@achmadya-dev/mcp-mssql-query

MCP server for Microsoft SQL Server. Runs a single T-SQL statement per tool call over stdio. Read-only by default — writes and DDL require explicit env flags.

Requirements

• Node.js ≥ 20
• A reachable SQL Server instance

Install from npm

{
  "mcpServers": {
    "mssql": {
      "command": "npx",
      "args": ["-y", "@achmadya-dev/mcp-mssql-query"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_PORT": "1433",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "your_password",
        "MSSQL_DATABASE": "your_database",
        "MSSQL_TRUST_SERVER_CERTIFICATE": "true"
      }
    }
  }
}

Or use envFile instead of inline env.

Develop from source

git clone https://github.com/achmadya-dev/mcp-mssql-query.git
cd mcp-mssql-query
pnpm install
pnpm run build
pnpm test

Open the repo root in Cursor. You need a reachable SQL Server instance — set connection env in .cursor/mcp.json or via envFile:

{
  "mcpServers": {
    "mssql": {
      "command": "node",
      "args": ["${workspaceFolder}/dist/index.js"],
      "env": {
        "MSSQL_HOST": "localhost",
        "MSSQL_PORT": "1433",
        "MSSQL_USER": "sa",
        "MSSQL_PASSWORD": "your_password",
        "MSSQL_DATABASE": "your_database",
        "MSSQL_TRUST_SERVER_CERTIFICATE": "true"
      }
    }
  }
}

Environment variables

Connection

| Variable | Default | Description | | -------------------------------- | ------------ | ------------------------------------ | | MSSQL_HOST | localhost | SQL Server host | | MSSQL_PORT | 1433 | Port | | MSSQL_USER | (empty) | Username | | MSSQL_PASSWORD | (empty) | Password | | MSSQL_DATABASE | (optional) | Database name | | MSSQL_INSTANCE_NAME | (optional) | Instance name (e.g. SQLEXPRESS) | | MSSQL_ENCRYPT | true | Encrypt connection | | MSSQL_TRUST_SERVER_CERTIFICATE | true | Trust server certificate (local dev) | | MSSQL_CONNECTION_TIMEOUT_MS | 15000 | Connection timeout (ms) | | MSSQL_REQUEST_TIMEOUT_MS | 15000 | Request timeout (ms) | | MSSQL_MAX_ROWS | 500 | Max rows for row-returning queries |

Write access

| Variable | Allows | | ------------------------ | -------- | | ALLOW_INSERT_OPERATION | INSERT | | ALLOW_UPDATE_OPERATION | UPDATE | | ALLOW_DELETE_OPERATION | DELETE | | ALLOW_DDL_OPERATION | DDL |

Enabled values: true, 1, yes, on.

Tools

| Tool | Statements | Env flag | | -------------- | --------------------------- | ------------------------ | | mssql_select | SELECT, VALUES, PRINT | always on | | mssql_insert | INSERT | ALLOW_INSERT_OPERATION | | mssql_update | UPDATE | ALLOW_UPDATE_OPERATION | | mssql_delete | DELETE | ALLOW_DELETE_OPERATION | | mssql_ddl | DDL | ALLOW_DDL_OPERATION |

Each tool accepts one sql string.

Behavior and security

• One T-SQL statement per request.
• Results are JSON text; row-returning queries include truncation metadata.
• Non-row commands return kind: "execute" with affectedRows.

Package scripts

pnpm run build
pnpm test
pnpm start