bytedance/deer-flow · warning

Failed to load demo thread ${threadId}

Error message

Failed to load demo thread ${threadId}

What it means

Static-demo loader: fetches /demo/threads/{threadId}/thread.json (a bundled fixture, not a gateway call) and throws when the response is not ok. The loaded fixture's thread_id is forced to the requested id and updated_at defaults to created_at.

Source

Thrown at frontend/src/core/threads/static-demo.ts:178

    return sortOrder === "asc" ? aValue - bValue : bValue - aValue;
  });

  const offset = Math.max(0, Math.floor(params.offset ?? 0));
  const limit =
    typeof params.limit === "number"
      ? Math.max(0, Math.floor(params.limit))
      : sortedThreads.length;
  return sortedThreads.slice(offset, offset + limit);
}

export async function loadStaticDemoThread(
  threadId: string,
): Promise<AgentThread> {
  const response = await globalThis.fetch(
    `/demo/threads/${encodeURIComponent(threadId)}/thread.json`,
  );
  if (!response.ok) {
    throw new Error(`Failed to load demo thread ${threadId}`);
  }
  const thread = (await response.json()) as AgentThread;
  return {
    ...thread,
    thread_id: threadId,
    updated_at: thread.updated_at ?? thread.created_at,
  };
}

export function staticDemoThreadState(
  thread: AgentThread,
): ThreadState<AgentThreadState> {
  return {
    values: thread.values,
    next: [],
    checkpoint: {
      thread_id: thread.thread_id,
      checkpoint_ns: "",

View on GitHub (pinned to 1dd6ba1acb)

Solutions

1. Open /demo/threads/<id>/thread.json directly in the browser to confirm the 404/serve failure.
2. Verify the id exists in the demo thread index (the data used by the thread list in static-demo.ts).
3. Ensure the static demo assets directory is deployed/served (check nginx config or Next public path).
4. If the fixture was renamed, update the id in links/bookmarks or restore the file.

const exists = demoThreadIds.includes(threadId); // from the same static index that powers the list
if (!exists) { router.replace('/demo'); }

function isKnownDemoThread(threadId: string): boolean {
  return staticDemoIndex().some((t) => t.thread_id === threadId);
}

try { thread = await loadStaticDemoThread(id); } catch { renderThreadNotFound(); return; }

When it happens

Trigger: Requesting a demo thread id with no corresponding public/demo data file (404), the static demo mode enabled but the /demo route not served (dev server misconfig, missing copy of demo assets), or a moved/renamed thread.json in the demo dataset.

Common situations: Deep-linking to a demo thread URL after the fixture set changed; running a frontend build where /demo assets were excluded; nginx not serving the demo directory in the docker stack.

Related errors

• Failed to create side conversation.
• Failed to load thread token usage.
• Failed to branch conversation.
• Failed to update conversation.
• Failed to compact context.

AI-assisted analysis of bytedance/deer-flow@1dd6ba1acb (2026-08-14). Data as JSON: /api/errors/121fed1e5cf5e584. Report an issue: GitHub.