[Bug]: This model does not support assistant message prefill. The conversation must end with a user message. #463
Description
Bug Description
Ever since 3.1.0, I've been occasionally getting an error in opencode: "This model does not support assistant message prefill. The conversation must end with a user message.". This halts the agents, and I have to prompt it to continue. This is usually preceeded by either a raw dcp tag, or a tool call inserted into the chat raw:
Expected Behavior
Pre 3.1 behavior, like 3.0.4
Debug Context Logs
None collected, ~/.config/opencode/logs emptyTool Call Details
No response
DCP Version
3.1.2
Opencode Version
1.3.2
Model
Claude Opus 4
Additional Context
No response