@iforge.it/mssql-mcp

Minimal, unrestricted MCP server for Microsoft SQL Server.

One tool. No restrictions. Full control over your database.

Why?

Most MSSQL MCP servers block system views (sys.sql_modules, sys.dm_*), DDL statements (ALTER, CREATE PROCEDURE), and admin operations (sp_add_jobstep, sp_start_job). This one doesn't.

execute_sql runs any SQL query — SELECT, ALTER, CREATE, DROP, EXEC, system views, everything. Security is handled by Claude Code's built-in tool approval — you see every query before it runs and approve or deny it.

Install

Option 1: npx (no install needed)

Configure .mcp.json in your project root:

{
  "mcpServers": {
    "mssql": {
      "command": "npx",
      "args": ["-y", "@iforge.it/mssql-mcp"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_DATABASE": "mydb",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "yourpassword",
        "MSSQL_PORT": "1433"
      }
    }
  }
}

Windows — use cmd /c wrapper:

{
  "mcpServers": {
    "mssql": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@iforge.it/mssql-mcp"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_DATABASE": "mydb",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "yourpassword",
        "MSSQL_PORT": "1433"
      }
    }
  }
}

Option 2: Global install

npm install -g @iforge.it/mssql-mcp

Then in .mcp.json:

{
  "mcpServers": {
    "mssql": {
      "command": "mssql-mcp",
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_DATABASE": "mydb",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "yourpassword",
        "MSSQL_PORT": "1433"
      }
    }
  }
}

Option 3: From source

git clone https://github.com/iforgeit/mssql-mcp.git
cd mssql-mcp
npm install

Then in .mcp.json:

{
  "mcpServers": {
    "mssql": {
      "command": "node",
      "args": ["/path/to/mssql-mcp/index.js"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_DATABASE": "mydb",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "yourpassword",
        "MSSQL_PORT": "1433"
      }
    }
  }
}

Environment variables

| Variable | Required | Default | Description | |---|---|---|---| | MSSQL_HOST | Yes | — | SQL Server hostname or IP | | MSSQL_DATABASE | Yes | — | Database name | | MSSQL_USER | Yes | — | SQL auth username | | MSSQL_PASSWORD | Yes | — | SQL auth password | | MSSQL_PORT | No | 1433 | SQL Server port | | MSSQL_ENCRYPT | No | true | Enable TLS encryption (true/false). Set to false only for local/trusted networks | | MSSQL_TRUST_SERVER_CERTIFICATE | No | false | Trust self-signed certificates (true/false). Enable for dev/local servers |

You can use system environment variables with ${VAR_NAME} syntax in .mcp.json:

"MSSQL_PASSWORD": "${MY_SQL_PASSWORD}"

Tool

execute_sql

Executes any SQL query against the connected database.

Input: query (string) — any valid T-SQL statement.

Examples:

-- Read data
SELECT TOP 10 * FROM users

-- DDL
ALTER TABLE users ADD email NVARCHAR(256)

-- Stored procedures
EXEC sp_help 'users'

-- View procedure source code
SELECT definition FROM sys.sql_modules WHERE object_id = OBJECT_ID('dbo.my_proc')

-- SQL Agent jobs
SELECT name, enabled FROM msdb.dbo.sysjobs

-- System views
SELECT * FROM sys.dm_exec_sessions WHERE is_user_process = 1

Returns: JSON with rowCount, columns, rows for SELECT queries, or rowsAffected for write operations.

Security

This MCP server has no built-in query restrictions. Security is handled at two levels:

1. Claude Code approval — every tool call requires user confirmation (unless you explicitly allow it). You see the full SQL before execution.
2. SQL Server permissions — the connected user's database permissions apply as usual.

Recommendations:

• Don't click "Allow always" for execute_sql — review each query
• Use a database user with appropriate permissions, not sa
• Add .mcp.json to .gitignore if it contains credentials
• Use environment variables for passwords instead of hardcoding them

License

MIT