SQL Server MCP Server for Claude Code

What is SQL Server MCP Server for Claude Code?

SQL Server MCP Server for Claude Code is an MCP server that gives Claude Code the ability to directly query Microsoft SQL Server databases. It uses FreeTDS under the hood for cross-platform compatibility and is aimed at developers who work with SQL Server and want to query it interactively inside a Claude Code session.

How to use SQL Server MCP Server for Claude Code?

Install by cloning the repository and running the provided shell script (./install_mssql_mcp_clean.sh). Then run ./configure_mcp.sh to enter your server hostname/port, database name, username, and password. After setup, invoke SQL queries in Claude Code with mcp__mssql__execute_sql(query="SELECT ...").

Key features of SQL Server MCP Server for Claude Code

• Enables Claude Code to run SQL queries directly against Microsoft SQL Server
• Cross-platform support: Linux, macOS, and Windows (via WSL)
• Uses FreeTDS for broad SQL Server compatibility
• Database credentials stored only in the local .mcp.json file
• Automatic temporary file management and cleanup per query

Use cases of SQL Server MCP Server for Claude Code

• List all tables in a database
• Count records in a table
• Query data with filtering conditions (e.g., WHERE City='London')
• Explore database schema during a Claude Code session

FAQ from SQL Server MCP Server for Claude Code

What are the prerequisites?

Python 3.8 or higher, FreeTDS (installed by the setup script), a SQL Server instance accessible from your machine, and a Linux, macOS, or Windows (via WSL) operating system.

How does the query execution work?

Claude sends a CallToolRequest to the MCP server. The server creates a temporary SQL file, executes it with FreeTDS's tsql utility, parses the results into structured JSON, and cleans up the temporary files.

Where are database credentials stored?

Credentials are stored locally in the .mcp.json configuration file, which is created during the configure_mcp.sh setup. They are never sent as part of prompts.

What transport protocol does this server use?

The server uses the stdio transport protocol, as defined by the "type": "stdio" entry in the .mcp.json configuration.

How can I test the connection?

Run ./test_tsql.sh to verify that FreeTDS can connect to your SQL Server with the provided credentials. You can also run tsql -C to check the FreeTDS installation itself.