tool | Description | |------|-------------| | get_query_plan | Estimated execution plan for any query | | get_active_queries | Currently running queries from sys.dm_exec_requests | | get_table_stats | Row count, total/used/unused size, and fragmentation % | | get_index_usage | Index seeks, scans, lookups, and update statistics | | get_missing_indexes | Missing index suggestions with ready-to-use CREATE INDEX DDL | | get_server_info | Server version, edition, CPU count, memory, uptime | | get_database_info | Database size, file layout, status, recovery model, object counts | | get_wait_stats | Top server wait statistics — identifies CPU, I/O, lock bottlenecks | | get_deadlocks | Recent deadlock events from the system_health Extended Events session | | get_blocking_chains | Current blocking chains — which sessions are blocking others | | get_long_transactions | Long-running open transactions that may be holding locks | | get_space_usage | Detailed disk space usage by table (data, index, unused) | | get_backup_history | Recent backup history: type, size, duration, device path | | get_query_store_stats | Top resource-consuming queries from Query Store (SQL Server 2016+) — sortable by CPU, duration, reads, writes, or executions | | rebuild_index | Rebuild or reorganize a fragmented index (requires admin mode) | | health_check | Connection health check with latency, version, active sessions |

Developer Utilities (6 tools)

compare_schemas — Schema Diff

Compare two databases side-by-side. Shows tables, columns, and type differences — perfect for dev vs prod comparison.

compare_schemas(source_database: "DevDB", target_database: "ProdDB")

Output includes: tables only in source/target, columns only in source/target, and column type/nullability differences.

generate_code — Code Generation

Generate typed code from any table's schema:

• TypeScript — interfaces with proper types (number, string, Date, Buffer | null)
• C# — classes with nullable value types (int?, DateTime?, decimal?)
• SQL — CREATE TABLE scripts with full column definitions

generate_code(table: "Products", language: "typescript")
→ export interface Products {
    productId: number;
    productName: string;
    unitPrice: number | null;
    ...
  }

generate_insert_scripts — Data Export as INSERT

Generate INSERT statements from existing table data — useful for migration scripts, seed data, or backing up small reference tables.

generate_insert_scripts(table: "Categories", top: 10)
→ INSERT INTO [dbo].[Categories] ([CategoryName], [Description]) VALUES (N'Beverages', N'Soft drinks...');

generate_er_diagram — ER Diagram

Generate a Mermaid ER diagram from foreign key relationships. Paste the output into any Mermaid-compatible renderer (GitHub, Notion, VS Code, etc.).

generate_er_diagram(database: "Northwind")
→ erDiagram
    Products }o--|| Categories : "CategoryID"
    Products }o--|| Suppliers : "SupplierID"
    Orders }o--|| Customers : "CustomerID"
    ...

generate_test_data — Test Data Generation

Generate realistic INSERT statements with fake data based on column names and types. Smart heuristics for common patterns (email, phone, name, city, price, etc.).

generate_test_data(table: "Customers", count: 5)
→ INSERT INTO [dbo].[Customers] (...) VALUES (N'Alice', N'user1@example.com', N'New York', ...);

sample_table — Random Sampling

Get a random sample of rows from any table using NEWID() — useful for AI assistants to understand data patterns without scanning entire tables.

sample_table(table: "Orders", count: 5)

Security

Three Security Modes

| Mode | SELECT | INSERT/UPDATE/DELETE | DDL | Stored Procedures | |------|--------|---------------------|-----|-------------------| | readonly | Yes | No | No | Read-only (list/describe) | | readwrite | Yes | Yes | No | Full (execute) | | admin | Yes | Yes | Yes | Full (execute) |

SQL Injection Protection

All user-provided values are passed as parameterized query inputs (@param). Object identifiers (database, schema, table names) are escaped using SQL Server bracket notation ([name] with ] → ]]).

Additional Security Features

• Database and schema allow/block lists
• Automatic row count limits (configurable maxRowCount)
• Blocked keyword detection (xp_cmdshell, SHUTDOWN, DROP DATABASE, etc.)
• Column-level data masking for PII protection
• Query type validation per security mode

Data Masking

Mask sensitive columns in query results:

security:
  maskColumns:
    - pattern: "*.password"
      mask: "***"
    - pattern: "*.ssn"
      mask: "XXX-XX-XXXX"
    - pattern: "dbo.users.email"
      mask: "***@***.***"

Pattern format: [schema.]table.column (use * as wildcard)

Authentication

| Method | Config type | Requirements | |--------|---------------|-------------| | SQL Server | sql | user + password | | Windows (NTLM) | windows | user + password + optional domain | | Windows (SSPI) | windows | No credentials needed; requires msnodesqlv8 | | Azure AD | azure-ad | clientId + clientSecret + tenantId |

Windows Authentication

NTLM — Works out of the box, no extra packages:

connection:
  host: YOUR_SERVER\SQLEXPRESS
  authentication:
    type: windows
    user: YourUsername
    password: YourPassword
    domain: YOUR_DOMAIN
  trustServerCertificate: true

SSPI / Integrated Security — Uses current Windows login session:

npm install msnodesqlv8

connection:
  host: YOUR_SERVER\SQLEXPRESS
  authentication:
    type: windows
  trustServerCertificate: true

Note: When using npx, optional dependencies like msnodesqlv8 may not be installed automatically. For SSPI, consider installing globally (npm install -g @tugberkgunver/mcp-sqlserver msnodesqlv8) or use NTLM mode instead.

Transport

stdio (Default)

Standard input/output transport — used by MCP clients like Claude Desktop, VS Code, Cursor, etc.

Streamable HTTP

For remote hosting or web integrations:

mcp-sqlserver --config mssql-mcp.yaml --http 3000

This starts:

• MCP endpoint: http://localhost:3000/mcp
• Health check: http://localhost:3000/health → {"status":"ok","mode":"readonly"}

Includes CORS support for browser-based clients.

Quick Start

Install

npm install -g @tugberkgunver/mcp-sqlserver

Configure

Create mssql-mcp.yaml in your working directory:

connection:
  host: localhost
  port: 1433
  database: MyDatabase
  authentication:
    type: sql
    user: sa
    password: YourPassword123
  trustServerCertificate: true

security:
  mode: readonly
  maxRowCount: 1000
  blockedDatabases:
    - master
    - msdb
    - tempdb
    - model

See config.example.yaml for all options.

Multi-Server Configuration

Define multiple named servers to manage dev/staging/prod from a single config:

defaultServer: dev

connections:
  dev:
    host: dev-server.example.com
    database: MyDatabase
    authentication:
      type: sql
      user: sa
      password: DevPass123
    trustServerCertificate: true
    security:
      mode: admin
      maxRowCount: 5000

  prod:
    host: prod-server.example.com
    database: MyDatabase
    authentication:
      type: sql
      user: readonly_user
      password: ProdReadOnly
    security:
      mode: readonly
      blockedDatabases: [master, msdb, tempdb, model]

# Global security defaults (applied to all servers unless overridden)
security:
  maxRowCount: 1000
  blockedKeywords: [xp_cmdshell, SHUTDOWN, DROP DATABASE]

Then use the server parameter in any tool call:

list_tables(server: "prod", database: "MyDatabase")
health_check(server: "dev")
compare_schemas(source_database: "DevDB", target_database: "StagingDB", server: "dev")

MCP Client Configuration

<details> <summary><strong>Claude Desktop / Claude Code</strong></summary>

{
  "mcpServers": {
    "mssql": {
      "command": "npx",
      "args": ["-y", "@tugberkgunver/mcp-sqlserver"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_DATABASE": "MyDatabase",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "YourPassword123"
      }
    }