{"record":{"id":"1dd7188b02f1bdfb","repo":"langflow-ai/langflow","slug":"flow-flow-id-str-has-no-data","errorCode":null,"errorMessage":"Flow {flow_id_str} has no data","messagePattern":"Flow (.+?) has no data","errorType":"exception","errorClass":"ValueError","httpStatus":500,"severity":"error","filePath":"src/backend/base/langflow/api/v1/endpoints.py","lineNumber":249,"sourceCode":"\nasync def simple_run_flow(\n    flow: Flow,\n    input_request: SimplifiedAPIRequest,\n    *,\n    stream: bool = False,\n    api_key_user: User | None = None,\n    event_manager: EventManager | None = None,\n    context: dict | None = None,\n    run_id: str | None = None,\n):\n    validate_input_and_tweaks(input_request)\n    try:\n        task_result: list[RunOutputs] = []\n        user_id = api_key_user.id if api_key_user else None\n        flow_id_str = str(flow.id)\n        if flow.data is None:\n            msg = f\"Flow {flow_id_str} has no data\"\n            raise ValueError(msg)\n        graph_data = flow.data.copy()\n        graph_data = process_tweaks(graph_data, input_request.tweaks or {}, stream=stream)\n        raise_if_hitl_unsupported(graph_data)\n        # Mirror the Playground's one-time fix in-memory: bind empty fields whose\n        # display_name matches a user global variable's default_fields. Without\n        # this, API-only workflows never trigger the frontend hook that persists\n        # load_from_db=true, so variables with \"Apply to Fields\" silently fail.\n        # See: https://github.com/langflow-ai/langflow/issues/11781\n        if user_id is not None:\n            graph_data = await apply_global_variable_defaults(graph_data, user_id)\n        graph = Graph.from_payload(\n            graph_data, flow_id=flow_id_str, user_id=str(user_id), flow_name=flow.name, context=context\n        )\n        # Forward the caller-supplied identifier to tracing providers without\n        # affecting authn/authz. The API-key owner remains the effective user\n        # for permissions, global variables, and job ownership.\n        if input_request.user_id:\n            graph.tracing_user_id = input_request.user_id","sourceCodeStart":231,"sourceCodeEnd":267,"githubUrl":"https://github.com/langflow-ai/langflow/blob/976ec789d2886a86de109c044d089d68e96c9a35/src/backend/base/langflow/api/v1/endpoints.py#L231-L267","documentation":"Error \"Flow {flow_id_str} has no data\" thrown in langflow-ai/langflow.","triggerScenarios":"Occurs when the requested flow exists in the database but its data column is null or empty, so there is no graph to execute.","commonSituations":"See trigger scenarios.","solutions":["Open the flow in the editor and save it so its graph data is persisted before running it via the API.","Verify you are using the correct flow id; the flow may have been created empty or corrupted."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"976ec789d2886a86de109c044d089d68e96c9a35","analyzedAt":"2026-08-14T18:23:12.227Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}