MSSQL MCP Server

Overview

The SQL Server MCP Client is a lightweight yet feature‑rich server that exposes Microsoft SQL Server functionality through the Model Context Protocol (MCP). It bridges the gap between AI assistants and relational databases by providing a standardized, query‑free interface for executing SQL, inspecting schemas, and managing stored procedures. Developers can now let an AI assistant perform complex data‑access tasks—such as retrieving table definitions or invoking a stored procedure—without writing raw SQL, simply by sending MCP messages that describe the desired operation.

At its core, the server offers a dual‑mode architecture. In Database Mode it limits all actions to a single database specified in the connection string, making it ideal for isolated applications or sandbox environments. In Server Mode—when the connection string omits a database—it exposes server‑wide operations, allowing cross‑database queries and procedure calls. This flexibility lets teams choose the level of scope that matches their security or architectural needs.

Key capabilities include:

• Query execution – Run arbitrary SQL statements and receive results as structured JSON, enabling the AI to interpret data without custom parsing logic.
• Schema discovery – List tables, view column types, row counts, and retrieve detailed metadata for any table or view.
• Stored procedure management – Discover parameters (including input, output, and default values), automatically convert JSON payloads to the correct SQL types, and execute procedures across databases.
• Advanced metadata – Return parameter information in JSON Schema format, supporting validation tools and ensuring type safety.
• Robust configuration – Adjustable timeouts, session‑based background execution for long queries, and environment‑driven security settings that let operators enable or disable specific tools.

In real‑world scenarios, the server shines when AI assistants need to answer data questions on demand. For example, a chatbot could ask “Show me the 10 most recent orders” and the MCP client would translate that into a SELECT statement, execute it on SQL Server, and return the results in JSON for the assistant to format. Similarly, a developer could let an AI draft and run a new stored procedure by providing the name and parameters; the server handles JSON‑to‑SQL conversion, validates against schema metadata, and executes the procedure safely.

By encapsulating database logic behind a well‑defined MCP interface, this server removes the friction of manual driver integration and promotes secure, reproducible AI workflows. It empowers developers to harness SQL Server’s full power while keeping the assistant’s codebase simple and declarative.