What probably matters to youSection of the release
What
Print mode runs Claude Code without its interactive screen, and the SDK lets other programs control it. In these modes, a message you queue while Claude is still working can now be sent straight away. The message first waits to go next. When you press send-now, it is delivered during the running turn. If it cannot be delivered, Claude Code reports that it was declined. Turn results also carry queued_turn_count.
Why
Apps and remote clients built on Claude Code can redirect a turn in progress with queued input instead of waiting for it to finish.