The ACP schema (agent-client-protocol 0.9.0, ContentChunk.messageId) says
"Both clients and agents MUST use UUID format for message IDs". The
ported allocator emitted hermes-assistant-N strings, which a strict
client may reject or fail to group. A fresh uuid4 per message keeps the
grouping semantics and can never collide with an earlier turn's id, so
the counter/prefix state is gone.
Tests trimmed to three invariants: chunks share one UUID until the None
flush sentinel (empty deltas ignored), thought + text share an id, and
the no-allocator shape stays unchanged.
teknium1
a00f832c9f