Configuration

Game system properties

Set these as JVM arguments on the client or server run, for example:

// Fabric:   loom { runs { client { vmArg('-Dmctest.port=25600') } } }
// NeoForge: neoForge { runs { client { systemProperty('mctest.port', '25600') } } }

Property	Default	Side	Meaning
mctest.port	25599	client	Port of the client control API
mctest.serverPort	25598	server	Port of the dedicated-server control API
mctest.logBuffer	10000	both	Log lines kept for mc_logs
mctest.pauseOnLostFocus	false	client	true keeps vanilla's pause menu when the window loses focus
mctest.mouseWarp	false	client	true lets the game capture and warp the OS cursor as in vanilla
mctest.tutorial	false	client	true keeps the tutorial hint toasts
mctest.onlineMode	false	server	true keeps authentication and signed chat as server.properties says
mctest.whitelist	false	server	true keeps the whitelist on at startup
mctest.autoOp	true	server	false stops opping players when they join

The control APIs always bind to 127.0.0.1.

MCP server environment

Variable	Default	Meaning
MCTEST_PORT	25599	Port of the client control API
MCTEST_SERVER_PORT	25598	Port of the dedicated-server control API

claude mcp add mctest --scope user -e MCTEST_PORT=25600 -- npx -y mctest-mcp