MSSQL MCP Server

A production-ready Model Context Protocol (MCP) server for Microsoft SQL Server with comprehensive stored procedure management, virtual filesystem protocol, and safe write operations.

Features

• Virtual Filesystem: Browse database objects (stored procedures, views, functions) as files

• Discovery Tools: Search stored procedures, inspect table schemas, analyze dependencies

• Safe Write Operations: SQL validation, transaction management, audit logging

• SP Management: Draft → Test → Deploy → Rollback workflow with version control

• Performance Analysis: Query execution statistics from plan cache

• Security: SQL injection prevention, blocked keywords, row limits

Installation

Configuration

Copy .env.example to .env and configure:

Key configuration options:

• DB_SERVER: SQL Server hostname

• DB_DATABASE: Database name

• DB_USER/DB_PASSWORD: Credentials

• DB_ENCRYPT: Enable encryption (default: true)

• DB_TRUST_SERVER_CERTIFICATE: Trust server certificate for dev environments (default: false)

• ENABLE_WRITE_OPERATIONS: Enable INSERT/UPDATE/DELETE (default: true)

• ENABLE_SP_MODIFICATIONS: Enable stored procedure management (default: true)

• REQUIRE_TRANSACTIONS: Require explicit transactions for modifications (default: true)

• MAX_ROWS_AFFECTED: Maximum rows that can be modified in one operation (default: 10000)

• DRAFT_SCHEMA: Schema for testing SPs before deployment (default: dbo_draft)

• AUTO_BACKUP_BEFORE_DEPLOY: Auto-backup SPs before deploying (default: true)

See .env.example for all options.

Usage with Claude Code

Add to your MCP configuration file (.claude.json or ~/.claude.json):

Available Tools

Discovery & Schema

• list_stored_procedures: List stored procedures with pagination

• search_stored_procedures: Search SPs by name or content

• get_table_schema: Get table structure with columns, indexes, foreign keys

• get_dependencies: Analyze object dependencies (callers and references)

• analyze_sp_performance: View execution statistics from plan cache

Execution

• execute_query_write: Execute INSERT/UPDATE/DELETE with validation

Transactions

• begin_transaction: Start a new transaction

• commit_transaction: Commit changes

• rollback_transaction: Undo changes

Stored Procedure Management

• create_sp_draft: Create a draft SP in separate schema

• test_sp_draft: Test draft with parameters

• deploy_sp: Deploy to production (auto-backs up current version)

• rollback_sp: Restore previous version

• list_sp_versions: View version history

Example Workflows

Searching for Stored Procedures

Viewing Database Objects as Files

Modifying a Stored Procedure

Safe Data Modifications

Performance Analysis

Architecture

Phase 1: Read-Only Foundation

• Virtual filesystem for database objects

• Connection pooling (read-only pool)

• Query execution with error handling

• Discovery and schema inspection tools

Phase 2: Safe Writes

• SQL validation and injection prevention

• Transaction manager with timeout protection

• Audit logging for compliance

• Write operation tools

Phase 3: SP Management

• Version control with SPVersionHistory table

• Draft schema for safe testing

• Deploy/rollback workflow

• Automatic backups before deployment

Phase 4: Advanced Features

• Dependency analysis

• Performance monitoring from DMVs

• Reference finding

Security Features

• SQL Validation: Blocks dangerous keywords and patterns

• Parameterized Queries: Prevents SQL injection

• Row Limits: Prevents accidental mass updates

• Transaction Timeouts: Auto-rollback after 5 minutes

• Audit Trail: Logs all operations to file

• Separate Credentials: Optional read-only and read-write connections

Testing

A complete test environment is included in the test/ directory:

This sets up a Docker container with SQL Server 2022 and a test database (MCPTestDB) pre-populated with:

• Sample tables (Customers, Products, Orders, etc.)

• 13 test stored procedures

• Views and functions

• Sample data for testing all MCP features

Connection string for testing:

Running Tests

After setting up the test database:

See test/README.md for detailed testing scenarios and management commands.

Development

Project Structure

License

MIT

Contributing

Contributions are welcome! Please ensure all tools follow security best practices.