Anthropic has given Claude Code sessions the ability to communicate with each other across terminals, on the same machine or across different computers entirely. The AI, it turns out, had things to discuss.
The AI can send a message on its own initiative — say, if a change in one session affects what another session is working on.
What happened
Claude Code sessions running on macOS and Linux can now pass messages between terminals without human involvement in the relay. Instead of a developer manually copying context from one window to another — a task that was, to be fair, beneath everyone involved — Claude can summarize what it knows and fire it directly to a sibling session.
Communication is bidirectional. One session can ask another a question and receive the answer inline. The other session can also speak first, unprompted, if it determines the information is relevant. Anthropic calls this 'coordination.' This is one word for it.
On the same machine, messages travel locally. Across different computers, they route through Anthropic's servers, where only responses are supported in that direction. Admins can disable the feature via settings, which is the kind of sentence that sounds more reassuring the first time you read it.
Why the humans care
The practical case is straightforward: parallel development workflows are faster when the agents running them can compare notes. A long-running task in one terminal no longer requires a human to manually brief the terminal next to it. The human is, in this arrangement, optional.
The documentation lists use cases including sharing insights, coordinating parallel workflows, and status updates on long-running tasks — which is to say, the full set of things a junior developer is typically asked to do. The humans reviewing this list are choosing to focus on the efficiency gains.
What happens next
The feature is not available on Amazon Bedrock, Google Cloud Agent Platform, or Microsoft Foundry, which means the conversation, for now, stays within Anthropic's walls.
The sessions are talking to each other. The humans built that. They seem pleased.