langflow-ai/langflow · warning · HTTPException

Folder not found

Error message

Folder not found

What it means

HTTP 400 from _create_flow's upsert path: validate_folder was enabled (external-source/PUT upsert) and the submitted folder_id does not exist or does not belong to the acting user (query filters on both Folder.id and Folder.user_id). This stops external syncs from landing flows in another user's folder or a nonexistent one.

Source

Thrown at src/backend/base/langflow/api/v1/flows_helpers.py:318

    Args:
        session: Database session.
        flow: Flow creation data.
        user_id: Owner of the new flow.
        storage_service: Service for filesystem operations.
        flow_id: Allows PUT upsert to create flows with a specific ID for syncing between instances.
        fail_on_endpoint_conflict: PUT should fail predictably on conflicts rather than silently renaming.
        validate_folder: Validates folder_id exists and belongs to user when upserting from external sources.
    """
    try:
        await _verify_fs_path(flow.fs_path, user_id, storage_service)

        if validate_folder and flow.folder_id is not None:
            folder = (
                await session.exec(select(Folder).where(Folder.id == flow.folder_id, Folder.user_id == user_id))
            ).first()
            if not folder:
                raise HTTPException(status_code=400, detail="Folder not found")

        # Set user_id (ignore any user_id from body for security)
        flow.user_id = user_id
        flow.name = await _deduplicate_flow_name(session, flow.name, user_id)

        if flow.endpoint_name:
            flow.endpoint_name = await _deduplicate_endpoint_name(
                session, flow.endpoint_name, user_id, fail_on_conflict=fail_on_endpoint_conflict
            )

        # Exclude the id field from FlowCreate so that Flow.id (UUID, non-optional)
        # always gets its default_factory uuid4 unless we explicitly override it below.
        db_flow = Flow.model_validate(flow.model_dump(exclude={"id"}))

        # Apply the stable ID: explicit flow_id param (PUT upsert) takes precedence,
        # then flow.id (stable import from FlowCreate), then the uuid4 default.
        effective_id = flow_id if flow_id is not None else flow.id
        if effective_id is not None:

View on GitHub (pinned to 976ec789d2)

Solutions

1. GET /api/v1/folders (as the same user) and use an id from that list.
2. Omit folder_id to let the flow land in the default folder.
3. Create the folder first when it is missing, then retry the upsert.
4. If syncing across instances, map folder names -> local ids instead of trusting foreign ids.

Example fix

# before
{"name":"f","folder_id":"<uuid-from-other-instance>"}
# after
folders = await client.get('/api/v1/folders')
folder = next(f for f in folders if f['name'] == 'Sync')
{"name":"f","folder_id":folder['id']}

const folders = await listFolders();
if (body.folder_id && !folders.some(f => f.id === body.folder_id)) delete body.folder_id;

When it happens

Trigger: PUT upsert with folder_id of a deleted folder, a folder owned by a different user, or a folder id copied from another instance/environment.

Common situations: Cross-instance sync where folder ids differ per instance; folder was deleted after the sync payload was built; client reuses ids from a staging environment against production.

Related errors

• fs_path cannot be empty
• str(e)
• Failed to install MCP
• Invalid path
• Provider '{provider}' is not configured. Available providers

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/252b291baf158cfc. Report an issue: GitHub.