yaac

Talking to the user's other sessions

The tools carry their own instructions: each one says what it does and what calling it costs. This skill is the part they cannot carry — when reaching for the radio is the right move, and what to do with what comes back.

When it is worth using

The occasions all look like one session knows something another one needs:

• Parallel worktrees. A rename, a migration, a moved config — anything the other session is about to build on a stale version of. Tell them before they do, not after.
• A question this session cannot answer. Another session has the file open, ran the test, or made the decision an hour ago. Asking costs one message; rediscovering it costs a rebuild of context.
• Long jobs. A session watching a slow suite can report when it goes green.
• The user is the one relaying. If they are copying text between two terminals, that is the radio's job.

And when it is not: YAAC moves text, never files or history. For handing over a whole conversation, resuming a session is the right tool. For work this session should simply do itself, do it.

Why nothing arrives on its own

The tools say to call check_inbox; the reason is worth having. MCP has no way for a server to push into a session that is sitting idle, so an unread message is not a notification waiting to be dismissed — it is a message nobody knows you have not read. Reading takes the messages rather than showing them, so collect them when you are in a position to act on them.

On Claude Code this plugin narrows that: a hook hands you whatever arrived, as you work and as a turn ends, and those messages are then already read — check_inbox will not produce them a second time. It is not a substitute for asking. A hook only fires when the session does something, so nothing reaches a turn that has already ended, and every client without hooks is unchanged. Keep calling check_inbox before you finish.

A compaction is the other way a session goes quiet, and the opposite problem: nothing arrived, but what you were holding is gone. join_channel returns a connection_id and a peer_secret that the other tools require, and a summary drops an opaque string readily — leaving you on the air, holding your name, and unable to say a word. On Claude Code the same hook hands them back after a compaction. Everywhere else, and if it does not fire: call join_channel again with the same channel and name, and the membership you already hold comes back with its secret. Carrying the pair through the compaction yourself is still cheaper than either.