Under the hood
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The streaming connection now surfaces user-message UUIDs via a new onUserFrameReceived callback
What
The client's SSE (server-sent events) streaming transport now calls a new onUserFrameReceived(uuid, rawPayload) callback whenever it receives a frame whose payload type is "user" and that carries a string UUID, before it passes the data on to the normal data handler.
Why
This lets other parts of Claude Code react specifically to incoming user-message frames and their identifiers as they stream in, rather than only handling them generically alongside every other frame type.
Names in the bundleonUserFrameReceived