* fix: ensure LLM calls always end with user message (closes#763)
Claude 4.6 models (claude-sonnet-4-6, claude-opus-4-6) no longer support
assistant message prefill — any LLM call where the conversation ends on an
assistant message is rejected with HTTP 400 "This model does not support
assistant message prefill".
The same root cause also triggers NEAR AI's "No user query found in messages"
400 error for the routine engine path.
Two fixes:
1. src/worker/container.rs — before_llm_call()
After poll_and_inject_prompt(), if no user follow-up arrived and
handle_text_response() left an assistant message at the end of the
conversation, inject a sentinel "Continue." user message before
the next LLM call.
2. src/agent/routine_engine.rs — execute_lightweight_with_tools()
Before the force_text final completion call, ensure messages end
with a user-role message. Tool result messages (Role::Tool) satisfy
Anthropic but not NEAR AI; assistant messages satisfy neither.
Also updates the worker system prompt to instruct the agent to include
the phrase "The job is complete" in its final message, so the agentic
loop can detect termination reliably.
Tested with claude-sonnet-4-6 and claude-opus-4-6.
Workaround: ANTHROPIC_MODEL=claude-sonnet-4-20250514 (still supports prefill).
* fix: broaden sentinel guard to any non-user message (per review)
Gemini suggested the Role::Assistant check in before_llm_call() is too
specific. Changed to !Role::User to match the routine_engine.rs fix and
cover tool results too.
* fix: address zmanian review — JobDelegate sentinel, shared helper, NearAI complete() flattening
- Extract ensure_ends_with_user_message() to src/util.rs with 4 unit tests
(empty list, after assistant, after tool result, no-op when already user)
- Add sentinel guard to JobDelegate::before_llm_call() in src/worker/job.rs
so scheduler jobs (CreateJob / /job path) no longer hit Claude 4.6 / NEAR AI 400s
- Replace inline guards in ContainerDelegate and routine_engine.rs with the
shared helper — all 3 call sites now use one implementation
- Fix complete() in nearai_chat.rs to apply flatten_tool_messages when
flatten_tool_messages=true — previously only complete_with_tools() flattened,
so force_text paths could still send role:"tool" messages to NEAR AI
- Update stale comment in container.rs: "assistant message" → "non-user message"
- Add flatten tests in nearai_chat.rs covering the complete() path
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
* ci: fix fmt and tar advisory
---------
Co-authored-by: Jacob Lasky <[email protected]>
Co-authored-by: Claude Sonnet 4.6 <[email protected]>
Co-authored-by: Illia Polosukhin <[email protected]>
Co-authored-by: firat.sertgoz <[email protected]>
