Culprit SQL Studio

Culprit connects to a database with a login that can read statistics, such as Query Store, the plan cache, pg_stat_statements or performance_schema. It runs 51 checks and ranks the findings by their share of database time. Covered problems include plan regressions, parameter sniffing, missing and unused indexes, N+1 query loops, implicit conversions, spills to disk, stale statistics, lock waits and deadlocks. Each finding comes with the evidence, a fix described as safe for production and a way to verify it.

The desktop app draws execution plans, explains them in plain words and compares any two plans, with a headline reason why one is slower. A regression view compares two time periods and lists what got slower, what is new and what improved, next to deploys and statistics updates. A live view shows blocking chains as a tree. The CLI prints JSON for every command, and culprit mcp serves 25 tools to MCP clients. Scans are read-only, fixes are shown and never applied, and anything beyond a provable read asks first on production.

Developers and database administrators who need to find why a SQL Server, PostgreSQL, MySQL or MariaDB database is slow, without installing anything on the server. It also suits teams that want coding agents to inspect database performance with read-only access.

Open source. Free and released under the MIT license. The site lists no paid plans.