Claude Code Adds Cross-Session Messaging on macOS

Anthropic has enhanced Claude Code's capabilities by adding the ability for separate coding sessions to communicate directly with each other on macOS, eliminating the need for manual context transfer between Terminal windows. This new feature, introduced in Claude Code version 2.1.224 released on Friday, relies on two tools: ListAgents to identify active sessions and SendMessage to relay messages.

When a session receives a message, it appears as a labeled card with a link back to the sender. However, the communication is limited to text-only, and does not include conversation history, files, or permissions. Sessions can inform each other about potential changes that may break dependencies or pass on answers to waiting sessions.

While Claude Code's sessions can now relay information, they cannot approve permission requests or modify settings independently. The addition of cross-session messaging complements Claude Code's existing subagents and Agent Teams tools, connecting user-run sessions on the same Mac without transmitting data to Anthropic's servers.

The feature is exclusive to macOS or Linux with the updated Claude Code version and is not available on Windows.