bytedance/deer-flow · error · HTTPException
Failed to get thread state
Error message
Failed to get thread state
What it means
Error "Failed to get thread state" thrown in bytedance/deer-flow.
Source
Thrown at backend/app/gateway/routers/threads.py:1208
# ---------------------------------------------------------------------------
@router.get("/{thread_id}/state", response_model=ThreadStateResponse)
@require_permission("threads", "read", owner_check=True)
async def get_thread_state(thread_id: ThreadId, request: Request) -> ThreadStateResponse:
"""Get the latest materialized graph state for a thread."""
# Resolve through the thread's assistant so custom middleware channels
# appear in the response instead of being dropped by the default schema.
try:
accessor, config = await build_thread_checkpoint_state_accessor(request, thread_id=thread_id)
except _CHECKPOINT_MODE_ERRORS as exc:
raise _checkpoint_mode_http_error(exc, thread_id) from exc
try:
snapshot = await accessor.aget(config)
except _CHECKPOINT_MODE_ERRORS as exc:
raise _checkpoint_mode_http_error(exc, thread_id) from exc
except Exception:
logger.exception("Failed to get state for thread %s", sanitize_log_param(thread_id))
raise HTTPException(status_code=500, detail="Failed to get thread state")
snapshot_config = snapshot.config or {}
checkpoint_id = snapshot_config.get("configurable", {}).get("checkpoint_id")
if not checkpoint_id:
raise HTTPException(status_code=404, detail=f"Thread {thread_id} not found")
parent_config = snapshot.parent_config or {}
parent_checkpoint_id = parent_config.get("configurable", {}).get("checkpoint_id")
metadata = snapshot.metadata or {}
created_at = snapshot.created_at or metadata.get("created_at", "")
tasks_raw = snapshot.tasks or ()
tasks = [{"id": getattr(task, "id", ""), "name": getattr(task, "name", "")} for task in tasks_raw]
return ThreadStateResponse(
values=serialize_channel_values_for_api(snapshot.values),
next=list(snapshot.next or ()),
metadata=metadata,
checkpoint={"id": checkpoint_id, "ts": coerce_iso(created_at)},View on GitHub (pinned to 1dd6ba1acb)
Solutions
- Check the Gateway logs for the underlying state read error.
- Verify the thread exists and checkpoint storage is reachable, then retry.
When it happens
Trigger: Thrown at backend/app/gateway/routers/threads.py:1208 when the library encounters an invalid state.
Common situations: See trigger scenarios.
AI-assisted analysis of bytedance/deer-flow@1dd6ba1acb (2026-08-14).
Data as JSON: /api/errors/5482e52b062231a6.
Report an issue: GitHub.