{"record":{"id":"4e7103d617784562","repo":"lfnovo/open-notebook","slug":"no-answer-generated","errorCode":null,"errorMessage":"No answer generated","messagePattern":"No answer generated","errorType":"http","errorClass":"HTTPException","httpStatus":500,"severity":"error","filePath":"api/routers/search.py","lineNumber":228,"sourceCode":"        final_answer = None\n        # LangGraph accepts a partial state dict at runtime, but its typed\n        # overloads require the full state type (langgraph typing limitation).\n        async for chunk in ask_graph.astream(  # type: ignore[call-overload]\n            input=dict(question=ask_request.question),\n            config=dict(\n                configurable=dict(\n                    strategy_model=strategy_model.id,\n                    answer_model=answer_model.id,\n                    final_answer_model=final_answer_model.id,\n                )\n            ),\n            stream_mode=\"updates\",\n        ):\n            if \"write_final_answer\" in chunk:\n                final_answer = chunk[\"write_final_answer\"][\"final_answer\"]\n\n        if not final_answer:\n            raise HTTPException(status_code=500, detail=\"No answer generated\")\n\n        return AskResponse(answer=final_answer, question=ask_request.question)\n\n    except HTTPException:\n        raise\n    except OpenNotebookError:\n        raise\n    except Exception as e:\n        logger.error(f\"Error in ask simple endpoint: {str(e)}\")\n        raise HTTPException(status_code=500, detail=f\"Ask operation failed: {str(e)}\")\n","sourceCodeStart":210,"sourceCodeEnd":239,"githubUrl":"https://github.com/lfnovo/open-notebook/blob/a7de90d38aaf18ee85fd661854d35c11e44613e2/api/routers/search.py#L210-L239","documentation":"500 from /api/search/ask/simple when the ask graph ran to completion but never emitted a 'write_final_answer' chunk, leaving final_answer falsy. The pipeline produced no answer (empty string or None).","triggerScenarios":"POST /api/search/ask/simple where the graph finishes without the write_final_answer node executing or writing a non-empty answer — e.g. retrieval returned nothing and the graph short-circuited, or a model returned an empty response.","commonSituations":"Empty knowledge base (no ingested sources), all retrieval scores below threshold, LLM returning empty content, graph version mismatch dropping the final node.","solutions":["Ingest at least one source and verify search finds it (test /api/search first)","Check logs for whether write_final_answer ran and what it received","Confirm the answer/final models actually return content (test directly)","Upgrade/align versions if the graph definition changed"],"exampleFix":null,"handlingStrategy":"fallback","validationCode":"const kb = await fetch('/api/notes').then(r => r.json()); // or sources count\nif (!kb.length) promptIngestFirst();","typeGuard":null,"tryCatchPattern":"catch (e) {\n  if (e.status === 500 && e.detail === 'No answer generated') suggestIngestAndRetry();\n}","preventionTips":["Ensure sources are ingested and searchable before ask","Test /api/search returns hits for typical questions"],"tags":["ask","empty-response","http-500","langgraph"],"backgroundTag":"pipeline-empty-result","analyzedSha":"a7de90d38aaf18ee85fd661854d35c11e44613e2","analyzedAt":"2026-08-27T02:39:58.166Z","schemaVersion":2},"datasetVersion":"2026-08-27T03:17:27.898Z"}