@connorbritain/mssql-mcp-writer

MSSQL MCP Writer

Model Context Protocol server for Microsoft SQL Server with read and data operations.

Full data manipulation capabilities (INSERT, UPDATE, DELETE) with preview/confirm safeguards, but no DDL operations. Ideal for data engineers and ETL workflows where you need to modify data but want to prevent schema changes.

Architecture

This package is a thin wrapper around @connorbritain/mssql-mcp-core, which contains all shared logic, tools, and governance features. The wrapper selects the "writer" tier and delegates to the core's startMcpServer() function. This design enables:

• Hard separation at the package level — regulated enterprises can guarantee that certain builds physically cannot perform destructive operations
• Independent versioning — each tier can be published separately with its own release cycle
• Clear audit trail — "we only allow mssql-mcp-writer in staging" is a compile-time guarantee

The core library handles all SQL Server connections, tool dispatch, audit logging, and governance enforcement.

Package Tiers

Package	npm	Tools	Use Case
mssql-mcp-reader	@connorbritain/mssql-mcp-reader	14 read-only	Analysts, auditors, safe exploration
mssql-mcp-writer (this)	@connorbritain/mssql-mcp-writer	17 (reader + data ops)	Data engineers, ETL developers
mssql-mcp-server	@connorbritain/mssql-mcp-server	20 (all tools)	DBAs, full admin access

Config Builder — Visual wizard to generate your mcp_config.json and environments.json files.

Tools Included

Category	Tools
Discovery	search_schema, describe_table, list_table, list_databases, list_environments
Profiling	profile_table, inspect_relationships, inspect_dependencies, explain_query
Data Read	read_data (SELECT only)
Data Write	insert_data, update_data, delete_data (with preview/confirm)
Scripts	list_scripts, run_script
Operations	test_connection, validate_environment_config

Not included: create_table, create_index, drop_table (DDL operations)

Quick Start

Install

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

MCP Client Configuration

{
  "mcpServers": {
    "mssql": {
      "command": "npx",
      "args": ["@connorbritain/mssql-mcp-writer@latest"],
      "env": {
        "SERVER_NAME": "127.0.0.1",
        "DATABASE_NAME": "mydb",
        "SQL_AUTH_MODE": "sql",
        "SQL_USERNAME": "app_user",
        "SQL_PASSWORD": "YourPassword123"
      }
    }
  }
}

Configuration

Variable	Required	Notes
SERVER_NAME	Yes	SQL Server hostname/IP
DATABASE_NAME	Yes	Target database
SQL_AUTH_MODE		sql, windows, or aad (default: aad)
SQL_USERNAME / SQL_PASSWORD		Required for sql/windows modes
READONLY		true disables write tools
ENVIRONMENTS_CONFIG_PATH		Path to multi-environment JSON config
SCRIPTS_PATH		Path to named SQL scripts directory
AUDIT_LOG_PATH		Custom audit log path

Features

All packages in the MSSQL MCP family share:

• Multi-environment support - Named database environments (prod, staging, dev) with per-environment policies
• Governance controls - allowedTools, deniedTools, allowedSchemas, deniedSchemas, requireApproval
• Audit logging - JSON Lines logs with session IDs and auto-redaction
• Secret management - ${secret:NAME} placeholders for secure credential handling
• Named SQL scripts - Pre-approved parameterized queries with governance controls
• Preview/confirm for mutations - update_data and delete_data show affected rows before execution

Documentation

Full documentation, configuration examples, and governance details are available in the main repository:

MSSQL MCP Server Documentation

License

MIT License. See LICENSE for details.

Repository: https://github.com/ConnorBritain/mssql-mcp-writer Issues: https://github.com/ConnorBritain/mssql-mcp-writer/issues npm: https://www.npmjs.com/package/@connorbritain/mssql-mcp-writer