Summary

Two tools, and the important one is the read-only flag.

execute_query runs whatever SQL you hand it, so the boundary is the ClickHouse user in your config plus CLICKHOUSE_READONLY, which is off by default. Switching database mid-session is a tool call rather than a restart.

What it is

A ClickHouse server with two tools: connect to a database, and execute queries against it.

What you get

A named database connected to on demand, with a confirmation when it succeeds (connect_database)
SQL executed and results returned as JSON (execute_query)
Several statements in one call when separated by semicolons
Connection settings from the environment — host, user and password, plus a default database if you want one
A read-only mode through CLICKHOUSE_READONLY, off unless you turn it on

Requirements

A reachable ClickHouse server, and the package installed with uv pip install clickhouse-mcp-server or pip. Host defaults to localhost and user to root.

Setup effort

One command — uv pip install clickhouse-mcp-server