A sub-agent's prose rendered as "claude" and its thinking as "thinking",
identical to the main assistant, because the label logic ignored
isSidechain — presenting sub-agent output as if the main Claude said it.
Now a sidechain AssistantTextMessage is labelled "agent" with a muted
stripe (never the coral claudeAccent brand), and sidechain thinking is
"agent thinking". Main-thread items are unchanged.
Tests: sidechain prose/thinking relabel, main-thread unchanged; golden
contrasting the muted agent stripe with the coral claude stripe.
This completes epic T-267 (conversation rendering streamlining): fold
success result (T-262), fold agent prompt (T-263), nest the agent run
(T-264), the shared holder primitive (T-266), and this attribution fix.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jpmschweitzerandClaude Opus 4.8
069879620f