# Is Ready The `isready` command can be used to wait for the engine to finish performing blocking operations[^blocking]. --- ## Response The `isready` command must be answered with the [[readyok]] command as soon as the engine is able to process input. [^blocking]: Large, I/O bound operations, that the engine cannot start calculating without finishing, such as loading an opening book from a file. The engine *must not* block while calculating moves.