Anthropic’s latest feature enables independent Claude Code sessions to send plain-text updates across machines and platforms, enhancing coordination without sharing full conversation histories , though with notable security and compatibility limitations.
Anthropic has documented a cross-session messaging feature for Claude Code that lets one running session send plain-text updates to another session on the same machine, on another machine or on the web. The system is designed for coordination rather than hand-off: it passes findings, status and decisions between independent sessions, but not full conversation history or files. The feature is enabled automatically when a session meets the version and platform requirements, with Claude Code v2.1.224 or later needed and support limited to macOS and Linux.
In practical terms, the feature is meant to reduce duplication when multiple Claude Code sessions are working in parallel. Anthropic says one session can warn another about a breaking change, relay the result of a migration or explain what has just landed in a shared repository. The documentation also points users towards other collaboration tools when cross-session messaging is not the right mechanism, including session resume for continuing one conversation, agent teams for coordinated work managed by Claude itself and agent view for supervising many sessions from one place.
The messaging model is deliberately narrow. Claude can discover reachable peers with a list-agents command and send messages through a separate send tool, but only the message text is transferred. The receiving session does not inherit the sender’s history, files or permissions. Claude Code also makes clear that messages cannot approve prompts, alter configuration or execute slash commands embedded in the text. If a message requires an action the receiving session is not allowed to perform, the normal permission rules still apply.
Delivery is controlled by inbound settings on the receiving session, which can accept, hold or refuse peer messages. By default, messages may be held for approval depending on the permission mode of the sender and receiver, with a five-minute expiry on that approval prompt. Anthropic says sessions can also be configured to block inbound messages entirely, and administrators can combine that with permission-deny rules to stop both sending and listing. There is also a machine-isolation setting for users who want explicit approval before any message crosses to another machine.
Anthropic has also documented where the feature works and where it does not. Cross-session messaging is not available on native Windows and is excluded from Amazon Bedrock, Claude Platform on AWS, Google Cloud’s Agent Platform and Microsoft Foundry. The company adds that certain feature-flag and telemetry settings can disable it as well. That places the tool closer to a controlled systems feature than a general chat convenience: useful for orchestrating work across terminals and hosts, but bounded by explicit security and deployment constraints. Related documentation on channels, session handling in the Agent SDK and Slack integration shows Anthropic building a wider ecosystem for routing events and coordinating work, though cross-session messaging remains the most direct peer-to-peer option inside Claude Code itself.
Disclaimer: This content is intended for informational purposes only. Readers are advised to exercise their own judgement, conduct due diligence, or consult a qualified expert before acting on any information provided.
