The opencode acp binary streams agent_message_chunk notifications with
an EMPTY messageId. The backend was already correct (it groups when a
messageId is present), but the UI rendered every chunk as its own
bubble, so a single 'count 1 to 5' reply showed as 9 separate bubbles.
Backend:
- internal/acp/history.go: add MessageID to Message; new AppendOrCreate
method that finds or creates an entry by messageId and appends text
to it (preserving the original timestamp).
- internal/acp/client.go: agent_message_chunk and user_message_chunk
use AppendOrCreate.
- internal/model/acp.go: expose MessageID in the wire response.
- internal/service/acp_service.go: copy MessageID into the API DTO.
- internal/acp/client_test.go: add TestHistoryAppendOrCreateGroupsByMessageID.
Frontend:
- web/src/components/acp/groupMessages.ts: new pure helper that
coalesces consecutive same-role history entries into a single bubble
(keeps the first chunk's time + messageId).
- web/src/components/acp/AcpPanel.tsx: render coalesced messages;
auto-scroll effect now depends on coalesced so it fires as the
agent streams.
Verified via e2e: 'count from 1 to 5' now returns a single agent entry
with text '1\n2\n3\n4\n5' instead of 9 separate entries.
tao.chen
789f62669c