langflow-ai/langflow · error · Error

Invalid file type

Error message

Invalid file type

What it means

ValueError raised by get_composer_sse_url when the project's auth config lacks oauth_host or oauth_port — the composer SSE URL cannot be constructed without them. It is not an HTTPException, so callers that do not catch it surface it as a generic 500 (via the install/check catch-alls).

Source

Thrown at src/frontend/src/hooks/flows/use-upload-flow.ts:40

          flows.push(flow);
        });
      } else {
        flows.push(object as FlowType);
      }
    });
    return flows;
  };

  const getFlowsToUpload = async ({
    files,
  }: {
    files?: File[];
  }): Promise<FlowType[]> => {
    if (!files) {
      files = await createFileUpload();
    }
    if (!files.every((file) => file.type === "application/json")) {
      throw new Error("Invalid file type");
    }
    return await getFlowsFromFiles({
      files,
    });
  };

  const uploadFlow = async ({
    files,
    isComponent,
    position,
  }: {
    files?: File[];
    isComponent?: boolean;
    position?: { x: number; y: number };
  }): Promise<void> => {
    try {
      const flows = await getFlowsToUpload({ files });
      for (const flow of flows) {

View on GitHub (pinned to 976ec789d2)

Solutions

1. Re-save OAuth settings ensuring oauth_host and oauth_port are provided (the settings UI normally collects both).
2. Inspect project.auth_settings JSON and add the missing keys.
3. Wrap calls to get_composer_sse_url in callers with a clearer 4xx if you control the route code.

Example fix

// before
project_sse_url = await get_composer_sse_url(project)
// after
auth_config = await _get_mcp_composer_auth_config(project)
if not auth_config.get("oauth_host") or not auth_config.get("oauth_port"):
    raise HTTPException(status_code=400, detail="Set OAuth host and port before requesting the composer SSE URL")
project_sse_url = await get_composer_sse_url(project)

auth_config = project.auth_settings or {}
missing = [k for k in ("oauth_host", "oauth_port") if not auth_config.get(k)]
if missing:
    raise ValueError(f"auth settings missing: {missing}; complete them before requesting composer URLs")

def has_composer_endpoint(auth_settings: dict) -> bool:
    return bool(auth_settings.get("oauth_host")) and bool(auth_settings.get("oauth_port"))

try:
    sse_url = await get_composer_sse_url(project)
except ValueError as e:
    if "OAuth host and port" in str(e):
        raise HTTPException(status_code=400, detail=str(e)) from e
    raise

When it happens

Trigger: Any code path calling get_composer_sse_url(project) for a project whose auth_settings have auth_type oauth but empty/missing oauth_host/oauth_port — install endpoint, install check, or settings PATCH response building.

Common situations: OAuth settings saved without host/port fields; auth settings edited directly in the DB; version change that renamed the keys.

Related errors

• Failed to reload bundle
• Failed to download files: ${response.statusText}
• Failed to delete MCP Server
• Failed to patch MCP Server
• Langflow was not able to connect to the server. Please make

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/bcc0bbe94e5a6465. Report an issue: GitHub.