mssql-mcp-writer by ConnorBritain - MCP Server

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.

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

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 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