You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Peer SessionsArea: what it touches
ImprovementsKind: in v2.1.318,
ImprovementsSection of the release
What
Claude Code sessions can receive messages from other sessions, called peers. A peer that a host session has declared can no longer send a message that includes a disallowed_tools list, which names tools to block. Claude Code refuses such a message and logs an error. This reason is checked before the other reasons for refusing a message.
Why
A peer's turn cannot apply a list of blocked tools. Refusing the message stops a block from appearing to be in place when it would be ignored.
