SQL Server MCP

A Model Context Protocol server that gives Claude deep visibility into SQL Server. Query your databases, diagnose performance problems, inspect locks and transactions, and explore schema — all through natural language.

Built with .NET 8 and Microsoft.Data.SqlClient. Communicates over stdio so it works with Claude Desktop, Claude Code, and any MCP-compatible client.

Features

• Query execution — run arbitrary T-SQL and get results as structured JSON
• Execution plans — retrieve estimated plans without executing, or actual plans with runtime statistics
• Lock analysis — see every current lock and trace full blocking chains with session context
• Transaction diagnostics — find open transactions, measure their age, see what they've locked, and spot log growth risks
• Session monitoring — list running queries with wait types, CPU, memory grants, and live plan XML
• Schema exploration — browse databases, tables, columns, indexes, stored procedures, views, and object definitions
• Index health — surface missing indexes with suggested CREATE INDEX statements, find unused indexes, measure fragmentation with rebuild/reorganize recommendations
• Wait statistics — identify server-wide bottlenecks from cumulative wait data
• Query Store — analyze historical top queries by CPU, duration, or I/O (SQL Server 2016+)

Tools

Query

| Tool | Description | |---|---| | execute_query | Execute T-SQL and return results as JSON. SELECT returns rows; DML returns rows affected. | | get_estimated_plan | Return the XML execution plan without running the query (SET SHOWPLAN_XML ON). Safe for production — no locks, no data read. | | get_actual_plan | Execute a query and capture the actual runtime XML plan alongside results (SET STATISTICS XML ON). |

Sessions

| Tool | Description | |---|---| | get_running_queries | List executing requests with elapsed time, wait type, blocking session, CPU, logical reads, full SQL text, current statement, and live query plan XML. | | get_session_detail | Full detail for a single session: isolation level, open transactions, memory, tempdb usage, connection info, and current SQL. | | kill_session | Kill a session (SPID) or check rollback progress with WITH STATUSONLY. |

Locks

| Tool | Description | |---|---| | get_locks | All current locks with resource type, mode, status, and owning session info. Filter by database. | | get_blocking_chains | Recursive blocking hierarchy showing root blockers and all dependent blocked sessions with chain_path (e.g. 52 -> 67 -> 91). |

Transactions

| Tool | Description | |---|---| | get_open_transactions | All open transactions with age, isolation level, log bytes used, and current SQL. Filter by minimum age. | | get_transaction_locks | All locks held by a specific transaction ID. |

Schema

| Tool | Description | |---|---| | list_databases | All online databases with size, state, recovery model, and compatibility level. | | list_tables | Tables in a database with estimated row counts and space usage. | | get_table_schema | Full table schema: columns with types/defaults/nullability, PK and unique constraints, and foreign keys. | | list_indexes | Indexes on a table or all tables, with key columns, included columns, and properties. | | list_stored_procs | Stored procedures with execution count, last run time, and cumulative CPU from the plan cache. | | list_views | Views, flagging which are indexed (materialized). | | get_object_definition | Source T-SQL for a stored procedure, view, function, or trigger. |

Index Health

| Tool | Description | |---|---| | get_missing_indexes | Missing index recommendations from DMVs, ranked by impact score, with ready-to-run CREATE INDEX statements. | | get_index_usage_stats | Per-index seeks, scans, lookups, and updates since last restart. Find unused indexes wasting

... View full README on GitHub