Files
multica/server/internal/handler/agent_builder.go
Bohan Jiang 168620fc15 MUL-5163 fix(agents): rebind the Agent Builder carrier when the runtime is switched (#5780)
Switching the runtime mid-conversation in Build with AI only updated local React state, so the picker could show runtime B while every subsequent message still executed on the runtime frozen at session create time.

- Add PATCH /api/agent-builder/sessions/{id}/runtime to rebind the hidden builder carrier (runtime_id/runtime_mode, model cleared since model ids are per-runtime). Creator-only, builder carriers only, target must be in-workspace, usable by the member, and online; a reply in flight returns 409.
- Serialise rebind against send: both take LockChatSessionForRuntimeBind on the chat_session row and SendDirectChatMessage re-reads the agent inside that transaction, so a send blocked behind a rebind cannot resume and stamp its task with the runtime the switch moved away from.
- Leave chat_session.runtime_id stale on purpose so the daemon starts a fresh provider session on the new runtime while Multica-side history and the draft survive.
- Frontend updates the draft only after the server reports the bound runtime, blocks sending during a rebind, disables the Mine/All filter alongside the trigger, and explains why the picker is locked during a pending reply.

Closes #5773
2026-07-23 10:56:53 +08:00

12 KiB