langflow-ai/langflow · error · Error

Invalid flow data

Error message

Invalid flow data

What it means

Thrown by the useUploadFlow hook when a parsed upload file yields a flow object that has no `data` property. Langflow expects every uploaded JSON entry to be a flow object whose graph lives under `data` (nodes/edges); an entry without it is treated as structurally invalid and the whole upload is aborted before any flow is saved or pasted.

Solutions

1. Open the uploaded JSON and confirm each top-level object contains a `data` object with `nodes` and `edges`
2. Re-export the flow from Langflow's UI (Flow Settings > Export) rather than copying a flow-list API response
3. If importing multiple flows, ensure the file is an array where EVERY element has `data` — one bad entry aborts the loop
4. Validate the file shape client-side before calling uploadFlow (see type guard below)

Example fix

// before
await uploadFlow({ files }); // throws mid-loop on first entry without data

// after
const flows = JSON.parse(await files[0].text());
const ok = (Array.isArray(flows) ? flows : [flows]).every(
  (f) => f && typeof f === "object" && f.data && Array.isArray(f.data.nodes),
);
if (!ok) throw new Error("File is not a valid Langflow flow export");
await uploadFlow({ files });

const isFlowExport = (v: unknown): v is { data: { nodes: unknown[]; edges: unknown[] } } =>
  typeof v === "object" && v !== null &&
  "data" in v && typeof (v as any).data === "object" &&
  Array.isArray((v as any).data?.nodes);

const parsed = JSON.parse(text);
const flows = Array.isArray(parsed) ? parsed : [parsed];
if (!flows.every(isFlowExport)) {
  alert("File is not a valid Langflow flow export (missing data.nodes)");
}

function isFlowExport(v: unknown): v is { data: { nodes: unknown[]; edges: unknown[] } } {
  return (
    typeof v === "object" && v !== null &&
    "data" in v && typeof (v as Record<string, unknown>).data === "object"
  );
}

try {
  await uploadFlow({ files });
} catch (e) {
  if (e instanceof Error && e.message === "Invalid flow data") {
    // show a file-format message; do not retry the same file
  } else throw e;
}

When it happens

Trigger: Uploading a JSON file via the flow-import UI (or drag-drop onto the canvas with a paste position) where getFlowsFromFiles returns objects lacking a `data` key — e.g. a hand-written JSON, an API response wrapper like {id, name} without the graph, or a partially exported/corrupted flow file.

Common situations: Users exporting from a different Langflow version or another tool, editing exported JSON and accidentally deleting the `data` field, or uploading a file that contains flow metadata (list endpoint output) instead of the full flow export.

Related errors

• Invalid JSON format.
• No valid MCP server found in the input.
• Deployment name is required
• error: invalid JSON in
• error: ambiguous_bare_names field must be a list

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/2b3f574f2e044f88. Report an issue: GitHub.

Appendix: source

Thrown at src/frontend/src/hooks/flows/use-upload-flow.ts:88

      ) {
        throw new Error(
          "You cannot upload a component as a flow or vice versa",
        );
      } else {
        let currentPosition = position;
        for (const flow of flows) {
          if (flow.data) {
            if (currentPosition) {
              paste(flow.data, currentPosition);
              currentPosition = {
                x: currentPosition.x + 50,
                y: currentPosition.y + 50,
              };
            } else {
              await addFlow({ flow });
            }
          } else {
            throw new Error("Invalid flow data");
          }
        }
      }
    } catch (e) {
      throw e;
    }
  };

  return uploadFlow;
};

export default useUploadFlow;

View on GitHub (pinned to 976ec789d2)