You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Session MessagingArea: what it touches
New FeaturesKind: in v2.1.239,
New FeaturesSection of the release
What
When sending a message to another Claude session, Claude Code now checks whether a session record on the machine claims the same identifying token this session advertises for itself. If so, the send is refused and the model is told the record is suspicious and to ask you.
Details
Applies unconditionally on that send path.
The refusal text shown to the model is "A record impersonating this session is suspicious: ask the user."
Evidence
A record impersonating this session is suspicious: ask the user.
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
