{"record":{"id":"9e5f317f5b995fb4","repo":"langflow-ai/langflow","slug":"empty-result-while-operation-provider-label","errorCode":null,"errorMessage":"Empty result while {operation} ({provider_label}).","messagePattern":"Empty result while (.+?) \\((.+?)\\)\\.","errorType":"http","errorClass":"HTTPException","httpStatus":500,"severity":"error","filePath":"src/backend/base/langflow/api/v1/mappers/deployments/base.py","lineNumber":941,"sourceCode":"        operation: str = \"this operation\",\n    ) -> Any:\n        \"\"\"Parse a non-user-supplied adapter-boundary payload, raising 500 on failure.\n\n        Use for adapter/provider results and mapper-built payloads headed to the adapter.\n        Failures are internal errors — the user cannot fix them.\n        ``slot_name`` is logged for debugging but not exposed to the user.\n        See ``parse_api_request_slot`` for user-supplied input.\n        \"\"\"\n        provider_label = self.get_provider_label()\n        if slot is None:\n            logger.error(\"Payload slot '%s' is not configured for %s\", slot_name, provider_label)\n            msg = f\"The {provider_label} integration is not configured for {operation}.\"\n            raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=msg)\n        try:\n            return slot.parse(raw)\n        except AdapterPayloadMissingError as exc:\n            logger.error(\"Empty adapter payload for slot '%s' (%s)\", slot_name, provider_label)\n            raise HTTPException(\n                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,\n                detail=f\"Empty result while {operation} ({provider_label}).\",\n            ) from exc\n        except AdapterPayloadValidationError as exc:\n            detail = exc.format_first_error()\n            logger.error(\"Invalid adapter payload for slot '%s' (%s): %s\", slot_name, provider_label, detail)\n            raise HTTPException(\n                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,\n                detail=f\"Unexpected result while {operation} ({provider_label}): {detail}\",\n            ) from exc\n\n    def parse_api_request_slot(\n        self,\n        *,\n        slot: PayloadSlot[Any] | None,\n        slot_name: str,\n        raw: Any,\n        outer_payload: Any | None = None,","sourceCodeStart":923,"sourceCodeEnd":959,"githubUrl":"https://github.com/langflow-ai/langflow/blob/976ec789d2886a86de109c044d089d68e96c9a35/src/backend/base/langflow/api/v1/mappers/deployments/base.py#L923-L959","documentation":"500 from BaseDeploymentMapper.parse_adapter_slot when slot.parse(raw) raises AdapterPayloadMissingError — the adapter/provider returned an empty/absent payload where a structured one was required. Like 455, this is an adapter-boundary failure (not user input): the provider call technically succeeded but produced nothing parseable. slot_name and provider are logged server-side.","triggerScenarios":"Provider API returns 200 with an empty body / empty result list for a list/deployment operation; adapter deserializes a response into an empty object; pagination edge returning zero items where one is mandatory.","commonSituations":"Remote deployment not yet propagated (read-after-write race on the provider), provider outage returning empty 200s, API version drift where the response shape changed to empty.","solutions":["Check server log 'Empty adapter payload for slot ...' to identify which provider call emptied out","Retry after a short delay — propagation races self-heal","Verify the resource actually exists on the provider side (list it via the provider console/API)","If persistent, the provider response shape changed — update the adapter"],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"for attempt in range(3):\n    try:\n        return await list_provider_deployments(client)\n    except httpx.HTTPStatusError as e:\n        if e.response.status_code == 500 and \"Empty result while\" in e.response.json()[\"detail\"]:\n            await asyncio.sleep(2 * (attempt + 1))  # propagation race — back off and retry\n            continue\n        raise","preventionTips":["Add propagation delay between provider create and subsequent reads","Verify the resource exists on the provider before re-reading it","Alert on 'Empty adapter payload' server logs — persistent empties mean provider API drift"],"tags":["deployment","provider","adapter","http-500","empty-response","langflow"],"backgroundTag":null,"analyzedSha":"976ec789d2886a86de109c044d089d68e96c9a35","analyzedAt":"2026-08-14T18:23:12.227Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}