Message your other Claude Code sessions

Claude Code v2.1.224 and later enables cross-session messaging on macOS and Linux, allowing Claude to send text messages between independent coding sessions to share findings, coordinate work, or report status without requiring manual re-explanation. Claude uses ListAgents and SendMessage tools to communicate between sessions when changes in one session affect another's work, such as alerting about breaking changes or delivering answers to blocked tasks. This feature is distinct from other multi-session capabilities like session resuming, agent teams, and remote control, each designed for different coordination scenarios.