You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Cross-Session MessagingArea: what it touches
New FeaturesKind: in v2.1.248,
New FeaturesSection of the release
What
When a subagent sends a message using the session's own address, Claude Code now attaches a note for the model and a suffix in the transcript, and distinguishes a one-way send from one whose replies come back into the main conversation.
Details
Two variants: a send that expects no reply, and one marked as having replies routed into the main conversation.
The same helper produces both the model-facing text and the display suffix, so what you see and what the model sees stay in step.
Evidence
replies go to the main conversation
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
