The SessionStart announce no longer forces a watch-loop bootstrap on every session — it now emits a short pointer instructing Claude to invoke the new mailbox-collaborate skill (or /collaborate slash command) when the user wants peers to wake them mid-task. Messages still surface on the next user prompt via the UserPromptSubmit hook even without the watcher, so nothing is lost; idle sessions just stop burning relaunch tokens.
The watch-loop protocol (exit codes, rename handling, mail handling) moves from the hook prose into the new skill body, where it only loads when actually needed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
